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Background: Harvesting ramus block grafts carries a potential risk of inferior alveolar nerve (IAN) exposure or injury, particularly when the osteotomy line is positioned close to the mandibular canal. Accurate evaluation of this anatomical relationship is essential to minimize neurosensory complications. This study aimed to evaluate the osteotomy line–IAN distance using cone beam computed tomography (CBCT) to assess the potential risk of nerve exposure.

Methods: A retrospective analysis was conducted on CBCT scans of 28 patients (56 mandibular halves), aged 18–60 years. Using Rainbow 3D Viewer 1.1.0 (Dentium) and following the Misch and Khoury technique, the ramus graft outline was traced. Key parameters measured included graft length, the distance between the osteotomy line and the IAN canal (IANC), total thickness of the graft and cortical bone.

Results: The mean distance between the osteotomy line and the IANC was 3.27 ± 1.14 mm. The mean maximum graft thickness and cortical thickness were 3.89 ± 0.46 mm and 3.67 ± 0.64 mm, respectively. In three cases, direct contact between the osteotomy line and the IAN was observed.

Conclusions: Temporary neurosensory disturbances remain a potential risk when the osteotomy line approximates the IAN, despite the rarity of permanent nerve damage. CBCT is a valuable tool for evaluating anatomical relationships prior to graft harvesting.

Autograft, inferior alveolar nerve; cone-beam computed tomography; paresthesia.