Clinical evaluation of the effects of radiographic distortion on the position and classification of mandibular third molars

Panoramic radiographs are routinely employed for surgical planning of unerupted third molars. The objective of this study was to evaluate distortions in the position of mandibular third molars on panoramic radiographs. Panoramic radiographs of 14 patients with indication for extraction of the mandibular third molars were used. Transurgical impressions of the crowns of the teeth to be extracted and adjacent second molars (n=19) were achieved with addition silicone and poured with type IV plaster for comparison of the inclinations of the third molars on the radiographs and study casts. There was a mean difference of -5.37 degrees between the position of the third molar on the panoramic radiograph and on the study cast (standard deviation 1.46, P