Journal of Oral & Facial Pain and Headache, 03/1993

The rejection of the old hypothesis concerning the role of occlusal factors in craniomandibular disorders has been suggested because of the lack of evidence supporting the hypothesis. However, it would be more helpful to seek tests that clearly show that the hypothesis is wrong. Most of the studies used to favor rejection of this hypothesis have incorporated designs precluding any causal conclusions on the role of occlusal factors. Time and resources have been wasted in repeated efforts to obtain what is only associative proof; studies designed to address the causal question are few. There are, as yet, no results clearly warranting the rejection of the hypothesis that occlusal factors are part of a causal complex of craniomandibular disorders.

The histologic character of the articular surfaces and synovial tissues in the temporomandibular joints of 20 young adults was described. Each joint compartment had a continuous connective-tissue lining that was fibrous on the articular surfaces, went through a transition, and was continuous with the lining tissue in the recesses. Areolar synovial tissue was found only in the upper posterior recess of the temporomandibular joint, fibrous synovial tissue was predominantly found in the upper anterior and lower posterior recesses, and an intermediate type of synovial tissue was found in the lower anterior recess. There was no distinct boundary between articular and synovial tissue. The structure and continuity of these lining tissues suggest that they constitute a continuous tissue system, here termed the articular-synovial lining tissue system, that has a histologic character which depends on location and functional demands. It is hypothesized that all of the lining tissues should be considered synovial, based on a functional definition of nonadherence.

The psychological characteristics of patients with temporomandibular disorders have received much attention in the literature. A multivariate clustering technique has been used in the study of psychological characteristics of other chronic pain conditions, and this has recently been applied to emporomandibular joint pain patients to develop homogeneous psychometric subgroups. The primary objective of this study was to determine if these subgroups could be replicated in a separate sample. A group of 109 consecutive patients, presenting with complaints of jaw pain, were administered a Symptom Checklist-90 Revised and a questionnaire regarding characteristics of the pain complaint. A multivariate clustering technique was used to identify three discrete psychometric subgroups, as in previous studies. Although similar, these subgroups were not identical to those of previous studies. The small number of subjects in the psychometrically abnormal subgroup was of special interest.

The incidence of internal derangement of the temporomandibular joint has been documented in patients with temporomandibular disorders. However, the detection and diagnosis of a displacement of the temporomandibular joint disc in relation to internal derangement is not always accurate, and it varies according to the method of examination. A prospective clinical investigation of 26 patients (45 temporomandibular joints) with signs and symptoms of temporomandibular joint pain and dysfunction was completed to examine the accuracy of clinical examination, sagittal recording device tracings, arthrography, and magnetic resonance imaging in detecting internal derangement in the temporomandibular joint. A group of 16 asymptomatic control subjects (32 temporomandibular joints) was examined for the presence of internal derangement by the methods under consideration. Incidence of bilateral internal derangement in the temporomandibular joints of the symptomatic patients was also assessed. Findings obtained through clinical examination and sagittal recording device tracings agreed most often with the arthrographic findings of internal derangement. Magnetic resonance imaging often failed to detect the presence of arthrographically detected internal derangement. Internal derangement was identified bilaterally in a significant number of patients, despite the absence of bilateral symptoms. This incidence varied according to the technique used. In the control group, 9% of the temporomandibular joints that had been assessed as normal according to clinical examination and sagittal recording device tracings were found to have internal derangement according to magnetic resonance imaging.

To evaluate effects of internal derangement, the sagittal lengths of the condylar, temporal, and disc articular surfaces, as well as those of the disc attachments, were measured in histologic sections of human temporomandibular joints obtained at autopsy, mainly from adolescent, young adult, and middle-aged subjects. While the upper joint compartment appeared little affected, anterior disc position was significantly associated with comparatively long inferior disc attachments and a short condylar articular surface, indicative of possibly aberrant insertions of the attachments. Such discrepancies in size or alignment between condyle and disc complex could primarily reflect a constitutional deviation or result secondarily from remodeling.

Fifty-five patients (46 women and 9 men) with craniomandibular disorders and a history of pain of at least 6 months' duration participated in this trial. The patients were randomly assigned to three groups: one group to receive acupuncture; one group to receive occlusal splint therapy; and one group to act as controls. Pressure pain threshold, clinical dysfunction score, and visual analog scale measures were used to evaluate patients before, immediately after, and 6 months after treatment. A moderate, but statistically significant, correlation was found between pressure pain threshold and the number of tender spots in the masticatory muscles (tau = -.43; P .001), degree of tenderness in the masticatory muscles (tau = -.43; P .001), clinical dysfunction score (tau = .32; P .001), and the visual analog scale (tau = -.25; P .01). The short-term results showed a statistically significant improvement in all evaluations for both treatment groups. No significant differences were found in the control group. The improvements resulted in significant differences between the control and each treatment group immediately after treatment. At the 6-month follow-up, no significant differences in pressure pain threshold or clinical dysfunction score were found in the two treatment groups compared with the short-term results.

Localized inflammatory conditions (eg, synovitis and capsulitis) of the temporomandibular joint are commonly seen in clinical practice. Regardless of their frequency of occurrence, these conditions must be differentially diagnosed from conditions that also may cause pain in the temporomandibular joint region. Capsulitis or synovitis should be considered if such pain is present and historical, physical, and laboratory findings do not indicate a referred pain phenomena or systemic, tumorous, or infectious involvement. This article reviews the clinical characteristics, etiology, physical examination methods, treatment, and prognosis for capsulitis and synovitis, and three cases that illustrate these conditions are reported.

Three cases of carcinoma, seen in a head/neck pain management practice during the past 2 years and presenting as craniomandibular dysfunction symptoms, are reported. Clinicians should always consider a differential diagnosis because of the variety of potential causes of the symptoms presented by the patient. These symptoms act as clues to help to differentiate between a routine or evil process. The need for imaging and remaining, when the clinical symptoms do not correlate with the clinical examination through established guidelines for craniomandibular dysfunction or head/neck pain, is of paramount importance.

Chronic paroxysmal hemicrania is an intermittent head-pain problem that is characterized by pain paroxysms lasting about 15 minutes. The attacks usually produce pain in the frontotemporal region and are responsive to indomethacin. A set of symptoms that defines chronic paroxysmal hemicrania is presented, and two cases in which the presenting symptom was toothache are reported. It is emphasized that clinicians should consider chronic paroxysmal hemicrania in the differential diagnosis of orofacial pain.

A case of Alport's syndrome and coincidental temporomandibular joint degenerative disease is reported. Alport's syndrome is an unusual genetic disease that ultimately results in renal failure and has a high incidence of sensorineural hearing loss. The patient presented had complaints of facial and joint pain that mimicked what is currently termed temporomandibular disorder, including headache, tinnitus, joint pain, and temporal swelling. The significance of renal osteodystrophy is briefly reviewed as it pertains to this clinical presentation. The clinician must be alert to the many potential causes of degeneration of the temporomandibular joint, one of which may be metabolic in origin.