Root trunk dimensions of 5 different tooth types.

The primary purpose of this study was to document mean, standard deviation, and range of root trunk dimensions of multirooted tooth types. A total of 412 extracted teeth were examined and classified as: maxillary first molars, maxillary second molars, maxillary first premolars, mandibular first molars, and mandibular second molars. The distance from the cementoenamel junction (CEJ) to the root groove and from the CEJ to the root division was measured. Mean CEJ to root groove distances ranged from 1.35 to 1.65 mm for maxillary first molars, from 1.49 to 1.89 mm for maxillary second molars, from 1.71 to 1.73 mm for maxillary first premolars, from 1.16 to 1.22 mm for mandibular first molars, and from 1.53 to 1.76 mm for mandibular second molars.