Evaluation of incidence of mental nerve loop in Central India population using cone beam computed tomography

Anatomical literature has described the anterior loop being an extension of the mental nerve which is present anterior to the mental foramen while the caudal loop has been described as the distance between the lower border of the mental foramen and the lowest point of the mandibular canal. The knowledge and identification of the anterior and caudal loop of the mental nerve are important in surgical procedures performed around the mental foramen to avoid inadvertent damage to these vital structures resulting in postoperative complications.

The present study was conducted to determine the incidence and measurement of mental nerve loop in the mandibular arches using cone beam computed tomography (CBCT).

A total of 200 CBCT images were retrieved and inspected for the presence of the mental nerve loop. The length of the anterior loop was measured by counting the number of consecutive contiguous vertical cross sections displaying two round hypodense images. This number was multiplied by the thickness of the slices. The caudal loop was measured as the distance between the lower border of the mental foramen and the lowest point of mandibular canal.

Shapiro-Wilk test and Mann-Whitney U-test were used. P < 0.05 was considered statistically significant.

57.5% (n = 200 scans) presented with the anterior loop of the mental nerve with a mean length of 0.50 mm and 0.37 mm on the right side and left side, respectively. All the samples of CBCT scans taken were having caudal loop extension with a mean length of 3.53 mm.

A considerable number of individuals (57.5%) in the present study presented with the anterior loop of the mental nerve. CBCT was found to be an effective imaging modality for the detection of anterior loop of the mental nerve.