title: Classifications of mandibular canal branching: A review of literature.
abstract: OBJECTIVE
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: 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.
authors.forename: Mauricio Augusto Aquino
authors.initials: MA
authors.lastname: Castro
authors.affiliation: 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.
authors.forename: Manuel Oscar
authors.initials: MO
authors.lastname: Lagravere-Vich
authors.affiliation: 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.
authors.forename: Tânia Mara Pimenta
authors.initials: TM
authors.lastname: Amaral
authors.affiliation: 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.
authors.forename: Mauro Henrique Guimaraes
authors.initials: MH
authors.lastname: Abreu
authors.affiliation: 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.
authors.forename: Ricardo Alves
authors.initials: RA
authors.lastname: Mesquita
keywords: Bifid mandibular canal; Cone-beam computed tomography; Dental radiography; Inferior alveolar nerve; Mandibular canal