Location of the mandibular lingula: Comparison of skeletal Class I and Class III patients in relation to ramus osteotomy using cone-beam computed tomography

Introduction: The aim of the study was to analyze the anatomic location differences of the mandibular lingula (ML) between dentoskeletal Class I and Class III patients, also between genders to obtain information that could be useful for sagittal split ramus osteotomy (SSRO) and other interventions in mandibular ramus. Methods: This study was conducted on cone-beam computed tomography (CBCT) images of 30 skeletal Class I (16 males and 14 females) patients aged between 18 to 37 years and 30 skeletal Class III (14 males and 16 females) patients aged 18 to 36 years. Results: Statistically, the mean distance of the ML from the occlusal plane in skeletal Class III patients (9.91 +/- 3.16 mm) was found to be greater than Class I patients (8.12 +/- 2.95 mm). The mean distance between the posterior border of ramus and the ML was found to be statistically lower (15.82 +/- 1.80 mm) compared to Class I patients (16.55 +/- 1.67 mm) but the mean distance from the anterior ramus was not found statistically significant. In both groups, the mean distance between the ML and posterior ramus was statistically greater in males. The mean distance from mandibular notch to ML was significantly greater in Class III patients (18.73 +/- 2.89 mm) compared to Class I patients (17.70 +/- 2.65 mm) (P < 0.05). The most commonly encountered shape was the nodular type in both groups. The second most common type was truncated in Class I patients and triangular in Class III patients. Conclusions: The ML is an important landmark for mandibular ramus surgery and inferior alveolar nerve block (IANB). The anatomic data provided by this study may help surgeons to reduce complications when performing mandibular ramus osteotomies and dentists to increase the success rates of IANB. (C) 2019 Elsevier Masson SAS. All rights reserved.