Mental foramen and accessory mental foramen: a dry human mandibles study in South Indian population

Introduction and aim: Mandible usually has a bilateral oval or circular mental foramen [MF] situated on the anterolateral aspect of the body of mandible. Variations of the MF are often encountered ranging from difference in incidence, shape, size, position and supernumerary [accessory MF] to even complete absence. So, the aim of the present study was to evaluate the incidence and the anatomical features of the mental foramen and the accessory mental foramen. Materials & method: 61 dry human mandibles of unknown sex were examined. Size and distance of mental foramen and accessory mental foramen from symphysis menti [Mandibular midline], inferior border of the mandible, posterior border of ramus and superior border of body of mandible were measured using vernier calliper and statistically analyzed by mean and standard deviation. Results: Bilateral mental foramina [MF] were present in all 61 [100%] mandibles. Out of 122 mental foramina [MF], 86 [70.5%] were round and 36 [29.5%] were oval in shape. Approximately half [47.54%] of MF were present below the apex of 2nd premolar tooth. MF was located approximately half way between alveolar crest and mandibular body. Bilateral AMF were present in 1.64% mandibles. All 5 AMFs were round in shape. AMF was separated from MF by a median distance of 2mm. Conclusion: The knowledge about incidence and variability in position of mental foramen and accessory mental foramen is important in order to avoid nerve damage in connection with surgical procedure and to achieve complete effect of anaesthesia after mental nerve block