What are the concepts, steps, tricks, and complications of a two-piece segmental Le Fort 1 (Lefort 1, a type of osteotomy) osteotomy?

Two-Piece Segmental Le Fort I Osteotomy: Concepts, Steps, Tricks, and Complications

A two-piece segmental Le Fort I osteotomy is a complex but effective surgical procedure for correcting maxillary deformities that require both vertical and transverse correction, with careful surgical technique and proper patient selection being critical for successful outcomes and minimizing complications.

Concept and Indications

The two-piece segmental Le Fort I osteotomy is a modification of the standard Le Fort I procedure that allows for correction of transverse discrepancies in addition to vertical and anteroposterior movements. This technique is particularly useful in cases where:

• Transverse maxillary deficiency exists alongside other maxillary deformities
• Differential movement of maxillary segments is required
• Correction of an asymmetric occlusal plane is needed
• Management of dental arch discrepancies that cannot be addressed with orthodontics alone

Surgical Steps

Preoperative Planning

1. Comprehensive cephalometric analysis and dental model surgery
2. Virtual surgical planning with 3D imaging when available
3. Fabrication of surgical splints to guide the desired occlusion

Surgical Technique

1. Standard Le Fort I Approach:

   • Horizontal vestibular incision from first molar to contralateral first molar
   • Subperiosteal dissection to expose the anterior maxilla, piriform aperture, and zygomatic buttresses

2. Osteotomy Design:

   • Standard horizontal osteotomy from piriform aperture to pterygomaxillary junction
   • Pterygomaxillary disjunction with curved osteotome
   • Nasal septum and vomer separation

3. Maxillary Downfracture:

   • Complete mobilization of the maxilla with Rowe disimpaction forceps
   • Removal of posterior interferences if necessary

4. Segmentation:

   • Vertical interdental osteotomy between the central incisors or at another planned location
   • Protection of palatal mucosa with a malleable retractor
   • Completion of the segmentation with fine osteotomes
   • Preservation of blood supply to segments by maintaining palatal soft tissue attachments

5. Positioning and Fixation:

   • Placement of intermediate splint for proper occlusal relationship
   • Positioning of segments according to surgical plan
   • Fixation with miniplates and screws at piriform aperture and zygomatic buttresses
   • Additional fixation between segments if needed

6. Closure:

   • Alar base cinch suture to prevent nasal widening
   • V-Y closure of the vestibular incision

Surgical Tricks and Technical Pearls

1. Preservation of Blood Supply:

   • Maintain palatal soft tissue attachments to preserve vascularity to segments
   • Avoid excessive stripping of periosteum

2. Segment Stabilization:

   • Use interdental wiring or temporary mini-screws to stabilize segments before final fixation
   • Consider "figure 8" sutures to stabilize adjacent cartilage segments 1

3. Prevention of Segment Displacement:

   • Use surgical splints meticulously to guide proper positioning
   • Consider additional fixation between segments with small plates or mesh

4. Management of Nasal Septum:

   • Carefully separate the septum from the maxilla to prevent deviation
   • Consider septal repositioning if deviation is present 1

5. Bone Grafting:

   • Consider bone grafting at the segmentation site if the gap exceeds 3mm
   • Autogenous bone or bone substitutes can be used

Complications

The overall complication rate for Le Fort I osteotomies is approximately 6.4%, with specific considerations for segmental procedures 2.

Intraoperative Complications

1. Hemorrhage (1.1%):

   • Bleeding from descending palatine artery is the most common source
   • May require ligation or packing with hemostatic agents
   • Severe cases may require blood transfusion 3, 2

2. Bad Fracture Patterns:

   • Unfavorable fractures during segmentation
   • Damage to adjacent tooth roots (reported in 5 studies) 4
   • Management: careful osteotomy design and execution

Early Postoperative Complications

1. Infection (32.62%):

   • Most prevalent complication in segmental Le Fort I 4
   • Management: appropriate antibiotic therapy and drainage if necessary

2. Oral Fistula:

   • Reported in 6 studies as a frequent complication 4
   • Management: local wound care and possible surgical closure

3. Vascular Compromise:

   • Aseptic necrosis of alveolar process (0.2%)
   • Gingival retraction (0.8%) 2
   • Management: careful preservation of blood supply during surgery

Late Postoperative Complications

1. Stability Issues:

   • Segmental Le Fort I provides stable outcomes in the sagittal plane
   • Less stable dentally than skeletally in the transverse plane
   • Limited stability in posterior segment after downward movement 4
   • Only about 50% of three-piece osteotomies achieve the target position within 2mm 5

2. Non-union (1.0%):

   • Failure of bone healing at osteotomy sites 2
   • Management: revision surgery with bone grafting

3. Nasal Septum Deviation (1.6%):

   • Can cause functional and aesthetic issues 2
   • Management: septoplasty if symptomatic

4. Dental Complications:

   • Pulp necrosis of adjacent teeth
   • Root resorption
   • Management: endodontic therapy or extraction if necessary

Risk Factors for Complications

1. Anatomical Irregularities:

   • Patients with craniofacial dysplasias, orofacial clefts, or vascular anomalies have enhanced risk 2
   • Careful preoperative planning is essential in these cases

2. Extent of Surgical Movement:

   • Extensive dislocations or transverse segmentation increase risk of ischemic complications 2
   • Maxillary setback with impaction has the highest complication rate (36.4%) 3

3. Surgical Technique:

   • Inadequate preservation of blood supply
   • Excessive tension on segments
   • Improper fixation

Conclusion

The two-piece segmental Le Fort I osteotomy is a valuable technique for addressing complex maxillary deformities requiring both vertical and transverse correction. While it carries specific risks compared to conventional Le Fort I procedures, careful surgical technique and proper patient selection can lead to successful outcomes with acceptable complication rates. The procedure provides stable results in the sagittal plane but may have limitations in achieving and maintaining the target position in complex three-dimensional movements 5, 4.