Ch5 orthodontic assessment Dentistry
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Transcript of Ch5 orthodontic assessment Dentistry
Ch 5 Orthodontics
Orthodontic
assessment
By : Cezar Edward
Introduction to orthodontic
assessment • taking a full history
• undertaking a clinical examination
• collecting appropriate records
Taking an orthodontic history 1-Patient’s perception of the problem
(Patient’s complaint)
2-Medical history
3-Dental historyany trauma, any previous or ongoing dental
treatment, TMJ problems, any known inherited dental problems
(e.g. hypodontia), any previous orthodontic treatment
4-Habits (e.g :digit sucking)
5-Physical growth status(identifying whether growth is
complete or still ongoing may affect the timing and nature of future treatment)
6-Motivation and expectation :if a patient is not
sufficiently motivated, then treatment should not be undertaken.
7-Socio-behavioural factors the patient’s ability to attend
regularly for appointments because it is long term therapy
Extra-oral examination
1-Anteroposterior assessment
2-Vertical assessment
3-Transverse Assessment
4-Smile aesthetics
5-Soft tissue examination
6-Temporomandibular (TMJ) examination
The patient is assessed extra-orally in the:
• frontal view (assessing in the vertical and transverse planes)
• profile view (assessing in the anteroposterior and vertical planes)
1-Anteroposterior assessmentThe anteroposterior relationship can be assessed in three ways:
• assessing the relationship of the lips to a vertical line, known as zero
meridian, dropped from soft tissue nasion
• palpating the anterior portion of the maxilla at A point and the mandible
at B point
• assessing the convexity of the face by determining the angle
between the middle and lower thirds of the face in profile
2-Vertical assessment
The face can be assessed vertically in two ways:
• using the rule of thirds
• measuring the angle of the lower border of the mandible to the maxilla
3-Transverse Assessment
The transverse examination of the face
should be done from the front, and from above the
patient (by standing behind and above the patient).
A patient with marked mandibular
asymmetry to the right.
4-Smile aesthetics• The whole height of the upper incisors should be visible on full smiling,
with only the interproximal gingivae visible. This smile line is usually
1–2 mm higher in females.
• The upper incisor edges should run parallel to the lower lip (smile arc)
• The upper incisors should be close to, but not touching, the lower lip
• The gingival margins of the anterior teeth are important if they are
visible in the smile. The margins of the central incisors and canines
should be approximately level, with the lateral incisors lying 1 mm
more incisally than the canines and central incisors
• The width of the smile should be such that buccal corridors should be
visible, but minimal. The buccal corridor is the space between the angle
of the mouth and the buccal surfaces of the most distal visible tooth.
• There should be a symmetrical dental arrangement
• The upper dental midline should be coincident to the middle of
the face.
5-Soft tissue examination
1-Lips
2-Tongue
Features of the lips to assess
• Lip competence
• Lip fullness
• Nasolabial angle
• Method of achieving an anterior seal
Lips can be competent (that is meet together at rest), potentially
competent (position of incisors prevents comfortable lip seal to be
obtained) or incompetent (require considerable muscular activity
to obtain a lip seal).
In some patients with incompetent lips the tongue
thrusts forward to contact with the lips to form an anterior seal. This
is usually adaptive to the underlying malocclusion, so when the treatment
is complete and normal lip competence can be achieved, the
tongue thrust ceases. In some patients there is a so-called endogenous
tongue thrust, which will re-establish itself after treatment, leading to
relapse.
Lips
Tongue
NasoLabial Angle
90-110 *
6-Temporomandibular (TMJ)
examination
Any tenderness, clicks, crepitus and locking should be noted.
there is no strong evidence to suggest that TMJ disorders are either
associated with malocclusions or cured by orthodontic treatment.
However, if signs or symptoms are detected then they must be
recorded and it may be worth referring the patient to a specialist before
commencing orthodontic treatment.
Intra-oral examination 1-Assessment of oral health
2-Assessment of each dental arch
3-Assessment of arches in occlusion :
Incisor classification
Overjet
Overbite
Centrelines
Canine relationship
Molar relationship
Crossbites
1-Assessment of oral health
Generally any pathology needs to be treated
and stabilised before any orthodontic treatment can be undertaken.
Dental pathology can have a significant influence on the treatment
plan, and additional radiographs and special tests (such as vitality
tests) may be required. We are particularly interested in detecting:
• caries
• areas of hypomineralisation
• effects of previous trauma
• tooth wear
• teeth of abnormal size or shape
• existing restorations which may change the way we bond to the
tooth, as well determine our choice of extractions if space is required
2-Assessment of each dental archEach arch is assessed individually for:
• crowding (see Box 5.4) or spacing
• alignment of teeth, including displacements or rotations of teeth
• inclination of the labial segments (proclined, upright or retroclined)
• angulation of the canines (mesial, upright or distal) as this affects
anchorage assessment later
• arch shape and symmetry
• depth of Curve of Spee
Box 5.4 Describing the amount of
crowding present
0–4 mm = Mild crowding
4–8 mm = Moderate crowding
> 8 mm = Severe crowding
3-Assessment of arches in occlusionThe arches are now assessed in occlusion. The incisor relationships are
assessed first: incisor classifi cation, overjet or anterior crossbites (anteroposterior),
overbite or openbite (vertical) and centrelines (transverse).
Then the buccal relationships are assessed: canine and molar relationships
(anteroposterior), any lateral openbites (vertical) and buccal
crossbites (transverse).
OVERJET :Normally be 2–4 mm
OVERBITE: normal value would be 1/3 coverage of the crown of the lower incisor.
Crossbites • Location (anterior or posterior)
• Nature of the crossbite (see Box 5.5)
Diagnostic records
Purposes:
• Diagnosis and treatment planning
• Monitoring growth
• Monitoring treatment
• Medico-legal record
• Patient communication and education
• Audit and research
1- Study models
Upper =Notch
Lower=Round
Study models should show all the erupted teeth and be extended into
the buccal sulcus. They are poured in dental stone and typically produced
from alginate impressions. They should be mounted in occlusion,
using a wax or polysiloxane bite. They are produced using a
technique known as Angle trimming, which allows models to be placed
on a flat surface and viewed in the correct occlusion from varying angles
2- Photographs
These provide a key colour record. The usual views taken are:
Four extra-oral (in natural head position):
• Full facial frontal at rest
• Full facial frontal smiling
• Facial three-quarters view
• Facial profile
Five intra-oral:
• Frontal occlusion
• Buccal occlusion (left and right)
• Occlusal views of upper and lower arch
3-Radiographs
• Presence or absence of teeth
• Stage of development of adult dentition
• Root morphology of teeth
• Presence of ectopic or supernumerary teeth
• Presence of dental disease
• Relationship of the teeth to the skeletal dental bases, and their
relationship to the cranial base
Types
Cone beam computed tomography
(CBCT) and 3D imaging
CBCT is a faster, more compact version of traditional CT with a lower dose of
radiation.
Through the use of a cone-shaped X-ray beam, the size of the scanner,
radiation dosage and time needed for scanning are all dramatically reduced.
Fig. 5.17 Cone-beam computed tomography
(CBCT) of the patient with the impacted
canine shown in Figs 5.15 and 5.16,
confirming that there is a small amount
of root resorption occuring on the palatal
aspect of the upper left lateral incisor, close
to the apex of the tooth.
Forming a problem list
The information collected from the history,
examination and records, produces a
database identifying a list of problems. It is
this list of problems that allows the clinician
to form a diagnosis
Reference
Thank You