The root and root canal morphology of the human mandibular first premolar: a literature review.

By Cleghorn BM, Christie WH, Dong CC.

Date: 05/2007
Journal: JOE


•Purpose: To undertake a comprehensive literature review of the root and root canal morphology of the mandibular first premolar.


– Published studies citing the anatomy and morphology of mandibular premolars report data (N=6,700) teeth.

– Studies were divided into anatomical studies reporting number of roots, number of canals, and apical morphology.

– Variations because of sex and ethnicity have been reported and case reports of anomalies.

Most highlighted Results: 

-98% of the teeth in these studies were single-rooted (Tables).

-The incidence of 2 roots was 1.8%.

-3 roots when reported were found in 0.2% of the teeth studied.

-4 roots were rare and were found in less than 0.1% of the teeth.

-Studies of the internal canal morphology revealed that a single canal was present in 75.8% of the teeth.

-Two or more canals were found in 24.2% of the teeth studied.

-One apical foramen was found in 78.9% of the teeth and 21.1% had two or more apical foramina.

-Higher incidences of teeth with additional canals and roots were reported in Chinese, Australian, and Africans.

– Sex differences in canal morphology were reported in the study by Sert and Bayirli. They found two or more canals in 44% of the females and 35% of the males in the Turkish population studied.

Clinical significance:

The root and root canal morphology of this tooth can be complex and requires careful evaluation prior to root canal therapy.