Safe zone in anterior mandible related to the genial tubercle for implant osteotomy in a Chinese-Malaysian population: A CBCT study

Abstract

Statement of problemThe genial tubercle is a clinically palpable landmark in the mandible and can be identified in cone beam computed tomography (CBCT). Its location can be used to measure the safe zone in the interforaminal region of the mandible. These measurements may be helpful for implant treatment planning in patients with complete edentulism. PurposeThe purpose of this clinical study was to evaluate the safe distance in the interforaminal region of the mandible measured from the genial tubercle level for implant osteotomy in a Chinese-Malaysian population. Material and methodsA total of 201 Digital Imaging and Communications in Medicine (DICOM) files were selected for the study from the CBCTs of dentate or edentulous Chinese-Malaysian adult patients with ongoing or completed treatments. Measurements were made with implant planning software. The anatomy of the whole mandible was assessed in the coronal cross-sectional, horizontal view and in panoramic view. Measurements were obtained in millimeters on one side by locating and marking a genial tubercle and then marking the mesial margin of the mental foramen and the anterior loop of the inferior alveolar nerve. The corresponding points of these landmarks were identified on the crest of the mandibular ridge to measure the linear distances. All the measurement steps were repeated on the other side. The linear distance of 2 mm was deducted from the total distance between the genial tubercle and the anterior loop separately for left and right side measurements to identify the safe zone. The mixed 2-way analysis of variance (ANOVA) test was used to analyze side and sex-related variations. ResultsThe mean safe zone measured at the crestal level from the genial tubercle site on the left side of the mandible was 21.12 mm and 21.67 mm on the right side. A statistically significant (P<.05) difference was found between the left and right sides of the safe zone measurements in both men and women. No statistically significant differences were found in the safe zone between men and women on either the left or right side (P=.655). The minimum distance from the genial tubercle to the right side safe zone in women was 12.82 mm and 14.99 mm in men; however, on the left side, the minimum distance was observed to be 14.81 mm in women and 15.54 mm in men. ConclusionsThe safe zone related to the genial tubercle was 21.12 mm on the left side and 21.67 mm on the right side, with no significant sex-related variations. Within the same individuals, a significant difference was found in the safe zone between the left and right side.