Surgical Accuracy of Maxillomandibular Clockwise Rotation Using Computer-Aided Surgical Planning in Skeletal Class III Patients.

Abstract

This retrospective study aimed to evaluate the 3-dimensional (3D) surgical accuracy by comparing the virtual movements of computer-aided surgical planning (CASP) with the outcomes of actual surgery (AS) in class III patients treated with clockwise rotation of the maxillomandibular complex. Twenty adult patients with skeletal class III malocclusion were included, all of whom received bimaxillary surgery using CASP, including LeFort I and bilateral sagittal split ramus osteotomies. The AS was performed using 3D surgical splints printed based on the CASP. Cone-beam computed tomography (CBCT) scans were taken before surgery (T0) and 1 month after surgery (T1). The virtual movements predicted by the CASP (CASP-T0) and the outcomes of AS (T1-T0) on 3D landmark coordinates were compared using paired t test or Wilcoxon signed-rank test. The maxillary landmarks at AS showed errors ranging from 0.02 to 0.68 mm compared with CASP in terms of advancement, impaction, and transverse movements. The impaction of posterior nasal spine at AS was significantly smaller than predicted by CASP (3.47 versus 4.15 mm; P<0.05). The mandibular landmarks at AS showed errors ranging from 0.06 to 1.16 mm compared with CASP in posterior, superior, and lateral movements. There was significantly less superior movement of the distal segment in AS. However, there were no changes in the condylar position and lateral ramal inclinations in AS. Application of CASP can help clinicians achieve predictable and accurate surgical outcomes.