[Measurement of mesiodistal root angulation for panoramic images and the effect of buccolingual root angulation]

Panoramic images were taken from an anatomically correct phantom with three different buccolingual angulations for each tooth (Original, 10 degrees buccal root torque, and 10 degrees lingual root torque). The true mesiodistal angulation of each tooth was determined with a three-dimensional coordinate measurement machine. Each tooth had at least one angle measurement that was statistically different from the other mesiodistal angles with different buccolingual orientations. Roots with buccal root orientations were projected more distally than they were in reality; and the roots lingually positioned were projected more mesially. The canine and premolars in both arches were most affected and the phenomenon was more pronounced in the maxilla than the mandible. Buccolingual orientation changes did not affect the root angulation expression on the incisor area.