LAUSR

BACKGROUND The purpose of this study was to identify and classify the anatomic variation of mandibular canal among Malaysians of 3 ethnicities. MATERIALS AND METHODS The courses of the mandibular canal in 202 CBCT scanned images of healthy Malaysians were evaluated, and trifid mandibular canal (TMC) when present, were recorded and studied in detail by categorizing them to a new classification (comprising of 12 types). The diameter and length of canals were also measured, and their shape determined. RESULTS TMC were observed in 12 (5.9%) subjects or 16 (4.0%) hemi-mandibles. There were 10 obvious categories out the 12 types of TMCs listed. All TMCs (except one) were observed in older than 30 years. The prevalence according to ethnicity is 6 in Malays, 5 in Chinese and 1 in Indian. Four (33.3%) patients had bilateral TMCs, which was not seen in any Indian subject. More than half (56.3%) of the accessory canals were located above the main MC. Their mean diameter was 1.32mm and 1.26mm for the first and second accessory canal, and the corresponding lengths were 20.42mm and 21.60mm, respectively. Most canals (62.5%) had irregularly shaped lumen; there were more irregularly shaped canals in the second accessory canal than the first branch. None of the second accessory canal was oval (in shape). CONCLUSIONS This new classification can be applied for the variations in the branching pattern, length and shape of TMCs for better clinical description.