7 mandibular osteotomies

ORTHOGNATHIC MANDIBULAR ORTHOGNATHIC MANDIBULAR SURGERYSURGERY

Dr V.RAMKUMARDr V.RAMKUMAR CONSULTANT CONSULTANT

DENTAL DENTAL &FACIOMAXILLARY &FACIOMAXILLARY SURGEONSURGEON

REG NO:4118-REG NO:4118-TAMILNADU-TAMILNADU-INDIA(ASIA)INDIA(ASIA)

Symmetrical malformationsSymmetrical malformationsCongenitalCongenital

Mand. PrognathismSevere RetrognathismCondylar Agenesis

AcquiredAcquiredInfl. disease of condyles

Severe Condylar Trauma

Etiology

EtiologyAsymmetrical MalformationsAsymmetrical Malformations

CongenitalHemihypertrophy of mand.Condylar HyperplasiaCraniofacial Microsomia

AcquiredInfectionsTraumaAnkylosis

Pathological CausesPathological Causes Plexiform Neurofibromatosis

Fibrous Dysplasia

Quantitative CriteriaQuantitative Criteria

Type of Surgery Bone: soft tissues

Le fort I = 3 : 1 Le fort II = 3 : 2 Le fort III = 1 : 1 Aug Genioplasty = 1 : 1(+/-) Slid. Genioplasty = 1 : 1(consistent)

Quantitative CriteriaQuantitative Criteria

The Rule of Fifths The Rule of Fifths

Mandibular DeficiencyMandibular Deficiency

I. Microgenia = I. Microgenia = Simple retrusion of chin

II. Retrogenia = Retrogenia = Deficient chin profileStevens(1968)

I Degree = < 10 mm II Degree = 10 – 20 mm

III Degree = > 20 mm

III . Sagittal Mandibular Deficiencies

IV. Mandibular deficiencyLow Angle typeHigh Angle type

Cont…

Mandibular ExcessMandibular Excess I. Asymmetric Mand Protrusion

With Open biteWithout Open bite

II . Unilateral Condylar HyperplasiaElongation of condylar neckDeviation of chin to normal sideLip line slopes to affected side & cross bite on unaffected side

Mandibular ExcessMandibular Excess

III . Mandibular HemihypertrophyLower border at lower level than affected sideMarked Convexity or BowingLittle or no displacement of chinNo midline deviation

GENERAL PRINCIPLESGENERAL PRINCIPLES

Access ( Primarily Intra-oral).Adequate Exposure.Good Postoperative Cosmesis.Good Postoperative Function.Preservation of essential structures.Maintenance of adequate nutrition and waste elimination.

Mandibular OsteotomiesMandibular Osteotomies

Body osteotomy (ostectomy)Body osteotomy (ostectomy) Sowray-Haskell Sowray-Haskell

modificationmodification Vertical subsigmoid osteotomyVertical subsigmoid osteotomy

Introral (IVRO)Introral (IVRO) ExtraoralExtraoral

Sagittal split osteotomySagittal split osteotomy Obwegeser/Dalpont; Obwegeser/Dalpont;

Bell/Epker; HunsuckBell/Epker; Hunsuck Inverted L-ramus osteotomyInverted L-ramus osteotomy

VariationsVariations Post condylar graftsPost condylar grafts

Mandibular setback osteotomiesMandibular setback osteotomies

Mandibular advancement Mandibular advancement osteotomiesosteotomies

Bilateral Sagittal Split OsteotomyBilateral Sagittal Split Osteotomy Introduced by Trauner & Obwegeser(1957) Obwegeser ( 1964) Modified by Dal Pont(1961) &

Hunsuck(1968) Use of natural plane of cleavage between

buccal and lingual plates Movements possible: Ant, Post & Rotations.

TechniqueTechniqueIncision & ExposureCorticotomyCorticotomy checkDivision by osteotome ( Wedge action)Nerve identification & preservationRelease of musculatureControl of bleedingFixationClosure Post-op care

Bilateral Sagittal Split OsteotomyBilateral Sagittal Split Osteotomy

Bony Cuts

Bilateral Sagittal Split OsteotomyBilateral Sagittal Split Osteotomy

ADVANCEMENT

The sagittal split osteotomy

Obwegeser/dal Pont

Bell/Epker procedure

Screw fixation for the sagittal split

The sagittal split advancement

Plate fixation

The reconstruction plate

Bilateral Sagittal Split OsteotomyBilateral Sagittal Split Osteotomy

Extraoral vertical subsigmoid Extraoral vertical subsigmoid osteotomyosteotomy

Vertical Ramus Osteotomy

Coronoidectomy

Retraction for the extraoral and intraoral V.S.S.

The inverted L osteotomy

Bone Grafting

Incision line – body ostectomyIncision line – body ostectomy

Ramus Osteotomy

Angle Osteotomy

GenioplastyGenioplasty

Indications

Retrogenia

Bird-face appearance

Prominent gonial angle

Shortened vertical ramus height

ProceduresProcedures

Sliding Horizontal Osteotomy

Double Horizontal Osteotomy

Hinge sliding Osteotomy

Oblique ( advancement) Osteotomy

Jumping Genioplasty

Wedge Osteotomy

Propeller Genioplasty

ProceduresProcedures

Triple Osteotomy

Quadruple Osteotomy

Genioplasty using Grafts

Kole’s Procedure

Lower Labial Segmental OsteotomiesLower Labial Segmental Osteotomies

Anterior Mandibular Subapical Osteotomies (AMSO)

AMSO with vertical alveolar osteotomy Vertical alveolar osteotomy Kole’s Procedure Symphyseal Ostectomy Anterior Mandibuloplasty

Lower Sub-apical

Osteotomy

IncisionsIncisions

Bur hole Bur hole MarkingsMarkings

ExposureExposure

Osteotomy Osteotomy cutscuts

Nerve Bundle Nerve Bundle RepositioningRepositioning

Kole’s ProcedureKole’s Procedure

Correction of minor degrees of AOB. Class 3 malocclusion Inferior border into defect caused due to

upward movement of ant. segment Chin augmentation Decreased ant. facial height