Vol. 4, Issue 1, Part B (2018)

Abstract: Our study aimed to define the available native bone dimensions and safe limits for implant placement in the mandibular inter-foraminal region using CBCT imaging. 100 CBCT scans were evaluated for bone dimensions, anterior loop of the inferior alveolar nerve, the lingual foramina and canals. Mean bone height was 20.34±3.3mm. Range: 13.69-26.98mm. Mean unilateral ridge length was 19.44±1.8mm. Midline lingual foramina showed a 99% prevalence-single canal in 41 cases, 2 canals in 53 cases, 3 canals in 5 cases. The bucco-lingual width traversed by the lingual canal from lingual cortex was upto the middle third in the majority of cases (77%). The anterior loop was present in 45% of the population: bilaterally in 30% and unilaterally in 15%.The mean anterior extent was 2.68±0.8 mm and range was 1.01 to 4.36mm. So keeping a standard reference level of 6 mm of crestal bone width, majority of cases showed a possibility to place implants upto 15 mm in length in the inter-foraminal region. The implant osteotomy could be positioned far enough buccally to avoid lingual vessel trauma. A safe zone of 3.5-4 mm anterior to the mesial border of the mental foramen should be maintained to account for the presence of an anterior loop.