Journal of Oral & Facial Pain and Headache, 03/1997

To study the role of the nervous system in temporomandibular joint arthritis, substance P-, calcitonin gene-related peptide-, and neuropeptide Y-like immunoreactivity in the trigeminal ganglia and temporomandibular joint of rats was examined. Arthritis was induced in female Lewis rats through bilateral injection of a suspension of heat-killed Mycobacterium butyricum in paraffin oil into the temporomandibular joint. Control rats received paraffin oil via the same route. Tissues were collected for neuropeptide extraction 28 days after injection and analyzed by radioimmunoassay and reverse-phase high-performance liquid chromatogrpahy. Calcitonin gene-related peptide was significantly increased in the arthritic trigeminal ganglia. Substance P, calcitonin gene-related peptide, and neuropeptide Y in the arthritic temporomandibular joint were significantly increased as compared to controls. The results of this study show that sensory and sympathetic neuropeptides may possibly be associated with the development of arthritis in the temporomandibular joint of rats.

This study presents an approach to the classification of temporomandibular disorders (TMD) based on acknowledgment of the interaction of physical, psychologic, and social factors using a multidimensional instrument that has been previously validated. The psychometric properties of this instrument were reevaluated in 140 women with TMD. Multidimensional clustering identified three subgroups of patients with TMD, including a highly distressed, psychosocially maladaptive group; a moderately distressed, behaviorally functional group; and a predominantly physical disorder group with an unremarkable psychosocial profile. These groups were termed maladaptive, adaptive, and uncomplicated, respectively, according to the consteallation of predominant symptoms and psychosocial profiles of each cluster. The groups showed no consistent differences in pain frequency, use of medication, or duration of pain. This finding supports earlier work that suggested the prominence of three subtypes of this disorder according to both physical illness and psychosocial illness impact parameters.

The role of trauma in the etiology of temporomandibular disorders (TMD) is controversial. The objectives of this study were to compare presenting signs, symptoms, and diagnoses in patients who had motor vehicle accident trauma-related TMD to patients who had nontrauma-related TMD. Files of 50 trauma and 50 matched nontrauma TMD patients were reviewed. Information concerning presenting pain, temporomandibular joint (TMJ) and related symptoms, examination findings, and diagnoses was recorded. Posttraumatic TMD patients reported higher facial (P = .006) and headache (P = .0001) pain ratings, neck symptom frequency (P .01), ear-related symptoms (P = .02), sleep disturbance (P .001), and occupational and avocational disability frequencies (P .0001). They had greater masticato ry muscle (P .001), neck muscle (P .001), and TMJ tenderness (P = .01) scores and myofascial pain (P = .006) and arthralgia/capsulitis (P = .008) diagnoses. The nontrauma group had more subjective (P = .01) and objective (P = .05) TMJ crepitus and higher self-reprots of parafunctional jaw habits (P = .05). Trauma may be an important etiologic factor for some TMD patients.

Temporomandibular disorders (TMD) has been suggested to be of multifactorial etiology. One factor that has been suggested is laxity of joint ligaments. The purpose of this study was to evaluate the relationship between generalized joint hypermobility and TMD. Thirty-eight asymptomatic volunteers and 62 symptomatic patients were included in this study. All asymptomatic volunteers did not have temporomandibular joint pain, limited jaw movement, joint sounds, or previous TMD treatment. All subjects had bilateral magnetic resonance imagaing scans in the sagittal closed and opened and coronal closed positions. The Beighton test was used to score joint laxity with a laxity score of >- 4 to define generalized joint laxity. The symptomatic group had an increase in joint laxity as compared to asymptomatic control subjects (odds ration 4.0 [95% confidence interval = 1.38 to 10.95, P = .01]). There were no differences in laxity between male and female symptomatic subjects (P > .05). This study suggests a positive correlation between generalized joint laxity and TMD.

The aim of this study was to compare sagittal condylar movement patterns (SCMP, Axiograph) and high-field (1.5 T) magnetic resonance imaging (MRI) findings of the temporomandibular disorders. One hundred forty-one patients with TMD signs and/or symptoms were selected for this study. SCMP was categorized into six patterns: normal, figure-eight (early/intermediate/late), limited, and otehr irregularities. The MRI findings of TMJ internal ment were defined as one of five stages according to Wilkes criteria and then compared to the SCMP findings. Among normal SCMP, MRI revealed disc displacement in 27%. Sixty-three percent of figure-eight SCMP were regarded as stage I or II with reducible disc displacement. The sensitivity and specificity of 0.62, respectively. The point of deflection in figure-eight SCMP and the degree of disc displacement were not significantly related. However, a significant relationship was observed between the point of deflection in figure-eight SCMP and any type of disc deformation (chi-square = 9.80, P = .002). Thus, SCMP is not y et accurate enough for diagnosing a TMJ condition, espeically in the case of chronic and/or adaptive internal derangement.

This study compared myofascial pain of the masticatory muscles to fibromyalgia. Study data show that, in both myofascial pain and fibromyalgia patients, facial pain intensity and its daily pattern and effect on quality of life are very similar. This indicated that fibromyalgia should be included in the differential diagnosis for myofascial pain of the masticatory muscles. However, with the higher prevalence of neurologic and gastrointestinal symptoms, and the stronger words used to describe the affective dimension of pain, it is apparent that fibromyalgia may be a more debilitating condition than myofascial pain of the masticatory muscles. Since the intensity of facial pain was strongly and significantly correlated to the body-pain index in fibromyalgia but not in myofascial pain patients, it can be concluded that facial pain may be part of the clinical manifestations of fibromyalgia, but it is unlikely to be related to body pain in myofascial pain patients. On the other hand, while body pain is episodic in most myofascial pain patients, it is constant and more severe in the majority of fibromyalgia patients. This difference in the pain patterns suggests that body pain in fibromyalgia and myofascial pain could have different etiologies. The lack of correlation between the intensity of pain and the length of time since onset also supports the concept that myofascial pain of the masticatory muscles and fibromyalgia are unlikely to be progressive disorders.

The objective of this study was to analyze the relationship between need for treatment of temporomandibular disorders, sick leaves, and use of health care services in a study population of 441 adults born between 1927 and 1967. The findings indicated that these were strongly associated. The results were in agreement with earlier studies suggesting that stomatognathic disorders are one link between medicine and dentistry in health care. Subjects with temporomandibular dis orders were significantly more often on sick leave, visited a physician more often, and had more physiotherapy and massage than subjects who did not need treatment for temporomandibular disorders. Intervention studies are needed to improve cooperation between different specialties, to eliminate unnecessary examinations as well as ineffective treatment modaliteis, and to decrease the cost of health care.

The aim of this study was to investigate whether the treatment effect of intramuscular glucocorticoid injection differs between paitents with fibromyalgia and those with localized myalgia of the masseter mucle concerning pain, tenderness to digital palpation, pressure pain threshold, pressure pain tolderance level, maximum voluntary occlusal force, or intramuscular temperature. Twenty-five patients with fibromyalgia and 25 patients with localized myalgia of th e masseter muscle were first asked to assess their pain on a visual analogue scale; afterward, a routine clinical exmaination, including tenderness to digital palatpion, was performed. For each patient, the pressure pain threshold, pressure pain todlerance level, and maximum voluntary occlusal force, as well as the intramuscular temperature, were recorded. Finally each patient received an injection of glucocorticoid. The examination and glucocorticoid treatment were repeated after approximately 2 weeks, and a follow-up was perfored after another 5 weeks. In the fibromyalgia group, there was a reduced tenderness to digital palpation in response to the treatment. The localized myalgia group responded with a general improvement of symptoms as well as a significant reduction of pain intensity and tenderness to digital palpation. The results of this study indicate that patients with fibromyalgia and localized myalgia in many respects show a similar response to local glucocorticoid treatment.

Although patient attrition might be a serious threat to the validity of treatment-outcome studies on temporomandibular disorders (TMD), studies on TMD patient attrition are scarce. Of the 1405 consecutive TMD patients examined in a recent 10-year period, 367 (26.1%) drop-out pati ents or patients identified with a control group were sampled. A mailed questionnaire failed to reach 41 patients, and 203 (62.3%) were returned. The questionnaire elicited information on reasons for dropping out, changes in symptoms, treatment received in other clinics after dropping out, present treatment needs, and current signs and symptoms. Dropouts were divided into two groups: (1) those who failed to show up for their first scheduled appointment after the clinical examination; (2) those who failed to complete treatment. A group of patients who were judged by the examiner not to need treatment were included as a control group. The main reasons for dropping were environmental obstacles, perceived improvement of the disease, and dissatisfaction with services. Only 21.7% considered themselves to be in need of treatment, and only 10.3% had visited other clinics after dropping out. Only 8.9% complained of the continued aggravation of symptoms, whereas 57.6% reported improvement. In addition, pain, dysfunction, and daily activity limitation tended to improve with time, although temporomandibular joint noise tended to persist. These results suggest that TMD signs and symptoms tend to devrease in patients after dropping out, and that the natural fluctuation of TMD signs and symptoms should be taken into consideration when treating TM