The aim of this study is to provide the anatomical data for protecting the inferior alveolar nerve (IAN) in clinic dentures implantation.The distance of mandibular canal to the alveolar border, the distance between the exterior margin of the mandibular canal and the buccal side or the lingual side of the mandibular plate were measured.The distance from the mandibular canal to the dental root of different teeth was as follows: 12.57 mm to central incisor, 10.06 mm to lateral incisor, 9.28 mm to cuspid teeth, 8.04 mm to second premolar, and 7.59 mm to second molar.