Most Impacted Wisdom Teeth Have No Direct Nerve Contact, Study Finds
A recent study published in the Journal of Dental Sciences and Oral Rehabilitation in July 2026 reveals that a vast majority of patients—81.9% of males and 79.0% of females—show no direct contact between their impacted lower wisdom teeth and the nerve canal. This highly reassuring finding indicates that the risk of surgical nerve damage may be far less common than traditionally feared.
While impacted lower wisdom teeth carry up to an 8% risk of inferior alveolar nerve (IAN) injury during extraction, traditional two-dimensional radiographs cannot map their precise three-dimensional position. To bridge this clinical gap, Dr. Shreya Verma and researchers at the Institute of Dental Sciences in Bareilly, India, used cone-beam computed tomography (CBCT) to evaluate the exact shape and proximity of the nerve canal to these teeth.
Therefore, the retrospective study analyzed 210 adult cone-beam computed tomography (CBCT) scans to evaluate third molar positions, nerve canal shapes, and tooth-to-canal contact across genders using Chi-square and t-tests. Patients with cleft lip and palate, severe jaw deformities, severe malocclusion, or prior orthognathic surgery were excluded.
Key clinical findings of the Study Includes:
Predominant Impaction Level: Study shows that Type A impaction was the most frequent pattern in both males (51.4%) and females (48.6%), with no significant gender-based association (p = 0.650).
Prevalent Canal Location: Investigation revealed that the apical position of the canal was the most frequent in both males (47.6%) and females (54.3%), while the buccal position was more common in males (40.0%) than in females (28.6%) without statistical significance (p = 0.195).
Anatomical Canal Shapes: Analysis demonstrated that the IAC was predominantly oval in males (50.5%) and round in females (56.2%), whereas the tear-drop shape was the least common morphology across genders (p = 0.195).
Canal-to-Root Contact Proximity: Assessment found that direct contact was absent in most subjects (81.9% of males and 79.0% of females), with contact occurring in only 18.1% of males and 21.0% of females (p = 0.728).
The results suggest that a high prevalence of Type A impactions and apical canal locations, along with a lack of direct contact in 81.9% of males and 79.0% of females, defines the typical anatomical relationship in this cohort. Furthermore, the canal shape is highly variable yet predominantly round or oval, demonstrating that gender does not significantly dictate these dental and neural spatial relations.
Thus, the study concludes clinicians can utilize these findings to better understand the anatomical variability of the IAC, allowing for safer preoperative planning and surgical execution of mandibular extractions to minimize the incidence of nerve injury.
Reference
Verma S, Aggarwal A, Upadhyay N, Sowmya GV, Gupta N, Srivastava J. Cone Beam Computed Tomographic Assessment of Impacted Mandibular Third Molars in Relation to the Inferior Alveolar Canal: An Observational study. J Dent Sci Oral Rehabil. 2026;17(1):16-20.
