Characterization and opioid modulation of inflammatory temporomandibular joint pain in the rat.

PURPOSE: Experimental inflammation of the rat temporomandibular joint (TMJ) is commonly used to study trigeminal nociceptive processing. This study describes spontaneous pain-related behaviors following TMJ inflammation in the rat. The ability of preemptive systemic morphine to attenuate behaviors as well as immediate-early gene expression in the trigeminal nucleus is described. MATERIALS AND METHODS: Adult male Sprague-Dawley rats received an intra-articular injection of mustard oil (0% to 20%, 50 microL) and were observed for behavioral changes. Morphine sulfate (0 to 10 mg/kg SC) was given 30 minutes before mustard oil; this was reversed in one group with naltrexone hydrochloride (5 mg/kg SC). Two hours after injection rats were killed and perfused. Immunohistochemistry for the protein product of the immediate-early gene c-fos was performed, and brain stem sections including the trigeminal subnucleus caudalis were examined for positive nuclei. RESULTS: Mustard oil inflammation of the rat TMJ induces dose-dependent, morphine-sensitive behaviors. Behaviors observed included excessive grooming of the region, a chewing-like behavior, and head shaking. Fos expression in the trigeminal subnucleus caudalis parallels changes in behaviors. Morphine dose dependently attenuates the number of behaviors, as well as Fos expression; this effect is reversed by the micro-opioid receptor antagonist naltrexone. CONCLUSIONS: Mustard oil inflammation of the rat TMJ causes reliable behavioral changes, which may be quantified and, together with Fos expression, used to assess various experimental TMJ treatment modalities.     

Massive macroglossia, amyloidosis and myeloma

A 74 year old man with light-chain myeloma developed amyloidosis with macroglossia after 10 years of therapy with alkylating agents. Over a 2-year period his tongue enlarged to persistently protrude from his mouth, inhibit his speech, interfere with normal swallowing and eventually threaten his airway. As a life-saving procedure the tumorous anterior two-thirds of the tongue was resected, with excellent primary healing. Within two weeks the patient's speech became comprehensible and his ability to eat returned to normal. Although rare in amyloidosis, massive macroglossia may occur and surgical correction is easily achieved.     

Subclinical peripheral nerve involvement in AIDS: an electrophysiological and pathological study.

Thirty patients with AIDS without symptoms or signs of peripheral neuropathy were compared electrophysiologically with 23 age and sex matched healthy controls. The patients had a mean reduction in the amplitude of common peroneal compound muscle action potentials of 37% (95% CI 11-70%) and of sural sensory action potentials of 34% (CI 18-49%). Mean conduction velocity of both motor and sensory nerves was reduced by between 1 and 7 m/s, with a prolongation of F waves corrected for height of 5% in the arms and 13% in the legs. The distal motor latencies were unchanged. These changes did not correlate with the duration of AIDS, degree of immunosuppression (CD4 count), Body Mass Index, albumin or vitamin B12 level. Four patients had subclinical mononeuropathies. Sural nerve taken at necropsy from five asymptomatic AIDS patients had evidence of axonal degeneration without inflammation or demyelination. There was a mean reduction in myelinated fibre density of 30.5% (CI 10-51%) compared with eight age matched sudden death controls (p = 0.01). This loss principally affected the larger fibres. The pathological and electrophysiological changes indicate axonal degeneration and are similar to those seen in other chronic disorders and in normal ageing. It is concluded that this axonal degeneration is not specific to HIV.     

Management of the subluxed crystalline lens.

There has been a traditional reluctance to remove a subluxed (ectopic) lens because of the high surgical risk. The use of closed intraocular microsurgical techniques, however, now allows greater intraoperative control with few complications. The authors present the results of subluxed lens extraction, by limbal or pars plana lensectomy, in 44 eyes of 24 patients, in which the indication for surgery was lens subluxation causing a reduction in visual acuity or uncorrectable refractive error. Visual acuity was improved in all cases after surgery, with no significant complications. Patients with reduced visual acuity secondary to ectopic lenses have a good visual prognosis after lensectomy using a closed intraocular microsurgical technique.     

Financial Considerations Regarding Acquisition of the Siemens Cerec Computer Reconstruction System

There has been much interest in the in-office fabrication of ceramic posterior restorations using computer-aided design and computer-aided manufacture (CAD-CAM) units. One concern that practitioners have concerning the use of one of these systems is the initial expense of the CAD-CAM unit for the office. This article deals with the financial implications involved when considering the purchase or lease of a CEREC (CAD-CAM) unit.