Condylar Positional Changes Following Manual Proximal Segment Positioning During Bilateral Sagittal Split Ramus...

Area of Science:

• Orthognathic surgery
• Temporomandibular joint (TMJ) research
• Skeletal Class III malocclusion treatment

Background:

• Maintaining condylar position during bilateral sagittal split ramus osteotomy (BSSRO) is crucial for TMJ biomechanics and skeletal stability.
• Muscle hypotonia under anesthesia can displace condyles, complicating proximal segment repositioning.
• Limited evidence exists on manual positioning's ability to preserve the preoperative condyle-fossa relationship.

Purpose of the Study:

• To evaluate changes in the condyle-fossa relationship after BSSRO using manual proximal segment positioning.
• To assess the long-term stability of condylar position following BSSRO.
• To compare immediate postoperative condylar position with final follow-up findings.

Main Methods:

• Retrospective analysis of lateral cephalometric radiographs from 14 patients with skeletal Class III malocclusion.
• Radiographs taken preoperatively (T0), immediately postoperatively (T1), and at final follow-up (T2).
• Condylar position assessed using Cartesian coordinates, joint space measurements, and Condyle Position Index (CPI).

Main Results:

• Significant changes in CPI and anterior joint space were observed over time.
• Increased CPI and decreased anterior joint space noted between T1 and T2 (final follow-up).
• No significant immediate postoperative changes in condyle-fossa relationship were detected.

Conclusions:

• Manual positioning may offer acceptable immediate postoperative condyle-fossa stability.
• The preoperative condyle-fossa relationship may not be fully maintained long-term after BSSRO.
• Further prospective studies with clinical TMJ assessment and 3D imaging are warranted.