Horizontal changes in the condylar head after sagittal split ramus osteotomy with bent plate fixation

Area of Science:

• Oral and Maxillofacial Surgery
• Orthognathic Surgery
• Biomedical Engineering

Background:

• Mandibular prognathism requires surgical correction, often involving sagittal split ramus osteotomy (SSRO).
• Maintaining condylar head position post-SSRO is crucial for functional and aesthetic outcomes.
• The use of bent plate fixation is a common method for stabilizing osteotomy segments.

Purpose of the Study:

• To evaluate horizontal changes in the condylar head after SSRO.
• To compare outcomes of SSRO alone versus SSRO combined with Le Fort I osteotomy.
• To assess the impact of bent plate fixation on condylar position.

Main Methods:

• 47 Japanese patients with mandibular prognathism were studied.
• 24 patients underwent SSRO, and 23 underwent SSRO with Le Fort I osteotomy.
• Computerized tomography (CT) assessed condylar long axis angle and displacement pre- and postoperatively.

Main Results:

• No significant difference in mandibular length reduction between the two surgical groups.
• No significant pre- to postoperative horizontal changes in condylar head angle or displacement.
• Proximal segment length was significantly shorter in the combined SSRO and Le Fort I group.

Conclusions:

• Bent plate fixation for SSRO does not significantly alter preoperative condylar angle or position.
• The addition of Le Fort I osteotomy does not negatively impact condylar head stability with bent plate fixation.
• This fixation method provides stable results in setback surgery for mandibular prognathism.