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Transcript of Orthognathic surgery by almuzian
Surgical Orthodontics, Corrective Jaw Surgery or Orthognathic Surgery
Definition
The correction of the functional and aesthetic consequences of severe
dentofacial deformity through a combination of orthodontic, surgical and
possibly restorative dentistry
Aims
A satisfied patient.
Improve facial aesthetics
Improve dental aesthetics
A functional, balanced and stable occlusion
History
Trauner and Obwegeser introduced the sagittal split ramus osteotomy in
1959.
In 1960s development by Bell, Epker and Wolford of the LeFort I
technique.
In the 1990s, rigid internal fixation greatly improved the surgical result
and increase patient comfortibility
Mohammed Almuzian, University of Glasgow 1
Prevalence
IN UK according to O’Brien 2009, the prevalence of jaw’s surgery is as
follow:
1. Gender and age distribution
Mean age 22y
More female
2. Malocclusion
45% class 2
43% class 3
12% AOB
3. Type of surgery
66% bimax
24% mand surgery only
10% max surgery only
4. Continuation & duration of treatment
28% overall didn't complete treatment
Mean duration of treatment 45months
Mohammed Almuzian, University of Glasgow 2
Timing and sequencing of surgical treatment
A. Usually all operations should be delayed until the completion of
growth
B. Early treatment
Indications
1. P sychosocial considerations
2. Mandible problems
Early mandibular advancement for sever mandibular retrognathia can be
done since most of postsurgical growth is expressed vertically, there is no
reason to delay mandibular advancement after sexual maturity
Rib grafts in craniofacial microsomia cases
Class II due to condylar ankylosis
Facial asymmetry to avoid compensatory mal-development of the maxilla
3. Maxilla problems
In general, maxillary advancement should be delayed until after the
adolescent growth spurt unless there are preponderant psychological
considerations. In this case, subsequent growth of the mandible is likely to
result in reestablishment of the abnormal relationships, and the patient and
parents should be cautioned about the possible need for a second stage of
surgical treatment later
No early surgery for vertical excess because vertical growth continues
Mohammed Almuzian, University of Glasgow 3
General Indications of Orthognathic treatment
The cases that can be corrected by OS include:
Severe CI 3
Severe CI 2
Long face syndrome/AOB
Facial asymmetries
Chin abnormalities
Craniofacial anomalies e.g. CLP
However the indications of OS are:
1. Facial aesthetics
Pre-treatment assessment of orthognathic patients found that less than
50% patients were unhappy with their pre-treatment facial aesthetics
(Cunningham et al 1996).
About 90% of patients who undergo orthognathic surgery report
satisfaction with the outcome and over 80% say they would recommend
such treatment to others and would undergo it again (Cunningham et al
1996).
Hunt et al 2001 in systematic review, he concluded that orthognathic
patient experience psychological benefits as a result of orthognathic
Mohammed Almuzian, University of Glasgow 4
surgery including improved self-esteem, body and facial image, and social
adjustment.
Sammaan in HK in 2010 found that the quality of life improved didn't
effected before surgery but only immediately after surgery. While the oral
health impact had been dropped in the decompensation phase and then
improved after surgery.
2. Dental aesthetics which cannot be addressed orthodontically
In a study of pre-treatment orthognathic patients, 72% were unhappy with
their teeth (Cunningham et al. 1996).
In non-growing patients when growth modification is not applicable
When too severe for orthodontics alone
When orthodontic treatment alone might cause determinately effect on the
facial and occlusal aesthetic as well as PD compromization
Presence of complete compensation
Presence of sever crowding that might use the whole extraction space
leaving nothing for more compensation by orthodontic means.
Sever vertical or transverse problem
3. Masticatory function
Speech problem like lisping in AOB
Mohammed Almuzian, University of Glasgow 5
Anterior open bites with chewing problems
NB: Evidence suggests that there is a change in the bite force experienced
by many post-operative patients. Work by Hunt and Cunningham (1997)
found that when mandibular advancement was undertaken for reduced
patients face height, the bite forces reduced in the post-surgical phase.
Conversely, in long face patients who underwent bimaxillary surgery the
bite force increased.
4. Airway In a few centres in the UK and in North America, orthognathic
surgery may be performed to increase the airway in patients with
obstructive sleep apnoea.
5. TMD This is an area of controversy. The evidence suggests we should
warn all patients that they have a 20% risk (approximately) of developing
TMD post-op but for those who have TMD pre-op, a percentage may
improve, other will stay the same or a small number may worsen.
6. Periodontal indications: especially in deep OB when it is traumatic and
cannot be addressed by conventional orthodontics. Complete overbites may
suffer trauma to the palatal or labial gingivae.
7. Prosthetic indications like a case of sever attrition in which the
prosthetic restorations are impossible without increasing the VH by
surgery.
Mohammed Almuzian, University of Glasgow 6
Contraindications &/or limitations
Growing patient
Minor cases
Medical condition
Psychologically unstable patient
Parameters indicators or Yardsticks for orthognathic surgery
1. For class II
Proffit 1992
OJ 10mm
ANB > 9°
Pog posterior to N perpendicular 18mm
Mandibular length less than 70 mm
Anterior facial height more than 125mm
Squire et al., 2006:
Positive overjet greater than 8mm,
A transverse discrepancy greater than 3mm were not considered to be
orthodontically treatable
Mohammed Almuzian, University of Glasgow 7
2. For class III
1. Squire et al., 2006:
A negative overjet of -4mm or greater,
A transverse discrepancy greater than 3mm were not considered to be
orthodontically treatable
2. Stellzig-Eisenhauer et al (2002)
Wits analysis value of –12.2 ± 4.3 mm while camouflage indicated when
Wits value is less than -4.6 ± 1.7 mm.
3. Kerr et al 1992
ANB = -4°;
maxillary mandibular ratio = 0.84 ,
lower incisor inclination (LI/MP = 83°)
Soft tissue profile (Holdaway angle = 3.5°)(soft tissue nasion-soft tissue
pogonion labrale superius). Interestingly, vertical dimension had little
influence on treatment decision.
The management protocol for facial deformity
1. History
2. Clinical examination
3. Psychological assessment
Mohammed Almuzian, University of Glasgow 8
4. Investigations
5. Clinical and radiographical examination.
6. Initial diagnosis
7. Initial Treatment plan
8. Presurgical orthodontics
9. Final treatment plan
10. Surgery
11. Postsurgical orthodontics
12. When appropriate, restorative dentistry, psychological intervention or
support and speech therapy will be required.
In details
History and patient assessment
1. Age and sex - influences amount of growth remaining
2. Race - influences profile considerations
3. PDH: To identify the cause (family trait, congenital deformity, or
trauma in infancy or adolescence)
4. CC: To know the main CC in order of priority
Mohammed Almuzian, University of Glasgow 9
5. MH: medical disorders, which require specific attention include:
Haemophilia or similar clotting disorders which require pre-and
intraoperative correction
Rheumatic or congenital heart valve lesions
Acromegaly patients may be a cardiomyopathy risk
Obstructive sleep apnoea should warrant a sleep study and specific
assessment.
Antibiotic or analgesic idiosyncrasy or allergy
Psychological assessment
Ideally all patients should be assessed by a psychologist to establish their
motives and to determine whether their goals are realistic.
A few patients have great difficulty in adapting to significant changes in
their facial appearance. This is more a problem in older individuals.
Also, a period of psychological adjustment following facial surgery must
be expected. In part, this is related to the use of steroids and Steroid
withdrawal, causes mood instability at 3 to 6 weeks post-surgery.
A. Body Dysmorphic Disorder
Patients who request treatment of a non-existent or very minor facial
deformity.
Mohammed Almuzian, University of Glasgow 10
BDD was diagnosed in 7.5% of patients attending for orthodontic
treatment and 2.5% of the general population (Hepburn and Cunningham,
2006).
Three criteria must be fulfilled for a diagnosis of BDD to be made
(American Psychiatric Association, DSM-IV, 1994):
1. Preoccupation with an imagined defect in appearance. If a slight
physical anomaly is present, the person's concern is markedly excessive.
2. The preoccupation causes clinically significant distress or impairment
in social, occupational, or other important areas of functioning.
3. Presence of another mental disorder (anorexia nervosa)
Treatment of BDD should ideally involve counseling and behavior
therapy or pharmacological treatment. Surgery should only be considered if
there is a defect to correct and there is appropriate psychological support
(Cunningham and Feinmann, 1998).
B. Ethnic Dysphoria
It is an uncommon BDD variant.
Dentofacial aesthetic norms vary between ethnic groups and when
planning surgical changes special consideration should be given as to
whether they are racially appropriate.
Mohammed Almuzian, University of Glasgow 11
Some ethnic patients, influenced by popular Caucasian features, may
demand changes which are either unsuitable or unattainable.
C. Gender dysphoria
It is an uncommon BDD variant in which the patient, usually a male,
wishes to change gender.
Where this is stated, or when the patient is referred from a psychiatric unit
specialising in gender reorientation, the aim of the treatment is obvious.
However, occasionally the demand for a less prominent mandible or more
prominent malar bones in an otherwise satisfactory face can be difficult to
understand unless seen as part of this problem.
Again, psychiatric assessment of the patient is essential.
Patient motivation types and reaction to orthognathic Treatment
Internal motivation are more likely to have satisfactory treatment
outcomes
External motivation poor outcomes
Patient with unachievable expectation like BDD has higher dissatisfaction
Patients with congenital deformities are at greater risk of experiencing
psychosocial problems.
Individuals with acquired deformities tend to be more critical and express
greater dissatisfaction compared to those with developmental problems
who have never had an image of normality
Mohammed Almuzian, University of Glasgow 12
The Psychopathology of Facial Deformity and Orthognathic Surgery
1. Social Aspects of Facial Deformity
Social reaction: Those who are blessed with an attractive face are
frequently perceived as being more friendly, sensitive and successful
Personality: Certain facial stereotypes are inappropriately portrayed as
being associated with particular characteristics, for example a Class III
malocclusion may be perceived as aggressive or a marked Class II as weak
or stupid.
2. The Psychological Assessment
The following standardised approach is essential to avoid overlooking
problem areas and should be done on a one-to-one basis and not in a large
multidisciplinary clinic,
A. In addition to patients in whom the clinician intuitively feels
concerns, those to be considered for referral include patients with:
A history of previous cosmetic surgery.
Minimal facial deformity.
Expectations that clearly exceed surgical feasibility.
An obsessional concern with certain features.
B. There are 8 questions which should be asked:
1. What is the main complaint?
Mohammed Almuzian, University of Glasgow 13
2. How does their dentofacial deformity interfere with their life?
3. How long has he/she been concerned about their face? Why is
he/she seeking treatment now?
4. What does the patient expect from treatment?
5. What is the main source of motivation?
6. Does the patient have family support?
7. Has the patient previously sought treatment elsewhere?
8. Has the patient received any medical treatment that may be of
importance from psychological point of view ?
In details
1. What is the main complaint? Those who offer vague non-specific
complaints such as “I just don't like my face” tend to make poor surgical
patients compared with those who are clear about their complaint — “I
think my chin sticks out and is not symmetrical”.
2. How does their dentofacial deformity interfere with their life? A patient
who can function in a normal way at work, socialise with friends and has
developed a reasonable body image despite the facial deformity is likely to
be satisfied following treatment. Those who have become reclusive as a
Mohammed Almuzian, University of Glasgow 14
result of their concerns must be investigated further, especially where the
extent of the deformity does not justify this abnormal behaviour pattern.
3. How long has he/she been concerned about their face? Why is he/she
seeking treatment now? Patients should always be asked how long they
have had these concerns. Those who have become concerned only recently
should again be assessed by a psychologist/psychiatrist as their worries
may have been triggered by a recent life event such as redundancy, divorce,
or bereavement.
4. What does the patient expect from treatment? It is helpful to ask “How
do you think this treatment will affect your life?” Those patients who want
to look better and feel more self-confident are classified as expecting
primary gain from treatment and tend to be good surgical patients. Patients
requiring psychological assessment prior to agreeing to treatment include
those who:
a) Are concerned with secondary gain such as promotion, a better job or
new partner
b) Do not have any idea what they expect from treatment
c) Are not able to verbalise their answers to these questions.
5. What is the main source of motivation? Externally motivated patients
may require a change in their environment rather than orthognathic
treatment. They require careful psychological assessment and counselling
Mohammed Almuzian, University of Glasgow 15
prior to consideration for treatment. Patients who are internally motivated
usually make better candidates for orthognathic intervention.
6. Does the patient have family support? Obviously patients should not be
refused treatment if they have little family or social support. However, in
this situation, the orthognathic team may need to offer more support than
usual, particularly in the immediate pre-and postoperative periods when
patients are at their most vulnerable.
7. Has the patient previously sought treatment elsewhere? Patients who
embark upon numerous consultations (or “doctor shopping”) often do so
because they are dissatisfied with a previous rejection or a treatment plan
which does not meet their unrealistic expectations. Other patients may
already have undergone previous operations for dentofacial complaints.
Such a history should be investigated fully, prior to agreeing to further
intervention .
8. Has the patient received any medical treatment that may be of
importance? This is to determine whether the patient has undergone any
previous psychiatric treatment. The general medical history may also
include conditions that make orthog-nathic treatment difficult or
impossible, such as haemophilia, severe thallasaemia, acromegaly or
osteoclast dysfunction bone dysplasias.
Mohammed Almuzian, University of Glasgow 16
C. Dissatisfaction with Treatment
Dissatisfaction may manifest itself in a number of ways including
1. Obsessional behaviour,
2. Depression
3. Even frank psychosis
4. Seeking additional surgical procedures,
5. Physical aggression.
6. Litigation
There are a number of causes of postoperative dissatisfaction
1. Patients who experience pain and numbness
2. Steroid withdrawal
3. Poor results
4. Unfavourable interpersonal relationship
Most forms of post-surgical dissatisfaction can be avoided by
1. Careful presurgical patient assessment
2. Realistic explanations of the procedure in terms of pain, swelling,
speech, eating and time off work.
3. Informed consent, the possibility of the most common and important
complications,
Mohammed Almuzian, University of Glasgow 17
Investigations
BOS guidelines regarding the minimum record for Orthognathic cases
1. Lateral Cephalograms
An immediate post-operative lateral cephalogram should not be taken
routinely. Only take in concern cases, where the post-surgical maxilla
position is in question and a quick return to theatre is likely.
The request for a lateral cephalogram taken at 1-3 weeks post-surgery
should be under the direction of the orthodontist. Any surgical wafer used
should be removed prior to this x-ray exposure and it should be carried out
on the same cephalostat as previously used. The teeth should be in
occlusion with much of the post-op swelling subsided. This view will
record a true and meaningful post-op position of the jaws prior to
significant postsurgery orthodontic mechanics, such as intermaxillary
elastic traction, commencing. In units using IMF for 4-6 weeks, the taking
of this film should be delayed until its release.
A pre-debond lateral cephalogramis conditional upon the post-surgical
orthodontic phase exceeding 6 months. This view will record the final post-
op position of the jaws at the completion of post-surgical orthodontics. For
patients with shorter periods (<6 months) of post-surgical orthodontics, the
‘1-3 week post-op’ cephalogram should suffice.
At 1-year post-surgery, a significant number of patients may have only
recently completed their post-surgical orthodontic treatment.
Mohammed Almuzian, University of Glasgow 18
2-years post-orthodontic debond i.e. a minimum of 1 year out of retention,
to assess the final outcome and any relapse associated with surgical
orthodontics.
2. OPT
At the end of the pre-surgical orthodontic phase, there is no need for an
OPT if 8s previously extracted as a result of the pre-treatment OPT.
If 8s haven’t been extracted and are to be removed at the time of surgery,
then obtain new OPT.
The immediate post-op OPT is the responsibility of the surgeon.
3. Study Models
The pre-surgical planning models are working models. It is not necessary
to keep these “mock-surgery” models long-term.
4. Clinical Measurements
It should be written record.
5. Altered Sensation
A baseline recording of any altered facial/intra-oral sensation present
prior to starting treatment is good practice.
A simple recording can be indicated on the proforma with further details
and drawing (if applicable) made in the patient’s clinical notes. Subjective
testing is sufficient with an additional note made as to whether the altered
sensation is of concern to the patient.
The validated methods to assess the altered sensation was published in
1998 by Ylikontiola, it include:
I. Light touch (LT),
Mohammed Almuzian, University of Glasgow 19
II. Two-point discrimination (2-P),
III. Tactile discrimination
IV. Thermal stimuli (TH),
V. Sensibility testing of the mandibular teeth by a vitality scanner
Mohammed Almuzian, University of Glasgow 20
6. Patient Questionnaires
Psychological-based questionnaire may also be available.
Clinical examination
Patient Evaluation involves:
i) Clinical examination. EOE and IOE
Extraoral examination includes
CFA read CFA notes by Almuzian
TMJ: Although there is no evidence of malocclusion or jaw deformity
causing temporomandibular joint symptoms, it is important to record any
abnormalities present in patients considering surgery. The examination of
the joint should include observation of the path of opening and closure of
the mandible, noting any clicking sounds whilst palpating the joints.
Intraoral Examination
1. Teeth present, unerupted, impacted, carious, over erupted or
periodontally involved.
2. Dental and base relationships
3. Dental centre line.
Mohammed Almuzian, University of Glasgow 21
4. Crossbite & associated displacement it is also important to note
whether the segments have attempted to compensate for the discrepancy by
tipping of the dentition
5. Overbite
6. Overjet from the most prominent incisor should also be recorded.
7. Arch form and the coordination of upper and lower arches.
8. The upper and lower incisor inclinations and in particular,
compensatory changes due to the jaw disproportion, e.g. retroclined lower
incisors and proclined upper incisors in a prognathous mandible.
9. Crowding or spacing and TSD.
10. Tilting and rotation.
11. COS
12. Occlusal plane canting.
13. Tongue size and mobility, and the speech pattern
14. Enlarged tonsils may jeopardise the patency of the airway. Adenoids
are rarely a problem as they have usually regressed in size during early
adolescence. However, remember that the micrognathic mandible will
create an intubation problem for the anaesthetist
Mohammed Almuzian, University of Glasgow 22
15. Cleft cases require careful analysis of the cleft site and bony defects
that will require grafting. Velopharyngeal competence should be examined
by endoscopy and speech recorded by a speech therapist.
ii) Radiographic examination
OPT
Used to diagnose:
The shape and relative size of each half of the mandible, including the
condyles, in two dimensions.
The presence of any pathological condition such as impacted unerupted
teeth, caries, periodontal disease, apical granulomas or cysts.
The trabeculation pattern of the bone, especially at the lingula, which
when visible is an indication of adequate thickness of the ascending ramus
and ease with which the ramus can be split.
For symmetry analysis, tracing of the normal side of the radiograph
has been superimposed on the abnormal side using the occlusal plane
as a guide. The discrepancy of the mandibular borders can be seen
readily
Mohammed Almuzian, University of Glasgow 23
Lateral Cephalometric
To provide precise details of the relationships of the parts of the
dentofacial complex as part of the diagnosis.
To plan tooth angulation movements and osteotomy cuts and movements
prior to treatment commencement.
Analysis of soft tissue and airway spaces
To provide baseline data against which later treatment response can be
measured
The tracing of lateral ceph
The soft tissue profile including glabella, nasion, nasal tip, upper lip,
lower lip and the soft tissue chin.
The inner outline of the sella turcica, the anterior aspect of the nasal bones
together with the frontonasal suture and the outline of the lower bony
margin of the orbit.
The maxillary outline, upper incisors and upper first molar.
The mandibular outline with the mandibular incisors and first molar and
articulare.
In general, where bilateral landmarks present two images, the average of
the two should be drawn. The exceptions to this are those cases where there
is an obvious asymmetry of the mandible, which has resulted in two
distinct lower borders to the mandible. From the point of view of
Mohammed Almuzian, University of Glasgow 24
measurement, it is normal practice to take the lower border which conforms
to the normal side of the face, as assessed clinically.
Mohammed Almuzian, University of Glasgow 25
The total anterior face height (TAFH) is the sum of the upper anterior face
height (UAFH), measured from nasion to the maxillary plane, and the
lower anterior face height (LAFH), maxillary plane to menton. The lower
anterior face height is usually 55+2% of the total anterior face height.
Posterior face height is similarly measured from sella to gonion using the
maxillary plane to divide the upper posterior face height (UPFH) from the
Mohammed Almuzian, University of Glasgow 26
lower posterior face height (LPFH). The lower posterior face height being
approximately 43 +2% of the total posterior face height
The angle of the maxillary to the mandibular plane (MxP/MP) is normally
27+4. This angle is important because as with the posterior face height
measurement, it reflects the surgically important pterygomasseteric sling
length (muscle, fascia and ligaments). For instance, a patient with a high
angle, i.e. greater than 35, tends to have a relatively short posterior face
height and therefore posterior musculo-ligamentous height. Any attempt to
stretch this posterior connective tissue by rotating the anterior body of the
mandible upwards, in an anticlockwise direction, around a fulcrum
produced by the posterior molar occlusion, is doomed to failure and will
lead to early surgical relapse.
If the SN/MxP value is outside this range then Eastman correction cannot
be applied and alternate analyses of the anteroposterior skeletal pattern
should be employed like Wits or McNamara analysis.
Posterior-anterior radiograph
A poster anterior view of the skull helps to reveal facial bone asymmetry.
Long cone periapical films are essential for assessing the space between
teeth when segmental surgery is required.
A maxillary occlusal radiograph defines the bone defect in cleft cases.
Mohammed Almuzian, University of Glasgow 27
Major deformity is best visualised with a 3-dimensional CT scan.
Chest radiograph: If the patient elects to have surgery, a preoperative chest
radiograph is required by some surgeons but is only justified where a
costschondral graft is to be harvested.
iii) Analysis of study models
iv) Psychological examination where appropriate.
Special investigations and assessment
Surgery prediction methods
1. Manual Cephalometric Prediction
A. Overlay Method Tracing
B. Template Method
2. Computer Prediction
E.g. CASSOS
3. Cast Prediction (Model Surgery)
Soft tissue prediction
Upton et al (1997) found that chin; upper lip and lower lip are predictable
in 80%, 80% and 50% respectively. The soft tissue changes depend on:
A. Type of surgery
B. Soft tissue composition and thickness
Mohammed Almuzian, University of Glasgow 28
C. Presence of dead space between ST and teeth
D. Racial and individual variations,
Error in perdition
1. Errors in carrying out ‘’surgically’’ the planned movements i.e. our
inability to move the teeth and bones to the exactly intended positions.
Overall, 80% of the results fell within 2 mm of the prediction and 43%
within 1 mm.
2. Errors in the equipment, materials and software used in the prediction
process. Again there are again two major sources of error:
I. The usual digitising errors e.g. point identification, posing errors etc.
PS: Cunningham 2004 compare OPAL and hand prediction and found that
hand type is better in bimax and similar in mand surgery alone. The main
problem of OPAL is in the region of lip (Eckhardt, 2004 #41). Smith and
Proffit 2004 found dentofacial planner the best as computer stimulation
II. Prediction of the soft tissue changes for a given hard tissue movement
What are the risks of showing computer simulations to patients? Bell
1997
1. No significant difference in the level of satisfaction
2. Reduce the anxiety about the surgical experience
3. Increase the concern about the possibility of surgical problems,
Mohammed Almuzian, University of Glasgow 29
4. Better method of informed consent to treatment
Presurgical orthodontics
Appliance
The use of ceramic brackets in orthognathic cases due to their potential
for fracture.
A 022” slot should be used to allow the use of full thick wires.
It is worthwhile considering the variations in bracket tip and torque
required in specific cases. In an ideal occlusion, the crown of the lower
incisor lies labial to the apex for ideal tooth inclination.
A. In Class II cases where proclined lower incisor require decompensation,
the use of MBT brackets with the 6 degree of additional lingual crown
torque can aid the mechanics.
B. Conversely, Super-torque TM brackets, with additional palatal root
torque to the upper incisors, can be useful in correcting severely retroclined
incisors in Class II division 2 cases.
C. In class III the use of low torqued upper incisors and inverted torqued
LLB.
Mesio-distal tooth angulation (tip) becomes important when considering
the preparation of a case for segmental surgery as it is important to
facilitate the surgery (see below) by ensuring the roots adjacent to the
Mohammed Almuzian, University of Glasgow 30
osteotomy site are either parallel or slightly divergent. Where the
osteotomy cuts are to be made distal to the canines, the use of the canine
bracket of the opposite side ensures that the tip incorporated into the
bracket keeps the apices forward and out of the way of the surgical cuts.
Segmental surgery requires the added facility of a double tube on the
mandibular molars and/or a triple.
The use of TPA to control arch width if segmental levelling is used in
AOB case, since intrusion of incisors can cause buccal flaring of the
posterior teeth.
TAD can be used for better decompensation aims.
The role of orthodontic component of orthognathic treatment
1. Relieve crowding
2. Alignment
3. Complete or partial levelling of the curve of Spee
4. Space closure or sometimes relocalisation prior to restorative
procedures
5. Correction of dental centreline discrepancy ( within each arch but not
necessarily relative to each other)
6. Transverse arch coordination for post-surgical occlusion(Q helix, RME,
SARPE, or Segmental Le Fort osteotomy)
Mohammed Almuzian, University of Glasgow 31
7. Creation of optimal buccal segment inclinations to ensure good stability
and function of the final occlusion and as much as possible that all teeth
have an opposing tooth contact at the end of treatment
8. Dentoalveolar decompensation of incisors. Decompensation helps in
allowing maximum jaw movement during surgery which enables the
achievements of optimal facial aesthetic.
9. Provide enough room for segmental osteotomies
10. The orthodontic appliance serve to provide the best means of
intraoperative intermaxillary fixation & to provide for the attachment of
post-operative intermaxillary elastics
Leveling of the curves of Spee in the mandible
The decision as to whether to fully level the arches is very much dependent
on the patient's facial height, chin prominence and the upper lip/incisor
relationship.
1. If the goal is to maintain face height when the mandible is advanced,
pre-surgical full levelling is required. Levelling the Curve of Spee without
space will procline the lower incisors, and reduce the potential for
mandibular advancement. If the intention is to maintain anteroposterior
arch length, then premolar extractions will be required, especially if there is
any crowding present
2. If the goal is to decrease face height when the mandible is advanced,
Mohammed Almuzian, University of Glasgow 32
pre-surgical incisor intrusion by orthodontic applianceis required;
If intrusion is difficult orthodontically, a segmented arch levelling is
indicated in the pre-surgical orthodontics and addressed finally by
subapical osteotomies.
Other prefer to deal with levelling similar to average face height then
reduced the skeletal problem surgically as bi-maxillary approach.
3. if the goal is to increase face height , which often is the case in
mandibular deficiency patients, pre-surgical intrusion of the lower incisors
would be a serious error and maintaining or leaving a curve of Spee is
indicated.
Maintaining the curve of Spee in low angle cases
1. Prior to surgery, the teeth are aligned and the anteroposterior position
of the incisors is established, but a curve of Spee is left in all the archwires,
including the surgical stabilizing wire. This means the surgical splint will
be thicker in the premolar region than anteriorly or posteriorly.
2. At surgery, normal overjet and overbite are created, and the space
between the premolar teeth is corrected post-surgically by extruding these
teeth with flat archwires. (three point landing)
3. This occurs rapidly, typically within the first 8 weeks after orthodontic
treatment resumes, because there are no occlusal contacts to oppose the
tooth movement and due to postsurgical increase in the metabolic changes.
Mohammed Almuzian, University of Glasgow 33
4. The alternatives to use an auxiliary wire to assist in pre-surgical
levelling. An auxiliary levelling wire 17*25 SS passed over the main AW
from auxillary molar tube and it can be tied over a continuous reverse
curve base archwire to increase its action.
5. In cases with a severe lateral open bites which are too large to close by
orthodontic extrusion of the premolars and canines. Many operators
consider 2 mm of extrusion from each arch as the absolute maximum that
can be achieved and remain stable without rebound. Beyond this, levelling
should be achieved through surgery, usually through a set-down of the
lower labial segment with an anterior mandibuloplasty. Where there is a
reverse Curve of Spee in the upper arch, as in some Class II division 2
cases, it may be necessary to undertake segmental surgery to both the upper
and lower labial segments.
Advantages of partial levelling
1. The absence of premolar contact postoperatively speeds levelling of the
occlusal plane
2. The posterior rotation of the mandible at surgery may lead to an overall
increase in face height in appropriate cases
Disadvantages of partial levelling
1. Patients prefer a shorter postoperative treatment period.
2. The extrusion of the posterior teeth with preoperative levelling is likely
to be very similar to the postoperative extrusion, so the face is likely to
Mohammed Almuzian, University of Glasgow 34
finish at a very similar face height. Certainly, intrusion of lower incisors is
not beneficial in low face height cases, but studies suggest that such
intrusion is very modest with most mechanics used to level the occlusal
plane and may not be significantly different in the preoperative or
postoperative situations.
Levelling of the curves of Spee in the maxilla
It depends on
Aetiology of AOB,
Facial height,
Amount of autorotation required,
Incisor show
Surgical technique used
The steepness of the COS
1. In a patient with open bite, severe vertical discrepancies within the
maxillary arch are an indication for multiple segment surgery. When this is
planned, the upper arch should not be levelled conventionally.
2. The presurgical orthodontics should accentuate the open bite through
intrusion of the labial segments and extrusion of the buccal segments. In
this way maximal surgical correction can be achieved and any postsurgical
incisor change will ensure closure of the anterior open bite
Mohammed Almuzian, University of Glasgow 35
3. Leveling should be done only within each segment, and the segments
are levelled at surgery.
4. This can be achieved by three segmental archwires, two running in the
buccal segments from premolar to molar on each side together with a third
segment for the canine and incisors. This approach tends to produce a lack
of control of the tooth positions and therefore a continuous arch is
preferred, from molar to molar but with an anterior step for the canines and
incisors.
5. In the latter case, the surgeon will cut the archwire across the
osteotomy site at the time of surgery. Although the segments are
immobilised using rigid internal fixation, it is essential to provide
additional fixation at the occlusal level. This can be done with
A prefabricated continuous archwire bent to the planned postoperative
segment’s position.
However, insertion of this wire intra-operatively can be extremely time-
consuming. It is preferable to use a rigid prefabricated horseshoe shaped
1.0 mm steel supplemental arch wire, engaged passively into double or
triple tubes on the molars and secured by ligatures to the three archwire
segments. Ultimately, the sectional arches can be replaced with a
continuous archwire once the patient has recovered.
Also wafer splint can help in this case
Mohammed Almuzian, University of Glasgow 36
6. If a one-piece osteotomy is planned and pre-surgical orthodontic
levelling is required, but extrusion of anterior teeth before surgery must be
avoided then TAD can be used to vertically stabilize the anterior segments.
Dentoalveolar decompensation of incisors
The extraction and mechanics for decompensation is opposite to
conventional orthodontic camouflage. But all should be done with
minimum dental health side effect. Presurgical preparation
(decompensation) objectives are:
Corrects the axial inclinations to maximise jaw movement.
For best dental aesthetic
For better function
For stability point of view
To compensate for future relapse
Periodontal health
In skeletal Class III cases,
Lower arch
A. Extraction or non-extraction
It depends on:
1. Degree of skeletal movement required as well as the target OJ
Mohammed Almuzian, University of Glasgow 37
2. Curve of Spee
3. LMA. It is better to avoid extraction in obtuse LMA
4. Degree of the existing compensation
5. Thickness of labial alveolar plate, so care to avoid destroying the
periodontal attachment, producing a dehiscence of the gingival margin.
Sometimes, periodontal grafting should be considered.
6. Degree of crowding. Severely crowded cases may need extractions to
provide the space for arch alignment. The extractions of choice are the
lower second premolars, assuming all teeth to be of good prognosis.
B. Appliance
1. Use +ve torque LLS as well as increased tip incorporated into the
canine bracket.
2. Invert the lower incisor bracket to get positive labial crown torque
3. “Laceback” avoided in lower but not upper.
Upper arch
A. Extraction or non-extraction
1. Degree of skeletal movement required as well as the target OJ
2. Curve of Spee
3. Degree of the existing compensation
Mohammed Almuzian, University of Glasgow 38
4. Thickness of labial alveolar plate, so care to avoid destroying the
periodontal attachment, producing a dehiscence of the gingival margin.
5. Degree of crowding. The upper incisors generally need to be retracted
with upper first premolars removal. In very mildly crowded cases, some
would prefer to move the upper arch distally using anchorage-reinforcing
devices on non-extraction base.
6. Differential impaction with rotation of maxillary occlusal plane.
B. Appliance
1. In maxillary brackets, laceback ligatures should be
employed and the canine brackets are swapped.
2. Low torque prescription in the maxillary incisor brackets
unless the posterior maxilla is impacted posteriorly by a
greater amount than the anterior segment, then the
presurgical preparation may intentionally leave the upper
incisors slightly proclined.
3. Class 2 traction is frequently required in these class 3 cases
and vice versa.
4. Additional active labial crown torque should on occasion be employed
to assist soft tissue recoil which means that the upper lip will apply a
palatally force after maxillary advancement which might cause some
relapse.
Mohammed Almuzian, University of Glasgow 39
In skeletal Class II cases
Exactly opposite to the above.
Transverse arch co-ordination
Methods of maxillary arch expansion relate to four factors:
1. The amount of discrepancy
2. The inclination of the buccal segments
3. Bone thickness buccally
4. The proposed surgical procedure. (i.e. single jaw, segmental)
Technique of arch coordination
1. Accept a bilateral posterior crossbite in some instances but may
complicate the achievement of a satisfactorily stable occlusion in the post-
operative period
2. Widening or narrowing of the full-sized archwires with buccal or
lingual root torque respectively (dental expansion or constriction)
3. A quadhelix tends to tip teeth and the hanging down of the palatal
cusps interferes with a good stable intercuspal and functional occlusion.
4. RME (e.g.: a rapid expansion splint) are less appropriate in an adult
with a closed mid-palatal suture.
Mohammed Almuzian, University of Glasgow 40
5. Surgically –Assisted Rapid Maxillary Expansion (SARPE): Advantages
and disadvantages:
No periodontal hazard like Lefort I two piece maxilla to expand the UA.
Simpler orthodontic preparation - no need to create spaces for segmental
osteotomy cuts
Less extractions required
Asymmetric expansion possible ( unilateral lateral corticotomy)
Better at canine expansion than molar expansion
6. Segmental Le Fort osteotomy
Segmental-midline- Le Fort surgery (Bailey et al 1997) must be very
carefully carried out to avoid periodontal damage between the upper central
incisors and some clinicians advocate the creation of a median diastema as
part of the orthodontic preparation if the constriction is required.
The surgery must be mimicked on models and an orthodontic archwire
and wafers made to the planned new archform to be created during the
surgery.
The new archwire should ideally be inserted during the operation and the
chance of the wafers not fitting well is increased.
Mohammed Almuzian, University of Glasgow 41
Advantages and disadvantages
No additional operation or two phase operation like SARPE
Better for molar expansion
Better stability
More complicated and lengthy Le Fort procedure
More complicated orthodontics to create and then resolve spaces for
interdental cuts
Pd damage.
Monitoring Arch Coordination
1. For Class II problems, testing of arch co-ordination in the
transverse dimension can be achieved by simple forward
posturing of the mandible.
2. In Class III corrections the use of
An acrylic template of the occlusal surfaces of the
lower arch is invaluable. The template can be prepared
by taking an alginate impression of the aligned lower
arch and pouring cold cure acrylic resin into the
occlusal portion of the impression. At successive
visits, the template of the lower arch can then be
occluded with the upper arch to check compatibility and avoid the need for
repeated study models.
Mohammed Almuzian, University of Glasgow 42
Another method is by using the lower AW as a guide which should fit
passively along the central fossae of upper teeth and touch the cingulum of
upper incisors.
Using study model
Using digital study model
The Definitive Treatment Plan
A. The key to successful surgery is to place the maxilla and the
decompensated maxillary incisors in the optimum anteroposterior,
transverse and vertical position in relation to the upper lip and face (PIP).
The mandible is then placed in a Class I incisor relationship to the maxilla.
B. The movements of the maxilla based on the clinical prediction of the
incisor position, can then be repeated on a digital image or tracing of the
patient's lateral cephalometric radiograph.
C. The clinician can use software package or hand tracing. When planning
using hand tracing it is important to trace all the teeth in order to avoid
missing potential premature contacts
The maxilla
1. The incisor exposure with the lips parted at rest — will decide the
vertical movement of the maxilla. Aesthetic exposure may vary from 1 to 4
mm. This is inversely proportional to the upper lip length which ranges
from 18-24 mms.
Mohammed Almuzian, University of Glasgow 43
2. Excessive or unaesthetic incisor exposure is corrected with appropriate
maxillary impaction. But where the upper lip is unduly short, the patient
can show a greater amount of incisor.
3. Rarely the patient has marked dento-alveolar hypoplasia and shows
little or no incisor with a normal lip length. This is corrected with an
inferior movement of the maxilla.
4. Horizontally, the maxilla advance until best stable and biologically
acceptable position achieved in relation to zero meridian
5. Horizontal movement similar to the vertical maxillary movements will
affect the incisor exposure. Advancing the maxilla will lead to greater
incisor exposure which will need to be adjusted for when considering the
vertical move. V-Y closure of the lip can be used to compensate for the
increased incisor show after maxillary advancement.
6. Coronal occlusal cants and midline rotations must also be corrected
7. Moving the maxilla will also affect the nose. Vertical impaction widens
the alar base and forward movements will elevate the nasal tip. Depending
upon the initial appearance these changes may or not be desirable. If not,
then a record should be made to provide a “cinch suture” across the lateral
alar cartilages or to reduce the anterior nasal spine at the time of surgery
NB:
Mohammed Almuzian, University of Glasgow 44
The inherent inaccuracy of the planning and surgical technique and the
eye's inability to perceive small anatomical changes, determine that units of
horizontal advancement should be no less than 3 mm. This also facilitates
planning as a 3 mm minor advancement; a 6 mm intermediate; and a 9 mm
major move. Cleft cases usually require 9 mm or more.
Similarly vertical moves of 2 mm for minor; 4 mm intermediate and 6
mm for major impactions are appropriate for all cases. These three
categories also simplify the decision making process.
The mandible
1. Having planned where the maxilla is to be placed, the final step is to
place the mandible in a Class I incisor relationship. This is built into the
final wafer.
2. If the definitive occlusion is not immediately possible because of the
need for further orthodontics or restorative treatment, the wafer maintains
the jaw relationship until orthodontics or restorative treatment can be
commenced.
3. The mandible will require
Autorotation, Any changes in the vertical and horizontal position of the
maxilla will necessitate a change in the vertical and AP position of the
mandible. This is mediated naturally through neuromuscular feedback
mechanisms and the mandibular elevator muscles.
Mohammed Almuzian, University of Glasgow 45
Antero-posterior, Forward movement of the mandible to establish a Class
I incisor relationship in Class II cases, will also increase lower face height
in deep overbite specially when advancing the mandible without levelling
the curve of Spee. The vertical facial height will increase and the everted
lip will unroll and upright. If this change is desirable, the consequent lateral
open bites need to be closed with postsurgical orthodontics to a stable
position. If too severe for orthodontic closure, then surgery must
incorporate a levelling of the occlusal plane with an anterior subapical
osteotomies. On the other hand, mandibular setbacks will evert the lip.
Occasionally this may correct the occlusion but reduce the chin prominence
which will require a paradoxical advancement.
Vertical, no anti-clockwise stretching allowed bec of relapse. The only
vertical movement is autorotation. Some evidences showed that the
tolerable degree of anti-clockwise stretching is between 5-8 degree.
Rotational or rarely transverse movements. These are required in
asymmetry cases, for example hemimandibular elongation where the need
is arch coordination especially with an adequate maxillary intercanine
width.
Revision of the plan after autorotation
1. Assessment of the lower incisor position of the autorotated mandible is
also important in determining if further adjustment of the maxillary
position is required in order to establish a positive overbite.
Mohammed Almuzian, University of Glasgow 46
2. With an anterior open bite autorotation leads to initial buccal segment
contact. Closure of the residual anterior open bite by (anticlockwise)
rotation of the mandible around this posterior pivot will lead to an
elongation of the pterygo-masseteric sling and relapse. In such cases it is
necessary to impact the posterior part of the maxilla differentially to that of
the anterior maxilla. The extent of the differential impaction can be
ascertained from the tracing.
3. With impactions for vertical maxillary excess, any minor incisor
discrepancy on simple autorotation can be overcome by forward or
backward adjusted movement of the maxilla. A significant discrepancy will
require a bimaxillary procedure to ensure the incisor Class I relationship
without compromising the upper lip incisor relationship.
Chin Position
Both anteroposterior and vertical movements of the mandible will affect
the position of the chin. It is important that the chin be carefully assessed to
avoid further surgery.
The immediate pre-surgical phase of treatment
1) Final records: Immediately prior to surgery records should be taken so
that final surgical plan can be confirmed. This include study models,
photographs and lateral cephalogram with OPT or even CBCT
Mohammed Almuzian, University of Glasgow 47
2) Model surgery: The models should be mounted on a semi adjustable
articulator. So the precise surgical movement can be performed on the
models. Acrylic intermediate and or final interocclusal wafers are also
constructed from the models
3) Final AW: Final rigid wire with hook is important to stabilize the wafer
and to allow the use of elastic later on.
4) Patient preparation:
Patient consent
Instruction about the post-surgical complication
postoperative regimens for feeding and oral hygiene
5) Preoperative Investigations like full blood count
6) Blood transfusion: With the increased concern about cross-infection,
autologous blood is now being used in some centres for elective surgery.
Model surgery and wafer splint for orthognathic patient
Cast Prediction (Model Surgery)
Model surgery is the dental cast version of cephalometric prediction of
surgical results.
It can be done before the orthodontic preparation but wax setting of
crowded teeth might needed .
Mohammed Almuzian, University of Glasgow 48
The primary goal of model surgery is to functionally and spatially
simulate the patient's jaws and dental structures as accurately as possible to
allow accurate simulation of the intended surgery.
The secondary goal is to construct the surgical wafers.
Procedure of cast prediction (Model Surgery)
1. The selection of articulator is the first step in preparation for effective
model surgery. it includes:
a. Plain line or simple hinge articulator used in case of:
Maxillary advancement with no height change of the Maxilla i.e.: no
impaction / no down graft.
Mandibular as a single jaw procedure.
Segmental surgery with no height change.
b. Semi-adjustable articulator
Maxillary osteotomies with height changes i.e.: impaction or downgraft.
Bi-Maxillary procedures.
Segmental or multi-part maxillary osteotomies.
Cases of facial asymmetry.
Mohammed Almuzian, University of Glasgow 49
Semi-adjustable articulator (Dentatus).
2. Face Bow Selection.
The function of the face bow recording is to mount the maxillary cast on
the articulator to reproduce the anatomical position of the maxilla in its
relation to the base of the skull. There are many types including:
a. The auricular face bow
Mohammed Almuzian, University of Glasgow 50
b. Condylar face bow
c. Condylar face bow with spirit
bubble
3. The maxillary dental cast is mounted on a semi adjustable articulator
with the aid of a facebow transfer from the patient.
4. Next, the mandibular dental cast is mounted with the aid of a bite
registration taken with the patient's jaws in the retruded contact position, or
centric relation.
5. Several measurement should be done first, This be accomplished by
drawing several vertical reference lines and two horizontal reference lines
on. The distance between the facial surface of the maxillary incisors and
the articulator pin is recorded.
Mohammed Almuzian, University of Glasgow 51
6. Model simulation of anticipated surgical movement (that has been
determined by cephalometric prediction tracing and/or clinical data)
performed next.
7. The sequence of movements are:
The maxillary cast is repositioned first according to the measurements
from the prediction tracing.
Once the maxillary cast has been fixed in the new position on the
articulator,
The first stage or the intermediate occlusal wafer splint is generated
The mandibular cast then is repositioned to oppose the maxillary cast,
simulating the final position of the jaws at surgery. This final position
generates the final occlusal wafer splint for use at surgery and during the
period of jaw rehabilitation following surgery.
It is easier for the surgeon to use a second identical set of dental casts
mounted in a hinge-type articulator for the final splint because the occlusal
surfaces of the first set of casts can be damaged in construction of the
intermediate occlusal wafer splint.
Then the measurement is compared to what had been planned before.
Technical advises
It is essential to use recent models for wafer fabrication;
Impressions must be taken at least two weeks after any final adjustment of
the orthodontic stabilizing arch wire.
Mohammed Almuzian, University of Glasgow 52
Proffit and White advised that the thinnest practical wafers had 1 to 2 mm
If the maxilla must be segmented at surgery, a combined or two-stage
splint can be constructed. This technique involves construction of the
final splint first (on a hinge articulator) followed by fabrication of the
combined splint
The uses of the surgical wafer
1. To translate the planned surgery to the reality in the theatre
2. Splint the segmented arch
3. Intermediate and final splinting in bimaxillary surgery
4. Maintain the maxillomandibular relationship in overcorrected position
if these are planned. They enable a positive occlusion in an
overcorrected position which is not dictated by the intercuspal
position. e.g. class 2 cases can be set up edge-to-edge and class 3
cases to a slightly increased overjet
5. For postoperative rehabilitation or Post-Operative Proprioceptive
Guidance. After rigid fixation of the mandible, the wafer may be
wired to the maxilla, or less frequently to the mandible, to provide
post-operative proprioceptive guidance for up to two weeks. The
wafer will help the patient to occlude into the planned position with
or without the help of elastics by overriding the patient’s pre-
operative proprioceptive drive. This also improves the arch
relationship for any final orthodontic refinement of the occlusion.
Mohammed Almuzian, University of Glasgow 53
Materials and Types of Occlusal Wafers for Orthognathic Surgery
1. Self-cured
2. Heat-cured methyl methacrylate
3. Cast in silver or cobalt chromium alloy for difficult cleft palate
cases.
4. A palatal wire may be added for reinforcement in case of
segemental osteotomies.
Causes of error in model surgery,
1. It is essential that the angle between the occlusal plane and the
Frankfort horizontal for the patient is the same as the angle between the
occlusal plane and the upper member of the articulator on the maxillary
model. If this is incorrect, the result of the model surgery is erroneous.
2. The other source of error is the difference in the patient’s mandibular
position when supine and upright; the mandible tends to be positioned
more posteriorly when the patient is lying down. Therefore, less maxillary
advancement would be achieved than predicted on the articulator and the
mandible has been overcorrected (more setback) to compensate for
maxillary under-advancement. BAMBER et al recommended recording the
centric relationship in the supine conscious position when planning
bimaxillary osteotomies.
3. Under general anaesthesia, the muscles of mastication are relaxed and
the mandible would not serve as a fixed reference plane for maxillary
surgery
Mohammed Almuzian, University of Glasgow 54
4. The other possible source of errors in planning orthognathic surgery is
the inaccuracy in registering and transferring the true hinge axis of the
condyle to the articulator specially when the condyle are in different level
which may incorporate a pseudo-cant.
5. The last cause of error is the main cause of this inaccuracy is that they
are not designed to record facial asymmetry accurately.
Several factors can increase the accuracy and good fit of wafers
1. Leave heavy wires passive for one visit before taking the impression
2. Either take the impression with rubber compound or if using alginate
ensure that it does not lift from the tray
Choosing a larger tray and therefore thicker sections of alginate
Use a tray adhesive
Block undercut by wax
Remove the impression by pushing on the alginate not by pulling on the
tray
3. Insure the facebow is accurately located
4. Construct any intermediate wafer in a different colour acrylic to avoid
confusion at operation
Mohammed Almuzian, University of Glasgow 55
Alternative method of model surgery
1. 3 D model surgery
2. Digital model surgery
3. In facial asymmetry the use of orthognathic articulator is preferable
Surgical procedures and treatment possibilities
Envelope of Surgery
Once the amount of anteroposterior movement required for correction
exceeds 1cm consideration should be given to operating on both jaws
Set back of the maxilla is possible by 5-6 mm but very difficult.
Care must be taken not to compromise the blood supply by over stretching
the tissues
Maxillary Surgery
A. Total maxillary osteotomy:
1- Le Fort I. The surgical cut goes through the wall of the maxillary
sinuses, the lateral nasal walls and the nasal septum at the level just
superior to the apices of the maxillary teeth. It is not indicated in maxillary
set back bec of the negative effect on the profile and bec of the anatomical
restriction as well as telescoping of the maxilla in the sinus. If down
grafting of the maxilla is performed, it is better to combine it with mand
relieving surgery
Mohammed Almuzian, University of Glasgow 56
2- Le Fort II. It is a pyramidal osteotomy, it differs from Le Fort I that it
passes anteriorly toward the orbit. It is used mainly with CLP.
3- Le Fort III. It is used for the correction of symmetrical mid-face
recession affecting zygomatico-maxillary and orbital regions.
4- Le Fort II modified Kufner
The nasal bridge is not involved, but the surgical cuts runs Anterior to the
lacrimal apparatus and laterally to the zygoma.
It is indicated when the nasal bridge and projection are both good, but the
infra orbital region and the dentoalveolus are retruded, with mild
zygomatic flattening.
5- High level Le Fort II
The cuts along the orbital floor may be extended laterally to include
increasing areas of the inferior orbital rim and malar body, full extension
will turn the procedure to sub cranial Le Fort III.
B. Segmental alveolar maxillary osteotomy:
1. Anterior segmental osteotomy. Mobilize the anterior segment of the
maxilla and allows the reposition in an upward, downward and a rotational
manner.
2. Posterior segmental osteotomy (The Posterior Dentoalveolar Segmental
Osteotomy of Schuchardt)
Mohammed Almuzian, University of Glasgow 57
3. Anterior and posterior segmental osteotomy.
C. Maxillary osteotomies for transverse problems
1. LeFort I down fracture surgery with parasagittal osteotomies
LeFort I downfracture surgery used for treatment of Maxillary transverse
problems. It consist of parasagittal
osteotomies in the floor of the nose
or floor of the sinus that are
connected by a transverse cut
anteriorly. A midline extension runs
forward between the roots of the
central incisors.
If constriction is desired, bone is removed at the parasagittal osteotomies
according to presurgical planning.
In expansion, either bone harvested in the downfracture or bank bone is
used to fill the void created by lateral movement of the posterior segments.
2. LeFort I down fracture surgery with midsagittal osteotomies
3. Surgically-assisted palatal expansion, using bone cuts to reduce the
resistance without totally freeing the maxillary segments, followed by rapid
expansion of the jackscrew, is another possible treatment approach for
adult patients with skeletal maxillary constriction.
Mohammed Almuzian, University of Glasgow 58
Soft tissue effects of Le Fort I advancement
1. Nasal tip is advanced by one sixth of the maxillary advancement
(Henderson et al 1984).
2. AP advancement of the lip 60-80% and the tip of nose 20%
3. NLA decreased.
4. Upper lip flattens.
5. Vermilion exposure increased.
6. Increase in the width of the alar base
7. Tip of nose move superiorly
8. Lower lip rolled and advanced
In case of maxillary impaction, the following should be noted
It is important to shorten the nasal septum or free its base so that the
septum is not bent when the maxilla is elevated.
The inferior turbinate can be partially resected if needed to allow the
intrusion, although this procedure rarely is necessary.
The overall facial height is shortened as the mandible responds by
rotating upward and forward. Further surgery to correct the anteroposterior
position of the mandible may or may not be necessary after this rotation,
depending on functional and esthetic concerns
Mohammed Almuzian, University of Glasgow 59
Excellent stability of the vertical position of the maxilla is observed post-
surgically, but long-term, some continued vertical growth of the maxilla
may occur.
In contrast, In case of maxilla moved downward, the following should
be noted:
It tends to relapse back up post-surgically, so that 20% or more of the
vertical change often is lost even when rigid fixation is used.
Both the use of more rigid graft materials (like synthetic hydroxylapatite)
and simultaneous osteotomy of the mandibular ramus have been reported to
improve the stability of downward movement of the maxilla, but this
remains one of the more problematic movements
Mandibular Surgery
Bilateral Sagittal Split Osteotomy (BSSO)
Indication1- Mandibular advancement(less than 10 -12 mm).
2- Mandibular set back (less than 7-8 mm).
3- Correction of asymmetry (Minor).
4- It is not recommended in patients with an anterior open bite without
considering a simultaneous maxillary operation to reduce the posterior
facial height.
Mohammed Almuzian, University of Glasgow 60
NB:
Patient should warn of parasthesia with mandibular advancement
About 20% - 25% will have some degree of long term altered sensation
In case of mandibular setback, Airway should be assessed
Vertical Subsegmoid Osteotomy (VSO)
Indication:
1. Large mandibular set back
2. Restricted mouth opening
3. When splat might occurs bec of thin ramus
(Yoshioka 2008) compared intraoral vertical ramus osteotomy (IVRO)
versus sagittal split ramus osteotomy (SSRO) and found similar outcome in
relation to condylar position and stability one year postoperatively.
Advantages
1. Less risk of damage to the ID nerve. Permanent paraesthesia is thought
to be approximately 5% for the VSSO versus 25% for the BSSO
2. This procedure requires less time than the sagittal split osteotomy
Disadvantages
1. Intermaxillary fixation is required because access for rigid fixation is
not possible
2. Reduce ramus length and height
Mohammed Almuzian, University of Glasgow 61
Inverted L osteotomy
Indications
1. Big advancement where the mandibular rami are deficient both
vertically and horizontally.
2. Big set back.
3. Big asymmetry.
Body osteotomy
The objective is to remove a pre-planned segment of mandibular body
allowing the anterior segment of the jaw to be set back.
Mohammed Almuzian, University of Glasgow 62
Lower labial segemental osteotomy (Subabical ostectomy)
Indications:
1- An exaggerated curve of Spee.
2- Correction of bimaxillary protrusion.
Anterior mandibuloplasty
It combines lower labial segment surgery with simultaneous genioplasty,
all the cuts being continuous.
Mohammed Almuzian, University of Glasgow 63
Genioplasty in Orthognathic Treatment
A. Reduction genioplasty:
1- Vertical reduction genioplaty.
2- Horizontal reduction genioplasty.
B. Augmentation genioplasty:
1- Vertical augmentation.
2- Horizontal augmentation. (sliding or double sliding genioplasty)
Technique
By free a wedge-shaped portion of the symphysis and inferior border that
remains pedicle on the genioglossus and geniohyoid muscles.
This segment can be advanced to augment chin contour, shifted sideways
to correct asymmetry, or downgrafted to increase lower face height.
By splitting the segment vertically, the distal aspects of the wedge can be
flared or compressed.
Mohammed Almuzian, University of Glasgow 64
If narrowing of the anterior portion is needed, bone is removed in that
area.
When reduction is desired in the distance from the incisal edge to the
inferior aspect of the symphysis, a wedge of bone can be removed above
the chin
Genioplasty as an adjunct to non-extraction orthodontic treatment
1. Prominence of the lower incisors relative to the chin traditionally has
been treated orthodontically, by retracting the incisors to establish proper
tooth-chin balance, But when the lower incisors are retracted, the upper
incisors also must be retracted.
2. For some patients, this creates the risk of an unesthetic flattening of the
lips and can make a large nose appear even more prominent.
3. For such patients, a lower border osteotomy to augment the chin
provides an alternative to premolar extraction and retraction of prominent
lower incisors
Mohammed Almuzian, University of Glasgow 65
4. In theory, advancing the chin decreases lip pressure against the lower
incisors and makes them more stable in an advanced position. Although
case reports suggest that this may be correct, it has not been established
scientifically
Integration of Orthognathic and Other Surgery
1. Rhinoplasty
It can correct the nasal prominence and elevation of the nasal bridge that
often accompanies severe Class II malocclusion. If the jaw asymmetry
exists, there is about a 30% chance that the nose also is affected, so it is
important to evaluate the nose carefully in asymmetry patients.
It is better for the patient to have both procedures done as part of the same
operation,
Simultaneous mandibular advancement and rhinoplasty usually can be
accomplished, but it is more difficult to combine maxillary surgery and
rhinoplasty, and still more difficult to combine nasal and two-jaw surgery.
A second-stage rhinoplasty, typically done 12 to 16 weeks after the jaw
surgery, often is the best plan for patients with major asymmetry
Mohammed Almuzian, University of Glasgow 66
Examination of the nose
A detailed examination of the internal and external aspects of the nose is
performed. Anterior rhinoscopy to detail mucosal, caudal septal and
turbinate deformities is supplemented with an endoscopic evaluation of the
posterior nasal cavity and middle meatal areas to exclude infective or
obstructive sinonasal disease.
The internal nasal valve area which is bounded by the upper lateral
cartilage, inferior turbinate, nasal septum
and nasal floor is specifically examined
and any high septal deformity noted. This
is the narrowest part of the nasal airway
and significant internal nasal valve collapse
can be examined by Cottle's test in which
the airway improves when the cheek
adjacent to the mid third of the nose is
pulled laterally.
Mohammed Almuzian, University of Glasgow 67
The importance of the balance of the nose to other aspects of the face is
important. Assessment of this relationship should form the initial part of
the external examination process.
The patient's ethnic characteristics must also be considered. Facial and
nasal asymmetries are documented and detailed to the patient.
2. Tongue Reduction
Indications: The enlarged tongue is an uncommon cause of anterior open
bite and osteotomy failure. If it appears to be large and the incisor teeth are
proclined and separated, surgical reduction is indicated and can be carried
out prior to orthodontics or with segmental osteotomies.
Where there is any doubt, the patient should be informed that it may be
necessary sometime after the dental alignment or osteotomy, and the case is
carefully followed up at 3-monthly intervals to prevent any gross relapse.
This will take the form of recurrent proclination and separation of the
incisors. Once this is obvious, reduction should be carried out and any
dental relapse can be corrected orthodontically.
3. Collagen and Botox
Collagen injections treat the same facial wrinkles that BOTOX®
Cosmetic does, including frown lines, crow's feet and forehead creases.
Collagen injections can also be used to compensate for fat loss in facial
tissues, lip augmentation, and to fill in acne scars or dark under eye circles.
While bovine collagen injections like Zyderm and Zyplast are still used
today, patients are required to undergo a skin test prior to treatment to
Mohammed Almuzian, University of Glasgow 68
ensure against allergic reactions. By comparison, human collagen
injections like CosmoDerm and CosmoPlast can cost more, but they are
proven non-allergenic treatments.
Botox injections don't technically qualify as a dermal filler because their
treatments use the botulinum toxin type A, a neuromuscular blocking toxin,
rather than a filler substance. The botulinum toxin relaxes tense facial
muscles so that the appearance of wrinkles and fine lines is temporarily
eliminated. Botox is FDA approved for the treatment of wrinkles and poses
the risk of a few minor side effects like temporary bruising. Overall, Botox
and collagen injections are considered safe procedures for the majority of
patients
Distraction Osteogenesis
Inducing a callus of bone by osteotomy or corticotomy followed by
distraction of proximal and distal ends resulting in increase of bone length .
Following an appropriately designed osteotomy, carefully controlled
tensile forces are gradually applied to the callus increasing the regenerative
immature bone laid down between the cut ends.
Over time, the bone remodels into mature bone and the surrounding soft
tissues adapt to their new content and length.
Indication
1. Correction of sever congenital craniofacial defects
Mohammed Almuzian, University of Glasgow 69
Micrognathia (up to 24mm elongation reported)
Correction of mid face retrusion
Craniofacial abnormalities, e.g. Crouzons; hemifacial microsomia;
2. Maxillary hypoplasias due to previous cleft palate surgery; to allow
slow and gradual soft tissue adaptation to the new bone position.
3. Palatal and mandibular expansion;
4. Dentoalveolar hypoplasia for implant insertion;
5. Tumour/trauma reconstruction;
6. TMJ ankylosis.
Advantages
1. Used at an earlier age
2. Improves soft tissue functional matrix
3. Less relapse
4. Reduces need for bone grafts
5. Some claim that distraction produces less disturbance of speech with
reduced incidence of VPI.
6. Can achieve movement in 3 plane of space
Mohammed Almuzian, University of Glasgow 70
Disadvantages
1. Movement limited by distraction device
2. Infection
3. 2 operations required: one to place, one to remove
4. Damages to
Teeth by screws, pins and bone cuts
Nerves by direct injury and traction injury
Skin scarring by transcutaneous pins if it is used
Tmj
Types of Distractors1. Internal Distractors
Are partially buried
give excellent control over vectors,
require adequate bone
patient with good manual dexterity to turn the
2. Extra-Oral Distractors
Are easier to activate,
give less control over the vectors of distraction,
Mohammed Almuzian, University of Glasgow 71
do not control the posterior maxilla well,
require a frame that is a disadvantage
Types of Extra-Oral Distractors LeFort I Distraction
LeFort II Distraction
LeFort III (Kufner) Distraction
Techniques1. Corticotomy or osteotomy
2. 7 day latency period, until intact vascular supply established
3. Prolonged, progressive and gradual distraction, correct rate and rhythm
of distraction which should be 1mm/day:
below 0.5mm / day-- premature union
above 1.5mm / day- non-union
4. Consolidation period of 8-10 weeks
5. Digital simulated distraction can also be carried out for the more
complicated cases prior to surgery with STL models.
Mohammed Almuzian, University of Glasgow 72
6. The control of the distraction vector of movement can be achieved
using three dimension distractor or with the aid of intermaxillary elastic to
counteract any unwanted movement.
Fixation for orthognathic surgeryFixation of the jaws following an osteotomy plays a very important role in
promoting the union of the repositioned segments. Any movement of the
osteotomised segment can impair healing, which may result in a fibrous
union, non-union or mal-union.
Types of fixationFixation methods can be classified as external, internal fixation (rigid or
non-rigid transosseous wire fixation) and supportive IMF.
a. Extra-osseous fixation.
1. Occlusal wafers.
2. Fixed orthodontic appliances with supplementary arch wires and tubes.
3. Cast metal splints. Cast metal splints have become less popular because
of the clinical and laboratory complexity and are usually confined to the
unstable components of a cleft case.
4. Arch bars either prefabricated flexible or cast cobalt chromium.
Prefabricated Flexible (Erich — Dentaurum, Pforzheim, FRG) is made of
semi-rigid stainless steel. It can be easily contoured to the arch form and
Mohammed Almuzian, University of Glasgow 73
ligated with stainless steel wires passed around the arch bar and the necks
of the adjacent teeth or it can be bonded directly to the tooth surface using
acid etch technique. Cleats for intermaxillary fixation are also an integral
part of the design.
Advantages
These are useful where orthodontic treatment has not been used.
No technical assistance since it can be easily adapted into the desired
shape, can be placed before the operation, occlusion can always be checked
and at the end of the fixation period the arch bars can easily be removed
without an anaesthetic.
Disadvantages
An adequate number of suitable teeth are required to get rigid and reliable
fixation.
They may not be suitable in osteotomies where there are many crowns
and bridges.
5. Eyelet wires. temporary intermaxillary fixation (IMF) is very important
to secure the mobilised segments of the maxilla and the mandible whilst
applying the internal fixation plates and screws.
6. Intra-oral intermaxillary fixation (Temporary IMF)
Mohammed Almuzian, University of Glasgow 74
Temporary IMF is required at operation to achieve and hold the correct
occlusion during osseous fixation. There are several methods available:
1. Fixed orthodontic appliances with occlusal wafers
2. Arch bars
3. Cortical screws and intermaxillary fixation
7.
b. Intra-osseous fixation.
1. Rigid internal fixation (RIF): RIF is the most common method of
fixation. It includes:
i. Mini-plates (titanium or absorbable plates)
Adapted to the lateral surface of the jaw bone and secured with
monocortical screws (titanium or absorbable screws)
The introduction of L-and Y-shape plates should eliminate apical damage
when screwing into the maxillary alveolar segment.
ii. Bicortical screws (positional screws) (titanium or absorbable screws)
It passes through both the lateral and medial cortices.
A bicortical screw (also known as positional screw) is a fully threaded
screw that binds both the lateral cortex of the distal segment and the medial
cortex of the proximal segment during a bilateral sagittal split osteotomy
(BSSO).
Mohammed Almuzian, University of Glasgow 75
This method of fixation does not place any compression on the bony
contact between the proximal and distal segments as the screw is tightened;
the screw engages both the lateral and medial cortex, while maintaining the
distance between the two cortices.
It is recommended that, for a BSSO to achieve maximum stability, three
screws are used and placed in a triangular pattern. Sometimes a
percutaneous approach is advised using a trocar to achieve the
perpendicular placement of the screws.
It has been suggested that the use of bi-cortical screw fixation in
mandibular advancement procedures can lead to condylar resorption;
torque may be applied to the mandibular condyle through lateral
displacement of the proximal fragment as the screws are tightened.
However, studies by Hoppenreijs et al (1998) and Hwang et al (2000) have
found that there is no significant difference in the incidence of post-
operative condylar resorption following BSSO fixation with transosseous
wiring, positional screws or mini-plate fixation.
NB: In a recent Cochrane review, it was concluded that there is no
statistically significant difference in post-operative discomfort, level of
patient dissatisfaction, plate exposure or infection for plate and screw
fixation using either titanium or resorbable materials in orthognathic
surgery (Federowicz et al. 2009). Despite this finding, however, resorbable
plates are not widely used in the UK because of the concerns outlined.
Mohammed Almuzian, University of Glasgow 76
Disadvantages of RIFExpense
Technique sensitive
Damage to vital structures if placed in an incorrect site e.g. mental nerve,
infraorbital nerve
10-15% of plates require removal
Inflammation of overlying soft tissue which may result in soft tissue
dehiscence.
Bulk - plates can sometimes be felt beneath oral mucosa
2. Transosseous wiring
Before the technique of direct rigid fixation with mini-plates was
introduced, transosseous wiring was the traditional method of immobilising
bony segments (together with supporting intermaxillary fixation IMF).
In the mandible, 0.5mm soft stainless steel wire is passed through the
medial and lateral cortices at either the upper or lower border during a
BSSO procedure.
In the maxilla, 0.35mm wire is used because of the thinner nature of the
maxillary cortical bone.
In cases where bimaxillary osteotomy is carried out, skeletal suspension
wires are added from sites with denser cortical bone such as the piriform
rim in the maxilla, and circummandibular wires in the mandible.
Mohammed Almuzian, University of Glasgow 77
c. Hybrid type: Cortical screws and intermaxillary fixation: Where there
has been no recent orthodontic treatment, a cortical screw placed in the
buccal alveolus in each quadrant or some form of arch bar is essential for
intraoperative fixation of wafer.
Rigid internal fixation (as compared to intermaxillary fixation)
Advantages1. Elimination of six weeks of IMF, so no need for time in intensive care
2. Early mandibular opening is possible.
3. Earlier return to a good diet
4. Better OH.
5. A very early revelation of any significant malposition of a jaw enables
an early return to the operating theatre before fibrosis starts. With rigid
fixation the question arises very soon after operation and not six weeks
later on release of IMF.
6. Generally better final bony stability (e.g. Blomqvist et al 1997 and
Forsell et al 1992)
Resorbable screws and plates
These screws are made from polylactide
with or without a percentage of polyglycide.
Mohammed Almuzian, University of Glasgow 78
Ferretti and Reyneke (2002), compare them with normal RIF screw and
found no difference in the post-operative stability.
It mainly used to overcome the disadvantages of metal fixation include
unacceptable palpability, exposure intraorally, passive migration, and
distortion of future magnetic resonance images (MRI) and computed
tomograms (CT). Titanium particulate matter may be shed into the adjacent
tissues and has also been found in regional lymph nodes. The ideal
bioresorbable material should not only support the bony fragments during
healing but also resorb fully once healing is completed. The resulting
metabolites should not cause any local or systemic disorders. LactoSorb is
a copolymer of poly-l-lactic and polyglycolic acid, in a ratio of 82:18%.
The copolymer is structured to provide adequate strength for 6–8 weeks
and to allow a resorption time of 9–15 months. It is metabolised in the
citric acid cycle and eventually excreted by the lungs as carbon dioxide and
water. No difference in the degree of relapse between the use of
bioabsirbable and metallic screw after BSSO (Mattew and Ayoub 2003)
Medication for Orthognathic cases
Preoperatively Immediate
postop
Up to 3 days
Amoxicillin 1G
intravenously at
500 mg
intravenously
orally 500 mg 8-
hourly for the
Mohammed Almuzian, University of Glasgow 79
induction 3 hours traditional 3
days
Metronidazole 1g rectal
suppository at
induction
1g rectal
suppository
3 hours
400 mg orally
12-hourly for 2-
3 days
Clindamycin 300 mg
intravenously at
induction
150 mg iv. 3
hours
300 mg 6-
hourly orally for
2-3 days.
Dexamethasone for
swelling
8 mg is given
intravenously
with the
anaesthetic
induction agents
8 mg is given
i.v. or i.m. 12-
hourly on
postoperative
day 1
4-5 mg 12-
hourly on day 2
non-steroidal anti-
inflammatory
analgesic,
A rectal
administration
such as
flurbiprofen 150
mg 12-hourly, is
also useful to
avoid
continuous
non-steroidal
anti-
inflammatory
analgesic,
Mohammed Almuzian, University of Glasgow 80
opiate analgesia.
Morphine for Pain 1 mg/ml by a Patient Controlled
Administration “pump” system.
long-acting local
analgesic 0.5%
(5 mg/ml)
bupivacaine
hydrochloride
with adrenaline
(1:200 000)
antiemetic such as
metoclopromide
10 mg with morphine
Postoperative Care
First day
1. A nasopharyngeal tube is left in situ overnight, with strict instructions
to staff to suck out the nasopharynx every 30 minutes with a fine catheter
passed through the tube to minimize vomiting.
2. Oxygen (40%) in air is usually administered by face mask at
approximately 5 litres/min.
Then later after complete recovery:
Mohammed Almuzian, University of Glasgow 81
3. Airway and chest clinically and if not clear, radiographically. All
patients benefit from chest physiotherapy.
4. Note the urinary output and ensure the patient's bladder has been
emptied, especially as transient retention may follow narcotic analgesics.
5. Fluid balance, i.e. blood and fluid replacement should approximate to
blood and fluid loss.
6. Nutrition. During the first 24 hours continue the Hartmann's solution, 2
litres i.v., but try 100 ml/h water by mouth, then tea or orange juice, etc. as
soon as the patient can tolerate feeding, using a syringe and quill, feeding
cup or straw. If this is not possible use a fine-bore (Clinifeed — Roussel,
UK) nasogastric tube which should be passed preoperatively to permit
feeding until the patient can accept fluid and calories by mouth.
7. Occlusion and elastic fixation if used.
8. Cutaneous sensation and facial motor function.
9. Oral hygiene with Chlorhexidine 0.2% solution is commenced.
Second Postoperative Day
Repeat the above but change from intravenous to an oral or nasogastric
regimen, increasing the feed to a full diet.
Follow-Up
1. The occlusion may be checked weekly or fortnightly.
Mohammed Almuzian, University of Glasgow 82
2. It is reassuring for the surgeon to assist maximal intercuspation with the
final wafer and elastics.
3. Soluble sutures should be left or removed when they are accessible and
are a source of irritation.
4. Patients require reassurance that impaired labial or infraorbital
sensation will return to normal within 6 months and that excess soft tissue
will also remodel and disappear over this period.
Immediate Postoperative Feeding
1. 0-24 Hours Post-Operation: Intravenous Fluids compound sodium
lactate (Hartmann's) solution is given to balance vomited fluid, gastric
aspirate, urinary output and metabolic needs. The volume will be 2 to 3
litres depending on the patient's weight and the ambient temperature. The
patient should also be encouraged to drink a little.
2. After 24 Hours
If the patient is well, and the surgical procedure allows, trials of oral fluid
should be commenced using a feeding cup, straw or a large bore syringe
and quill. Most orthognathic cases can cope,
if oral intake is proving difficult, enteral feeding should be commenced
using a fine bore nasogastric feeding tube. Supplemental intravenous fluids
are often needed
Mohammed Almuzian, University of Glasgow 83
3. After 48 Hours Patients who have commenced nasogastric feeding
should continue to receive this until the optimum oral intake has been
established. Patients who have tolerated oral fluids from the start can
progress to a full diet. In many cases of bimaxillary surgery involving the
lower labial sulcus with impaired mental sensation, adequate oral feeding
may not be possible for up to 7 days and need special attention.
4. On Discharge the patient should have a comprehensive assessment and
education regarding food preparation, food fortification and the use of
dietary supplements.
General Guidelines for Patients
Aim for weight maintenance.
Aim to include as much variety in the diet as possible
Liquids are more filling than solids, so more will be needed to prevent
weight loss.
Liquidised foods must be thin and smooth enough to pass through a straw
or quill.
Foods are often more palatable if liquidised separately to preserve
individuals flavours and colours.
Milk is a useful source of protein and calories, and can be fortified further
by adding dried milk powder; 3-4 tablespoons of any dried milk powder to
1 pint of full cream milk.
Mohammed Almuzian, University of Glasgow 84
Vitamin C is an important nutrient for wound healing; a glass of pure
orange juice or blackcurrant drink should be taken daily.
This diet also requires a dedicated oral hygiene regime with a child's soft
tooth brush and a chlorhexidine mouth wash after meals to control plaque.
Problems of orthognathic surgery treatment
A. Orthodontic
1. decalcification,
2. breakage of tooth in debonding,
3. attrition with ceramic bracket,
4. root resorption,
5. alveolar bone loss,
6. pulpitis,
7. pulp obliteration,
8. gingivitis,
9. failed treatment,
10. stopped treatment,
11. relapse
B. Surgical
Mohammed Almuzian, University of Glasgow 85
A. Intraoperative
1. Damage to the neurovascular bundle
2. Hemorrhage
3. Failure to relocate the osteotomised fragments
4. Damage to the teeth
5. Death
Postoperatively
1. Immediate surgical complication including
a. Swelling,
Oedema is reducible with pre-and postoperative dexamethasone and
antibiotic cover.
Contrary to some popular practice vacuum drains can dramatically reduce
the swelling arising from mandibular osteotomies, and the minivacuum
drain is equally valuable for infraorbital haematomas following dissection
through a subciliary incision.
The same applies to the iliac crest donor site. Where possible leave drains
for at least 24 hours after they cease to function.
Where there is gross postoperative swelling and pain, the presence of a
haematoma is more likely than oedema alone. Treatment should be the
Mohammed Almuzian, University of Glasgow 86
release of the haematoma, especially if expanding, as it may be the
presenting feature of a persistent arterial bleed, which needs to be identified
and arrested.
b. Bleeding Problems
Minor Haemorrhage
Even with previously healthy patients not receiving any medication which
would predispose to excess bleeding, intraoperative blood loss is
significantly reduced by the administration of an antifibrinolytic agent such
as tranexamic acid 25 mg/kg orally or 0.5-1 g by slow intravenous injection
pre-and postoperatively.
Tearing the periosteum on the medial aspect of the ascending ramus
whilst exposing it for a sagittal split may produce a troublesome bleed,
which can be controlled with a hot wet tonsil swab and pressure for 3
minutes.
Damage to the facial vessels through the base of the subperiosteal pouch
prepared for the mandibular buccal cortex cut responds to the same
pressure and patience.
Rarely the maxillary, tonsillar or lingual arteries may be damaged, giving
rise to prolonged serous haemorrhage. Again, packing firstly with a swab,
and secondly with a large piece of oxidised cellulose (Surgicel) should be
sufficient, assisted by 0.5-1 g t.d.s. tranexamic acid (Cyclokapron, Kabi)
given intravenously.
Mohammed Almuzian, University of Glasgow 87
If vigorous bleeding persists the external carotid may need to be tied off,
Persistent Haemorrhage
Failure to control bleeding despite efficient conservative measures may be
due to the following.
i) A patent damaged artery, either the maxillary or tonsillar that require
identification and ligation. Do not delay ligation of the external carotid if
significant bleeding persists despite local ligation, packing and
antifibrinolytic therapy for more than 30 minutes. This should allow time
for investigation.
ii) A rare manifestation of a latent coagulation defect or defibrination. In
both cases there is an evident lack of clot formation on the drapes and the
wound oozes “watery blood”.
Secondary Haemorrhage
The patient may suddenly bleed profusely postoperatively in the ward, or
even at home. The common causes are a partially divided large vein or
untied artery in the depths of a mandibular osteotomy wound. Occasionally
an undetected coagulopathy such as von Willebrand's is the underlying
problem, especially when the bleeding is repeated. The management must
commence with pressure applied to the bleeding site with swabs, and rapid
transfer to theatre for exploration and haemostasis, as described. As with
all severe haemorrhage up to 10 mg intravenous morphine should be given
immediately by slow intravenous injection as a sedative analgesic, together
Mohammed Almuzian, University of Glasgow 88
with tranexamic acid 0.5-1 g intravenously to help conserve clotting factors
and clot in favour of haemostasis.
Gastric Haemorrhage
The chance of stress-induced gastric erosion is small, even after prolonged
orthognathic surgery. However, the combination of a patient with a history
of peptic ulceration, a stressful surgical procedure, anti-inflammatory
steroids and analgesics can produce a gastric bleed. Abdominal discomfort,
tachycardia, true melaena and/or haematemesis and a fall in haemoglobin
(a late sign) should alert one to this possibility. Initial treatment should
include intravenous fluid support and administration of a proton-pump
inhibitor (omeprazole), first as an intravenous bolus dose (40 mg), then as
an intravenous infusion for 72 hours. Early endoscopy should be
considered after consultation with a gastroenterologist so that the bleeding
point can be injected or banded. The aim of drug treatment is to raise
gastric pH to above 4, thereby stabilising any clots that may have formed at
the bleeding site. This is the reasoning behind the use of proton pump
inhibitors over H2 receptor blockers such as ranitidine, which have a lesser
effect on pH. With vulnerable patients a regular prophylactic proton pump
inhibitor, such as omeprazole or lansoprazole, should be administered as
well as eliminating both steroids and non-steroidal antiinflammatory
analgesic drugs from the intraoperative and postoperative regimen.
c. The Airway
Mohammed Almuzian, University of Glasgow 89
After an uneventful operation, the airway should be maintained with a
nasopharyngeal tube, which is sucked out throughout the postoperative 12-
18 hours at 30-minute intervals. Unless the nurse ensures that the fine
suction catheter passes beyond the end of the nasopharyngeal airway tube,
the end will gradually become blocked with blood clot and will become an
efficient airway obstruction the same can occur with a tracheostomy tube.
Some anaesthetists leave an endotracheal tube in situ which with modern
closed suction units can be kept unobstructed with minimum effort and
nursing intervention. A facemask with 40% oxygen at a flow rate of
approximately 5 litres/min ensures adequate tissue perfusion.
Nasal obstruction with blood clot and mucous crusting can be prevented
by steam inhalations containing Friar's Balsam or some similar aromatic
vapour.
Occasionally an asthmatic patient develops acute bronchospasm and
airway obstruction despite the dexamethasone cover. This may be resolved
by a salbutamol nebuliser; 2.5-5 mg of salbutamol in a pre-prepared
solution via a nebuliser mask on 8 litres oxygen per minute repeated as
required
Emergency Airway Procedures. Acute upper airway obstruction is more
likely to follow trauma then operative procedures. In the non-intubated
patient, obstruction secondary to haemorrhage into the neck tissues may
prevent the clinician from inserting an endotracheal tube through the cords
Mohammed Almuzian, University of Glasgow 90
to establish airway patency. In such cases needle cricothryroidotomy and
surgical cricothyroidotomy may be used to maintain ventilation and
oxygenation whilst formal endotracheal intubation is attempted.
Needle cricothyroidotomy and jet insufflation can provide supplemental
oxygenation for around 20-30 minutes, the time constraint being carbon
dioxide retention, as only minimal expiration is possible through the
obstructed airway via this method. This relatively simple technique buys
time to perform more definitive airway procedures by a clinician skilled in
difficult and emergency situations.
Surgical cricothyroidotomy involves the insertion of a small endotracheal
tube or tracheostomy tube through the cricothyroid membrane. Using this
method the patient can be successfully oxygenated and ventilated with a
bag valve system with supplemental oxygen until intubation or retrograde
intubation is achieved.
d. Soreness,
e. Difficulty eating,
f. Bruising,
g. Mild post-operative depression.
h. Pneumothorax
Occasionally, despite every care on removing a rib graft, there is a breach
in the pleura and the patient develops a pneumothorax. The presenting
Mohammed Almuzian, University of Glasgow 91
signs are breathlessness and tachypnoea with absent breath-sounds over the
area. The typical radiographic appearance where the visceral pleura is
breached. The most convenient, comfortable and cosmetically pleasing site
for drainage is in the fourth or fifth intercostal space in the mid-axillary
line.
i. Vomiting Postoperative
Vomiting in patients with intermaxillary fixation was a well-recognised
problem. Predisposing factors are blood escaping intraoperatively and
postoperatively into the stomach, where partial digestion together with bile
reflux creates an irritant stagnant mixture. An additional factor is the
emetic effect of opiate analgesics. Prevention
Avoid intermaxillary fixation by using internal rigid fixation.
ii) A 12-16FG nasogastric tube passed at the time of the anaesthetic
induction enables postoperative aspiration of gastric contents. The tube is
attached to a bile bag to create a closed collecting system for any
spontaneous reflux. As the patient is monitored throughout the
postoperative night the stomach should be aspirated hourly and the fluid
loss noted. Initially flushing the tube with 20 ml water before aspiration
prevents the end becoming clogged with clot.
The administration of an antiemetic, e.g. metoclopromide 10 mg
intravenously at the end of the operation, and with any required opiate
analgesics, reduces drug-induced emesis (up to a maximum of 30 mg/24
Mohammed Almuzian, University of Glasgow 92
hours). Metoclopromide 10 mg intravenously should also be given at any
other time if vomiting is anticipated.
j. Iliac Crest Problems
The removal of bone from the iliac crest for orthognathic purposes is
becoming less popular. However, the inverted L osteotomy may require a
substantial amount of corticocancellous bone to correct a very small
mandible. Postoperative pain is the most frequent complication and can be
reduced by drainage and analgesics. Some surgeons leave a fine cannula
for infusion of a long acting local analgesic such as bupivacaine (Marcain).
It is difficult to be certain if this is of significant value. If a large graft has
been removed near the anterior superior iliac spine, this may fracture with
sudden movement once the patient is mobilised.
k. Urinary retention
Catheterisation Catheterisation is necessary for prolonged surgical
procedures, especially where large quantities of fluid have been infused.
This is uncommon with orthognathic cases except where there has been
unexpected major blood loss. Another occasional indication is the patient,
usually male, who has postoperative urinary retention. This may be due to
opioid-induced sphincter spasm, diffidence in using a urinal, or a
combination of both, leading to gross distension.
l. Deep Vein Thrombosis
Mohammed Almuzian, University of Glasgow 93
This is a rare event in orthognathic patients, usually occurring
unexpectedly in young women.
As a precaution, all women should cease taking oestrogen containing
contraceptive pills 4 weeks prior to surgery.
If this has been overlooked, subcutaneous low molecular weight heparin
prophylaxis should be considered,
Both high and low risk patients benefit from elasticated thromboembolic-
deterrent stockings being worn during the operation.
Any complaint of postoperative calf tenderness must be taken seriously,
lower limb Doppler ultrasonography should be carried out and if this is
positive (or not possible) the patient is anticoagulated to prevent extension
of the thrombus and embolism.
m.
2. Late complications:
a. Failure of bony union
b. infection of the surgical plates 10%,
c. Permanent damage to nerve, 20-25% risk of permenant altered
sensation with BSSO.
d. Soft tissue problem:
increase alar width and fullness of upper lip with maxillary impaction
Mohammed Almuzian, University of Glasgow 94
double chin with mandibular set backs
lip sag following augmentation genioplasty
e. Fixation Problems
Infection may occur around screws and plates. Miniature plates are an
essential part of the osteotomy and surprisingly in the maxilla rarely get
infected. If drainage and a course of antibiotics do not suppress the
infection, the plate and screws have to be removed. Similarly, uninfected
bone plates may become palpable subcutaneously or submucosally and also
require removal.
Incorrectly placed screws and plates may displace the bony parts. This
occurs more commonly in the third molar area with the sagittal split
operation, but is also with Le Fort I procedures where maxillary
displacement can distort the nasal septum.
Less commonly plates break. Whenever displacement or loss of control
takes place, the patient should be taken back to theatre for correction.
If the condyle is pushed to the back of the fossa when temporary
intermaxillary fixation is put on to facilitate the insertion of the bicortical
screws or buccal plate, on its release, with the patient conscious and
upright, the condyles will tend to recoil downwards and forwards. This is
favourable for the Class 2 Division I mandibular advancement but gives a
postoperative prognathous malocclusion with the Class 3 setback. To avoid
these artefacts (a) the model surgery should be based on a conscious supine
Mohammed Almuzian, University of Glasgow 95
centric relation squash bite and (b) the ascending ramus proximal fragment
should be displaced backwards for Class 2 advancements but pulled
forwards prior to fixation with the Class 3 mandibular setback. Such
problems were less likely to happen with a loose interosseous wire loop at
the osteotomy site and prolonged intermaxillary fixation for 6 weeks. This
enabled the ascending ramus proximal fragment to achieve an optimum
condylemeniscus-fossa relationship by functional adjustment brought about
by swallowing and speech.
Disturbed muscular proprioception and intracapsular oedema may also
give a transient deranged postoperative occlusion when using rigid fixation.
In these cases, light elastics for 7 days will help to restore the occlusion to
the planned relationship. The final occlussal wafer is often left in situ even
where there is no occlussal problem. This is very uncomfortable for the
patient and there is no evidence that it helps. However, if after this elastic
“proprioceptive regimen” there still appears to be marked displacement and
malocclusion — re-operate.
f. condylar resorption specially in high angle class II, specially on
patients who has:
Posteriorly inclined condyles.
Deliberately increased maxillary-mandibular plane angle.
Reduced posterior face height.
Mohammed Almuzian, University of Glasgow 96
As this may result in an increased risk of progressive condylar resorption
following surgery, with subsequent relapse of the malocclusion (Hwang et
al., 2004).
g. Relapse
It arises from inadequate planning or inappropriate surgical technique. The
latter may be roughly divided into two overlapping groups:
1. Operative Structural Causes of Relapse
Inadequate separation of the proximal mandibular bone and the medial
pterygoid muscle from the buccal plate when doing a sagittal split. A finger
firmly inserted to the depth of the split is used to remove the restraining
periosteum and muscle fibres, which hold the two cortices together at the
lower border.
Inadequate bone removal from the posterior wall of the antrum or
separation of the pterygoid plates in a Le Fort I impaction can also create
problems.
The untrimmed nasal septum will create a buckling effect and either
displace the maxilla and disturb the occlusion, or displace the nose and
produce an asymmetric tip deformity, and obstruct the airway. Late
correction will require a rhinoplasty.
2. Postoperative Functional Causes of Relapse
Mohammed Almuzian, University of Glasgow 97
The most notorious is the recurrent anterior open bite following attempted
correction with a mandibular osteotomy. This will occur in patients with a
high mandibular-maxillary plane angle where the low posterior facial
height reflects a short pterygomasseteric sling. This is stretched as the
mandible is rotated around the fulcrum created by the occluding molar
crowns when the anterior teeth are brought into occlusion to close the gap.
The inelastic ligaments and the return of postoperative muscular tone may
even produce a relapse despite internal fixation. This is avoided by a
posterior maxillary impaction equivalent to the anterior open bite to be
corrected.
Postoperative tooth movement can be favourable, especially with the
spontaneous or assisted closure of lateral open bites. However,
unfavourable tooth movements may arise.
Repositioned lower incisors are proclined by a large or “anteriorly
postured” tongue.
Upper incisors are proclined by the lower lip after a maxillary
segmental pushback procedures is carried out on a marked Class II,
Division 1 patient without a mandibular forward correction to an edge to
edge relationship.
Continued eruption (occlusal drift) of the lower incisors will follow an
anterior segmental setdown unless they are placed in a stabilising contact
with the cingula or incisive edges of the opposing teeth.
Mohammed Almuzian, University of Glasgow 98
Expansion of the maxillary premolar and molar segments may tilt those
teeth buccally. Subsequent palatal drift will produce intercuspal contact on
closure with the creation of an anterior open bite. Major expansion of the
palate should be done surgically with a midline osteotomy to avoid dental
relapse.
Occasionally lower lip sag may follow a bone graft procedure to
increase the chin depth by augmentation, or a mandibular forward
movement with a genioplasty. It is difficult to be sure whether it is due to
inadequate freeing of the periosteal pouch and overlying soft tissues, or
failure to re-attach the mentalis high enough on the anterior mandibular
surface, or abnormal muscle activity. The lip sag should be avoided by the
creation of a large loose periosteal pouch to accommodate the enlarged
chin, carefully suturing the divided mentalis to the deep muscle fibres on
the alveolar surface, and the application of a firm pressure dressing
overlying the labiomantal groove. Once formed it can be eliminated in
some cases by vigorous exercising of the lower lip, i.e. the lip is actively
stretched upwards over the incisor edges. If this fails, it will be necessary to
deglove and reposition the soft tissues upwards using heavy polyglycollate
(Vicryl) sutures to elevate the soft tissues of the chin.
h. Idiopathic periapical and internal resorption may occur in teeth adjacent
to an osteotomy cut, even without untoward bur contact. The cause is
unknown but may be due to a vascular response to the adjacent surgery.
Mohammed Almuzian, University of Glasgow 99
i. Orthodontic depression of lower incisors in adults, before surgery, may
cause proclination with alveolar dehiscence and gingival recession.
Furthermore, the proclined incisors may then upright spontaneously once
fixation is removed.
j. Tooth damage may occur with the bone cuts of segmental osteotomies,
either apically or laterally. Avoid the former by marking the estimated
apical site with a shallow bur hole prior to the section. Lateral root damage
arises when burs are used interdentally. Only the buccal and lingual
(palatal) bone should be cut with a bur and the actual division should be
made with a fine osteotome or saw. Although root damage often appears to
be self-limiting and most teeth survive, occasionally the exposed dentine
undergoes progressive resorption. An attempt may be made to preserve the
tooth by root canal therapy with calcium hydroxide. However, should root
loss progress, extraction and an implant or bridge will be required to
salvage the situation. Segmental cuts in the older patient with incipient
periodontal disease may also create intractable bony pockets unless
anticipated. The cuts must be done carefully with a fine osteotome after
prior periodontal therapy followed by postoperative oral hygiene
instruction.
k. Nerve Damage
i) It is important to warn the patient preoperatively of impaired sensation
that may arise in the mental or mylohyoid nerve distribution of the lower
lip and chin following a sagittal split or anterior segmental operation, and
Mohammed Almuzian, University of Glasgow 100
in the infraorbital area following a maxillary osteotomy. The former
usually recovers in 2-6 months, although some patients have a permanent
deficit, which is less noticeable if the operation is otherwise successful.
When the inferior dental nerve is exposed and torn during the sagittal split,
it may be possible to hold the separated ends together with a 6/0 Prolene
suture prior to fixation.
ii) Facial nerve damage with weakness can be localised following external
incisions for a subsigmoid (subcondylar) osteotomy but will involve a
wider distribution of the facial nerve if it is damaged near its main trunk.
This can occur with a sagittal split pushback or an intraoral subsigmoid
(subcondylar) operation. The cause is probably traumatic instrumentation.
They prognosis is usually very good, with gradual recovery over 6-8
weeks.
iii) The lingual nerve is rarely damaged during an osteotomy. However,
persistent impaired lingual sensation after 6 weeks requires open
exploration and repair. This is most easily done by removing the overlying
sublingual salivary gland.
iv) A rare disturbance is nasal vasomotor hyperfunction, which may occur
after a Le Fort I osteotomy. The patient develops continuous rhinorrhoea,
which look like but not a cerebrospinal fluid leak. The cause is uncertain
and may be either loss of sympathetic vasomotor control or damage to the
sphenopalatine ganglion with enhanced stimulation. There is no
satisfactory treatment.
Mohammed Almuzian, University of Glasgow 101
l. Emotional and Psychiatric Problems
Agitation can arise both from intolerance of intermaxillary fixation or
simply nasal airway obstruction. Both can now be avoided.
Unanticipated anxiety of an alien environment, especially the intensive
care unit,
Emotionally unstable individuals, especially those who have a history of
body dysmorphic disorder, may also become aggressive.
Postsurgical orthodontic
The aims of postsurgical orthodontics are:
1. Final tooth positioning
2. Root paralleling
3. Vertical movements of buccal segments with inter-arch elastics. In the
arch where most vertical movement is required, a more flexible archwire
may be used such as rectangular nickel titanium or rectangular braided
steel wire. In the opposing arch where vertical movement is not required, a
stiffer rectangular steel wire can remain in place
Mohammed Almuzian, University of Glasgow 102
4. In cases of segmental surgery, where canine brackets have been
reversed preoperatively, it is necessary to re-bond the canine brackets,
placing brackets of the correct side in order to produce a normal canine
angulation.
5. Retention
Orthognathic Surgery
The aetiology of relapse
1. Dental relapse
2. Incorrect osteotomies with improper seating of the condyles,
3. Skeletal relapse due to bone remodelling
4. The soft tissue and muscles,
5. Remaining growth
Stability depends on
1. Surgical technique employed
2. Direction of movement
3. Magnitude of movement
4. Type of fixation used.
5. Adaptive capacity of muscle fibres
Mohammed Almuzian, University of Glasgow 103
6. Buccal interdigitation
A hierarchy of stability (Proffit 1996, 2007)
A. Superior repositioning of the maxilla and mandibular advancement is
the most stable procedure
B. Forward movement of the maxilla is reasonable stable with or without
RIF
C. Mandibular setback is not stable, if the ramus is pushed to a more
vertical inclination when the chin is moved back, the mandibular
musculature tends to return the ramus to its original inclination when
function resumes and carries the chin forward again. The principal
circumstance in which neuromuscular adaptation does not occur is when
the pterygomandibular sling is stretched during mandibular osteotomy
Mohammed Almuzian, University of Glasgow 104
D. Downward movement of maxilla is also problematic (relapse 20%) due
to forces from occlusion, three approaches has been suggested to improve
stability of maxillary downward movement:
Placement of heavy fixation bars from the zygomatic arch to maxillary
posterior teeth,
Interposition of synthetic hydroxyapatite graft
Use of simultaneous ramus osteotomy to minimize stretching of the
elevator muscles
E. Transverse widening of the maxilla is the least stable procedure, due to
stretches of the palatal mucosa and its elastic rebound is a major cause of
relapse
A different pattern of stability is evident after twelve months once surgical
healing is complete.
1. Mandibular advancement is associated with some decrease in length,;
2. Maxillary superior positioning will relapse by > 2-mm in a 35% of
patients;
3. Significant changes occur in jaw positions after bimaxillary surgery,
but these are not necessarily reflected in changes of overjet or overbite bec
the dentoalveolar adaptation prevents an increase in overjet in more than
half these patients
Mohammed Almuzian, University of Glasgow 105
4. Class III correction are more stable in the long-term than class II.
As a general role, late relapse >lyr post op in 2.5-8% of patients,
Advantages of surgery fist Eliminate cuspal interference during expansion
Faster movement
Better teeth movement in the new ST environment
Repair imperfect surgery
Less impact on aesthetic during decompensation
Quick facial changes
Other Dental Treatment associated with orthognathic casesFour special points should be considered when orthognathic surgery is
involved:
1. Incision lines contract somewhat as they heal, and when incisions are
placed in the vestibule, this can stress the gingival attachment, leading to
stripping or recession of the gingiva. This is most likely to be a problem in
the lower anterior area in relation to the incision for a genioplasty .Gingival
grafting should be completed before genioplasty if the attached gingiva is
inadequate.
2. If the surgeon will use rigid fixation (bone screws) placed in the third
molar area, it is desirable to have the teeth removed far enough in advance
of the orthognathic procedure to allow good bone healing (minimum 6
months). If the wisdom is extracted at the time of surgery and the screw
Mohammed Almuzian, University of Glasgow 106
passed through the extraction socket, there will be high chance of weak
fixation and infection around the screw.
3. Orthognathic surgery has no influence on TMD. If joint surgery will be
required, usually it is better to defer this until after orthognathic surgery
because the joint surgery is more predictable after the new joint positions
and occlusal relationships have been established.
4. Definitive restorative and prosthetic treatment is the last step in the
treatment sequence
Facial deformity and the proposed treatment orthodontically and
surgically
Mandibular Prognathism
Presurgical orthodontics will be required to
correct arch size discrepancy,
overcrowding
to decompensate the incisors.
Surgery:
sagittal split osteotomy,
oblique subcondylar (subsigmoid) osteotomy
a) extraoral,
b) intraoral (buccal approach),
Mohammed Almuzian, University of Glasgow 107
c) intraoral (medial approach).
Mandibular Asymmetry (Unilateral)
Presurgical orthodontics will be required to
Insufficient maxillary intercanine width to accommodate the lower arch is
common which need an expansion.
with large discrepancies surgical expansion of the maxilla may be the
treatment of choice or distraction osteogenesis with a bone borne expansion
appliance.
Surgery:
Asymmetry, with or without prognathism, can be corrected by a bilateral
ramus osteotomy, such as the sagittal split, which shortens the affected side
and allows rotation at the contralateral angle.
Recurrent growth creates a difficult decision and will require a careful
high condylar shave preserving the meniscus.
Hemimandibular Hyperplasia
Early
High condylar shaving
subsigmoid osteotomy with osteoplasty of the body of the mandible
Mohammed Almuzian, University of Glasgow 108
Late
The most economical correction is simply reducing the lower border
convexity. This improves the facial appearance and corrects the obliquity
of the mouth,
bimaxillary procedure elevating the maxilla with a Le Fort I osteotomy
and the mandible must then be adjusted to this horizontal occlusal plane,
either by a sagittal split or subcondylar osteotomy as well as the convex
lower border will still need to be trimmed.
Condylar Hypoplasia
Features:
1. Deviation of the chin to the affected side
2. The condyle is usually short, flattened or deformed.
3. An exaggerated antegonial notch is present on the affected side.
4. Deficiency in ramus height gives rise to a secondary canting in
maxillary growth that is tilted downwards towards the normal side.
5. Joint ankylosis
6. Greater asymmetry
Treatment
Mohammed Almuzian, University of Glasgow 109
Moderate degrees
Moderate degrees of hypoplasia may be treated like an asymmetrical
hyperplasia, with a bilateral sagittal split osteotomy. This will lengthen the
affected side and provide a rotation adjustment on the normal side.
However, the maxillary occlusal plane has to be levelled first. In
adolescence this can be achieved orthodontically after the mandibular
surgery by creating a lateral open bite intraoperatively with a unilateral
thickened occlusal wafer or splint.
A large unilateral deficiency,
The downward and forward mandibular reconstruction can only be
achieved with an inverted L osteotomy and interpositional bone graft or
distraction osteogenesis . Again, the maxillary occlusal plane will also
require correction. If the patient is an adult, a Le Fort I osteotomy will be
necessary to level the transverse occlusal tilt
Mandibular Retrognathism or Hypoplasia
Treatment
Decompensation of the incisors and a forward osteotomy of the mandible
to an overcorrected edge to edge incisor relationship, giving a three-point
contact occlusion, i.e. incisors and distal molars, followed by orthodontic
closure of the lateral open bites.
Mohammed Almuzian, University of Glasgow 110
Separate orthodontic levelling of the canine and incisors, and the buccal
segments. This will be followed by a lower anterior mandibulotomy
setdown carried out at the same time as the mandibular lengthening
procedure. This has the advantage of maintaining the lower facial height.
Mandibular Incisor Proclination
the first premolars can be extracted and the canine-incisor segment
brought backwards with a Kole subapical (labial segmental) osteotomy.
If the tongue looks large, reduce it with the osteotomy. If there is any
doubt, warn the patient that should incisor proclination relapse occur,
tongue reduction may be necessary
Maxillary Hypoplasia
Orthodontically: expansion of the intercanine is important
The treatment of choice is a Le Fort I osteotomy with a forward
movement
the Kufner modification of the Le Fort III osteotomy produces an
advancement of the malar bones and infra-orbital margins
Nasomaxillary Hypoplasia
Le Fort II osteotomy
Mohammed Almuzian, University of Glasgow 111
Malar Hypoplasia
the Kufner modification of the Le Fort III osteotomy
The Kufner osteotomy followed by distraction osteogenesis.
The alternative solution is a Le Fort I advancement with simultaneous
alloplastic malar onlays.
Maxillary Protrusion
Anterior segmental osteotomy (Wassmund/Wunderer). The canine-incisor
segment is set back after extraction of the first premolars. A midline split is
necessary to maintain a natural dentoalveolar arch.
Le Fort I setback, very difficult and limited.
Bimaxillary surgery
Traditional techniques
B. Initial bony cuts are completed bilaterally for mandibular sagittal-split
osteotomy, delaying the separation of the tooth-bearing segment of the
jaws from the proximal condylar segment.
C. The wounds arc packed with moist gauze
D. Then the leFort I osteotomy completed.
Mohammed Almuzian, University of Glasgow 112
E. With an intermediate occlusal splint (or the combined two-stage splint)
the maxilla and the mandible are wired temporally by IMF and the maxilla
is repositioned and stabilized with RIF.
F. Then, At this point, the IMF is released.
G. Then Sagittal-split osteotomies are completed bilaterally in the
mandible with osteotomes.
H. The tooth-bearing segment of the mandible is repositioned, with the
final occlusal splint used as a guide. With the patient's teeth again held
firmly together, a temporary IMF is performed
I. Then the mandibular osteotomy sites are stabilized and fixed with RIF,
then IMF released.
Alternative techniques
A. Buckle, Tucker, and Fredette have suggested another sequence for two-
jaw surgry.
B. The mandibular BSSO to be completed before LeFort 1 .
C. RIF with position or large screws provides stable, repositioned
mandible.
D. The intermediate splint in this instance uses the intact maxilla as the
guide.
E. With the mandible held in the new position with RIF, the final occlusal
splint properly repositions the maxilla after leFort I osteotomy.
F. The advantages are minimizes the chance of displacement of maxillary
segments once they have been repositioned specially when there is a
Mohammed Almuzian, University of Glasgow 113
difficulty in stabilizing the maxilla after LeFort I osteotomy such as in
repeat Le Fort I osteotomy or with a multi-segmented maxilla.
The Deep Overbite
With a poor profile, consisting of a retrognathic mandible, increased
lower facial height and the lower lip trapped behind the upper incisors ,
treatment comprises orthodontic decompensation of the incisors followed
by a combination of a lower anterior dentoalveolar setdown and a sagittal
split osteotomy to bring the whole mandible forward to an overcorrected
edge to edge incisor relationship.
3 point landing BSSO
Secondary surgical correction for CLP patient
Important Factors to be considered
1. The amount of tissue in the original embryological defect: early cleft
closure cause more growth retardation
2. Preservation of tissue: Also important is the preservation of tissue,
tissue removal should be avoided whenever possible.
3. The nature and quality of the primary surgery: different surgical
technique result in different outcomes.
Mohammed Almuzian, University of Glasgow 114
Specific Problems in Cleft Patients
1. Sever Class III skeletal problem in all direction with malar hypoplasia.
2. Anterior open bites are common
3. Posterior cross bites are common
4. Dental development may also be delayed in both arches but is most
evident in the cleft segment and may compromise the presurgical
orthodontics.
5. The repaired alveolar cleft is a potential site for fracture at the time of
the down-fracture.
6. If the maxillary alveolus has not been reconstructed, alignment of the
alveolus can be incorporated into the orthognathic procedure. However it
complicates the planning of the surgery and increases the potential
morbidity. Segmental osteotomies are less stable than one-piece maxillary
osteotomies.
7. Previous surgery produces scarring of the labial and buccal vestibule,
the palate and behind the maxillary tuberosities. This presents problems
with the surgical incisions, mobilisation and postoperative closure of the
surgical wound.
8. A pharyngeal flap may make advancement of the maxilla difficult and
will need to be divided. The patient has to be informed well in advance
Mohammed Almuzian, University of Glasgow 115
about the possibility of VPI and speech problem that might developed after
the surgery.
Treatment Planning for CLP
The basic facial and orthognathic evaluation is the same as the non-cleft
case with important refinements.
1. Lip-incisor relationship. As in the non-cleft case, the lip to maxillary
incisor relationship is extremely important. The major surgical moves are
predominantly in the maxilla and with a tight, previously scarred upper lip,
small skeletal moves have a pronounced effect on the incisor exposure.
Surgical and orthodontic changes in incisor angulation will have a similar
effect.
2. Asymmetries. Both dental and skeletal asymmetries are dominant
features, often with compensatory asymmetries in the mandible. This
should be considered
3. Pharyngeal obstruction can be caused by hypertrophied adenoidal tissue
or pharyngeal flaps. Nasal airway obstruction may arise from a deviated
nasal septum narrowing of the nares, hypertrophied turbinates, nasal polyps
and posterior choanal constriction from sub-periosteal bone and
asymmetrical vomer flaps. The management of these problems is an
essential part of the orthognathic procedure. Paradoxically the adenoid
mass may contribute to velopharyngeal function and its removal may
precipitate velopharyngeal inadequacy.
Mohammed Almuzian, University of Glasgow 116
4. Preoperative speech assessment and counselling.
5. However, infection, bone and soft tissue necrosis, delayed healing, loss
of teeth and relapse all occur with greater frequency due to multiple
previous surgeries.
The Choice of Operation for CLP
Maxillary Hypoplasia
1. LeFort I osteotomy either one piece or two pieces maxilla for
transverse maxillary widening.
2. High LeFort I level osteotomy.
3. The modified LeFort II and Kufner LeFort III osteotomy
4. SARPE
5. Rhinoplasty may be necessary.
6. Mismanagement of the soft tissues during closure of the labial
vestibular incision may cause shortening and thinning of the upper lip. The
V-Y closure of a maxillary vestibule incision may increase the vermilion
show in patients with a thin upper lip.
7. Maxillary advancement widens the alar base, increases the projection
and elevation of the nasal tip and the width of the nares. Various surgical
manoeuvres can be used to prevent these unwelcome side effects. These
include an alar base cinch suture, recontouring the bony piriform aperture
Mohammed Almuzian, University of Glasgow 117
either by trimming and/or asymmetric bone grafting and alar base
resections.
Mid Face Distraction Osteogenesis
Indications:
With gross maxillary hypoplasia and a severe degree of scarring, the
degree of advancement may be beyond the expected limits of stability of a
conventional osteotomy. Distraction of the maxilla is preferable to a
surgical compromise such as a mandibular setback.
If the deformity is complex particularly in the upper mid face then a
higher level osteotomy with distraction often gives a better result than a
modified LeFort I with masking onlay bone grafts or modified LeFort II
and LeFort III osteotomies that are difficult to perform and can give
unsightly steps particularly over the radix of the nose.
Mandibular setback (BSSO, VSO)
Mandibular set back indicated in case of:
1. Mandibular prognathisism
Mohammed Almuzian, University of Glasgow 118
2. When there is a maxillary surgical limitations such as severe palatal
scarring, borderline velopharyngeal insufficiency or a tight inferiorly based
pharyngoplasty flap.
3. During maxillary advancement and inferior positioning, the anterior
maxilla is differentially positioned more inferiorly. This will produce a
posterior open bite deformity unless a mandibular ramus procedure is
undertaken simultaneously. Differential down grafting of the anterior
maxilla also results in a counter clockwise rotation of the mandible which
may make the chin retrogenic. This can be corrected by a simultaneous
augmentation genioplasty.
Airway Considerations for CLP during surgery
1. The surgeon can do the following whilst the maxilla is down fractured
Contouring of the inner aspects of the nose
Asymmetries in the piriform region
The mucosa of the nostril floor can be repaired
Septoplasty may be indicated
Partial or complete inferior turbinectomies
Antral and nasal polyps can be removed
Mohammed Almuzian, University of Glasgow 119
2. Pharyngeal flaps raise additional concerns for the anaesthetist and
surgeon which may make intubation difficult and restrict the nasal airway,
so submental intubation might be indicated
Postoperative considerations for CLP
1. Speech therapy: The soft palate mechanism in non-cleft patients has
considerable reserve capacity and can adapt to an increase in length. The
repaired cleft soft palate does not have this capacity to adapt especially
after major advances. The patient with borderline velopharyngeal
incompetence preoperatively is likely to develop worsening of their speech
postoperatively.
2. Relapse: As a prophylactic measure, extraoral elastic traction using a
face mask can be used in patients who are considered particularly at risk of
relapse either due to scarring or who have had large surgical moves
anteriorly and inferiorly.
3. Stability: The factors that increase stability include:
High quality orthodontic preparation.
Avoiding segmental procedures
Overcorrection where possible.
Compromise position must be planned and if necessary with
incorporatation of a mandibular setback.
Mohammed Almuzian, University of Glasgow 120
Alveolar bone grafting.
Bone grafting for inferior repositioning of the maxilla.
Internal rigid fixation for all moves.
Feeding and Postoperative Nutritional Support
Malnutrition is a well-recognised problem in hospitals, with 40%-50% of
all patients found to be malnourished on admission and 70%-80% on
discharge.
Consequences of malnutrition for the postoperative patient include
decreased wound healing, decreased immune function and increased
infection risk which can lead to unnecessary morbidity.
Optimum Daily Requirements, Men and women average 2000-3000 kcal.
0.8 g protein/kg; 2-3 litres fluid.
Mohammed Almuzian, University of Glasgow 121