The root and root canal morphology of the human mandibular premolars: A literature review

Abstract

The objective was to review thoroughly the literature of the root and root canal morphology of the human mandibular premolars. Published studies were divided into anatomic studies reporting the number of roots, number of canals, and apical anatomy. Differences caused by gender and ethnicity have also been reported. Individual case reports of anomalies were included to demonstrate the extreme range of variation. Almost all of the teeth in the anatomic studies were single rooted (99.6%). The incidence of two roots (0.3%) and three roots (0.1%) was extremely rare. Anatomic studies of the internal canal morphology found that a single canal was present in 91.0% of the teeth. A single apical foramen was found in 91.8% of the teeth. However, the root and root canal morphology of the mandibular premolars can be extremely complex and requires careful assessment.