What factors affect the attachment of the inferior alveolar nerve to the buccal plate following sagittal split osteotomy?

Purpose: This study aimed to assess the factors that can possibly affect the positioning of the inferior alveolar nerve (IAN) in the proximal or distal segment following sagittal split osteotomy (SSO). Materials and methods: This was a prospective cohort study. The patients were assigned according to the position of the IAN: the IAN was attached to the buccal plate in group 1 (27 SSOs), while it was in the distal segment in group 2 (83 SSOs). Results: The mean of the buccolingual thickness of the proximal segment at the vertical cut of the osteotomy (BLTP) was 5.0 +/- 0.62 mm in group 1 and 4.16 +/- 0.72 mm in group 2. The mean of the distance between the IAN and the external cortical bone at the distal of the second molar before the osteotomy (IANB) was 0.5 +/- 0.24 mm in group 1 and 1.24 +/- 0.45 mm in group 2. There were significant differences for the mean BLTP and IANB between the two groups (P = 0.001). Conclusion: It seems that the thickness of the buccal plate of the proximal segment, the distance from the IAN to the external cortical bone, the osteotomy technique, and the presence or absence of impacted third molars may be associated with the positioning of the IAN following SSO. (C) 2020 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.