Stability After Bilateral Sagittal Split Osteotomy With Rigid Internal Fixation in Surgery-First Approach

Area of Science:

• Orthodontics and Maxillofacial Surgery
• Skeletal Malocclusion Research
• Surgical Stability Studies

Background:

• Skeletal Class III malocclusion presents significant challenges in orthodontic and surgical correction.
• The surgery-first approach (SFA) is increasingly utilized for treating complex malocclusions.
• Evaluating the stability of surgical procedures is crucial for long-term treatment success.

Purpose of the Study:

• To assess the skeletal stability following bilateral sagittal split ramus osteotomy (BSSO) setback using rigid internal fixation within a surgery-first approach (SFA).
• To determine the degree of horizontal and vertical relapse after BSSO in patients with skeletal Class III malocclusion treated with SFA.

Main Methods:

• A cohort of 27 consecutive patients with skeletal Class III malocclusion underwent BSSO with SFA.
• Lateral cephalograms were acquired pre-surgically and at 1 and 6 months post-surgery.
• Cephalometric analyses were performed using repeated-measures ANOVA to compare skeletal changes.

Main Results:

• No significant horizontal anteroposterior changes were observed for the pogonion (0.9 mm) and B point (0.6 mm) during the postsurgical period.
• The pogonion showed a minor superior movement post-surgery (2.4 mm) with minimal subsequent change (0.6 mm).
• The B point exhibited superior movement post-surgery (2.3 mm) and during the postsurgical period (1.2 mm), with a slight labial inclination of lower incisors (2.4°).

Conclusions:

• Bilateral sagittal split ramus osteotomy (BSSO) with rigid fixation in a surgery-first approach (SFA) demonstrates excellent horizontal stability, with minimal relapse (<1 mm).
• Vertical skeletal stability is generally maintained, with the exception of a 1.2 mm superior displacement of the B point.
• BSSO using SFA is an effective and predictable surgical method for managing skeletal Class III malocclusion.