Assessment of the anterior loop of the mandibular canal: A study using cone-beam computed tomography

Abstract

PurposeSufficient 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).Materials and MethodsCBCT 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.ResultsAn 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).ConclusionIn 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.

Morphometric Analysis of the Mental Foramen Using Cone-Beam Computed Tomography

“…In this study, we found no significant differences in the length of MF between the sexes. There was also no significant difference in the size of MF between the age groups in this study, as in some recent studies [ 13 , 22 ].…”

“…We found a significant difference between the sexes (13.1 mm in men and 11.9 mm in women), but not between the age groups. Previous studies have reported that the MF was located 13.2 mm above the lower border of the mandible, with significant sex differences (men tended to have higher values than women) [ 13 , 15 , 22 – 24 ].…”

The Use of Cone‐Beam Computed Tomography in Management of Patients Requiring Dental Implants: An American Academy of Periodontology Best Evidence Review

“…Different studies have reported the importance of various neurovascular anatomic structures identified on cross‐sectional imaging, including: 1) inferior alveolar (mandibular) canal; 2) anterior loop and mandibular incisive canal; 3) mental foramen; 4) lingual canal; and 5) maxillary incisive/nasopalatine canal, and highlight the variability of imaging identification and characteristics of these structures in relation to implant placement 98‐109 . Hence, efforts are underway to automate identification of the mandibular canal 110 …”

“…Different studies have reported the importance of various neurovascular anatomic structures identified on cross-sectional imaging, including: 1) inferior alveolar (mandibular) canal; 2) anterior loop and mandibular incisive canal; 3) mental foramen; 4) lingual canal; and 5) maxillary incisive/nasopalatine canal, and highlight the variability of imaging identification and characteristics of these structures in relation to implant placement. [98][99][100][101][102][103][104][105][106][107][108][109] Hence, efforts are underway to automate identification of the mandibular canal. 110 In addition, the use of CBCT has been found to be effective in locating blood vessels in the lateral wall of the maxillary sinus, which should be appreciated prior to sinus augmentation procedures.…”

Association between the Anatomy of the Mandibular Canal and Facial Types: A Cone-Beam Computed Tomography Analysis

“…In this study, we assessed anterior loop variants on CBCT images (Types A, B, and C), as previously described by Li et al [ 17 ] and Do Nascimento et al [ 18 ]. We found a higher prevalence of the anterior loop (Type A) and the lowest prevalence of Type B.…”