Orthognathic surgery

Dr. Akhila K. MDS

Assistant professor

OMFS department

MES dental college and hospital

Frontal view

Profile view

Definition

• Orthognathic surgery is the art and science of diagnosis, treatment planning and execution of treatment by combining orthodontic and oral and maxillofacial surgery to correct musculoskeletal,dento-osseous and soft tissue deformities of the jaws and associated structures.

​

(Peterson )

Contents

• Diagnosis and treatment planning
• Maxillary surgical procedures
• Mandibular surgical procedures
• Complications
• Recent advances

The word orthognathic comes from the Greek word 

​

Orqos🡪to straighten

Gnaqos🡪jaw

​

INDICATIONS

• Gross jaws discrepancies

​

(Anteroposterior

Vertical

Transverse discrepancies)

​

​

• Facial Skeletal Discrepancies Associated with Documented Sleep Apnea, Airway Defects, and Soft Tissue Discrepancies

​

• Facial Skeletal Discrepancies associated with TM Joint pathology

​

• Facial skeleton deformities associated with syndromes

• Hemifacial microsomia
• Crouzon syndrome
• Apert syndrome
• Pfeiffer syndrome
• Stickler syndrome
• Treacher Collins syndrome

• Deformities associated with cleft lip and palate

• Maxilla:

- vertical maxillary excess

- vertical maxillary deficiency

​

• Mandible:

- mandibular prognathism

- mandibular retrognathism

​

• combination:

patient

orthodontist

Oral surgeon

OBJECTIVES

• Function: Normal mastication, speech, ocular function, respiratory function

​

• Esthetics: Establishment of facial harmony and balance

​

• Stability: Prevention of short and long term relapse

​

• Minimizing treatment time: Provision of efficient and effective treatment

​

Diagnosis and treatment planning

SYSTEMATIC PATIENT EVALUATION

1. GENERAL PATIENT EVALUATION

• Medical history.
• Dental evaluation.

2. SOCIO-PSYCHOLOGICAL EVALUATION

3. CLINICAL EXAMINATION

4. FUNCTIONAL EXAMINATION

5. MUSCLE AND TEMPOROMANDIBULAR JOINT EVALUATION

6. PHOTOGRAPHS

7. RADIOGRAPHS

8. STUDY MODELS

9. COMPUTER ASSISTED ANALYSIS

​

​

MEDICAL HISTORY

Risk management and potential complications related to medical problems should be discussed with patient and physician.

​

Medical problems which can complicate general anesthesia and reconstruction procedures.

DENTAL EVALUATION

• History

​

• Present Dental health
• Periodontal
• Occlusal
• Functional

COMPREHENSIVE SOCIO-PSYCHOLOGICAL EVALUATION

Socio-psychological makeup of patient is often neglected.

​

Dissatisfaction of results can be because of :

a. unrealistic patient expectation.

b. failure of clinician to inform realistic probable treatment result.

​

Internally motivated/ Externally motivated

​

​

​

Aesthetics

• The appearance of the face most important element of attractiveness
• Patients visualize themselves from FRONTAL ASPECT
• Traditionally more emphasis placed on profile analysis

Facial Examination

• Upper third
• hair loss

​

​

• Middle third
• eyes 🡪 scleral show / inter-canthal distances
• cheek widest point 1cm lat & 2cm inf to lat canthus
• nose from above, below and in profile

​

​

• Lower third
• lips relation to incisors, competence width & height
• Chin symmetry, vertical/AP relations , mentalis activity

​

Rule of thirds

​

​

Trichion🡪 glabella🡪 subnasale🡪 stomion🡪 gnathion

Rule of fifths

​

• middle fifth : medial canthi
• medial two-fifths : medial canthi canthi and lateral canthi
• outer two-fifth : lateral canthi to helix

​

Bigonial width 30% less than bi-zygomatic width

(Projection of malar eminences from outer canthus)

​

DIRECT MEASUREMENT AS A BIOMETRIC TOOL

• Philtrum height Upper 22+/- 2 mm 20 +/- 2 mm

Lower 44+/- 2 mm 40+/- 2 mm

• Commisure height should be less than philtrum height

​

• Interlabial gap 1 to 3 mm

​

• Amount of incisor show at rest 2 to 3 mm

​

• Amount of incisor show on smiling full incisor with 1 mm of gingiva is acceptable

​

• Crown height 9 to 12 mm

​

• Gingival display gummy smile is more esthetic than aged smile

​

• Smile arc consonant and non-consonant

​

• Upper to lower lip vermillion ration 1: 1.25

• Nasal anatomy esthetics
• alar base
• columella
• nasal tip
• dorsum

​

• Orbit
• Intercanthal distance (34+/- 4 mm)
• Inter occular distance (65+/- 4 mm)
• Upper eyelid lower eyelid
• (ptosis, ectropion, entropion)

​

​

TRANSVERSE SYMMETRY

• Nasal tip to midsaggital plane (gull wing)
• Maxillary dental midline to midsagittal plane
• Mandibular dental midline to symphysis
• Mandibular asymmetry with or without functional shift
• Maxillomandibular asymmetry
• Chin asymmetry

​

​

• Neck
• Skin
• Lipomatosis
• Hyoid bone level (2cm from chin )

� VERTICAL CHARACTERSTICS OF THE SMILE

​

​

Lip-tooth- gingival relationships

• Gingival display on smile – adequate/ inadequate
• philtrum height – long/short
• clinical crown height – long/ short
• maxillary incisors – upright/ flared
• tooth form-contact- gingival architecture

TRANSVERSE CHARACTERISTICS ON SMILE

• Arch form
• Buccal corridor
• Cant of transverse occlusal plane

​

OBLIQUE VIEW �

​

Midfacial

• Orbital position
• Nasal form
• Cheek and zygomatic form

(Cheekbone –nasal base-lip curve)

Lower facial

• Lip form
• Philtrum
• Vermillion
• Mandibular form
• Chin projection

​

OBLIQUE VIEW �

​

• Orientation of palatal and occlusal planes (posterior cant)
• Smile arc

​

PROFILE VIEW�

​

• Lower facial
• Maxillomandibular projection or facial divergence
• Lip form

1.size

2. projection

3. labiomental sulcus (130^.)

• Chin projection

Chin-throat angle (110^.)

Chin length (42 +/- 6 mm)

• Nose (2:1 ratio)

Nasolabial angle (85 to 105^.)

PROFILE VIEW�

• Overjet
• Incisor angulation
• Upright maxillary
• Flared maxillary
• Retroclined mandibular

​

​

​

Dental Examination

• Alignment
• Crowding
• Spacing
• Missing or supernumerary
• Anteroposterior
• Angle classification
• Overjet
• compensation
• Bite depth
• Anterior
• Posterior
• compensated
• Transverse
• Compensated
• Functional occlusal issues
• Missign teth and sequelae
• Occlusal interferences and parafunction

FUNCTIONAL EXAMINATION

​

• ORAL CAVITY
• NOSE
• MASTICATORY MUSCLE AND TEMPOROMANDIBULAR JOINT EVALUATION
• Masticatory muscle
• Mandibular movements
• Temporomandibular joint symptoms
• Temporomandibular joint signs
• VELOPHARYGEAL EVALUATION
• Speech examination
• Nasoendoscopy
• TONGUE EVALUATION
• Speech examination
• Posture

RADIOGRAPHY

OPG

PERAPICAL

CEPHALOGRAMS

TOMOGRAMS

CT

MRI

​

COMPUTER ASSISTED ANALYSIS

• Videomanipulation
• 3-D CT reconstruction

• NEW TECHNOLOGY 
• 3D Facial Measurement
• Dolphin Treatment Organizer
• Orthodontic FAB
• Cephalometric Program
• Surgical FAB Cephalometric Program

PREVOUS METHODS OF DATA COLLECTION

Only Static diagnostic records are poor diagnostic records for the following reasons

​

• Static records cannot reflect the dynamic relationships that are important in the overall functional assessment of the patient. (Incisor exposure)
• Information which may have not looked important during cursory examination may seem important later
• Thorough and comprehensive records is an accurate medico-legal record

​

CEPHALOMETRIC ANALYSIS

Lateral cephalogram- COGS analysis

​

​

Cephalometrics for OrthoGnathic Surgery

​

• Careful diagnosis is the key to orthognathic surgery.

​

​

• Cephalometric analysis can aid in the diagnosis of skeletal and dental problems and tool for simulating surgery and orthodontics as a overlay.
• Post surgery changes can be evaluated.

• Designed for the patient who requires maxillofacial surgery
• Developed to use landmarks that can be altered by common surgical procedures.

​

• The measurements are primarily linear that can be readily applied to prediction overlays and study cast mountings and may serve as a basis for the evaluation for post treatment stability

• HARD TISSUE
• SKELETAL

​

• DENTAL

​

• SOFT TISSUE

HARD TISSUE ANALYSIS LANDMARKS

• Sella (S) - The center of pituitary fossa

​

• Nasion (N) -The most anterior point of the nasofrontal suture in the midsagittal plane.

​

• Articulare (Ar) - The intersection of the basisphenoid and the posterior border of the condyle mandibularis.

​

• Ptreygomaxillary fissure (PTM) – the most posterior point on the anterior contour of the maxillary tuberosity.

​

• Anterior nasal spine (ANS) the most anterior point of the nasal floor, the tip of the premaxilla in the midsagittal plane.

​

• Posterior nasal spine (PNS) the most posterior point on the contour of the palate

​

• Nasal Floor (NF) a plane constructed from ANS to PNS

​

• Subspinale (A) the deepest point in the midsagittal plane between the anterior nasal spine and prosthion, usually around the level of and anterior to the apex of the maxillary central incisor.

​

• Pogonion (Pg) the most anterior point in the midsagittal plane of the contour of the chin

​

​

• Supramentale (B) the deepest point in the midsagittal plane between the infradentale and the pogonion usually slightly below and anterior to the mandibular incisors

• Mandibular plane (MP) a plane constructed from menton to angle of the mandible (Gonion)
• Gonion (Go) located by bisecting the posterior ramal plane and mandibular plane
• Menton (M) the lowest point in the contour of the symphysis
• Gnathion (Gn) the midpoint between Pogonion and Menton located by bisecting facial line N-Pg and mandibular plane (lower border)

​

Cranial base

• Frankfort Horizontal plane: for baseline of comparison a horizontal plane is constructed by drawing a line 7^. to S-N plane.
• Most measurements are either made parallel or perpendicular to this plane.

​

Cranial base

Length of cranial base:

​

Measurement parallel to HP from Ar to N. This should not be considered absolute value but a baseline to obtain proportional maxillary and mandibular length.

​

​

Proganthism and retroganthism can be evaluated

SKELETAL PROFILE

Degree of skeletal convexity: line drawn from N-A and A-PG the NA is advanced to get the angle.

​

​

Concave or convex profile

SKELETAL PROFILE

• Perpendicular line from HP from N is drawn. The distance from A, B, and Pg is measured to this line

​

• Maxillary (anterior or total) advancement or reduction
• Mandibular (anterior or total) advancement or reduction
• advancement or reduction genioplasty.

​

​

VERTICAL SKELETAL AND DENTAL

• Vertical skeletal measurements help in assessing anterior, posterior and total maxillary hypo or hyperplasia requiring clockwise or counter clockwise rotations.
• Advancement or reduction in vertical plane may also be established.

VERTICAL SKELETAL AND DENTAL

• Vertical measurements are divided into anterior and posterior components.
• Mid facial height: N-ANS
• Lower facial height: ANS-GN
• Posterior midfacial height: HP-PNS
• Divergence of mandible: MP-HP
• Posterior maxillary height and divergence of mandible define vertical dysplasia in posterior components

VERTICAL DENTAL MEASUREMENTS

• Anterior and posterior components
• U1 to NF
• U6 to NF
• L1 to MP
• L6 to MP
• These values should be related to ANS-Gn and MP-HP to asses skeletal dental or both discrepancies

​

​

MAXILLA AND MANDIBLE

• Length of maxilla: PNS-ANS
• Mandibular ramal length: Ar-Go
• Mandibular body length: Go-Pg
• Relation between ramal plane and MP: Ar-Go-Gn angle
• Prominence of Chin: B-Pg from MP

DENTAL

• Occlusal plane(OP): drawn from occlusal groove of 6 through point 1 mm apical to incisal edge
• HP to Upper OP
• HP to Lower OP

DENTAL

• Upper 1 to NF

​

• Lowert 1 to MP

​

• A-B

OVERALL SKELETAL ANALYSIS

• Cranial base males females
• Ar-PTM (parallel to HP ) 37.1 32.6
• PTM-N (parallel to HP ) 52.8 50.9

Horizontal (skeletal)

• N-A-Pg (angle) 3.9 2.6
• N-A (parallel to HP ) 0.0 -2.0
• N-B (parallel to HP ) -5.3 -6.9
• N-Pg (parallel to HP ) -4.3 -6.6

males females

maxilla and mandible

PNS-ANS (parallel to HP ) 57.7 52.6

Ar-Go (linear) 52.0 46.8

Go-Pg (linear) 83.7 74.3

B-Pg(parallel to HP ) 8.9 7.2

Ar-Go-Gn (ANGLE) 119.1 122.0

Dental

OP Upper-HP (ANGLE) 6.2 7.1

OP Lower-HP (ANGLE) - -

A-B (parallel to OP ) -1.1 -0.4

Upper 1 to NF (ANGLE) 111.0 112.5

Lower 1 to MP (ANGLE) 95.9 95.9

​

SOFT

TISSUE ANALYSIS

SOFT TISSUE ANALYSIS

• Soft tissue deviations and abnormalities have to be borne in mind while doing a cephalometric analysis for orthognathic patient.

​

​

• Legan and Burstone modified the previous soft tissue analysis to the most relevant measurements and new measurements added that are significant to orthognathic surgery.

​

• Important factors in soft tissue
• Lip
• Nose
• Chin

​

Landmarks

• Glabella (G) most prominent point in the midsagittal plane of the forehead

​

• Columella point (Cm) the anterior most point on the columella of nose

​

• Subnasale (Sn) the point at which the nasal septum merges with the upper cutaneous lip in midsagittal plane.

​

​

• Labrale superius (Ls) a point indicating the mucocutaneous border of upper lip
• Labrale inferius (Li) a point indicating the mucocutaneous border of lower lip

​

​

• Stomion superius (Stm) the lowermost point on the vermillion of the upper lip
• Stomion inferius (Sti) the lowermost point on the vermillion of the lower lip

​

• Mentolabial sulcus (Si) the point of greatest concavity in the midline between lower lip and chin

​

• Soft tissue pogonion (Pg^/ ) the most anterior point in the midline on the chin

​

• Soft tissue menton (Me^/) lowest point on the contour of the chin found by dropping a perpendicular from horizontal plane through menton.

​

• Cervical point (C) the innermost point between the submental area and the neck

​

FACIAL FORM

• Angle of facial convexity (G-Sn- Pg )
• Convex or concave profile
• Maxillary prognathism : protrusion or retrusion of maxilla (G-Sn)
• (variable glabellar position)
• Mandibular prognathism(G- Pg )

FACIAL FORM

• Vertical height ratio: G-Sn: Sn-Me^/ = 1:1

​

FACIAL FORM�

• Lower face throat angle Sn -Gn -C

​

​

LIP POSTION AND FORM

• Nasolabial angle (Cm-Sn-Ls)

​

• Upper lip protrusion Ls to (Sn-Pg’)

​

• Lower lip protrusion Li to (Sn-Pg’)

​

LIP POSTION AND FORM

• Mentolabial sulcus Si to (Li-Pg’)
• Maxillary incisor exposure Stm – upper 1
• Vertical lip- chin ratio Sn-Stmu: StmL-Me’
• Interlabial gap Stmu - StmL

MEAN

FACIAL FORM

• Angle of facial convexity (G-Sn- Pg’ ) 12 degrees
• Maxillary prognathism (G-Sn) 6
• Mandibular prognathism (G- Pg’ ) 0
• Vertical height ratio: G-Sn’: Sn’-Me’ 1
• Lower face throat angle Sn’-Gn’ -C 100 degrees
• Lower vertical height and depth ratio (Sn’–Gn’:C-Gn’) 1.2

LIP FORM AND POSITON

• Nasolabial angle (Cm-Sn’-Ls) 102 DEGREES
• Upper lip protrusion Ls to (Sn’-Pg’) 3
• Lower lip protrusion Li to (Sn’-Pg’) 2
• Mentolabial sulcus Si to (Li-Pg’) 4
• Maxillary incisor exposure Stm – upper 1 0.5
• Vertical lip- chin ratio Sn-Stmu: StmL-Me’ 2
• Interlabial gap Stmu - StmL 2

PA cephalogram

• Grummons analysis

Posteroanterior cephalometric analysis

• Done for facial asymmetry(craniofacial abnormalities)
• Triangular analysis of maxilla, mandible, and chin

POINTS TO PONDER

• Ceph analysis is only one step in diagnosis
• Soft tissue are important to be kept in mind
• Facial skeleton will approach normative standard
• Function and stability to be kept in mind
• Normal bones sometimes have to be altered to obtain desired results
• Reference plane arbitary
• Helps in planning in terms of millimeters
• Useful in diagnosis of nature of facial dysplasia and abnormalities in tooth position
• Limitation of 2D ceph

POINTS TO PONDER

• Both Soft Tissue And Hard Tissue Analysis Required
• SOFT TISSUE drape can mislead diagnosis
• Hard tissue repositioning can change soft tissue position
• Soft tissue surgery may be only indicated without need to touch hard tissue
• Minor alterations in soft tissue can lead to drastic changes in facial esthetics
• Need to alter soft tissue should be considered thoroughly

​

​

Limitations

• Variation in baselines in dentofacial deformities
• Interpretations should not be from one analysis
• Limitations of radiograph technique
• Interpretations of abnormal findings and their etiology is very essential
• Although important …….should not take precedence over clinical evaluation

Model surgery

SYNTHESIS OF OPTIMIZED TREATMENT LIST

• Proper clinical, radiological, and video analysis can lead to proper treatment planning
• Patient evaluation and proper preoperative counseling (expectation) can lead to lesser postoperative problems.
• The final treatment list optimized must be explained to the patient
• Patient education is prime importance

Timing of orthognathic surgery

• General assumption that facial growth retards post surgery
• Surgery before completion of growth is variable and outcome less predictable
• Safe approach :Performing single operation is preferred and in patients best biologic interest
• Psychosocial concerns should be weighed against biologic interest
• Risk benefit ratio should be established.

​

​

Treatment is divided into 3 phases:

​

1) pre-surgical orthodontics:

( close spaces, derotation, eliminate dental interferences)

​

2) surgery

​

3) post-surgical orthodontics:

( settling of occlusion, closure of spaces, finer tooth alignment)

​

​

Surgery first orthognathic approach

SFOA

����INTRODUCTION�

• Pre surgical orthodontic preparation was uncommon for patients requiring orthognathic surgery until the 1960’s.

​

​

• Having orthodontic interventions both before and after orthognathic surgery include a long treatment time of 7–47 months, dental caries, gingival recession and root resorption.

• To overcome the disadvantages and inconveniences of pre surgical orthodontics, surgery first orthognathic approach has been introduced by Behrman and Behrman in 1988.

​

​

​

• An alternative methodology to conventional orthognathic surgery which performs directly an orthognathic surgery, followed by a post-surgical orthodontic treatment to achieve the desired final dental alignment.

Regional Acceleratory Phenomenon (RAP)�

• The surgery first approach utilizes the opportunity to speed up the decompensation process which occurs after the surgery unlike the traditional approach.
• Since the decompensation of the arches is the most time consuming step of the way, the regional acceleratory phenomenon is used when it is needed the most.

​

​

• In addition, corticotomies can be executed in the maxilla and mandible to accelerate postoperative orthodontic movement according to the regional acceleratory phenomenon (RAP) theory.

​

• Corticotomies should be extended through the entire thickness of the buccal cortical layer and interrupted when penetrating the medullary bone.

INDICATIONS

• Patients which cannot afford the cost of extended orthodontic preparation.
• Skeletal Class III cases requiring two jaw surgery, with well-aligned to mildly crowded teeth, mild curve of Spee and mild proclined/retroclined incisors teeth.
• Pronounced soft tissue imbalance in skeletal class III patients, severe skeletal class II deformities, in which decompensation is not required.
• Patients who want immediate esthetic result or who want to improve both function and esthetic, patients with facial asymmetries, cleft lip and palate patients

CONTRAINDICATIONS

• Patient who require definite decompensation
• Severe crowding and arch-incoordination
• Severe vertical or transverse discrepancy
• Patients with high expectations of treatment outcomes in terms of dental esthetics and stable occlusions
• Severe proclination of upper and lower anteriors

ADVANTAGES

• Allows the chief complaint of the patient to be addressed at the beginning of treatment.
• Provides efficient and shortened treatment time of around 1 – 1.5 years or less.
• Eliminates the unsightly pre-surgical profile
• If a surgical error or skeletal relapse occurs, compensation can be made with Skeletal anchorage system (SAS) mechanics.

DISADVANTAGES

• Predicting the final occlusion is the hardest challenge

​

• Cases requiring extractions are especially very difficult to plan.

​

• The occlusion cannot be used as a guide for establishing treatment goals.

Success of the surgery first approach requires:

​

• careful patient selection
• precise treatment planning
• feedback between the surgeon and the orthodontist

• Clinical evaluation
• Photographs
• Radiological evaluation
• Mock surgery

• Prof MSN Ginwalla – father of orthognathic surgery in India
• Started surgeries in 60’s

Maxillary osteotomy procedures

Segmental maxillary osteotomies

1. Single tooth dento-osseous osteotomy

2. Interdental osteotomies- corticotomy

​

3. Anterior segmental maxillary osteotomies

Wassmund technique

Wunderer technique

Cupar technique

4. Posterior segmental maxillary osteotomies

Schuchardt technique

Kufner technique

Perkel & Bell technique

Total maxillary osteotomies

​

1. Le Fort I osteotomy

Classic down fracture

Buttress release

Quandrangular osteotomy

2. Le Fort II osteotomy

Anterior

Pyramidal

Quandrangular osteotomy

3. Le Fort III osteotomy

Gillies technique

Tessier technique

4. High level midface osteotomy

Zygomatic osteotomy

Malar maxillary osteotomy

5. Surgically assisted maxillary expansion (SARPE)

6. Anterior maxillary distraction osteogenesis

​

Mandibular osteotomy procedures

Mandibular body osteotomies

• Mandibular body osteotomies

Anterior body osteotomy

Posterior body osteotomy

Midsymphysis osteotomy

• Segmental subapical mandibular surgeries

Anterior subapical mandi. osteotomy

Posterior subapical mandi. osteotomy

Total subapical mandi. osteotomy

• Genioplasties

Michelet genioplasty

Sliding genioplasty

Alloplastic genioplasty

Sagittal split genioplasty

​

​

​

​

Mandibular ramus osteotomies

• Subcondylar Ramus osteotomy

Intraoral vertical ramus osteotomy (IVRO)

Extraoral vertical ramus osteotomy (EVRO)

C ramal osteotomy (extroral)

Inverted L osteotomy (extraoral)

• Bilateral Sagittal split osteotomy (BSSO)
• Endoscopically assisted osteotomies

LEFORT I OSTEOTOMY

History

• Von Langenback- 1859- nasopharyngeal polyp
• Cheever- to relieve nasal obstruction
• 1901- Lefort- natural planes of maxillary fracture
• Wassmund- corrected midfacial deformities
• Modifications by- Axhausen, Schuchardt, Willmar
• Obwegeser- 1965- complete mobilization of maxilla
• 1973- Bell- blood supply to maxilla

​

​

​

Indications

• Maxillary hypoplasia with Class III skeletal pattern
• Vertical Maxillary Excess- gummy smile, increased mandibular plane angle, reduced U- facial height, increased anterior facial height
• In conjunction with mandibular osteotomy- to correct open bites
• OSA
• Preparation for prosthetic rehabilitation for atrophic maxilla
• Access for nasopharyngeal and spinal cord tumours
• To advance maxilla in cleft palate and post traumatic patients.
• Correction of maxillary cants.
• Advancement of the maxilla in class III patients.

​

MAXILLA

​

​

Osteology of Maxilla

Parts of the maxilla:

​

• Body- 4 surfaces

- Anterior surface

- Infratemporal surface

- Orbital surface

- Nasal surface

​

• 4 Processes

- Zygomatic process

- Frontal process

- Palatine process

- Alveolar process

​

Maxillary Sinus

• Largest of the paranasal sinuses
• 1^st paranasal sinus to develop
• It is a three sided pyramid in shape

​

Biological basis

• Maxilla receives its blood supply from branches of maxillary artery – the palatine artery and superior alveolar arteries. It also receives collateral supply from the branches of facial artery.
• Ascending palatine and pharyngeal artery major contribution to palatal blood supply

​

Arteries maintaining perfusion to the osteotomised maxilla:

​

​

Ascending palatine branch of facial artery

Anterior branch of ascending pharyngeal artery

Both of them enter the soft palate posterior to the pterygoid muscles

Maintain the posterior palatal soft tissue pedicle after le-fort 1 osteotomy

Average distance from the most inferior point of pterygomaxillary junction to

​

• PSA: 15mm
• Infra orbital artery: 32mm
• Descending palatine artery: 25mm

​

Distance of descending palatine artery from

​

• Tuberosity/ pterygomaxillary fissure: 10mm
• Piriform rims- 34mm

​

Maxillary artery position

​

• 23-25mm superior to base of junction of maxilla with pterygoid plates

​

​

Surgical technique

� OPERATIVE TECHNIQUE

• Anesthetic and positioning considerations
• External reference marker
• Incision and subperiosteal dissection
• Maxillary osteotomy
• Pterygomaxillary dysjunction
• Septal, vomerine and lateral nasal osteotomies
• Down fracture

​

• Evaluation of descending palatine arteries
• Mobilisation of maxilla
• Maxillary segmentation- optional
• IMF, repositioning , adjustment
• Maxillary fixation
• Bone grafting- optional
• Occlusal evaluation
• Suturing- alar cinch , wound closure

​

Anesthetic and positioning considerations�

• Controlled hypotensive anesthesia
• 30% below the pts baseline pressure( minimum 50mmHg)
• Post op blood transfusion
• Bladder catheter- urine output
• Nasal intubation
• Shoulder roll
• Sterile preparation and draping
• LA with adrenaline- only in labial sulcus

​

External reference marker

• Marker at Nasion
• Markers- K- wire, screw, suture, tape

​

• To maxillary dental midline/ bilateral canine tips/

orthodontic bracket

​

• Curvilinear incision given from first molar of one side to the other leaving at-least 5mm of non-keratinized tissue anteriorly and increased to 10mm posteriorly for ease of suturing.
• Incision carried through mucosa, sub-mucosa, periosteum upto bone.

​

Wider flap posteriorly to perfuse the maxilla

• If incision carried out too far posteriorly or too high herniation of BFP occurs

Le fort 1 osteotomy

• Nasal aperture is exposed with careful dissection along the piriform rim and lateral nasal wall
• Mucosa and periosteum from the floor of the nose are elevated as far as the nasal crest of the maxilla in the midline

​

• Careful reflection and dissection of nasal mucosa with as few perforations as possible minimizes blood loss and postoperative discomfort

​

• In addition a gauze pack soaked with LA with adr is placed in the nasal cavity to reduce bleeding.

• Vertical reference landmarks placed at piriform region and the zygomatic maxillary buttress using a bur.

​

Coupled with the external reference these intraoral reference marks allow vertical orientation when osteotomy is complete and the maxilla is mobilized.

​

• Horizontal references in bone are not necessary since the teeth and the occlusal splint guide the correction in the sagittal plane.

• Osteotomy of the lateral maxilla begins posteriorly zygomatic maxillary buttress, just above the inferior vertical reference mark, usually about 35 mm above the maxillary occlusal plane

​

• With a reciprocating saw or surgical bur, the osteotomy advances through the thicker bone at the buttress and the thin bone of the lateral maxillary wall to the piriform rim where the bone thickens again

​

• Should be parallel to occlusal plane
• directed downwards.. if advancement and height is to be increased

​

• angled superiorly … create an open bite and reduce facial height.

• Retractor is placed subperiosteally at the junction of the maxilla and pterygoid plate and under direct vision, the osteotomy is directed inferiorly and posteriorly, from the zygomatic maxillary buttress to the junction of the maxilla and pterygoid plate, 5 mm superior to the second molar

• With care taken to reflect intact nasal mucosa, a septal osteotome is malleted posteriorly along the septal crest of the maxilla, freeing the cartilaginous septum and sectioning the bony septum at the nasal floor.

• Lateral nasal wall is sectioned with a safe sided osteotome directed posteriorly and inferiorly, along the lateral nasal wall toward the perpendicular plate of the palatine bone not more than 25mm
• malleted too far posteriorly, injury to the descending palatine vessels

​

• The lateral nasal wall -thin , offers little resistance to sectioning until the vertical pillar of the palatine bone is reached.
• Resistance to the advancing osteotome and change in sound indicate that the palatine bone has been encountered
• Partial section of the perpendicular part of the palatine bone is necessary to prevent the palatine bone from fracturing higher than the level of the nasal floor during maxillary downfracture

Pterygomaxillary dysjunction

• Under direct vision, a curved osteotome is positioned and directed anteriorly, medially and inferiorly; at the lowest part of the junction between the maxilla and the pterygoid plate.
• For orientation prior to malleting, an index finger placed on the palate at the hamular notch region should feel the tip of the osteotome.
• Osteotome is malleted to achieve bony separation
• Procedure is repeated on the opposite side
• By utilizing finger pressure on the anterior aspect, the maxilla is forced down. Simultaneously, the remaining attached nasal soft tissues are elevated carefully from the nasal floor.

​

​

• Maxilla should downfracture with ease.
• If it does not, the osteotomies are redefined

​

​

• The most common reasons for failure of downfracture are
• Pterygoid plates and tuberosity are not sufficiently separated
• Lateral nasal osteotomy is too short
• Maxillary bone may be thick making downfracture difficult

​

​

• maxillary distraction and mobilization devices are placed bilaterally on the buccal side at the posterior aspect of the maxilla, and under direct vision, the maxilla is brought forward, fracturing any remaining posterior attachment.

​

• A hole can be drilled through the lateral part of piriform rim on each side of downfractured maxilla
• A wire is passed through the holes and held by a wire twister.

​

This positioning wire is helpful to:

• Assist with the final mobilization of the maxilla
• Pull the maxilla anteriorly for better visualization and access to the posterior area
• Assist in final repositioning of the maxilla

​

​

• With a rongeur, any remaining vomer and the septal crest of the maxilla are removed, particularly if superior repositioning of the maxilla is planned.

​

• The anterior nasal spine may require reduction if the maxilla must be moved forward or in a superior direction, but it is not intentionally removed otherwise

​

• Similarly, the lateral nasal walls are reduced with a rongeur to permit visualization of the perpendicular portion of the palatine bone and to facilitate any superior movement

• The descending palatine neurovascular bundle commonly is visualized posterior and medial to the maxillary sinuses.
• Bone is removed carefully from the posterior maxilla and from around the descending palatine vessels. If possible these vessels should be preserved to enhance blood supply to the maxilla through the soft tissue pedicle on the palate.
• If the descending palatine vessels are violated, bleeding can be controlled by vascular clamps, cautery, or packing.
• Bone should be removed from the inferior aspect rather than from the superior aspect of maxilla or pterygoid plates.

​

• If the maxilla is repositioned superiorly, bone from the septal crest of the maxilla and bone and cartilage from the nasal septum should be resected sufficiently.
• Prevent buckling
• A trough can be created in the nasal floor to accommodate the nasal septum after maxillary repositioning.

• Piriform rim should be contoured to accommodate the nasal tissues after maxillary repositioning.

​

• At the same time a hole is drilled through the anterior nasal spine which will be later used to position and secure the nasal septum and placement of cinch suture.

​

Insufficient removal of bone on these areas could lead to flaring of the alae, lifting of the nasal tip, and/or asymmetry of the nose

• For superior or posterior repositioning, remove a sufficient quantity of bone at the posterior and medial maxilla.
• If insufficient bone is removed, planned repositioning of the maxilla is not possible.

The mandible and its condyles are easily displaced inferiorly from the fossa by this bony interference as the mandibular-maxillary complex is repositioned.

​

• After maxillary mobilization, bony reduction, and insertion of the occlusal wafer splint, MMF is done.

• When the mandible is rotated closed, it should be held at the inferior border, just anterior to the angles bilaterally, and guided so that the condyles remain seated.

​

• The vector of force while positioning are a slight backward pressure on the chin and an upward and slightly anterior pressure on the angles.

​

• If deviations or premature bone contacts are detected, sufficient bone must be removed from the maxilla to allow the maxillo-mandibular complex to be repositioned passively

• If the inferior turbinates are interfering with repositioning the maxilla, after the overlying mucosa is injected with a vasoconstrictor, the turbinates may be trimmed with Mayo scissors

​

• Any gross tears in the nasal mucosa should be repaired with 4·0 chromic gut suture to minimize nasal bleeding in the immediate post surgery period

• Wires are placed in the buttress holes and tightened
• If any doubt about the condylar position, MMF should be removed and occlusion checked
• The distance between the vertical reference points (external and internal) is measured to be certain that the expected amount of repositioning has occurred
• If maxillary position and occlusion is satisfactory, MMF is done.

​

• By incremental removal of bone, good bone contact can be obtained anteriorly at the piriform region even if maxillary walls telescope posteriorly

​

• Large defects in the maxillary walls may result from overzealous removal of the bone from the lateral maxilia and zygomatic maxillary buttress region and should be avoided.

​

Maxillary segmentation:

• to facilitate expansion or contraction
• leveling of the occlusal plane
• space closure

Fixation:

• Bone plates are the most commonly used.
• Metal/bioresorbable plates can be used
• Placed at the 4 anterior buttresses – piriform rims and zygomatico-maxillary buttress region bilaterally
• Plates must be well contoured with atleast 2 screws on either side
• After fixation, MMF should be removed and occlusion checked.
• In case of any deviation or open bite, plates are removed and maxilla repositioned.
• Posterior bony interferences can lead to condylar distraction downwards, once MMF is removed condyles go back to their postion causing an anterior open bite.

Bone grafts:

• When the maxilla is positioned so that the piriform rim and zygomatic buttress are not in contact, bone grafts can be placed at these vertical pillars to bridge the defects and stabilize the new position of the maxilla
• Significant defects (>5mm) at the piriform rim and the zygomatic buttress require bone grafts for stabilization
• The graft should be mechanically locked between bone segments or should be supported with wire or screw fixation.

Closure:

• Nasal septum is secured in the trough created in nasal floor by a suture passing through the septum and the hole in the anterior nasal spine
• Alar cinch suture: prevents widening of alar bases
• V-Y closure: prevents shortening of upper lip

Alar cinch suture:

• With the lip everted, the index finger is placed extra-orally over the alar rim
• Using a toothed forceps the lateral alar tissues are grasped intra-orally opposite the extra-oral index finger
• Releasing the lip the pull of the forceps should pull the ala medially indicating the correct tissue is grasped.
• A 3-0 vicryl suture is passed through this tissue and the hole at the anterior nasal spine and procedure repeated on the opposite side.
• A figure of 8 suture is placed and tightened to allow some post-op widening

​

V-Y closure

• The recommended V-Y mucosal closure with begins posteriorly, with the vector of closure pulling the superior mucosal edge anteriorly.
• A skin hook placed in the midline of the superior wound edge helps apply traction during the closure.
• The resulting excess tissue is closed in a straight line

This wound closure pattern transfers mucosa from the posterior aspect of the wound anteriorly to minimize retraction of the vermilion surface and to provide support for the philtrum of the lip

lip bulk in the midline is developed at the expense of the loss of vermilion surface from the lateral lip areas

Modifications

Traditional le fort l osteotomy

• Inclined antero-posteriorly
• Anterior repositioning leads to reduced upper incisor exposure
• If not planned properly can be detrimental to aesthetic treatment objectives.
• Advantage in superior and anterior repositioning

​

Maxillary step osteotomy

• To eliminate ramping effect
• To improve predictability and accuracy
• Lateral maxillary osteotomy parallel to FH plane, vertical step in ZM buttress region, horizontal osteotomy continued posteriorly parallel to anterior horizontal osteotomy

Advantages:

• Pure anteroposterior movement possible when vertical change is undesirable
• Enables surgeon to make posterior osteotomy lower down (thus easier and safer downfracture)
• After advancement defect permits bone graft placement.

​

High le-fort l osteotomy

• The anterior horizontal component – high enough to include paranasal portion of maxilla
• Extending posteriorly through the zygoma just anterior to zygomatico-temoral suture approx 6-10 mm from the inferior of zygomatic arch.

​

• Indicated for correction of maxillomandibular abnormal relations, paranasal and zygomatic deficiency

​

​

​

Advantages:

• Allows augmentation of zygomatic and paranasal areas
• Reduction of telescoping of posterior maxillary wall

​

​

Disadvantages:

• Technically difficult
• Zygoma fracture
• Undesirable soft tissue changes if osteotomy not planned well

Horse shoe osteotomy

• Horse shoe shaped palatal osteotomy combined with le fort 1 osteotomy
• Allows high superior positioning of maxilla while safeguarding desending Palatine Artery and maintaining nasal chamber volume

Maxillo-malar osteotomy

• Indicated in patients affected by severe hypoplasia of the middle third of the face with flattening of the suborbital areas and zygomatic buttresses

​

• Introduced by Obwegeser

Technique:

• Intra-oral exposure of maxilla and zygomatic buttress and orbital floor
• First Osteotomy- from lateral border of piriform rim to medial aspect of inferior orbital rim
• Second osteotomy line starts from the lateral aspect of the inferior orbital rim and is directed towards the zygomatic buttress as far back as is possible.
• Two osteotomies are then connected along the anterior orbital floor
• The osteotomy of the nasal septum
• The osteotomy of the medial walls of the maxillary sinuses are carried out in a higher position

​

​

Advantages:

• Inclusion of buttress- better aesthetics, reduced fractures of anterior wall of sinus

​

​

​

Drawbacks:

• Infra-orbital nerve paraesthesia - 70% of patients (temporary)
• Maxilla cannot be rotated; cannot be used in skeletal open bites, dentofacial asymmetry
• Not indicated in cases of vertical hypoplasia of more than 4-5mm

​

Complications

Unfavourable osteotomy in pterygo-palatine region

Common type of unfavorable osteotomies:

• Fracture at the junction of horizontal process of palatine bone and the palatal process of maxilla
• Fracture of the pyramidal process of palatine bone
• Fracture of both pterygoid plates

​

Causes:

• Improper position of osteotome
• Incomplete osteotomies
• High force used for downfracture

​

Consequences:

• Maxilla mobilization difficult
• Stretching/tearing of palatal pedicle
• Damage to adjacent vascular/neural structures
• Predispose to relapse

Bleeding

Common sources:

• Lateral & medial pterygoid muscles-majority of cases
• Posterior superior alveolar artery-small artery
• Pterygoid venous plexus
• Greater palatine artery
• Terminal branches of maxillary artery
• Internal carotid artery

​

​

Descending palatine artery

​

​

• Causes
• Using saw deeply within the posteromedial aspect of maxillary sinus

​

• Osteotomy along the lateral nasal wall more than approx. 25-30mm posterior to the piriform rim

​

• Mobilizing the maxilla without removing bony spicules around the vessels

Internal maxillary artery:

• To avoid:
• Posterior lateral maxillary osteotomies angled downwards
• Proper technique for pterygo-maxillary dysjunction

​

​

Prevention of bleeding:

• Knowledge of anatomy esp. of posterior maxilla
• Gentle surgical technique
• Completing osteotomies before downfracture
• Avoiding use of high force during downfracture

​

• Post-operative epistaxis is usually the 1^st sign
• Mostly occurs within 2weeks of surgery

​

​

Management:

• anterior and/or posterior nasal packing
• packing of the maxillary antrum
• reoperating with clipping or electrocoagulation of bleeding vessels
• use of topical hemostatic agents in the pterygomaxillary region
• external carotid artery ligation
• selective embolization of the maxillary artery and its terminal branches

Bradycardia

• Seen during maxillary downfracture or mobilization
• The trigemino-cardiac reflex (TCR) is the sudden-onset of bradycardia and hypotension during manipulation of any of the branches of the trigeminal nerve.
• Management:
• Manipulation of maxilla should be stopped immediately
• Administration of anticholinergic drugs

​

Aseptic necrosis

• Usually related to multiple segmentation of the maxilla in conjunction with superior positioning and transverse expansion or palatal perforations.
• Early sign: blanching & cyanosis of attach gingiva and mucosa

​

Management:

• Returning the maxilla back to its original or intermediate position & checking for improved tissue color & blood flow.

​

• Oral hygiene maintenance and systemic antibiotics to prevent secondary infection

​

• Surgical debridement of necrotic tissue with the use of hyperbaric oxygen.

​

Relapse

• Proffit et al coined the phrase “Hierarchy of stability” In which they quantified according to different types of procedure

Maxillary repositioning relapse rate

• Advancement 5-19% (11%)
• Posterior movement
• Superior movement 0-18% (11%)

​

​

• Inferior movement 9-54%(28%)
• Transverse movement 8-14%(11%)

​

​

stable

Less stable

Non-union/delayed union

Causes:

• Scarring due to previous surgery
• Poor surgical planning
• Para-functional habits
• Posterior and superiorly positioned maxilla with poor bone contact
• Systemic- diabetes, smoking

​

Prevention-

• when unstable maxilla anticipated- bone fixation plates+ auxillary fixation
• IMF: 1-6weeks, skeletal wires
• Use of bone grafts for large defects

Non-union/delayed union

Mobility of maxilla seen post-op

• Management:

Early-

• If patient not in IMF-short period of fixation
• If patient in IMF- removing it may allow consolidation
• Use of flat plane splints-distribute occlusal load
• Occlusal correction for premature contacts
• Discontinue heavy elastics

Late-

• Re-operation for bone graft and rigid stabilization

Post operative vision loss

​

• Rare complication (0.25%)

​

• Reasons :
• Postoperative intraorbital bleeding

​

• Intraoperative Hypotension & hypoperfusion of the optic nerve

​

• Adverse transmission of forces during pterygomaxillary separation by sphenoid bone to the skull base

​

​

​

CSF leak

​

• Fracture of floor of middle cranial fossa at the root of pterygoid plates

Other complications

• Dental/periodontal injuries
• Occlusal discrepancies
• Oro-nasal/oro-antral fistulas
• Paresthesia of mucosa/teeth
• Nasal septum deviation
• Alar base widening
• Upturned nasal tip
• Flattening of upper lip
• Sinusitis
• Epiphora

​

Anterior maxillary osteotomy (AMO)�

​

• Mostly used to correct maxillary anterior protrusion( esp. in bimax cases)
• Allows for posterior and inferior movement of the anterior segment

​

​

Three techniques :

• Wassmund’s
• Wunderer’s
• Cupar’s

Wassmund’s technique:

​

• LA with adrenaline- above the canines and premolars bilaterally

​

• Vertical mucosal incision is made between the canine and premolar from the gingival margin superiorly to the level of the anterior nasal floor, superior to the root apex of the maxillary canine

• Keep the gingival papilla distal to the canine attached to bone, mucoperiosteum is reflected superiorly until the apical third of the maxillary canine

​

• Reflect anterior superior margin of the mucoperiosteal incision
• Tunnell forward subperiosteally to expose the nasal piriform aperture

​

• Release mucoperiosteum inside the nasal aperture

• First premolar should he removed or orthodontically space for vertical bony cuts
• The measured amount of alveolar bone is removed

​

• The palatal mucosa is reflected to just past the midline

​

​

• Bony cuts - leaving at least 2 mm of bone over adjacent teeth

​

• The bone cut is then extended above the teeth and forward to the lateral aspect of the nasal aperture, staying at least 4 mm above root apices
• If more than 1 to 2 mm of superior movement is planned, a measured amount of bone must be removed from the piriform rim area

• Next palatal bone is removed from the alveolus to the midline.
• The palatal bony cuts can be made with a bur, a reciprocating saw, or an osteotome.
• If any difficulty is encountered in removing bone at the midline of the palate. a small antero-posterior mid-palatal incision can be made for access.
• The palatal vascular pedicles are not compromised by this additional incision.
• A similar osteotomy is accomplished on the opposite side

• Following the bony cuts, the anterior dento-alveolar segment occasionally can be disarticulated from the nasal septum with hand pressure

​

• Usually a small vertical mucoperiosteal incision is required over the anterior nasal spine.

• After the mucoperiosteum has been carefully reflected from the anterior nasal spine and the inferior aspect of the cartilaginous nasal septum with a flexible Freer elevator, a nasal septal osteotome is malleted above the nasal spine to free the anterior dento-alveolar segment from the nasal septum.

​

• If required, the anterior dento-alveolar segment can be split in the midline into two pieces

• The anterior segments should be mobile and easily repositioned into the occlusal splint.

​

• Interfering bone can be removed with a bur.

​

​

• Inspect palatal soft tissue pedicle 🡪 not folded, compromising blood supply.

​

• The facial soft tissue pedicle should still be attached to the anterior dento-alveolar segment

Wunderer’s technique

• Facial soft tissue incisions for access to the lateral maxilla and the piriform nasal aperture are similar to those for the Wassmund’s technique
• For the palatal osteotomy, a mucoperiosteal incision is made transversely across the palate just anterior to the planned osteotomy site
• The palatal mucosa posterior to the incision is raised with a periosteal elevator, taking care to preserve palatal vessels.

​

• Palatal bone should be removed carefully with as little trauma to the nasal mucosa as possible.

​

• Once all bony cuts are complete, the anterior maxillary dento-alveolar segment can be mobilized manually, carefully separating the nasal septum from the segment through the palatal osteotomy site.

​

Cupar method

• Buccal vestibular incision
• Nasal septum is first released
• Horizontal osteotomy followed by vertical buccal osteotomy.
• Trans palatal osteotomy under direct vision.

​

Advantages:

• Direct access to the nasal structures & superior maxilla
• Preservation of the palatal pedicle for good blood supply.
• Ease of placement of rigid fixation
• Ability to remove bone from palate

Complications of AMO

​

1. Loss of vitality of the dentition

2. Damage to tooth roots

3. Persistent periodontal defects

4. Osseous necrosis of the dentoosseous segments

5. Communication with the maxillary sinus and nasal cavity

6. Hemorrhage

7. Oronasal or oroantral fistulas

8.Atrophic rhinitis – complete inferior turbinectomy

9. Unfavourable nasolabial esthetics

- Shortening & thinning of the upper lip

- widening of the alar bases

- upturning of the nasal tip

10. Nasal Septal Deviation

​

​

Posterior sub-apical osteotomy

Indications

​

​

• Unilateral cross-bites
• Supra-eruption of posterior maxillary segment following loss of mandibular teeth.

​

• Infiltration of LA with vasoconstrictor
• Mucoperiosteal incision is made from the maxillary canine posterior beneath the zygomatico-maxillary buttress to the tuberosity
• Mucoperiosteum is reflected superiorly, leaving the mucoperiosteum inferior to the incision attached to bone.
• If planned, the teeth are carefully removed at this time to keep alveolar bone intact.
• Mucosa is carefully reflected inferiorly to expose bone for the vertical cut

​

• Palatal incision may be required if the fragment has to be moved medially more than a few mm or if it appears unlikely that the fragment will telescope medially in position; palatal bone may need to be removed.
• a supplementary palatal incision is made medial to the planned palatal cut

• After adequate exposure, horizontal osteotomy above the dentoalveolar segment to be mobilized is made through the thin lateral maxillary wall in to the maxillary sinus with a bur or reciprocating saw.
• 5mm above the root apices
• If necessary, a measured amount of bone is removed to allow superior repositioning, By avoiding telescope into the sinus

• Vertical cut is carried out by a fissure bur extending medially almost through the alveolar process
• Then a thin spatula osteotome malleted into these cuts, the osteotomy is extended through to the palate, taking care to minimize trauma to the palatal mucosa

• When sufficient bone exists posterior to the terminal molar, vertical bone cuts may be made in this area

​

OR

a curved osteotome may separate the maxillary tuberosity from the pterygoid plates.

​

• Palatal bone can be cut with a curved osteotome directed through the lateral horizontal bony cut and the maxillary sinus
• By malleting the curved osteotome along the superior aspect of the palatal bone from posterior to anterior, bony cuts are connected.
• If access through a palatal incision is required, bone cuts are completed on the palate with a bur or osteotome
• After appropriate bone removal, the posterior dento-alveolar segment is positioned into the occlusal splint.
• Adequate vascular supply is maintained to the mobilized segment from both facial and palatal soft tissue pedicles.

• Segment is stabilized by MMF/ Orthodontic stabilizing arch wire
• Rigid fixation is applied
• When the patient has multiple missing teeth or when lateral expansion of more than 5 to 7 mm of the maxillary segment has occurred 🡪 transpalatal orthodontic stabilization

​

​

​

• Closure

Le fort II osteotomy

​

• Henderson and Jackson (1973)

​

• Pyramidal naso‐orbital maxillary osteotomy
• Allows the central midface to be moved anteriorly (or inferiorly) with the maxillary dental arch

​

​

INDICATIONS�

Patient with:

• Nasomaxillary hypoplasia
• Skeletal class III malocclusion
• Posttraumatic defects
• Maxillonasal dysplasia
• Secondary correction of cleft deformity

​

• V‐shaped incision with the apex at the glabella is made to extend bilaterally along both sides of the nose to reach just above the alar base.
• The columella of the nose is pulled down, and the cartilaginous and bony part is separated.
• Osteotomy starts at the bottom of the nasal bone towards the medial wall of orbit towards the floor of orbit posterior to the nasolacrimal apparatus.
• Then it continues to the infraorbital margin medial to the infraorbital nerve and extends to the alveolar bone posterior to the second premolar.
• A flap in the posterior buccal area is raised.
• The osteotomy is completed through the intra oral incision towards the pterygoid plates.

​

• Down fracture
• Mobilize and advance
• Fixation
• Bone grafts
• Take care of🡪 skin coverage, nasal lining, nasolacrimal apparatus

LE FORT III OSTEOTOMY(GILLIES, 1940)

INDICATIONS

• Naso-maxillary hypoplasia along with underdevelopment of malar bone
• Retruded midface due to trauma
• Pseudo-exophthalmos as a result of shallow orbit
• Mild hypertelorism and telecanthus

Surgical access

• Orbit and nasal root is approached by coronal incision
• Subperiosteal dissection from FZ suture to expose lateral orbital wall
• Periosteum is split vertically at nasal root and malar area
• Orbital floor is approached by separate conjunctival or subciliary incision
• Buccal vestibular incision to complete osteotomy in posterior maxillary area

Osteotomy

• Ostoetomy starts at lateral orbital wall extending to the inferior orbital fissure
• Extend through orbital floor crossing the pathway of infraorbital nerve
• Bone cut at nasal bridge links up with osteotomy in the floor behind lacrimal duct
• Osteotomy in lateral orbital wall carried downward tangentially through zygomatic bone passing below the buttress
• Pterygomaxillary dysjunction

Fixation

MANDIBULAR ORTHOGNATHIC �PROCEDURES

Classification of Osteotomies of the Mandible

Ramus osteotomies

(a) Oblique subcondylar-condylotomy.

(b) The vertical subsigmoid osteotomy through extraoral and intraoral approaches.

(c) The sagittal split and its modification

(d) The inverted L and C osteotomies of the ramus.

(e) Condylectomy

Osteotomies of the body of the mandible including the symphysis

Segmental procedures

Genioplasties

(Moore classification)

​

Ramus osteotomies

Vertical Ramus osteotomy (VRO)

• Used for setback for horizontal mandibular excess or to be rotated for mandibular asymmetry.

​

​

Extra-oral approach:

• 5cm incision made 2cm below Angle and inferior border of mandible. Used for large mandibular setbacks of greater than 10mm and difficult asymmetries.
• Skin🡪 CT tissue🡪 platysma🡪 superficial layer of the deep cervical facia (identify and secure MMN)🡪 masseter🡪 periosteum
• Release medial pterygoid
• The cut is carried through the medial cortex, starting in the middle of the ramus. It is carried superiorly to the sigmoid notch and then finished at the inferior border.

​

​

Intra-oral approach

​

• It is made in the mucosa from midway up the anterior border of the ramus to the first molar area.

​

​

• Advantages: No scar, No facial nerve injury

​

Bilateral Sagittal Split Osteotomy

​

​

• The sagittal split ramus osteotomy was first introduced by Schuchardt in 1942.
• The current technique was refined and popularized by Trauner & Obwegeser in 1957.

​

​

Modifications

• 1961 – DALPONT-changed lateral corticotomy from horizontal to vertical

​

• 1968 – HUNSUCK- terminated medial corticotomy just posterior to mandibular foramina

​

• use of internal rigid fixation - SPIESSL

Incision

• Starting superiorly, two-thirds up the anterior border of the ramus, an incision is made through mucosa

​

​

​

​

• The incision is carried inferiorly, Lateral to the external oblique ridge to the area of the second molar

​

​

​

​

• The incision is made more lateral into the vestibule to the distal first molar.

​

• Subperiosteal dissection is carried out
• Expose the external oblique ridge
• A coronoid notched retactor is used to retact superiorly – till the tip of the coronoid
• The exposure should be limited posteriorly to maximize the blood supply to the proximal fragment
• Strip stylomandibular ligament and the medial pterygoid muscle

• Medial cortex of ramus—just superiorly and posteriorly to lingula, to anterior border of ramus
• External oblique ridge – along anterior border of ramus, medial to external oblique ridge then forward to about second molar region.
• Vertical cut—Lateral cortex of the body down to and through lower border of the mandible.

Osteotomy

• Nerve should be with distal segment
• If the nerve is encountered it is carefully separated from the proximal (lateral) fragment.
• Ensure freedom of movement between the two fragments.
• Similarly its carried out on the other side

​

​

​

A portion of the lateral cortex of bone will need to be removed to allow posterior positioning.

​

• Mobilise the segment🡪 occlusal splint🡪 IMF

​

​

• A mini bone plate is used to rigidly fix the mesial and distal segments.
• Usually a 2 - 2.5mm 4-hole with gap mini plates and 2-2.5 x 6-8mm screws are used.
• Lag screws

​

Complications

Condylar position

Malocclusion

Unfavorable splits

Relapse

Nerve injury

TMJ dysfunction and hypomobility

Hemorrhage

​

Condylar positioning devices

Malocclusion

• Open bite
• Lateral shift

​

Unfavorable splits

Proximal segment fractures

1. Small proximal fragment

2. Large proximal fragment

Distal segment fractures

1. Splits short of the lingula

2. Medial splits up the condyle

3. Distal segment splits (Behind the second molar)

Incidence- 3% - 20%

​

Proximal segment fractures

Causes

​

• Failure to cut the inferior border prior to applying chisel.
• Impacted 3^rd molars

​

​

Management

​

re-stabilise the fragments

bi-cortical screws can be used percutaneously.

free segment 🡪 residual proximal segment 🡪 distal segment.

​

Distal Segment Fractures - causes

Splits Short of the Lingula

failure to en­sure that the bone cut dips into the fossa behind the lingula

​

Medial splits up the condyle

Caused by starting the medial bone cut several milli­meters superior to the lingula or angling the cut in an oblique fashion toward the condylar neck

​

Distal segment splits (Behind the second molar)

This fracture is most frequently associated with retained third molars

Excessive prying of the segments along the ascending ramus before the lateral cut is ensured

Difficult to manage

​

Relapse

- Expected with mandibular advancements greater than 7 mm

- Prevention: suprahyoid myotomies and orthodontic overcorrection.

Nerve injury

• Paresthesia of the lower lip is the most common immediate postoperative finding following a BSSO
• Majority are neurapraxias
• Neurapraxic injuries may be secondary to stretch or compression as the mandible is mobilized and fixed in its new position
• When a transec­tion occurs, immediate repair of the nerve is recommended

​

​

​

​

​

​

​

​

TMJ dysfunction and hypomobility

• Incidence between 20% and 25%
• Frequent symptoms were pain and clicking

​

​

​

• Hypomobility reasons🡪post op MMF , intraarticular hemorrhage, fibrosis, and preexisting temporomandibular joint disorders.
• Physical rehabilitation necessary🡪 return to preoperative interincisal opening within 3 months.

​

​

​

Hemorrhage

• Intraoperative life-threatening hemorrhage is a rare complication during a BSSO
• Pressure packings and ligation

​

​

Other ramus osteotomies

• Variation of the vertical subcondylar osteotomy was suggested by Wassmund in 1927 which is similar to what is now called the inverted L-osteotomy.

​

• Caldwell and colleagues modified the inverted L by adding a horizontal cut just above the inferior border of the mandible to create what is now called the C-osteotomy.

BODY Osteotomies

• The mandibular body osteotomy, first described extraorally by Blair 19078, is now mainly an intraoral procedure.

​

• This approach is indicated in cases which may require-
• mandibular setback
• anterior open bite closure
• curve of Spee reduction
• progenia correction
• mandibular advancement

Anterior Body Osteotomy

INDICATION:

• Mandibular prognathism with functional posterior occlusion
• Class III malocculsion with or without anterior open bite

​

Posterior body Osteotomy

INDICATION

​

• Class III deformity
• For correction of Cross Bite
• Anterior open bite
• Mandibular dental arch asymmetry

​

Procedure�

• Extraction of the first premolars.
• Transoral circumvestibular incision
• Release periosteum
• Incision is made distal to the 2^nd PM
• Expose subapical area
• The horizontal osteotomy ends about 2–3 mm anteriorly to the mental foramen.
• The vertical osteotomies are preferably positioned at the extraction sites. Horizontal osteotomy connected with two vertical osteotomies at the extracted first premolars.
• Downfracture and separate
• reposition the anterior segment posteriorly
• reposition the anterior segment upwards to close an anterior open bite
• Bone graft in the gap

Total Mandibular Body Osteotomy�

• Incision: Begins on the external oblique ridge of the base of vertical ramus. The incision is carried down to bone and extends forward where it meets the contralateral incision at the midline.
• Vertical cut posterior to the terminal molar is made first and carried down to the level of planned horizontal osteotomy.
• Horizontal cut made at a safe distance from root apices.

Anterior sub apical osteotomy

Indications

• Correction of Dentofacial deformities
• Nonskeletal open bite
• Bi-max protrusion
• Level the plane of occlusion
• Uprighting the anterior teeth

Procedure

• Incision- vestibular, bicuspids B/L.

​

• Dissection carried out along the inf border until mental neurovascular bundle.

​

• If the vertical cut is proximal to mental foramen, it is necessary to reposition & retract mental nerve.

​

• After completing vertical cut, a horizontal cut is connected to the vertical cuts which is 5mm below the apices of the roots

​

• A surgical splint should be used to guide the segment into the predetermined position without disturbing the lingual soft tissues

​

• Segment is secured by transosseous wire or semi-rigid fixation

Kole’s Procedure:

• Anterior subapical osteotomy with bone graft placed after harvesting from symphysis region to stabilize the gap caused by superior repositioning of the osteotomy segment.

​

​

• Indicated for anterior open bite

Helps prevent long face appearance due to lengthening of lower third of face .

Posterior Subapical Osteotomy

​

Indications

​

• Correction of supraeruption of mandibular posterior teeth or ankylosis of the posterior teeth
• Uprighting the posterior segment
• Closing posterior tooth space

​

Procedure �

Incision

• Transoral
• From anterior border of the vertical ramus to cuspid region
• 3 to 4mm below to the attached gingiva
• Around the margins of the teeth with starts one tooth behind the proposed osteotomy anteriorly and posteriorly.

Osteotomies

• Horizontal cut subapical 5mm🡪 only through buccal cortex
• Vertical Cuts b/w 1^st molar and 2^nd PM🡪 through both cortices
• Reposition the posterior segment

​

Genioplasties�

• Correction of a chin deficiency in three different dimensions🡪 vertical, transverse, and sagittal
• Augmentation, reduction, straightening, lengthening

​

Types

• Sliding horizontal osteotomy
• Double horizontal osteotomy
• Hinge sliding osteotomy
• Oblique osteotomy for advancement
• Jumping genioplasty
• Wedge osteotomy
• Propeller genioplasty
• Triple osteotomy
• Quadruple osteotomy
• Genioplasty using grafts or implants

Procedure

Genioplasty for OSA

References

• Principles of oral & maxillofacial surgery Peterson- 3 rd edition
• Surgical Orthodontic Treatment William R Proffit
• Orthognathic surgery Fonseca Vol 2
• Orthognathic surgery Reynecke
• Principles of oral & maxillofacial surgery Peterward booth
• Textbook of oral & maxillofacial surgery Nilima Anil Mallick