Quantitative assessment of ramal bone width and the proximity of the inferior canal for the predictable insertion of ramal implants: Cone-beam computed tomography study

Abstract

The study aimed to investigate the optimum level for the placement of ramal implants as a source of anchorage for disimpacting mandibular molars. The criteria in relation to the maximum transverse width of the ramal bone and proximity of the implant to the inferior alveolar canal (IAC) were evaluated using a three-dimensional cone-beam computed tomography scan for predictable placement of ramal implants. The cone-beam computed tomographic scans of 53 untreated patients (aged between 18 and 48 years) were utilized in this study. The maximum transverse width of the ramus and the proximity to the IAC from the site of insertion were measured at six different levels above the central groove of the mandibular first molar. To measure the proximity to the IAC, the mid-point of the maximum transverse width of the ramus was selected as the site of insertion of the implant. The maximum and minimum transverse ramal width was 12.48 ± 1.76 mm at 3 mm and 10.42 ± 2.08 mm at 8 mm above the central groove of the permanent mandibular first molar. An average clearance of 9.62 ± 2.59 mm was measured from the site of insertion to the IAC at the different levels evaluated. The ramus of the mandible can be a predictable site for implant placement provided the variations in the anatomical structures have been carefully analyzed. It can be concluded that the ramal implants can be safely placed at a level 3–8 mm above the permanent mandibular first molar in relation to the occlusal plane.