Pre prosthetic surgery.pptx

8/10/2019 Pre prosthetic surgery.pptx

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GOOD

MORNING


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Pathophysiology of edentulous

bone loss

Causes Physiologic, environmental, pathologic orcombination of any of the above


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Patterns of bone loss Most of the bone loss occurs during the first year of

the denture wearing

It is 10 times greater in the first year than that seen inthe following years

Bone loss in mandible 4 times greater than in maxilla

Resorption in maxilla on buccal and inferior portion

of the alveolar ridge--- resulting in reduced width ofmaxilla


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Mandible resorbs downwards and outwards causingrapid flattening of the ridge.

Average bone loss 1mm per year


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Aims of preprosthetic surgery To provide adequate support for the placement ofRPD/CD

To provide adequate soft tissue support/vestibular

depth Elimination of pre existing bony deformities eg: tori,

prominent mylohyoid ridge etc

Correction of maxillary and mandibular ridge relations

Elimination of pre existing soft tissue deformities eg:epulis, f labby ridges etc


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Relocation of frenal or muscle attachments

Relocation of the mental nerve

Establishment of the correct vestibular depth


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Treatment Planning Conventional dentures:1. History taking and physical examination including

radiographs

2. Facial esthetic examinationfor unsupported upperlip, poor vermillion show, poor/obtuse nasolabialangle, loss of nasolabial forld etc

3. Intraoral examinationRidge form and contour,

quality and quantity of the overlying tissues, frenaland muscle attachments, presence /absence of bonyor soft tissue pathologies and relationship ofmaxillary ridge to mandibular ridge


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Alveoplasty: Recontouring of the alveolar process

Alveolectomy: The excision of a portion of the alveolar

process


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Objectives and principles of

alveoplasty Immediate goal in performing an alveoplasty is to

provide optimal ridge contour quickly, this should becounterbalanced with ultimate goal of preserving asmuch bone as possible for continued denture stability

Alveolar ridges should be left as broad as possible formaximum distribution of the masticatory load

All undercuts especially the opposing ones should beremoved


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Sharp edges should be rounded and gross irregularitiesshould be reduced

Mucosa covering the ridge should be uniform inthickness

The younger the patient less amount of the boneshould be removed during alveoplasty


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Types of alveoplasty Compression alveoplasty:

a. Easiest and quickest

b. Compression of outer and inner cortical platesbetween the fingers

c. Done after extractions

d. Compression reduces the width of the socket and

many otherwise troublesome bony undercuts


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Simple alveoplasty:

a) Usually used to reduce sharp buccal or labial cortical

and occasionally lingual or palatal cortical margins.b) Usually an envelop flap is used

c) With a rongeur or bone cutting forceps held parallelto the bone margin of the alveolar bone, just the

right amount of bone can be removed


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Labial or buccal cortical alveoplasty:

a) Incision made in the gingiva and full thickness

mucoperiosteal flap elevatedb) A sharp side cutting/Blumenthal forceps is held with

one beak beneath the bony rim of the socket andother on the crest of the ridge.

c) Small bits of the bone can thus be bitten offd) A bony file can be used to smoothen and perfect the

contour.

This type of alveoplasty is most commonly performedafter the tooth removal


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Labial / Buccalcortical alveoplasty

A. Pre op

B. After removal ofteeth the labialgingiva is elevated

C. Rongeur is usedto reduce the bone

D. Condition after

bone trim E. Suturing


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Deans intraseptal(intercortical) alveoplasty:

a) After extraction of the teeth , the interradicular bony

septa should be removed with a rongeur forceps.b) Dean used a chisel to make an inverted V shaped

excision of the bone in the labial cortex of the cuspidsocket, thus three sides of the labial cortical flap are

freedc) Finger pressure is then applied to reduce the labial

cortical plate

d) This plate recieves its blood supply from the

overylying periosteum


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Deans Intraseptalalveoplasty

A. For cases withmoderate inclination of

the teeth B. After removal of

teeth, gingival papillaeare removed

C. Bone bur is used to

remove theinterradicular medullarybone

D. Bone cut is made inthe labial cortex at the

distolabial aspect ofeach cuspid socket E. Broad, flat

instruments are insertedinto the bone trough and

outward force is used tofracture the labial cortex


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Obwegeserstechnique:

a) He suggested further modification of Deanstechnique for extreme maxillary protrusion cases

b) He fractured both labial and palatal cortical plates asfollows-

1. The teeth are removed as usual

2. The sockets are connected, and rongeurs or burs areused to remove the medullary interradicular bone

3. With a bur the sockets and their interconnectionstrough id then enlarged.


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4. Both labial and palatal plates are cut with burs in thecuspid area to weaken the bone and to form threesided bone flaps in both cortical plates

5. Palatal cortex usually needs to be scored

6. A pair of broad flat elevators are inserted into the

sockets and the labial plate is fractured labially and thepalatal plate palatally. Finger pressure is then used tomould the alveolar process into the desired shape.Sutures close the gingiva on the socket.

7. A Denture on splint is used to stabilize the fracturesalveolar process which heals in 4 to 6 weeks.


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Obwegeserstechnique A. For cases with

extreme labial

protrusion B. A broad trough iscreated with a bonebur connecting all thesockets

C. The labial andpalatal sockets are cutwith a bur

D. Palatal cortex ispartially cut

E. Labial and palatalcortices fractured

F. Finger pressure usedto compress and mould

the socket G. Suturin


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Reduction of mylohyoid ridge and

lingual alveolar crestAlveolar atrophy sometimes accentuates the

mylohyoid ridge, which can be plapated through thelingual surface of the mandible

Mylohyoid ridge should be reduced whenever theridge is found to be at level or higher than the alveolarprocess

Sometimes the overlying mucosa becomestraumatized, ulcerates and fails to heal. In such casesthe bony edges should be removed to permit theclosure of the ulcerated tissues with sutures


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Technique Incision is made in the residual gingiva on the alveolarcrest of the alveolar process in the molar region.

Lingual mucoperiosteum is reflected carefully,

exposing the mylohyoid ridge and the muscle. The mylohyoid muscle is attached to the edge and

inferior surface of the mylohyoid ridge and must beincised with a scalpel

Once the muscle has been reflected, the bony edge canbe reduced with a chisel or rongeurs and bony file.

The detaches muscle will then reattach at a lower level


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Reduction of Tori and Exostoses


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Torus palatinus It is a benign, slowly growing, bony projection of the

palatine processes of the maxillae and occasionally thehorizontal plates of the palatine bones.

It occurs bilaterally along the medial suture on oralsurface of the hard palate.

Slow growing

Females > males

Etiology - Unknown


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Palatal tori removal is indicated when:

1. They become so large that they interfere with thespeech

2. The overlying mucosa becomes traumatized,ulcerates and fails to heal because of its poorvascularity

3. The torus interferes with the design andconstruction of a removable dental prosthesis


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Technique Local anaesthesia is used to block the right and left

anterior palatine nerves and the nasopalatine nerve.

Median palatal incision is made in the mucosa the fulllength of the torus with two short, diverging incisionsat the anterior and the posterior ends of the torus,avoiding the vascular foramina.

Posteriorly care must be exercised to avoid accidentalperforation into the soft palate into the nasal cavity


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Each flap is reflected with a periosteal elevator andthen sutured to the mucosa of the alveolar process tokeep it out of the operative field.

If the torus is small and pedunculated and the palatalbone is thick then it can be cleaved from the palatewith a sharp blow of the mallet.

If the torus is thick and broad based then a 703 fissurebur can be used to cut longitudinal and transversegrooves in the torus to desired depth.


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Once the torus has been grooved, the pieces can beremoved using the rongeur forceps or mallet and chisel

The stump of the torus can be smoothened with bonefiles, chisels or large bone burs.

Prevention of post operative hematoma formation isvery important by use of rubber drain splint or stent


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Removal of palatal torus

A. Pre op

B. Right and left

mucosal flapsreflected. Dental burused to cut grooves intothe torus

C. Sharp chisel used toremove the smallpieces of the torus

D. A bone bur used tosmoothen the stump ofthe torus

E. Suturing


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COMPLICATIONS:

1. Haemorrhage

2. Hematoma3. Necrosis and sloughing of the palatal mucosa

4. Perforation of the floor of the nose

5. Fracture of the palate


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Torus Mandibularis It is an exostosis that usually occurs bilaterally on the

median surface of the body and the alveolar process ofthe mandible

Generally located in the canine-premolar region

Etiology- unkown

Equally occur in both the sexes


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TechniqueArea is anaethetised with inferior alveolar and lingualnerve blocks

Incision is made on the crest of the alveolar process

from molar to incisor region. If bilateral tori are to beremoved in the same appointment the mucosa in theincisor region should not be reflected

Moucperiosteal flap reflected.

Mandibular tori can be easily removed with chisel andmallet. A bur can also be used.

A stent is usually not required post op in mandibulartori removal


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Removal of Torusmandibularis

A. Pre op

Incision made overthe crest of thealveolar ridge frommolar to central

incisor. Chisel isused to remove thetorus

C. Bone bur is used

to smoothen thestump

D. suturing


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Corrective soft tissue surgery


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Labial Frenectomy The labial frenum is a band of fibrous connective

tissue, covered with mucous membrane that binds thelip to the alveolar process.

The upper labial frenum is usually more prominentand fibrous than the lower.

When a frenum is attached at or near the crest of the

alveolar ridge, it maybe subjected to repeatedirritation from a denture flange


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Technique The lip is elevated, everted and tensed so that the

frenum becomes prominent.

The purpose of the frenectomy is to eliminate thefibrous part of the frenum and the mucosa should berepositioned to cover the surgical defect.

A narrow V shaped incison is made in the mucous

membrane around the frenum and is carried to thebone.


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The apex of the V should correspond to the inferiorextent of the frenum.

When the frenum is detached from the bone withperiosteal elevator, most of the connective tissue fibresretract into the upper lip.

The small tag of labial mucosa and any surplus

connective tissue can beremoved easily with scissors.

The margins of the resultant diamond shaped defectcan be undermined and closed with sutures

L bi l F t


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Labial Frenectomy A. Lip is everted and

the frenum is tensed B. Narrow V shaped

incision is madearound the frenumthrough the mucosaand the periosteum

C. Fibres of the frenum

are stripped away fromthe bone D. Small tag of labial

mucosa and redundanttissue can be removed

with scissors E. Margins of the

diamond shaped defectundermined

F. Suturing


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Lingual FrenotomyAnkyloglossia/ tongue tie is usually present in children

and is corrected in the childhood itself. Occasionallyan adult patient maybe foung to have an untreated

hypertrophied lingual frenum Test of lingual Function: Patient is asked to to touch

the upper lip with the tip of his tongue. When thepatient is unable to do frenectomy is indicated.


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Technique Bilateral lingual nerve blocks are performed.

A traction suture is placed on the tip of the tongue sothat the tongue may be elevated and the frenumtensed.

A transverse incision was made in the mucousmembrene of the frenum midway between the ventral

surface of the tongue and sublingual caruncles withsharp scissors.

Deeper dissection is performed in the midway to avoidducts of the submandibular salivary glands.


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The dissection is continued till the tip of the tonguecan be retracted sufficiently to touch the maxillaryincisor teeth or alveolar process while the mouth is

open. The mucosal flaps are undermined with scissors and

closed as a longitudinal linear incision.

Li l F t


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Lingual Frenotomy

A. Pre op.

B. Suture is placed

through the tip ofthe tongue to retractthe tongue and tensethe frenum.

Transverse incisionmade

C. Deeper dissectionis done

D. Margins of thediamond shapeddefect undermined

Suturing


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INFLAMMATORY PAPILLARY

HYPERPLASIA OF THE PALATE Inflamatory papillary hyperplasia is a painless

irreversible disease of the oral mucous membrane

It commonly occurs in the hard palate in patients whowear complete maxillary denture

Younger patients affected more than older patients

Etiology is obscure


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Number of contributing factors include

1. Poorly fitting denture

2. Wearing a denture 24 hours a day3. Poor oral hygiene

4. Patients wearing dentures with palatal relief


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Treatment includes early stages non-surgicaltreatment such as proper denture adjustmentscombined with tissue conditioner

If removal is required a mucousal excision superficialto periosteum is recommended

Another technique to use is electrosurgical loops

After excision patients denture or a specially preparedsurgical stent can be lined with an analgesic paste andused to cover and protect the surgical site

Granulation and reepithelization take 3 - 6 weeks after

which new denture can be made


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Fibrous Hyperplasia of maxillary

tuberosity Surgical reduction of hyperplastic submucosa of

maxillary tuberosity can be performed under localanaesthesia

Elleptical Incisions are made around the gingivalmasses and are carried to the bone so that fullthickness block of tissue can be removed with rongeurforceps

Buccal and palatal f laps should be thinned uniformly

The incision is then closed with dissolvable sutures


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Fibroushyperplasia of

maxillarytuberosity


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VestibuloplastyVestibuloplasty is a surgical procedure whereby the

oral vestibule is deepened by changing the soft tissueattachments

This procedure increases the size of the denturebearing area and height of the residual alveolar ridge


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Vestibuloplasty procedure can be divided intofollowing categories

1. Mucosal advancement(Submucous) Vestibuloplasty- The mucous membrane of vestibule is underminedand advanced to line both the sides of the extendedvestibule

2. Secondary epithelization(Reepithelization)Vestibuloplasty The mucosa of thevestibule is used to line one side of the extendedvestibule and the other side heals by growing newepithelial surface

3. Grafting Vestibularplasty Skin mucosa and dermiscan be used as a free graft to line one or both the sidesof the extended vestibule


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Mucosal Advancement

(Submucosal) Vestibuloplasty Primary criterion for this type of procedure is presence

of adequate amount of bone and healthy mucosa

A test can be performed to determine whethersufficient mucosa is available

With lips in a relaxed position mouth mirror isinserted into the vestibule to the depth requiredprosthetically if the upper lip is not displaced upwardor drawn inward it can be assumed that there issufficient mucosa for the advancement procedure


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Closed submucous vestibuloplasty Objectives

1. To extend the vestibule to provide the adequate ridgeheight and

2. To excise or transfer the submucous connective tissueto a position farther from the crest of the ridge toprevent relapse

Given by Obwegeser (1959)


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Technique Vertical incision is made in the midline ofthe vestibule through the mucosa only extending fromthe muco gingival junction into the lip

With the lip everted in the horizontal plane a scissioris introduced into the incision and blunt dissection isperformed on both the sides

A tunnel is formed mucosa and submucosa extending

from the mucogingival junction into the lip The tunnel is carried posteriorly to zygomatic

buttresses of the maxilla or to mental foramen area ofthe mandible


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When the submucous tunnels have been completedthe vertical incision is deepened to periosteum at themidline

Super periosteal dissection extended as far as theproposed vestibular extention required

The freely mobile mucosa then is adopted to thedeepened sulcus with fingure pressure

Vertical incision is sutured

Closed submucous


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Closed submucousvestibuloplasty

A. Median incisionmade

B. Mucousmembraneundermined withblunt dissection asdar aszygomaticomaxillryridge

C. Tunnels createdon either side with

suopraperiostealdissection D. Connective tissue

septum excised E. Suturing


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Secondary

epithelialization(reepithelialization)vestibuloplasty

It is indicated when sufficient bone is present but themucosa is either insufficient or of poor quality

There are two basic techniques each with several

variations Given by Kazanjian(1935) and another by Clark(1953)


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Kazanjian Technique Incision is made in the mucosa of the lip and a large flap oflabial and vestibular mucosa is reflected

The vestibule is deepened by supraperiosteal dissection

The flap of mucosa is turned downward from itsattachment on the alveolar ridge and is placed directlyagainst the periosteum to which it is sutured

Rubber catheter stent is placed into the deepened sulcusand fixed with percutaneous sutures

Catheters removed after 7 days The labial donor sight is left to granulate and heal by

secondary epethelization

K ji t h i


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Kazanjianstechnique


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Lipswitch Vestibuloplasty Variation of Kazanijian Technique The mucosal f lap is developed in the same way as given by

Kazanjian with the free margin in the lip and the base

attached to the crest of the residual alveolar ridge. Butinstead of being excised the periosteum is incised and highon the alveolar ridge just below the crest and reflected fromthe bone

The flap consisting of periosteum connective tissue, and

muscle, is tranposed outwardly and sutured to the marginof the raw wound in the lip

Thus the vestibule is lined on the osseous side withmucosa and on the labial side with periosteum


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Clarks technique Incision is made on the alveolar ridge and dissection is

carried out to the depth desired

Mucosa of the lip is undermined to the vermillionborder

Sutures are placed in the free margin of the mucosalflap and are tied to the skin over a cotton roll

Soft tissue of the vestibule is thus covered withmucosa, whereas, on the osseous side, the raw

periosteal surface is left to granulate and epithelialize


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Clarks Technique


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Lingual Sulcoplasty Used in patients with grrossly resorbed mandible

Extention of the lingual sulci or the floor of the mouthis lowered to increase the denture bearing area.


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Anterior lingual sulcoplasty:

Suggested by Cooley(1952)

Consists of lingual frenotomy and transplantation ofthe lingual fibres of the genioglossus muscle.

It is often combined with reduction of the genialtubercles

Posterior lingual sulcoplasty:


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Posterior lingual sulcoplasty:

The floor of the mouth frequently becomes elevatedabove the level of the residual alveolar ridge during

normal functional movements especially the posteriorfibres of the residual alveolar ridge.

Mylohyoid ridge should be palpated.

If the mylohyoid ridge reduction is to be performed ,the periosteum should be reflected as described byCaldwell (1955), If not then , incision of the mylohyoidmuscle fibres and supraperiosteal dissection willpermit the extention of the lingual sulcus as describedby Trauner (1963)


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AugmentationA. Mandibular augmentation1. Superior bone augmentation- Bone grafts, cartilage

grafts or alloplastic grafts

2. Inferior border augmentation- bone grafts orcartilage grafts

3. Interpositional or sandwich grafts- bone, cartilage orhydroxyapatite blocks

4. Visor osteotomy5. Onlay grafting- autogenoue, alloplastic or allogenic

material


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B. Maxillary augmentation procedures

1. Onlay bone grafting: autogenous/allogenic materials

2. Onlay grafting of alloplastic materials

3. Interpositional or sandwich grafts

4. Sinus lift procedure

Augmentation in combination with orthognathicsurgery

1. Mandibular osteotomy procedures

2. Maxillary osteotomy procedures

3. Combination procedures


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Mandibular augmentation Superior border grafting: Describe by davis(1970)

Used 15cm autogenous rib grafts

Rib is scored at the cortex and adapted to the shape ofthe mandible and fixed with transosseous orcircummandibular wiring

The other rib graft is made into corticocancellousparticles and moulded around the first rib graft


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Inferior border grafting:


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Inferior border grafting:

Indicated when the alveolar ridge is less than 5 to 8mm in height and is at risk of pathological fractures

First described by Marx and Sanders and modified byQuinn

Bilateral supraclavicular incision made and dissectionin subplatysmal plane done upt inferior border of the

mandibkeA freeze dried cadaveric mandible is hollowed out and

multiple perforations made into it to allow it forrevascularization and is used as a tray

The cadaveric bone is then filled with cancellous bonegraft harvested from iliac crest and is fixed to themandible using circummandibular wiring

l f / d h


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Interpositional grafts/sandwich

graftingA horizontal osteotomy is performed in residual

maxilla or mandible

Allogenic bone/ hydroxyapatite grafts can be used to

augment the jaw. Secondary vestibuloplasty procedurs maybe necessary


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Onlay grafting Used when adequate height is present but width of thejaw is inadequate

Oldest technique of onlay grafting advocated by

Obwegeser using allograft(hydroxyapatite) throughsubmucosal vestibuloplasty.

After creating a submucosal tunnel in the midlinehydroxapatite crystals mixed with saline/blood isinjected via a syringe into the tunnel.


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Visor osteotomy Goal of this procedure is to increase the height of themandibular ridge for denture support.

Consists of central splitting of the mandible in the

buccolingual dimension and the superior postioningof the lingual section of the mandible which is wiredinto position

Cancellous bone is placed at the outer cortex over thesuperior labial junction for improving the contour


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Modified Visor osteotomy Consists of splitting the mandible buccolingually usinga vertical osteotomy only in the posterior region and ahorizontal osteotomy in the anterior region


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Sinus lift procedures or sinus grafts Used to assist placements of osseointegrated implants

in the posterior maxilla.

In older patients the sinus f loor is lowered almost to

the level of the alveolar crest due to pneumatization Thus to improve support the sinus floor is lifted up

surgically and a bone graft is placed between sinuslining and the inner aspect of the alveolar crest

A t ti i bi ti ith


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Augmentation in combination with

orthognathic proceduresAnterior maxillary osteotomies

Total lefort I osteotomy with interpostional grafts

Le fort I osteotomy


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