Abstract: ] PURPOSE:This study was aimed to analyze the anatomical structures in the mandibular interforminal region by cone-beam CT (CBCT), and provide recommendations to the surgeon about a new safe surgical margin in this region. METHODS: A total of 104 CBCT radiographs were obtained, the mental canal, mandibular incisive canal, mandibular lingual foramen and its bony canal were measured on CBCT. The mean value and standard deviations were calculated. The data were analyzed with SPSS19.0 software package. RESULTS: The mental canal was visible in 55.29% of the scans, and the mean length was 1.12 mm.The lingual foramen and its canal were visible in 94.23% of the scans, and the mean length was 1.77 mm. The distances from the incisive canal to buccal plate were smaller than to lingual plate. CONCLUSIONS: In the absence of CBCT scans, the new relative safe margins should be a distance of at least 6 mm between the anterior border of the mental foramen and the most distal interforaminal implant fixture or bone harvest site; the maximum bone harvest depth is suggested to be 3 mm and implants length should be less than 14 mm in the placement of the anterior mandible implant.

Key words: Mental canal, Mandibular incisive canal, Mandibular lingual foramen, Cone beam CT