INTRODUCTION: This cross-sectional study assessed the influence of patient demographics on the worldwide prevalence of a lingual canal in mandibular incisors.
METHODS: 26,400 mandibular incisors were evaluated using cone-beam computed tomography imaging by pre-calibrated observers from 44 countries. A standardized screening method was employed to collect data on the presence of a lingual canal, the anatomic configuration of the root canal, and number of roots. Patient demographic information (age, sex, and ethnicity) was also recorded. Multiple intra- and inter-rater tests assessed the reliability of the observers and groups, and a meta-analysis was used to examine differences and heterogeneities (α=5%).
RESULTS: The prevalence of the lingual canal in mandibular central and lateral incisors varied from 2.3% (0.06%-4.0%; Nigeria) to 45.3% (39.7%-51.0%; Syria) and from 2.3% (0.06%-4.0%; Nigeria) to 55.0% (49.4%-60.6%; India), respectively. Ethnicity had a significant impact on the prevalence of the lingual canal, with African, Asian, and Hispanic groups having the lowest proportions (P
* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.