Location and applied anatomy of the mandibular foramen among individuals of different sagittal facial types in Asians.

BACKGROUND

Failure of inferior alveolar nerve block may be attributable to anatomical variations in the location of the mandibular foramen. This study aimed to determine the 3D location of the mandibular foramen (MF) using cone-beam computed tomography (CBCT) and compare the measurements across different sagittal facial types in Asians.

MATERIALS AND

METHODS

CBCT scans of 60 mandibles (10 retrognathic, 10 normal, 10 prognathic per gender) were analyzed. The injection pathway was simulated as a line through MF and contralateral lower premolar (MF-cL4). The distances from MF to ramus borders and the angles between MF-cL4 and the mid-sagittal plane (MSP), the mandibular plane (MP) and the lower occlusal plane (LOP) were measured. Data analysis was conducted using descriptive statistics and two-way ANOVA.

RESULTS

Distances from MF to the ramus borders were significantly greater in males than in females (p < 0.05). The distance between MF and the sigmoid notch of prognathic mandibles was greater than in normal/retrognathic types (p < 0.05). Angle MF-cL4-MSP was highly stable at 50.9° ± 2.9°, whereas angle MF-cL4-LOP exhibited significant individual variation with a coefficient of variation (CV) of 63.9%.

CONCLUSIONS

In Asians, MF was consistently located within the upper posterior quadrant of the ramus. Its anteroposterior position remains stable when referenced to MSP and cL4. In prognathic mandibles, MF positioned inferiorly relative to normal and retrognathic mandibles.