Furcation depth and interroot separation dimensions for 5 different tooth types.

The purpose of this study was to document mean, standard deviation, and range of furcation depth and Interroot separation dimensions of 5 multirooted tooth types. A total of 412 extracted teeth were examined and classified as: maxillary first molar, maxillary second molar, maxillary first premolar, mandibular first molar, and mandibular second molar. The furcation depth was measured at the level of the furcation dome and 3 and 5 mm apical to the dome. Interroot separation was measured 3 and 5 mm apical to the furcation dome. Mean furcation depth at the dome was 7.48 mm buccally and 6.67 mm mesiodistally for maxillary first molars; 6.69 mm buccally and 5.94 mm mesiodistally for maxillary second molars; 3.54 mm mesiodistally for maxillary first premolars; 7.96 mm buccolingually for mandibular first molars; and 7.46 mm buccolingually for mandibular second molars. Interroot separation dimensions 3 mm apical to the dome were: 2.58 mm buccally, 4.17 mm mesially, and 4.48 mm distally for maxillary first molars; 1.92 mm buccally, 3.89 mm mesially, and 4.04 mm distally for maxillary second molars; 2.47 mm mesially and 2.58 mm distally for maxillary first premolars; 3.15 mm buccally and 2.95 mm lingually for mandibular first molars; and 2.54 mm buccally and 2.75 mm lingually for mandibular second molars.