Morphological assessment of the anterior loop of the mandibular canal in Koreans

Abstract

The mandibular canal divides into the mental and incisive canals at the premolar region, forms the anterior loop which crosses anterior to the mental foramen, and turns back to reach the mental foramen. The aim of this study was to elucidate the general anatomical structure of the anterior loop of the mandibular canal using morphometry. Twenty-six hemimandibles from 19 cadavers (16 males, 3 females; mean age at death, 54.4 years) were studied by meticulous dissection with the aid of a surgical microscope. The location of the anterior loop, the diameters of the mandibular, mental, and incisive canals, and their distances from bony landmarks were measured using digital calipers. The anterior loop of the mandibular canal was located 3.05±1.15 mm (mean±SD) anterior to the anterior margin of the mental foramen and 2.72±1.41 mm inferior to the superior margin of the mental foramen, and was 4.34±1.46 mm long. The diameters of the mandibular, mental, and incisive canals were 2.8±0.49, 2.63±0.64, and 2.22±0.59 mm, respectively. The distances between the inferior border of the mandible and each of these canals were 7.82±1.52, 10.11±1.27, and 9.08±1.66 mm, respectively. The anterior loop of the mandibular canal was located a mean of 3.1 mm anterior and 2.7 mm inferior to the mental foramen, and continued upward and backward into the mental canal, and forward into the incisive canal. These detailed morphological features of the anterior loop of the mandibular canal represent useful practical anatomical knowledge regarding the interforaminal region.

Morphometric study on mandibular foramen and incidence of accessory mandibular foramen in mandibles of south Indian population and its clinical implications in inferior alveolar nerve block

“…The inferior alveolar nerve and vessels pass through the MF and traverse the mandibular canal and divides into mental and incisive branches to supply the mandibular teeth and participates in the formation of the anterior loop [12]. Inferior alveolar nerve block is a common local anaesthetic technique used in dental practice.…”

3-dimensional reconstruction of mandibular canal at the interforaminal region using micro-computed tomography in Korean

“…As the anterior loop length in previous researches, the horizontal distance from the mental foramen to the tip of the anterior loop varies in the range 0.2 – 7.6 mm, 19 and its prevalence has been reported an wide range of 0 – 88%. 5 In the present study, the midpoint of the mental foramen was most commonly found below the second premolar and the tip of the anterior loop was most commonly found below the first premolar, with a mean length of 5.19 mm ranged from 2.98 to 9.45 mm.…”

“…On the three-dimensionally reconstructed images, the mandibular and mental canals, mental foramen, and tip of the anterior loop, which coincides with the starting point of the mental canal, were identified. According to the result of Yu et al 19 that the mean diameters of the mandibular and mental canals are 2.80 and 2.63 mm, respectively, the tip of anterior loop was set a cutoff point of 2 mm for its minimum diameter. After that, at both the midpoint of mental foramen and the tip of anterior loop, the bucco-lingual distances from the mandibular canal to external cortex and the height from the inferior border of the mandibular canal to the inferior border of the mandible were measured.…”

Position of the Mandibular Foramen in Different Facial Shapes Assessed by Cone-Beam Computed Tomography - A Cross-Sectional Retrospective Study

“…The mandibular foramen is an irregular foramen located on the internal surface of the mandibular ramus, slightly above the center of the medial aspect of the mandibular ramus. The inferior alveolar nerve and vessels pass through the mandibular foramen and traverse the mandibular canal to give origin to the mental and incisive nerves [1]. Inferior alveolar nerve block, one of the anesthetic techniques used in dental practice, has a reported failure rate of about 20% to 25%, which is considered high [2].…”