The appearance of mental foramina on panoramic and periapical radiographs. II. Experimental evaluation.

The image of the mental foramen was studied on panoramic and periapical radiographs taken on four dry skulls with a variety of vertical and horizontal angulations, skull positions, and exposure times. It was found that any change in exposure conditions affected both the type of appearance (continuous, separated, diffuse, or unidentified) and the relative vertical position of the foramen. The radiographic position agreed with the actual position less than half the time regardless of technique, although the apparent diameter of the foramen was close to the true diameter.