Prevalence of Taurodontism of Permanent Molars in Dental School of Shahid Beheshti University from 2000 to 2006

Taurodontism is a dental anomaly characterized by elongation of root body and apical displacement of the pulp chamber floor associated with shortening of roots and their narrowing at the cementoenamel junction (CEJ). Due to having a dilated apical one-third, these teeth may cause complications during extraction, locating canal orifices and instrumentation. This study aimed to assess the prevalence of taurodontism of permanent molars in a small Iranian population. This retrospective descriptive study was conducted on 1,100 dental records of patients that were randomly selected among 5,672 records available in the archives of School of Dentistry, Shahid Beheshti University of Medical Sciences from 2000 to 2010 that met the inclusion and exclusion criteria. Teeth with extensive restorations or carious lesions were excluded. One observer evaluated all the radiographs and the teeth were classified based on the presence or absence of taurodontism. All positive cases were re-evaluated by two examiners and accurate measurements were made using a caliper according to Shifman and Chanannel criteria. A total of 1,184 radiographs were evaluated; of which 447 (47.7%) belonged to males and 737 (62.3%) belonged to females. A total of 5,532 first and second molars of both jaws were evaluated in these radiographs. There were 1,310 (23.7%) maxillary first molars, 987 (17.8%) mandibular first molars, 1,731 (31.3%) maxillary second molars and 1,504 (27.7%) mandibular second molars. Overall, 293 teeth had taurodontism; of which, 179 belonged to females and 114 belonged to males. The prevalence of taurodontism in the understudy population was 6.41%. It appears that taurodontism is not as rare as it is thought to be.