Bilateral root or root canal aberrations in a dental school patient population.

Clinicians have often noted that aberrant root morphology in a given tooth is also observed with varying degrees of frequency in the corresponding contralateral tooth. The purpose of this study was to determine the proportion of bilateral morphological root aberrations in a random sample of adult human dentition. Five hundred one dental records were selected from the retired record section at the University of Oklahoma College of Dentistry and their full-mouth radiographs were reviewed for aberrant root canal morphology. Bifurcation of the canal in mandibular first premolars was the most common finding (22.8% of patients), with 60% of these being bilateral. Maxillary anterior teeth had the least aberrations. It was observed that unusual root morphology is bilateral approximately 60% of the time. Therefore, the incidence of root or root canal abnormalities reported by the percentage of patients involved will always exceed the incidence of abnormalities reported by type of tooth (e.g. mandibular or canine) involved except for abnormalities which are found bilaterally in 100% of the patients studied. Radiographic interpretation appears to result in a lower incidence of anatomical aberrations than direct identification. The more rare the aberration, the more likely it is to be bilateral in occurrence.