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Biomedical subjects

R W Bessette

Publications and source records attributed to R W Bessette.

34 records · Page 2Linked to original sources
PubMed1986

Normal and abnormal temporomandibular joint: MR imaging with surface coil.

The normal temporomandibular joint (TMJ) was evaluated using magnetic resonance (MR) imaging with a surface coil in five subjects and compared with the abnormal joint in 37 patients (aged 14-59 years; total joints studied, 76). Multisection 3-mm-thick sagittal, coronal, and axial images were obtained with a 1.5-T MR system and 6.5-cm-diameter surface coil using both partial saturation and spin-echo sequences (TR = 1,000 msec, TE = 20 or 25 msec). A comparison with arthrography (n = 13 joints), computed tomography (CT) (n = 11), and surgical (n = 5) findings demonstrated that MR imaging with a surface coil provided an accurate depiction of both normal and abnormal TMJs. MR provided information about meniscal position, morphology, and histology that was not available with either arthrography or CT alone. The imaging potential of MR and its noninvasive characteristics warrant priority for further examination of MR as a useful modality in the diagnosis of TMJ pain and dysfunction.

Adolescent↗
PubMed1985

Diagnosis and reconstruction of the human temporomandibular joint after trauma or internal derangement.

This study reviewed the standardized records of 1100 patients with the symptoms of temporomandibular joint syndrome. Of these patients, only 4.5 percent required surgical intervention. The remaining patients were found to have masticatory muscle spasm and were treated by conservative dental methods. Over half the surgical patients had significant macrotrauma to the jaws in their past history. In addition, electromyographic measurement of the masseteric silent period duration in these patients did not reveal muscle spasm. These factors further serve to differentiate the surgical patient from the patient with myofascial pain dysfunction. The patients selected for surgery demonstrated moderate to severe joint disease and required arthroplasty with partial meniscectomy. A surgical technique is presented demonstrating the reconstruction of the meniscus with silicone implant. This same surgical technique is studied in 10 monkeys, and their joints are examined histologically. The results of surgery reveal that 87 percent of the patients reported improvement 1 year after surgery. In all patients complaining of temporomandibular joint clicking or crepitus, surgery produced complete alleviation of these symptoms. The results of surgery were also associated with a 62 percent increase of jaw opening. Histologic evaluation of the human meniscal resections revealed that in addition to an anatomic displacement of the meniscus, there are also significant cellular changes. These changes consisted of calcification, a decrease in cellularity, hyperemia, and a decrease in elastin content.

Adolescent↗
PubMed1985

Temporomandibular joint clicking with nonreducing anterior displacement of the meniscus.

Patients who have temporomandibular joint (TMJ) clicking and pain are assumed to have an anterior displacement of the meniscus with reduction on opening of the jaw. On the basis of this assumption, these patients are treated nonsurgically with splint therapy. Of 301 TMJs examined, 108 (36%) produced clinically audible clicks on opening, closing, or both. Fluoroscopy and arthrotomography studies for 16 (15%) showed anteriorly displaced menisci without reduction. The mean age of this group was 32 years, with a range of 17-51 years. The duration of the patients' symptoms ranged from three months to eight years (mean 3.7 years). Bilateral degenerative joint disease was noted in 8/16 (50%). Operative findings in four patients suggested the cause of the clicking sound as a frictional impact between the degenerated surface of the condyle and the hypertrophied displaced meniscus. These observations demonstrate that an audible click may not imply a reduction of a displaced meniscus.

Adolescent↗
PubMed1981

Histological evaluation of pore size and shape in silicone implants in rhesus monkeys.

Silastic has been used with varying success as an implant material. When Silastic implants fail, migration and infection are generally involved. Perforation of the implant has been suggested as a means of minimizing implant migration. In this study, 30 implants were studied in Rhesus monkeys. The implants varied in external geometric form and in perforation size. Results indicated that fibrous encapsulation of the implant occurred within two weeks. The tissue readily invaded the perforations regardless of pore size. The configuration of connective tissue was unaffected by external geometry. Perforated implants were less mobile than non-perforated implants, and implants with perforations of 3 mm or more contained dense fibrous connective tissue supported by an underlying vascular mesenchymal tissue not seen in implants with smaller pores. As a result of this study, we recommend that perforations be used in Silastic implants and that these perforations be at least 3 mm in diameter.

Animals↗
PubMed1979

Predicting by electromyography the results of nonsurgical treatment of temporomandibular joint syndrome.

This study of 308 patients demonstrated that reliance upon physical findings alone is not reliable for the diagnosis and the prediction of treatment success in TMJS. However, those patients who had a lengthened masseteric silent period on the EMG had a 93% success rate from treatment with occlusal splint and occlusal adjustment. In contrast, those patients who had a normal masseteric silent period on the EMG had only a 21 percent success rate from the same therapy.

Adolescent↗
PubMed1979

Cryosurgery of major and minor salivary gland: a light microscopic evaluation in the Rhesus monkey.

The minor salivary glands in the hard palate and the submandibular gland of the Rhesus monkey were subjected to a liquid nitrogen, direct-spray, one-cycle freeze. A 4-min freeze in the temperature range of -40 degrees C to -60 degrees C was used. The extent of tissue destruction was determined at intervals up to 1 year. Clinically relevant findings resulted and form the basis for subsequent studies by this group of investigators.

Animals↗