Effects of mandibular setback surgery using the surgery-first approach versus conventional orthognathic approach on...

To compare the effects of mandibular setback surgery on the upper airway and sleep quality using two approaches: the surgery-first approach (SFA) and the conventional orthognathic approach (COA).

A prospective, comparative clinical study was conducted in 20 patients, with 10 in each group undergoing isolated mandibular setback surgery. Three-dimensional upper airway analysis using cone-beam computed tomography and sleep quality assessments through questionnaires and sleep studies were performed preoperatively (T0), within 1 month postoperatively (T1), and six months postoperatively (T2).

The SFA group demonstrated greater mandibular setback and rotational changes compared to the COA group. Both groups exhibited postoperative reductions in airway volume and minimum cross-sectional area, with no significant intergroup differences. Significant differences in the change in airway length in the upper airway segment (0.9 ± 1.0 mm for SFA vs. -1.2 ± 3.4 mm for COA, P = 0.002) and total airway length (3.3 ± 1.8 mm for SFA vs. -0.1 ± 2.3 mm for COA, P < 0.001) were observed at T2 compared to the preoperative period. Subjective and objective sleep parameters were comparable between the groups. Objective sleep quality initially worsened but improved over time.

Isolated mandibular setback surgery, whether performed using SFA or COA, resulted in comparable changes in upper airway dimensions and sleep quality.

The choice between SFA and COA for isolated mandibular setback surgery does not significantly influence surgical decision-making regarding upper airway changes and sleep quality.