Abstract: Objective To detect and locate mandibular incisive canals (MICs) on 3dimension images scanned from conebeam computerizing tomography (CBCT) in vivo, and to discuss its clinical significance. Methods Based on an inout standard, a sample was screened out of the CBCT databank of radiology department in our hospital, which involved a part of individuals at the age of 18 to 85. Teeth of 44~34 were selected as the sites of our study. Beneath them MICs were distinguished, of which the visibilities were decided, and the diameters and distances to some anatomic landmarks were measured. Results The visibility of lower first premolar and canine obviously excelled incisors. Most MICs stretched their ways slightly nearer to the buccal or labial cortex in the perpendicular middlethird of mandible in the crosssectional images. The diameters of MICs became thinner while running closer to the mental symphyseal region, and mostly invisible below incisors. Conclusions Clinical significance of MICs may not be so important as assumed. It is essential to inform of MICs damage and nerve dysfunction risks before surgical operations, however, which is taken into account grounded on ethicality and forensicality. Customized preoperative 3Dimage examinations and measurements, and avoidance from MIC injury as much as possible, are still basic clinical requests.

Key words: mandibular incisive canal, cone beam CT, clinical significance