Imaging of the Trigeminal Nerve

Abstract

The clinical neurosensory testing of the patient who sustains an injury to the lingual nerve or inferior alveolar nerve is comprised of both objective tests and subjective tests. It has been suggested that there are no “purely” objective testing modalities available for the evaluation of iatrogenic injuries to the terminal branches of the trigeminal nerve, and this makes the clinical diagnosis and management of these conditions complex for the clinician. All available clinical neurosensory testing modalities require patient cooperation and are based upon a patient response, thus introducing a subjective component to the testing protocol. Furthermore, all testing is commonly performed following the nerve injury, so no individual baseline testing results are available for comparison and true determination of the magnitude of the resultant damage for each individual patient. For objective radiographic assessment, a number of imaging modalities are available to assist in the preoperative risk assessment of the trigeminal nerve, as related the commonly performed procedures in the vicinity of the nerve, mostly third molar surgery. In addition, these studies may be applied for objective functional monitoring of either spontaneous or surgically assisted recovery of the inferior alveolar (IAN) and lingual (LN) nerves. This chapter will provide a review of all currently available imaging modalities and their clinical application relative to the preoperative nerve injury risk assessment, and post-injury and postsurgical repair status of the IAN and LN.