Peripheral trigeminal nerve injury as a consequence of dental surgery has been reported to range from 1 to 4 out of 1000 molar extractions. The most frequently injured nerves are the inferior alveolar (60%), followed by the lingual nerve. The imaging of post-surgical trigeminal neuropathy is not routinely performed and has not been described in the literature, as this is most often a clinical diagnosis.  

The role of the radiologist is to understand the normal anatomy and enhancement pattern of the trigeminal nerve as well as to be able to discern any abnormal findings. The CN V intracranial portions include its brainstem nuclei, prepontine cistern, Meckel cave and cavernous sinus segments. The extracranial segments are formed by V1, V2, and V3 which merge at the posterior cavernous sinus to form the trigeminal ganglion. An extensive perineural venous plexus obscures and gives the appearance of an enhancing trigeminal ganglion.  

On the other hand, true neuritis could produce isolated or unilateral nerve enhancement on all MRI planes. The most common intracranial causes can be discerned based on the location of abnormality (e.g. multiple sclerosis for brainstem, neurovascular compression at the cisterns, or tumors at the Meckel cave and cavernous sinus).