Summary of Orthognathic Surgery for Craniofacial Deformities

## Introduction Orthognathic surgery addresses the surgical correction of jaw discrepancies and associated skeletal abnormalities that affect both facial function and aesthetics. This material outlines the general principles of planning and fundamental procedures for commonly encountered dentofacial deformities, osteotomy techniques, and the principles of guided bone growth (distraction osteogenesis), including outcomes and potential complications. > Definition: Orthognathic surgery is a surgical discipline focused on the correction of skeletal and dental abnormalities of the jaws to restore proper function of biting, breathing, speech, and aesthetic appearance. ## Core Problem Areas - Skeletal Class II (Mandibular Retrognathia) - Skeletal Class III (Prognathism versus Maxillary Deficiency) - Transverse Deficiencies (Maxillary Constriction) - Specific Techniques: Le Fort I Osteotomy, Sagittal Split Osteotomy of the Mandible, Distraction Osteogenesis (DO) ### Skeletal Class II (Mandibular Retrognathia) - Examples of Etiologies: Syndromes such as Treacher–Collins, Stickler Syndrome, Pierre Robin. - Primary Treatment: **Mandibular Advancement** (if the primary cause is in the mandible). - Options: - Isolated mandibular advancement. - Bimaxillary advancement, if the maxilla is also deficient or for improved soft tissue definition in adults. - Orthodontic correction without surgery, if malocclusion is minimal and dental compensation is absent. - Practical Example: A patient with a small mandible and minimal dental compensation may benefit from surgical advancement to improve profile and function. > Definition: Dental compensation means that teeth are tilted or shifted to partially mask a skeletal discrepancy; after orthodontic decompensation, the skeletal disproportion may become evident. ### Skeletal Class III (Mandibular Prognathism or Maxillary Deficiency) - Treatment Options: - Maxillary advancement (Le Fort I or multi-piece Le Fort I), - Posterior mandibular repositioning (setback), - Combination of procedures (bimaxillary solution) and/or genioplasty for chin correction. - Separate assessment of the mandible and chin is important: sometimes only genioplasty is needed. - As with Class II, the principle applies: minimal malocclusion without compensation can be managed orthodontically; after decompensation, surgery may be necessary. ### Maxillary Constriction (Transverse Deficiency) - In younger patients (up to approximately 15 years old), orthopedic expansion (palatal expander) is possible. - If orthopedic treatment fails or the patient is older, SARPE (surgically assisted rapid palatal expansion) can be used. - When multi-dimensional correction is needed, a **two-piece or multi-piece Le Fort I** is used for simultaneous advancement and transverse expansion. ## Le Fort I Osteotomy Technique (Basic Steps) 1. Access and Exposure: Mucoperiosteal reflection to the piriform aperture, zygomatic buttress, and posterolateral maxilla. 2. Incision and Osteotomy: Typically, a high Le Fort I osteotomy is performed horizontally from the piriform aperture to the zygomatic buttress, at least 5 mm below the infraorbital foramen. 3. Vertical Osteotomy: From the lateral edge of the horizontal osteotomy to a level approximately 5 mm above the dental root apices. 4. Lateral Nasal Walls: Cut with a uniball osteotome; avoid mucosal damage. 5. Separation of the Pterygomaxillary Junction: Using a 10 mm curved osteotome or by performing a tuberosity osteotomy behind the last molar (fewer complications, better downfracture). 6. Downfracture: Performed digitally or with Rowe disimpaction forceps. 7. Correction of Alveolar Defects: If an alveolar fistula is present, the segments can be compressed; plan this during model surgery. 8. Fixation: Surgical splint, MMF with wire ligatures, condylar seating, and rigid fixation with plates and screws. For greater vertical lengthening (>5 mm), bone grafts are inserted. 9. Specifics for Cleft Pati