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

Ayumi Moro,Shigehiro Abe,Naoko Yokomizo,Yutaka Kobayashi,Takashi Ono,Toshiaki Takeda

doi:10.1016/j.heliyon.2018.e00812

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.

Highlights

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)
We 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%
The neurovascular canals and foramens consist of the bifid mandibular canal (BMC) [1, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17], accessory mental foramen (AMF) [18], medial lingual canal (MLC) [19], lateral lingual canal (LLC) [19], buccal foramen (BF) [20], and lingual alveolar canal (LAC) [21]

Summary

Introduction

Damage to neurovascular canals and foramens in the mandible during oral surgical procedures causes many complications, the most serious of which are sensory disturbances and bleeding [1, 2, 3, 4, 5, 6].The neurovascular canals and foramens consist of the bifid mandibular canal (BMC) [1, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17], accessory mental foramen (AMF) [18], medial lingual canal (MLC) [19], lateral lingual canal (LLC) [19], buccal foramen (BF) [20], and lingual alveolar canal (LAC) [21]. Damage to neurovascular canals and foramens in the mandible during oral surgical procedures causes many complications, the most serious of which are sensory disturbances and bleeding [1, 2, 3, 4, 5, 6]. Panoramic images are often used as a preoperative diagnostic tool in oral surgical procedures; the data indicate that the full extent of the BMC and AMF has not been detected. Reported detection rates for the MLC, LLC, BF, and LAC are 97.0%, 99.0%, 44%, and 95.5%, respectively [19, 20, 21]. Previous studies report the expression rates and diameters of each type of canal and foramen; not all types occur in the same patient, so it is very important to evaluate their distribution in the mandible. The presence of these structures in panoramic images is important for screening

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Conclusion