[Interforaminal regions of 287 Han adults evaluated by cone-beam computed tomography]

The mandibular anatomical structures including mental foramen, accessory mental foramina, anterior loop were measured and analyzed by cone-beam CT (cone-beam computed tomography, CBCT) , in order to provide some information during surgical procedures in interforaminal regions.

Two hundred and eighty-seven Chinese Han patients who visited Stomatological Department of Xiangya Hospital were included in this study. Patients were scanned by cone-beam computed tomography, and the information of interforaminal region was collected from the images. SPSS17.0 software package was used for statistical analysis.

The mental foramen was usually apical to the second premolar or between the premolars（60.80% and 30.14%, respectively). The accessory mental foramina was observed in 4.88% of the mandibles, most of which were located under the second premolar, superiorly and distally to the mental foramen. The anterior loop was identified in 89.20% of cases with the mean length being (1.99±1.39) mm. The distance from the apex of the second mandibular premolar to the anterior loop or the inferior alveolar nerve was (5.21±2.50) mm.

Accessory mental foramina is present in some mandibles. The anterior loop is highly prevalent in Chinese Han people, and its length is highly variable.