Unilateral widening of the inferior alveolar nerve canal: a rare anatomic variant mimicking disease

We report a case of an asymptomatic healthy 49-year-old male patient with an incidental finding of enlargement of the right inferior alveolar nerve (IAN) canal (9 vs. 4 mm). After 2 years, follow-up magnetic resonance imaging (MRI) revealed no change in the findings. In addition, MR-based diffusion tensor imaging with tractography of the right and left mandibular nerves showed that the difference in size between the right and left nerves was caused by an increased number of nerve fibers in the right IAN. During the entire follow-up period of 4 years, the patient remained symptom-free. Therefore, we suggest that the enlargement in our patient was a pure anatomic variant. However, a multitude of conditions are known to produce the identical radiological appearance in conventional radiology, including benign and malignant tumors, vascular malformations, and inflammatory disorders. We describe these pathologies in more detail as well as the possibilities for examinations with different MRI sequences.