Central squamous cell carcinoma of the mandible. Computed tomographic findings.

Five cases of central squamous cell carcinoma of the mandible were investigated with the use of computed tomography. Bucco-lingual extent and spread along the mandibular division of the trigeminal nerve were evaluated. Three patients with trismus showed involvement of the masseter or medial pterygoid muscle on computed tomography. Involvement of more than two landmarks along the trigeminal nerve were observed in cases with both paresthesia of the lower lip and severe pain that resembled neuralgia. Perineural invasion was confirmed histologically in four cases, and all of these patients had both severe pain and mandibular canal involvement that could be demonstrated with computed tomography. When localized soft tissue changes are evident along the course of the trigeminal nerve in the region between the mandibular foramen and foramen ovale, ascending perineural spread should be suspected. Computed tomography findings correlated well with clinical symptoms but added information about the spread of the lesion within the surrounding soft tissue.