Change of TMJ Space Volume After Mandibular Setback Surgery With Intended Manual Condylar Positioning.

PURPOSE

Temporal mandibular joint (TMJ) space volume is pivotal in upholding optimal joint function and occlusal stability. Mandibular setback surgery can impact TMJ space volume due to condylar positioning adjustments. This study aims to investigate the changes in TMJ space volume following mandibular setback surgery with intended manual condylar positioning.

METHODS

This is a retrospective study of 20 patients of class III (skeletal), who underwent Le Fort I osteotomy and BSSO surgery at the OMFS Department of PNUDH between 2015 and 2022 by one surgeon. CBCT scans were obtained preoperatively (T0) and at specified postoperative time points (T1) and (T2). The groups were categorized into group A (Total space volume), group B (non-asymmetric), and group C (asymmetric). TMJ space volume measurements were taken using CBCT imaging software. Each slice of the TMJ space was drawn manually using specialized software. The measured areas in each slice were added to determine the TMJ volumes, and the statistical analysis was done.

RESULTS

Preliminary findings from this study indicate that there was a highly significant difference in TMJ space volume between group A, group B, and group C at T0, T1, and T2 following surgery. However, there were no significant differences within the groups, which means that the intended manual condylar positioning gives stability to the TMJ joint space.

CONCLUSIONS

This study suggests that mandibular setback surgery with intended manual condylar positioning can lead to transient changes in TMJ space volume, with subsequent recovery and adaptation.