Neuropathic pain in the orofacial region: clinical and research challenges.

Neuropathic pain in the orofacial region poses a difficult challenge to the treating physician. In some cases diagnosis is far from easy. Common causes of orofacial neuropathic pain are reviewed here, with a focus on the 2 most common: postherpetic neuralgia and posttraumatic painful peripheral neuropathy. In addition, the discussion includes idiopathic trigeminal neuralgia (tic douloureux), a neuropathic pain syndrome that is nearly unique to the trigeminal distribution (very rarely, it has also been reported in the glossopharyngeal region). Brief summaries of major research problems and successes are also provided.