Topographical distribution of neurovascular canals and foramens in the mandible: avoiding complications resulting from their injury during oral surgical procedures

Abstract

PurposeCertain oral surgical procedures can injure neurovascular canals and foramens in the mandible. Hence, before performing surgical procedures, it is important to assess the distribution of the bifid mandibular canal (BMC), accessory mental foramen (AMF), medial lingual canal (MLC), lateral lingual canal (LLC), buccal foramen (BF), and lingual alveolar canal (LAC). This study aimed to assess the distribution of different types of canals and foramens. Furthermore, we investigated the limitations associated with finding these structures in panoramic images.MethodsFifty-eight patients who had undergone panoramic radiography and computed tomography (CT) scans at our hospital were randomly selected for this study. Imaging data obtained from these patients were retrospectively reviewed.ResultsWe found that the occurrence of BMC was 60.3%, AMF was 6.9%, MLC was 98.2%, LLC was 75.9%, BF was 43.1%, and LAC was 98.3%. Edge-contrasted inverted panoramic images revealed BMCs in 21.7% and AMFs in 25%; however, most of these canals could not be detected. In the panoramic images, the average diameter of the BMC was significantly different between the detected group and not detected group. The number of canals and foramens in the anterior region to the molar region decreased on the buccal and lingual sides, and most BMCs were in the retromolar to the ramus region.ConclusionOur results indicated different distributions and occurrence rates of each type of neurovascular canal and foramens.

The clinical anatomy of accessory mandibular canal in dentistry

“…Yang et al () reported that the average BMC diameter was 1.46 (±0.26) mm in males and 1.27 (±0.20) mm in females, and 1.33 mm on the right side and 1.28 mm on the left. Recently, Moro et al () reported an average diameter of 1.22 ± 0.42 mm, consistent with the other two studies. Their new addition, described as the ramus canal, has a diameter of 0.87 ± 0.12 mm.…”

“…CT and CBCT have been used to overcome the limitations of panoramic radiography (Fukami et al, 2012). So far, four studies have used both panoramic and CBCT (López-Videla et al, 2010;Moro et al, 2018;Muinelo-Lorenzo et al, 2014;Neves et al, 2014), two have used a combination of CT and CBCT (Rouas, Delbos, & Nancy, T A B L E 1 The prevalence of BMCs reported in various studies Authors (year) Method of investigation…”

“…CT and CBCT have been used to overcome the limitations of panoramic radiography (Fukami et al, ). So far, four studies have used both panoramic and CBCT (López‐Videla et al, ; Moro et al, ; Muinelo‐Lorenzo et al, ; Neves et al, ), two have used a combination of CT and CBCT (Rouas, Delbos, & Nancy, ; Shen et al, ), 21 have used only CBCT, one of them determining the prevalence of BMC in children (Afsa & Rahmati, ; Borgonovo et al, ; de Castro et al, ; de Oliveira‐Santos et al, ; Kang et al, ; Kuribayashi et al, ; Li et al, ; Luangchana et al, ; Naitoh et al, ; Neves et al, ; Ogawa et al, ; Okumu & Dumlu, ; Orhan et al, ; Orhan et al, ; Rashsuren et al, ; Shah et al, ; Sonneveld et al, ; Villa et al, ; Yang et al, ; Yi et al, ; Yoon et al, ; Zhang et al, ), and two have used only CT (Fu et al, ; Lins et al, ). These CT and CBCT studies reported a higher prevalence of BMC, in the range 0.05 to 69.0% (Table ).…”

“…Muinelo‐Lorenzo et al () added a category that they termed the superior canal, which coursed upwards and did not meet the criteria for Naitoh's classification. Similarly, Moro et al () added a fifth category to Naitoh's classification, which they called the ramus canal, that is, a canal that extends from the IAC to the ramus region, which is above the mandibular foramen.…”

Assessment of Accessory Canals and Foramina in the Mandibular Arch Using Cone-Beam Computed Tomography and a New Classification for Mandibular Accessory Canals

“…These accessory canals may contain neurovascular elements, and if they were injured, they could cause intraoperative and postoperative surgical complications [ 32 ]. Although prosthetic restorations with implants are reliable in the medium [ 10 , 11 ] and long term [ 32 ], early complications during the surgical phase can occur due to accessory canals [ 33 ]. Therefore, it will be necessary to make use of a 3D imaging technique to increase accuracy, have a higher resolution, and reduce scan time and radiation dose.…”