Evaluation of the Lingual Splitting Patterns and the Lateral Bone Cut Ends Following Mandibular Bilateral Sagittal Split Osteotomy Using Cone Beam Computed Tomography (CBCT)

The bilateral sagittal split osteotomy (BSSO) is the most popular orthognathic procedure performed by maxillofacial surgeons to treat skeletal class II and class III and to correct mandibular asymmetries. The study aimed to evaluate the lingual splitting patterns and lateral bone cut end (LBCE) in bilateral sagittal split osteotomy (BSSO) and their relation with the ramal thickness and the presence of impacted third molars using cone beam computed tomography (CBCT). This prospective observational study included patients with mandibular prognathism who were treated with BSSO with or without Le Fort I osteotomy. Cone beam computed tomography was used to measure the ramal thickness preoperatively and to evaluate the LBCE, and the lingual splitting patterns postoperatively. Twenty-one patients (42 sides) were included in this study. The most commonly observed lingual splitting pattern was type III (47.6%), while the most common LBCE was type B (59.5%). The bad split was encountered 8 times on 42 sides (16.7%). A nonsignificant relationship between the ramal thickness and bad splitting was observed ( P =0.901). Impacted third molars were present in 16 of the 42 sides (38.1%) and had no significant effect on the occurrence of bad splitting ( P =0.063). Type III lingual splitting pattern and type B LBCE were the most commonly observed patterns. No direct association was observed concerning the presence of impacted mandibular third molars and the thickness of the ramus with the occurrence of bad splitting.