title: Assessment of the anterior loop of the mandibular canal: A study using cone-beam computed tomography.
abstract: OBJECTIVE
  Sufficient area in the interforaminal region is required for dental implant placement, and the anterior loop of the mandibular canal is located within the limits of this area. The aim of this study was to evaluate the prevalence and extent of the anterior loop in a Brazilian sample population using cone-beam computed tomography (CBCT).
  
  
  METHODS
  CBCT images from 250 patients (500 hemimandibles) obtained for various clinical indications were randomly selected and evaluated to determine the presence and length of the anterior loop. The length of the anterior loop was then compared based on gender, age, and the side of the mandible. The data were analyzed using the Pearson chi-square test and linear regression analysis.
  
  
  RESULTS
  An anterior loop was identified in 41.6% of the cases, and its length ranged from 0.25 mm to 4.00 mm (mean, 1.1±0.8 mm). The loop had a greater mean length and was significantly more prevalent in males (p=0.014). No significant differences were found between the right and left sides regarding length (p=0.696) or prevalence (p=0.650).
  
  
  CONCLUSIONS
  In this study, a high prevalence of the anterior loop of the mandibular canal was found, and although its length varied greatly, in most cases it was less than 1 mm long. Although this is a prevalent anatomical variation, safety limits for the placement of implants in this region cannot be established before an accurate evaluation using imaging techniques in order to identify and preserve the neurovascular bundles.
authors.affiliation: Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas (UNICAMP), São Paulo, Brazil.
authors.forename: Eduarda Helena Leandro
authors.initials: EH
authors.lastname: do Nascimento
authors.affiliation: Department of Clinical and Preventive Dentistry, School of Dentistry, Federal University of Pernambuco (UFPE), Recife, Pernambuco, Brazil.
authors.forename: Maria Luiza
authors.initials: ML
authors.lastname: Dos Anjos Pontual
authors.affiliation: Department of Clinical and Preventive Dentistry, School of Dentistry, Federal University of Pernambuco (UFPE), Recife, Pernambuco, Brazil.
authors.forename: Andréa
authors.initials: A
authors.lastname: Dos Anjos Pontual
authors.affiliation: Department of Clinical and Preventive Dentistry, School of Dentistry, Federal University of Pernambuco (UFPE), Recife, Pernambuco, Brazil.
authors.forename: Danyel Elias
authors.initials: DE
authors.lastname: da Cruz Perez
authors.affiliation: Instituto de Medicina Integral Professor Fernando Figueira - IMIP, Recife, Pernambuco, Brazil.
authors.forename: José Natal
authors.initials: JN
authors.lastname: Figueiroa
authors.affiliation: Division of Oral Radiology, Recife Dental School (FOR), Recife, Pernambuco, Brazil.
authors.forename: Marco Antônio Gomes
authors.initials: MA
authors.lastname: Frazão
authors.affiliation: Department of Clinical and Preventive Dentistry, School of Dentistry, Federal University of Pernambuco (UFPE), Recife, Pernambuco, Brazil.
authors.forename: Flávia Maria de Moraes
authors.initials: FM
authors.lastname: Ramos-Perez
keywords: Anatomic Variation; Cone-Beam Computed Tomography; Mandible