Morphometric Analysis of the Midline Mandibular Lingual Canal and Mandibular Lingual Foramina: A Cone Beam Computed Tomography (CBCT) Evaluation

Abstract

Background: This study aimed to evaluate the midline mandibular lingual canals and foramina and their anatomic variations using CBCT scans.

Methods: This study used retrospective analysis. A total of 320 CBCT scans were used to evaluate the study parameters, which comprised the presence or absence of the mandibular lingual foramen (MLF)/mandibular lingual canal (MLC) and its category, the distance between the buccal cortex and the start of the MLC, the distance between the inferior border of the mandible and the superior border of the foramen at its lingual and buccal terminals. The length and diameter of each canal at its lingual and buccal terminals.

Results: MLC was found in all included CBCT scans. Out of 320 included CBCT scans, a single canal was represented by 30.9%, double canals (Supra with Infra -spinosum) configuration appeared in 54.7%, and triple canals (Supra-Inter-Infra) represented 14.7%. The supraspinosum canals averaged 5.81 ± 2.08 mm in length and 0.87 ± 0.30 mm in diameter at the lingual terminal. In terms of the number of canals, there was a significant difference between men and women (p ≤ 0.001), with 60% of the men in the sample having double canals and 43.1% of the women having single canals. Moreover, the male gender had a higher prevalence of triple canals (21.3% vs. 8.1%) than females. Males and females were distributed equally among the supraspinosum canals, with no statistically significant difference (p ≤ 0.7). A considerable increase in the finding of interspinosum and infraspinosum canals was seen in the male sample (p ≤ 0.001).

Conclusions: midline mandibular canals were found in all investigated CBCTs of the sample of both sexes; however, the anatomy and location of the MLF and canals varied significantly among the Saudi population.

Keywords: CBCT; lingual foramen; mandible; mandibular lingual canal; prevalence.

Figure 1

CBCT scan orientation. (A) Axial cut at the level of the genial tubercle to orient the midline. (B) Sagittal cut at the midline showing the mandibular lingual canals. The yellow arrow points to the supra-spinosum foramen, which is the opening of its corresponding canal (i.e., yellow line). The green arrow points to the infra-spinosum foramen, which is the opening of its corresponding canal (i.e., green line).

Figure 2

CBCT sagittal cut photograph showing study variable measurements: (A) Inferior border to the buccal terminal; (B) inferior border to the lingual terminal; (C) buccal cortex to the buccal terminal; (D) canal length; (E) lower border reference line.

Figure 3

Sagittal view at the mandibular lingual canal/s of CBCT scan showing three different variations, (A) single, (B) double, (C) triple canals. The yellow arrow points to the supra-spinosum foramen, which is the opening of its corresponding canal (i.e., yellow line). The blue arrow points to the inter-spinosum foramen, which is the opening of its corresponding canal (i.e., blue line). The green arrow points to the infra-spinosum foramen, which is the opening of its corresponding canal (i.e., green line).

Figure 4

Correlation between supra-spinosum canal length and its diameter at the lingual terminal (mm). r_s: Spearman coefficient; *: statistically significant at p ≤ 0.05.