The Distance from the Coronoid Notch to the Mandibular Lingula: Is This a Safe Reference Point for Bilateral Sagittal Split Osteotomy?

Introduction: Sagittal split osteotomy is a standard procedure performed by maxillofacial surgeons. Patients usually present with either aesthetic or functional concerns. Surgical landmark identification is crucial to a successful surgical procedure. Various diagnostic preoperative tools have been used to identify these landmarks, such as imaging studies or cadaveric dissections. The cone-beam computed tomography (CBCT) is currently the most common preoperative tool used.

Aim: This study aims to identify whether the deepest part of the ascending ramus (coronoid notch) distance to the mandibular lingula can be used as a safe reference prior to performing medial horizontal osteotomies.

Materials & methods: Data were extracted from a database of patients who underwent CBCT scanning for various reasons. A total of 313 CBCT scans were included in this study. Patients younger than 18 years, with a history of mandibular pathology, or whose scans were suboptimal were excluded. Statistical analysis was performed via IBM SPSS v29 (IBM Corp., Armonk, NY, U.S.), and the predetermined p-value was < 0.05. Statistical significance was present in both the right and left measurements.

Results: A total of 313 (626 sides) CBCT were included in this study. Most patients were of the female gender, with 171 scans (54.6%) and 142 scans (45.4%) from males. Our study focused on the distance from the specific reference point, the coronoid notch (the most concave point at the ascending ramus in the retromolar area), to the anterior part of the mandibular lingula. For the total sample, the standard deviations for each side were 2.25 (p-value = < 0.001) and 2.07 (p-value = 0.003), left and right, respectively. This finding indicated that the distances on each side were statistically significant.

Conclusion: The authors suggest that the anterior aspect of the ramus can be used as a reference point for horizontal medial osteotomy, as both distances were statistically significant. This finding has important implications for the safety and efficiency of bilateral sagittal split osteotomy procedures, as it provides a reliable reference point for surgeons to use during the procedure, potentially reducing the risk of complications, surgical time, and improving patient outcomes.