Short-term and long-term alterations of condylar position after bilateral sagittal split ramus osteotomy for mandibular setback: A preliminary before-after clinical trial.

Background: Because of the importance of the condyle, it is crucial to document all changes in its position after orthognathic surgery. Since previous studies in this regard are mostly controversial and limited by two-dimensional radiography technique, this study was conducted.

Materials and Methods: This prospective clinical trial was performed on 102 measurements (17 patients, 2 condyles each, and 3 time points). Cone-beam computerized tomography imaging was done for 17 skeletal Class-III patients (10 females and 7 males, mean age, 24.05 ± 4.78 years) undergoing fixed orthodontic treatment, at three time points T0 (before surgery), T1 (immediately after surgery), and T2 (8 months after surgery). Condylar positions were measured. Position changes were evaluated during the course of the study. They were also compared between right/left sides and between men and women. Tests in use were repeated-measures one- and two-way analysis of variance and paired t -tests (α =0.05, α =0.017).

Results: Alterations in various anatomical condyle parameters over the 8-month course of the study did not reach the level of significance ( P ≥ 0.078). At all intervals, mean anterior-posterior index (API) remained between -12 and +12 (indicative of central position of the condyle in the glenoid fossa). Between men and women, left superior joint space, left anterior joint space, and left API differed ( P ≤ 0.05). Left condyle mean superior joint space and anterior joint space were greater in men compared to women in all the three intervals; left condyle mean API was greater in women compared to men (more posterior in men, P ≤ 0.05).

Conclusion: Condyles might not change significantly after 8 months post-surgery. However, small changes might be observed, and these changes might differ between the left and right sides and between males and females.