Bucco-lingual Orientation of the Inferior Alveolar Nerve as Adjunct Information for Implant Planning Amongst the Three Ethnicities of Malaysians

Background: Information on bucco-lingual orientation of the inferior alveolar nerve (IAN) can reduce the risk of iatrogenic injury to the nerve during implant placement, especially in settings where CBCT is not available. Objectives: To determine the bucco-lingual orientation of the IAN and the buccal and lingual bone width at the canal level in molar regions amongst the 3 ethnicities (Malay, Chinese, Indian) of Malaysians. Methods: 105 CBCT-DICOM files (n=35 per ethnic group) randomly selected from the IMU-dental clinic to determine the bucco-lingual orientation of the IAN in the 1st and 2nd molar regions. The canal size, buccal and lingual bone-width at the canal level were measured. One-way analysis of variance (ANOVA) was separately performed to identify side- and ethnicity-related variations. Results: In the Malay population, 48.6% (36 region) and 51.4% (46 region) of IANs were located at the centre; 62.9% (37 region) and 77.1% (47 region) were placed lingually. In the Malaysian-Chinese population, 48.6% (36 region) and 51.4% (46 region) of IANs were located at the centre; 60% (37 region) and 60% (47 region) were placed lingually. In the Malaysian-Indian population, 48.6% (36 region) and 65.7% (46 region) of IAN were located at the centre; 77.1% (37 region) and 74.3% (47 region) were placed lingually. A statistically significant (P.05) difference was found between the left and right sides of all measurements in the 2nd molar region, and the buccal bone width and canal size of IANs in the 1st molar region. A statistically significant difference was found in buccal bone width and IAN canal size in 37 region between Malaysian-Indian and Malay populations. Conclusion: The IAN was located at the centre in first molar regions and on the lingual side in second molars region, with significant variations in buccal, lingual bone width and canal size on both sides. Ethnicity-associated variations were identified between Malaysian-Indian and Malay populations. Keywords: Implant dentistry, implant surgery, safe zone, mandible anatomy