Worldwide Prevalence of a Lingual Canal in Mandibular Premolars: A Multicenter Cross-sectional Study with Meta-analysis

Jorge N R Martins; Yuerong Zhang; Murilo von Zuben; Walter Vargas; Hussein C Seedat; Fábio Santiago; Ruben Rosas Aguilar; Magnús F Ragnarsson; Gianluca Plotino; Peter Parashos; Hani F Ounsi; Christian Nole; Adam Monroe; Jojo Kottoor; Jose Antonio Gonzalez; Daniel Flynn; Antonis Chaniotis; Imran Cassim; Carlos Boveda; Luiza Berti; Zaher Altaki; Moataz-Bellah A M Alkhawas; Hussam Alfawaz; Emmanuel J N L Silva; Marco Aurélio Versiani

doi:10.1016/j.joen.2021.04.021

Worldwide Prevalence of a Lingual Canal in Mandibular Premolars: A Multicenter Cross-sectional Study with Meta-analysis

J Endod. 2021 Aug;47(8):1253-1264. doi: 10.1016/j.joen.2021.04.021. Epub 2021 Apr 24.

Authors

Jorge N R Martins¹, Yuerong Zhang², Murilo von Zuben³, Walter Vargas⁴, Hussein C Seedat⁵, Fábio Santiago⁶, Ruben Rosas Aguilar⁷, Magnús F Ragnarsson⁸, Gianluca Plotino⁹, Peter Parashos¹⁰, Hani F Ounsi¹¹, Christian Nole¹², Adam Monroe¹³, Jojo Kottoor¹⁴, Jose Antonio Gonzalez¹⁵, Daniel Flynn¹⁶, Antonis Chaniotis¹⁷, Imran Cassim¹⁸, Carlos Boveda¹⁹, Luiza Berti²⁰, Zaher Altaki²¹, Moataz-Bellah A M Alkhawas²², Hussam Alfawaz²³, Emmanuel J N L Silva²⁴, Marco Aurélio Versiani²⁵

Affiliations

¹ Department of Endodontics, Faculdade de Medicina Dentária, Universidade de Lisboa, Lisbon, Portugal; Instituto de Implantologia, Lisbon, Portugal. Electronic address: jnr_martins@yahoo.com.br.
² Department of Conservative Dentistry and Endodontics, School of Stomatology, Nanjing Medical University, Nanjing, China.
³ Private Practice, Brussels, Belgium.
⁴ Instituto de Estudios Avanzados en Odontología Dr. Yury Kuttler, Mexico City, Mexico.
⁵ Private Practice, Durban, South Africa.
⁶ Private Practice, Paris, France.
⁷ Department of Endodontics, Escuela Nacional de Estudios Superiores Universidade Nacional Autônoma do México, León, México.
⁸ Private Practice, Hafnarfjördur, Iceland.
⁹ Private Practice, Rome, Italy.
¹⁰ Melbourne Dental School, University of Melbourne, Melbourne, Australia.
¹¹ Department of Restorative Dentistry and Endodontics, Lebanese University, Beirut, Lebanon; Department of Endodontics and Restorative Dentistry, Siena University, Siena, Italy.
¹² Private Practice, Lima, Peru.
¹³ Private Practice, San Diego, California.
¹⁴ Department of Conservative Dentistry and Endodontics, Royal Dental College, Kerala, India.
¹⁵ Departamento de Endodoncia y Conservadora, Facultad de Odontología, Universitat Internacional de Catalunya, Barcelona, Spain.
¹⁶ Private Practice, London, England.
¹⁷ Private Practice, Athens, Greece.
¹⁸ Private Practice, Tauranga, New Zealand.
¹⁹ Department of Endodontics, Faculty of Dentistry, Universidad Central de Venezuela, Caracas, Venezuela.
²⁰ Department of Radiology, Faculdade de Odontologia São Leopoldo Mandic, Campinas, Brazil.
²¹ Department of Endodontics, Damascus University, Damascus, Syria.
²² Department of Endodontics, Al-Azhar University Faculty of Dental Medicine, Cairo, Egypt.
²³ King Saud University, College of Dentistry, Riyadh, Saudi Arabia.
²⁴ Department of Endodontics, School of Dentistry, Grande Rio University, Rio de Janeiro, Rio de Janeiro, Brazil; Department of Endodontics, Fluminense Federal University, Niteroi, Rio de Janeiro, Brazil.
²⁵ Dental Specialty Center, Brazilian Military Police, Minas Gerais, Brazil.

PMID: 33901542
DOI: 10.1016/j.joen.2021.04.021

Abstract

Introduction: The presence of multiple root canals is an important morphologic aspect of mandibular premolars. This study aimed to perform a worldwide analysis on the prevalence of a lingual canal in mandibular premolars and to evaluate its influence on patients' demographics in 23 countries using cone-beam computed tomographic images.

Methods: Observers from 23 countries were instructed to evaluate cone-beam computed tomographic images of 300 first and 300 second premolars (13,800 teeth) regarding the presence of a lingual canal, canal configuration, and data related to patients' ethnicity, age, and sex following a standardized screening methodology. Intra- and interrater evaluations were performed using the Cohen kappa test and intraclass correlation coefficient. Proportion and odds ratio forest plots were calculated in order to compare groups. Statistical significance was set at 5%.

Results: Both kappa and intraclass correlation coefficient values were above 0.60, and the percentage of agreement was 94.9% (first premolar) and 97.8% (second premolar). A significant statistical difference was observed between the worldwide proportion of a lingual canal in mandibular first (23.8%; range, 12.0%-32.7%) and second (5.3%; range, 1.0%-15.3%) premolars (P < .05). Asians and patients over 60 years old were associated with the lowest proportions of a lingual canal (P < .05), whereas Africans and younger groups were associated with the highest proportions (P < .05). The prevalence of a lingual canal in males (27.9%) was higher than females (20.0%) for the first premolar only (P < .05). Males were associated with 1.533 and 1.597 higher odds of presenting a lingual root canal in the first and second premolars, respectively.

Conclusions: The worldwide proportion of a lingual root canal was 23.6% and 5.3% for the first and second premolars, respectively. Ethnicity, geographic region, age, and sex had an influence on the outcomes.

Keywords: Anatomy; cone-beam computed tomography; mandibular premolar; meta-analysis; multicenter; prevalence study.

Publication types

Meta-Analysis

MeSH terms

Bicuspid / diagnostic imaging
Cone-Beam Computed Tomography
Cross-Sectional Studies
Dental Pulp Cavity* / diagnostic imaging
Female
Humans
Male
Mandible / diagnostic imaging
Middle Aged
Multicenter Studies as Topic
Prevalence
Tooth Root*