Systematic Reviews
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Radiol. Dec 28, 2015; 7(12): 531-537
Published online Dec 28, 2015. doi: 10.4329/wjr.v7.i12.531
Classifications of mandibular canal branching: A review of literature
Mauricio Augusto Aquino Castro, Manuel Oscar Lagravere-Vich, Tânia Mara Pimenta Amaral, Mauro Henrique Guimaraes Abreu, Ricardo Alves Mesquita
Mauricio Augusto Aquino Castro, Tânia Mara Pimenta Amaral, Ricardo Alves Mesquita, Department of Oral Surgery and Pathology, School of Dentistry, Federal University of Minas Gerais, Belo Horizonte MG 253 31270-901, Brazil
Manuel Oscar Lagravere-Vich, Graduate Orthodontic Program, University of Alberta, University of Alberta, Edmonton T6G1C9, Canada
Mauro Henrique Guimaraes Abreu, Department of Social and Preventive Dentistry, School of Dentistry, Federal University of Minas Gerais, Belo Horizonte MG 253 31270-901, Brazil
Author contributions: Castro MAA, Lagravere-Vich MO, Amaral TMP, Abreu MHG and Mesquita RA contributed equally to this work; all authors read and approved the final manuscript.
Supported by Grants from National Council for Scientific Technological Development (CNPq, #309209/2010-2).
Conflict-of-interest statement: All the authors declare that they have no competing interests.
Data sharing statement: The technical appendix and dataset are available from the corresponding author at ramesquita@ufmg.br.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Ricardo Alves Mesquita, PhD, Department of Oral Surgery and Pathology, School of Dentistry, Federal University of Minas Gerais, Av. Antonio Carlos, 6627, Pampulha, Belo Horizonte MG 253 31270-010, Brazil. ramesquita@ufmg.br
Telephone: +55-31-34092499 Fax: +55-31-34092430
Received: May 29, 2015
Peer-review started: June 1, 2015
First decision: August 4, 2015
Revised: October 20, 2015
Accepted: November 3, 2015
Article in press: November 4, 2015
Published online: December 28, 2015
Processing time: 213 Days and 4.6 Hours
Abstract

AIM: To gather existing radiographic classifications of mandibular canals branching, considering the criteria on which these were based.

METHODS: The search for studies on mandibular canals based on imaging exams included literature reviews, epidemiological studies of prevalence, descriptive studies, or case reports. An electronic search in the MEDLINE (OvidSP), PubMed, EMBASE (OvidSP), Web of Science (Thompson Reuters), and Scopus (Elsevier) databases was performed, as well as a manual evaluation of the references of the selected articles. Combinations of key words were placed in each database. No restrictions were imposed regarding the year of publication or language. References collected in duplicate were removed by the authors. A table was drawn up, containing the included studies and respective interest data.

RESULTS: Six classifications of mandibular canals branching were selected for the present literature review. Four were based on two-dimensional radiographic exams, and two were performed based on three-dimensional tomographic exams. Three-dimensional classifications were determined based on the analysis found in the least number of exams, comparatively to two-dimensional studies. The prevalence of mandibular canal branching varied from 0% to 38.75% in the works based on two-dimensional exams, while those found in three-dimensional exams ranged from 15.6% to 65%. The studies were mostly referred to branches that began in the mandibular ramus. Just one classification considered the branches that began in the mandibular body region.

CONCLUSION: Three-dimensional exams appear to be the best method to view mandibular canal branching. Further studies are warranted to determine its true prevalence and questions concerning to associations.

Keywords: Inferior alveolar nerve; Mandibular canal; Bifid mandibular canal; Dental radiography; Cone-beam computed tomography

Core tip: The identification of the mandibular canal and its branching are important for the planning of dental procedures. Due to the limitations of the two-dimensional exams, the three-dimensional view of the structures provided by computed tomography (CT) exams allowed for greater sensitivity for the detection and evaluation of mandibular canals. Nevertheless, some studies performed with CT exams continued to use the classifications based on two-dimensional exams. Given the variability of information on this aspect, this study aimed to gather existing information in an attempt to provide researchers and clinical professionals with a stronger basis for their studies and procedures.