Background: Trauma to the inferior alveolar nerve (IAN) is one of the complications during surgical procedures in the posterior mandible. Most of the time, this is due to inaccurate assessment of an operator from conventional radiographs. Lately, with the availability of advanced imaging techniques such as cone beam computed tomography (CBCT), precise location of anatomic structures has become a reality. This study was designed to evaluate the course and position of IAN in relation to the alveolar crest, buccal cortical bone, lingual cortical bone, and inferior border of the mandible using CBCT in South Indian population.
Materials and methods: A total of 139 CBCT scans were assessed using sagittal section done at every 5-mm interval beginning 1 mm posterior to the mental foramen extending till the anterior border of the ramus. Measurements were made on sectional images as CN - alveolar crest to the nerve, BN - buccal cortex to the nerve, LN -lingual cortex to the nerve, and IN - inferior border to the nerve.
Results: IAN showed a wavy pattern from posterior to anterior in relation to the alveolar crest and was positioned inferiorly in males when compared to females at Section one of CN1 (P = 0.004). IAN was more away from the lingual cortex in dentulous compared to partially dentulous group (P = 0.003). Females showed more bone present lingual to nerve near the first molar region. Gender and presence or absence of dentition had an influence on overall results.
Conclusion: There is a considerable variation in the position of IAN throughout its course in the mandible. Henceforth, advanced diagnostic images such as CBCT should be strongly recommended in evaluating the position of IAN preoperatively before advanced implant surgical techniques, nerve repositioning, and any other surgical procedures.
Keywords: Cone beam computed tomography; implant guidance; inferior alveolar nerve; nerve repositioning.