Inferior alveolar nerve dysfunction in mandibular fractures: a prospective cohort study

Objectives: To assess the prevalence and recovery of inferior alveolar nerve dysfunction (IAND) in mandibular fractures. Materials and Methods: This was a prospective cohort study. Clinical neurosensory testing was done preoperatively and the IAND was categorized as mild, moderate or severe. Postoperatively, neurosensory testing was repeated at 1 day, 1 week, 1 month, 3 months and every 3 months thereafter. Results: A total of 257 patients with 420 fractures were included in the study with a mean age of 31.7 years. Body fractures (95.9%) had the highest incidence of IAND, followed by the angle fractures (90.1%) and symphysis fractures (27.6%). The condyle and coronoid fractures did not have any IAND and hence were excluded from further study. After eliminating those cases, 232 patients remained in the study with 293 fractures. The overall prevalence of IAND in fractures occurring distal to the mandibular foramen was 56.3%. The changes until 1 week were minimal. From 1 month to 6 months, there was a significant reduction in the severity of IAND. A significant number of cases (60.0%) were lost to follow-up between 6 and 9 months. At 6 months, 23.9% of cases still had some form of IAND and 95.0% of the symphysis, 59.0% of the angle and 34.8% of the body fractures with IAND had become normal. Conclusion: This study documents the reduction in the degree of severity of IAND in the first six months and provides the basis for future studies with longer periods of follow-up.