Evaluation of the Breakage Process of Absorbable Plates After Bilateral Sagittal Split Ramus Osteotomy Using 3-Dimensional Computed Tomography.

Abstract

Introduction: This study aimed to evaluate the association between maxillofacial morphology and absorbable plate breakage in patients undergoing bilateral sagittal split ramus osteotomy (BSSO).

Materials and methods: A total of 67 patients (134 sides) underwent BSSO with absorbable plate and screw fixation. Maxillofacial morphologic factors were measured by using 3-dimensional (3D) computed tomography (CT) and posteroanterior and lateral cephalograms. Plate and screw coordinates, buccolingual distance between the proximal and distal mandibular segments, condylar angle, and the angles between the proximal and distal mandibular segments and the line connecting the left and right external auditory foramina were measured using 3D CT. Plate breakage was determined using 3D CT images that were taken 1 year postoperatively. Occlusal force was measured preoperatively and 1 year postoperatively.

Results: The χ2 test showed that breakages were significantly more frequent in the class III group than in the class II group. The stepwise multiple regression analysis of plate breakage in 67 patients with classes II and III relation showed that the buccolingual distance between the proximal and distal mandibular segments, setback amount, and overjet were associated with plate breakage.

Discussion: These findings suggest that regardless of the skeletal relation or occlusal force, a greater buccolingual distance between the proximal and distal segments immediately after surgery tends to increase the risk of absorbable plate breakage in patients undergoing bilateral sagittal split osteotomy.