Unilateral triple mandibular canal with double mandibular foramen: cone-beam computed tomography findings of an unexpected anatomical variant

Abstract

The mandibular canal is a bony channel located within the spongiosa of the mandible. The main structure contained in the mandibular canal is the inferior alveolar nerve (IAN). The IAN is a very important structure that requires due consideration during dental or surgical procedures involving the mandible. Therefore, a detailed morphological analysis of the mandibular canal should be carried out before any surgical procedure in the mandibular region in order to avoid complications and to reduce the risk of inadequate local nerve blocking. The human mandible typically has a single mandibular canal on each side; however, accessory mandibular canals have been described previously in the literature. The most common variant of the mandibular canal is the bifid mandibular canal, which has a prevalence ranging from 10-66% on cone-beam computed tomography (CBCT) examinations. A rare variant of bifid mandibular canal is the trifid canal, accounting for less than 6% of all bifid canals. In some cases, the bifid and trifid mandibular canals are associated with a double mandibular foramen, which is a rare anatomical variant with a reported incidence of 1.35% on CBCT images. Herein, we present the interesting CBCT images of an unexpected anatomical variant characterized by unilateral triple mandibular canal with double mandibular foramen in a young Caucasian woman.

Mandibular Canal Branching Assessed With Cone-Beam Computed Tomography

“…Previous radiographic studies reported various prevalence rates for MCB, ranging from 0% to 38.7% in panoramic and from 9.8% to 66.5% in CBCT assessments. 3,18,20,[22][23][24] The prevalence rate of 43.7% in this study is relatively high and similar to the values reported by Okmus and Dumlu, 8 de Castro et al, 20 15 reported high prevalence rates of 66.5% and 65%, respectively, for bifid mandibular canals.…”

“…The prevalence of MCB was calculated as 43.7% (131 out of 300 patients) in the present sample. Previous radiographic studies reported various prevalence rates for MCB, ranging from 0% to 38.7% in panoramic and from 9.8% to 66.5% in CBCT assessments 3,18,20,22–24 . The prevalence rate of 43.7% in this study is relatively high and similar to the values reported by Okmus and Dumlu, 8 de Castro et al, 20 and Orhan et al 2 (40%, 41.1%, and 46.5%, respectively).…”

Topography of the mandibular canal in male human skulls originating from different time periods

“…The mandibular canal, nowadays referred to as the inferior alveolar (nerve) canal [29,36,63], is located in the spongy bone of the mandible and is available for diagnosis only by imaging techniques using X-rays [1, 3, 8, 20-22, 29, 32, 66]. Panoramic images acquired with classical and digital techniques, or increasingly popular computed tomography are clinically relevant [3,8,43,67]. Panoramic radiography is part of the standard dental diagnostics procedure performed before planning treatment.…”

Detection Rate and Variability in Measurement of Mandibular Incisive Canal on Cone-Beam Computed Tomography: A Study of 220 Dentate Hemi-Mandibles from Italy

“…The high spatial resolution of CBCT provides detailed anatomical information regarding the canals and foramina located within the mandible, and has revealed many anatomical variants [ 28 , 29 ]. The frequency of these anatomical variations in CBCT scans varies among ethnic groups, with higher incidence among Asians than Caucasians [ 28 ].…”

“…The frequency of these anatomical variations in CBCT scans varies among ethnic groups, with higher incidence among Asians than Caucasians [ 28 ]. However, unexpected anatomical variants of foramina and canals of the mandible have also been described in Caucasians [ 28 , 29 ]. Therefore, preoperative planning based on CBCT should help oral and dental surgeons avoid iatrogenic complications during any surgical procedures involving the mandible.…”