Locating the mandibular canal in panoramic radiographs.

The entire course of the mandibular canal is normally not visible on a panoramic radiograph. Locating the course of the mandibular canal at the site of implant placement is important. This study was carried out to determine whether the course of the mandibular canal can be more clearly visualized by tilting the patient's head approximately 5 degrees downward with reference to the Frankfort horizontal reference bar of the Orthopantomogram machine. In 91% of the radiographs taken in this position, the mandibular foramen, mandibular canal, and mental foramen were visible. The angulation of the patient's head reduced the chances of superimposition on the contralateral sides, making these structures clearly visible.