The purpose of this study was to examine the precise anatomical location of the lower labial branches (LLBs) of the mental nerve as they run beneath the oral vestibular mucosa (OVM), in order to prevent the complication of injury to the LLB during oral implant-related surgery.
Fifty-one mental neurovascular bundles were dissected from 26 cadavers to determine the course and depth of the LLBs between the mental foramen (MF) and the lower lip. The following items were measured:1) the number of LLBs, 2) the angle between the main branch of the LLB and the inferior border of the mandible (IBM), 3) the distance between the MF and the shallowest point of a LLB beneath the OVM, and 4) the depth from the shallowest point of the LLB to the OVM.
The results of the anatomical investigations were:
1) the number of LLB, 1~3 and 1.39±0.60 (mean±S.D.); 2) the main branch of the LLB-IBM angle, 25.00~70.00° and 50.40±12.40°; 3) the MF-LLB distance, 2.00~28.00 mm and 12.10±6.80 mm; and 4) the LLB-OVM depth, 0.05~5.40 mm and 0.90±1.03 mm.
These measurement results show that the LLB, upon exiting from the MF, runs in an anterosuperior direction at approximately 50°relative to the IBM and travels at an extremely shallow level directly beneath the OVM near the mandibular canine area.
View full abstract