Demonstration of the accessory mental foramen using rotational panoramic radiography compared with cone-beam computed tomography.

OBJECTIVE: Rotational panoramic radiography is routinely used in dental practice. It has not been clarified, however, whether an accessory mental foramen can be demonstrated using this technique. The visibility of accessory mental foramina on rotational panoramic radiographs was compared with those on para-panoramic images reconstructed from cone-beam computed tomographic (CBCT) images.

MATERIALS AND METHODS: A total of 365 patients (130 males and 235 females) were retrospectively analyzed. Para-panoramic images were reconstructed from CBCT images with the accessory mental foramen/foramina using three-dimensional visualization and measurement software, and then the accessory mental foramen on rotational panoramic images was compared with that on para-panoramic images.

RESULTS: A total of 37 accessory mental foramina were observed in 28 patients on CBCT images. The rate of being able to visualize the accessory mental foramen or bony canal between the point of bifurcation from the mandibular canal and the accessory mental foramen on rotational panoramic radiographs was 48.6% (18 of 37 accessory mental foramina).

CONCLUSION: Approximately half of the accessory mental foramina-positive CBCT images demonstrated the accessory mental foramen, or bony canal between the point of bifurcation from the mandibular canal and accessory mental foramen on rotational panoramic radiographs.