Perioperative validation of localisation of the mental foramen.

AIM To assess the accuracy of panoramic radiography and spiral or computed tomography for the localisation of the mental foramen. MATERIALS AND METHODS The distance from the alveolar crest to the mental foramen was measured from panoramic radiographs, spiral tomograms and CT scans. The same distance was measured during implant surgery using a specially designed caliper. RESULTS Panoramic radiography showed more deviation (+0.6 mm) from the perioperative measurements than either spiral or computed tomography (+0.4 and -0.3 mm respectively). The difference was significant (P<0.05). In general, distances were overestimated on the panoramic radiographs. CONCLUSIONS Cross-sectional imaging techniques are recommended for the pre-operative planning of implants in the posterior mandible.