Residency · Residency · Oral Maxillofacial Surgery
Orthognathic Surgery in the Cleft Patient
Introduction
Maxillary hypoplasia is the most common skeletal deformity in patients with cleft lip and palate, occurring in approximately 25 to 60% of cleft patients. This deficiency results from a combination of intrinsic growth disturbance and the scarring effects of prior surgical repairs. Orthognathic surgery addresses the functional and aesthetic consequences of this skeletal discrepancy and represents the final major reconstructive milestone for many cleft patients.
Etiology of Maxillary Hypoplasia in Cleft Patients
Intrinsic growth deficiency reflects mesenchymal deficiency in the cleft-affected maxilla. Iatrogenic scarring from palatal scar tissue after primary palatoplasty restricts anterior and lateral maxillary growth. Deficient bone stock from residual alveolar cleft or failed bone graft limits skeletal support. Sagittal, vertical, and transverse maxillary deficiency may all be present. The mandible is typically normal in size, creating a pseudo-Class III skeletal relationship.
Preoperative Assessment
Clinical Evaluation
Full facial analysis includes profile, symmetry, lip posture, nasal projection, and chin position. Dental evaluation assesses occlusion, missing teeth, dental compensations, and dental health. Speech assessment evaluates velopharyngeal function, as maxillary advancement may worsen velopharyngeal insufficiency (VPI). Airway assessment is important because cleft patients may have pre-existing airway compromise. Psychosocial assessment addresses patient expectations and readiness for surgery.
Imaging
A lateral cephalogram provides skeletal analysis (SNA, SNB, ANB, maxillary-mandibular plane angle). CBCT offers 3D evaluation of skeletal deficiency, airway dimensions, condylar morphology, and residual cleft defects. A posteroanterior cephalogram assesses transverse discrepancy and facial asymmetry. Virtual surgical planning (VSP) is increasingly used for precise planning of movements and splint fabrication.
Orthodontic Preparation
Presurgical orthodontics typically spans 18 to 24 months to decompensate dental alignment. Dental compensations are corrected, including proclined upper incisors and retroclined lower incisors. Arch forms are coordinated and arches leveled for optimal surgical occlusion. Missing teeth are addressed with space management (closing gaps or maintaining space for prosthetics). Adequate alveolar bone graft maturity is ensured before surgery.
Surgical Options
Le Fort I Osteotomy
The Le Fort I osteotomy is the primary procedure for maxillary hypoplasia in cleft patients. It allows advancement, inferior repositioning, and correction of cant and transverse width. Typical advancement is 4 to 10 mm, which is greater than in standard orthognathic cases. Large advancements (greater than 6-8 mm) have higher relapse rates in cleft patients due to scar tissue resistance. Down-fracture is more difficult because of scar adhesions, requiring careful dissection of palatal scar tissue. Interpositional bone grafts may be required for large advancements to prevent relapse.
Segmental Le Fort I
A segmental Le Fort I is indicated for significant transverse discrepancy or residual alveolar cleft. It allows differential movement of maxillary segments but carries increased risk of devascularization of segments, so the palatal soft tissue pedicle must be preserved. It may be combined with simultaneous alveolar bone grafting.
Bilateral Sagittal Split Osteotomy (BSSO)
Mandibular setback may be considered as an adjunct when maxillary advancement alone is insufficient. It should be avoided if possible to preserve mandibular projection and airway volume. It is indicated for true mandibular prognathism, which is uncommon in cleft patients.
Genioplasty
Advancement genioplasty enhances chin projection and soft tissue profile. It may be performed simultaneously with Le Fort I for optimal aesthetic result.
Distraction Osteogenesis
Distraction osteogenesis is an alternative to conventional Le Fort I for large maxillary advancements (greater than 8-10 mm). Its advantages include gradual distraction of the soft tissue envelope, which reduces relapse, and generation of new bone. Disadvantages include the external device, compliance challenges, longer treatment time, and difficulty with vector control. Internal distraction devices such as the RED system improve compliance but require secondary removal.
Comparison: Le Fort I Advancement vs. Distraction Osteogenesis in Cleft Patients
| Parameter | Conventional Le Fort I | Distraction Osteogenesis |
|---|---|---|
| Ideal advancement | ≤8 mm | >8-10 mm |
| Relapse rate | 20-30% for large advancements | Lower (gradual tissue adaptation) |
| VPI risk | Higher with >10 mm advancement | Lower (gradual soft tissue stretch) |
| Treatment duration | Single stage + 6-8 weeks healing | 7-14 days latency + 1 mm/day distraction + 8-12 weeks consolidation |
| Patient compliance | Standard postoperative | Device management required; higher burden |
| Vector control | Precise with rigid fixation | Difficult; may require revision |
| Bone grafting | Often required for stability | Not required (regenerate bone) |
| Secondary surgery | Rarely needed | Device removal required |
Special Considerations
Velopharyngeal Insufficiency
Maxillary advancement increases the distance between the soft palate and posterior pharyngeal wall. Advancement of greater than 10 mm significantly increases the risk of VPI. Preoperative nasendoscopy and videofluoroscopy should evaluate velopharyngeal closure. If marginal preoperative VPI exists, concurrent or staged pharyngoplasty should be planned. Distraction osteogenesis may reduce VPI risk compared to single-stage advancement.
Scarring and Soft Tissue
Palatal and labial scar tissue creates significant resistance to maxillary advancement. Scar release during down-fracture improves mobilization. Interpositional bone graft and rigid fixation are essential to resist scar contracture forces. Soft tissue advancement may not fully match skeletal advancement, particularly at the upper lip.
Dental and Prosthetic Planning
Missing lateral incisors are common, and planning should address implant placement, canine substitution, or prosthetic replacement. Coordination with the prosthodontist ensures definitive dental rehabilitation. Implant placement is typically deferred until 6 months after orthognathic surgery when bone is stable.
Stability and Fixation
Rigid internal fixation with titanium plates and screws is standard. Cleft patients have higher relapse rates than non-cleft orthognathic patients, up to 20 to 30% for large advancements. Bone grafting of the cleft site and osteotomy gaps improves stability. Overcorrection of 1 to 2 mm may compensate for anticipated relapse. Postoperative orthodontics and elastics are maintained for 6 to 12 months.
Postoperative Management
The standard orthognathic postoperative protocol includes a soft diet for 6 to 8 weeks, jaw exercises, and oral hygiene. VPI is monitored with speech evaluation at 3 to 6 months postoperatively. Serial cephalometric analysis assesses stability at 6 weeks, 6 months, and 1 year. Orthodontic treatment resumes at 4 to 6 weeks for final detailing. Psychological support and patient satisfaction assessment are integral components.
Complications
Relapse is the most common complication and is managed with overcorrection, rigid fixation, and bone grafting. VPI may require secondary pharyngoplasty or a speech prosthesis. Avascular necrosis may occur to maxillary segments if palatal blood supply is compromised. Plate infection occurs in 3 to 5% of cases and may require hardware removal. Infraorbital nerve hypoesthesia is usually temporary. Unfavorable aesthetic outcome may require revision surgery or rhinoplasty.
Clinical Pearls
Velopharyngeal function must be assessed preoperatively, as maxillary advancement of greater than 10 mm significantly increases VPI risk. Distraction osteogenesis is preferred when advancement exceeds 8 to 10 mm due to improved stability and reduced VPI risk. Cleft patients have higher relapse rates than non-cleft patients, so overcorrection and rigid fixation are essential. Virtual surgical planning significantly improves accuracy and reduces operative time in complex cleft orthognathic cases. Coordination with the full cleft team (orthodontist, speech pathologist, prosthodontist) is critical for optimal outcomes.
References
- Posnick JC. Orthognathic Surgery: Principles and Practice. 2nd ed. Elsevier; 2022.
- Good PM, et al. "Stability of Le Fort I Advancement in Cleft Lip and Palate Patients." International Journal of Oral and Maxillofacial Surgery. 2020;49(12):1545-1553.
- Cheung LK, Chua HDP. "A Meta-Analysis of Cleft Maxillary Osteotomy and Distraction Osteogenesis." International Journal of Oral and Maxillofacial Surgery. 2006;35(1):14-24.
- Scolozzi P. "Distraction Osteogenesis in the Management of Cleft Maxillary Hypoplasia." Clinics in Plastic Surgery. 2019;46(2):181-191.