Local anesthetic effects in the presence of chronic osteomyelitis (necrosis) of the mandible: implications for localizing the etiologic sites of referred trigeminal pain.

The aims of this study were: (1) to demonstrate how reproducible variations in incomplete anesthesia of the inferior alveolar nerve can be used as a guide to locate the etiologic sites of referred trigeminal pain emanating from the mandible; (2) to describe the salient histopathologic features of a lowgrade, nonsuppurative osteomyelitis seen in this patient population. Forty-six patients with idiopathic facial pain were subjected to a specific protocol of local anesthetic injections to sequentially block branches of the mandibular nerve to determine the effects on his/her pain. If this significantly reduced or altered the pain on three separate appointments, then exploratory surgery was conducted near identified zones of unanesthetized gingiva. Blocking (92%), bridging (4%), and divergence (4%) were observed patterns of anesthetic resistance of the mucogingival tissues used to categorize the incomplete anesthesia. A 100% correlation was found between the identified zones of unanesthetized gingiva and the discovery of intramedullary pathology. Medullary fibrosis with ischemic and degenerative changes in the cancellous bone were common findings, along with chronic inflammatory cell infiltrates and clusters of lymphocytes. It is concluded that Ratner's method of diagnostic anesthesia be implemented when searching for occult pain producing pathology of the jaws.