Relationship Between Impacted Mandibular Third Molars And Inferior Alveolar Nerve

Abstract

Inferior alveolar nerve injury can be one of the most serious complications that can result from performing extraction of impacted mandibular third molar teeth during oral and maxillofacial surgical procedures. Because of the anatomical location of this nerve, it can be iatrogenically traumatized during various surgical procedures such as management trauma, cancer, pre-prosthetic problems, orthognathic surgery, and more often due to the extraction of the third molar.

AIM

To study the relationship between the impacted mandibular third molars and inferior alveolar nerve.

MATERIALS AND METHODS

This study was performed in the Department of oral surgery of the Saveetha Dental College and Hospitals in Chennai. The data of patients who had their impacted mandibular third molar extracted of age group 10-90 yrs were included in the study. The bar graphs were plotted and the results were statistically analysed using an SPSS Software system. Pearson’s chi-square group test was used to find the association between categorical variables. For the test, P <0.05 is to be considered statistically significant.

RESULTS

Males had more impacted teeth than females. Analysing the impacted mandibular molar teeth and nerve canal patterns, most of the nerve canals were normal. Dark and bifid root, darkening of a root, deflection of a root, diversion of the canal, interruption of white line canal, narrowing of root and narrowing of the canal are the anatomical variations of inferior alveolar nerve canal observed in this study. In the left impacted mandibular third molar 39.50% had normal nerve canals,0.83% had dark and bifid roots, 3.85% had darkening of roots, 1.35% had deflection off roots, 0.52% had roots with diversion of canals, 4.26% had nerve canals with interruption of white line canal, 2.18% had narrowing of canal and 0.94% had narrowing of roots. In the right impacted mandibular third molar 35.45% had normal nerve canals, 0.62% had dark and bifid roots, 3.53% had darkening of roots, 1.04% had deflection off roots, 0.52% had roots with diversion of canals, 3.01% had nerve canals with interruption of white line canal, 1.04% had narrowing of canal and 1.35% had narrowing of roots.

CONCLUSION

Within the limitations of the study, we found that there was a high incidence of mandibular third molar impaction in 10–30 years of age group, with the left impacted third molars more commonly involved, and a male predominance was observed. Most of the nerve canals were normal and some patients had a predilection to develop nerve injury-related complications due to the differences in the positioning of the nerve and the tooth root. Darkening of the roots and Interruption of the white line canal was the most commonly seen patterns associated with both impacted 38 and 48.