Journal of Oral & Facial Pain and Headache, 01/2002

Aims: To evaluate the potential capacity of a chewing exercise to differentiate chronic myofascial pain (MFP) patients from healthy controls and to test whether there are distinct pain response differences among MFP patients. Methods: Eighty-nine subjects participated in the study; 49 were diagnosed as belonging to the MFP subgroup of temporomandibular disorders (TMD) and had suffered from MFP for at least 6 months, and 40 healthy age- and gender-matched subjects comprised the control group. After completion of a clinical examination, all subjects performed a chewing exercise. Subjects chewed on half a leaf of green casting wax for 9 minutes and then held their jaw at rest for another 9 minutes. They indicated the intensity of the pain experience on a visual analog scale (VAS) every 3 minutes from the beginning (P0) to the end (P18) of the chewing exercise. Only changes in pain report of more than 5 mm on the VAS were considered. Analysis of covariance with repeated measures was used to analyze fluctuations in pain levels during the test, with the pain level at baseline (P0) as a covariant. Results: Statistical analysis revealed a significant main effect for group (MFP versus control); a significant main effect for activity (chewing versus rest); an interaction between activity and time; and an interaction between activity, time, and group. The latter revealed the significant effect of the chewing activity on pain levels in both groups along the axis of time and its recovery at rest. In the MFP patients, pain had increased by 32 mm at P9 in 84% of the patients and recovered to almost the initial pain levels by P18; 6% reported a decrease in pain sensation and 10% reported no change in pain. In the controls, pain had increased 4.9 mm by P9, a value within the recording error range of the scale. Conclusion: (1) A strenuous chewing exercise is a potentially beneficial tool in the diagnostic process of myofascial pain patients and, if validated, could be incorporated into clinical examinations. (2) The increase in pain intensity following the chewing exercise is typical of most of the MFP group. (3) The phenomenon of pain decrease in a small percentage of MFP patients should be further investigated. Keywords: chewing test, myofascial pain, temporomandibular disorders

Aims: Temporomandibular joint (TMJ) discs displaced simultaneously, dorsoventrally, and mediolaterally are assumed to be rotated. However, a pilot study performed with individualized oblique-axial scans on supposedly rotated discs did not show disc rotation consistently. The aim of this study was the quantitative evaluation of disc rotation on a larger sample size, assessing the mediolateral disc geometry and position by the use of a reference system determined by the condylar long axis. Methods: Eighty-five TMJs from 50 subjects were analyzed. One series of sagittal and 1 of 14 individualized oblique-axial magnetic resonance (MR) scans were taken for each joint. The dorsoventral disc position was diagnosed by means of the sagittal scans. The mediolateral disc width and position were then measured on every oblique-axial scan. The width and midline was computed for each disc and its deviation from the perpendicular to the condylar long axis was calculated. Finally, a statistical analysis was performed to study whether the disc width and the direction of the disc midline varied between discs normally positioned and anteriorly displaced. Results: The disc width varied significantly more within the anteriorly displaced discs than within the normal ones. The midline of the anteriorly displaced discs deviated more from the perpendicular to the condylar long axis than that of normally positioned discs and was mostly in a lateral direction. The disc midline also deviated more in the ventral than in the dorsal part of the disc. Conclusion: Most anteriorly displaced discs were laterally displaced and showed a larger width variation than normally positioned discs. This fact seems to indicate disc deformation. Keywords: temporomandibular joint, mandibular condyle, temporomandibular joint disc, magnetic resonance imaging, comparative study

Aims: To determine the impact of myofascial face pain (MFP) on dietary intake of selected nutrients. Methods: Sixty-one MFP women meeting the criteria for the myofascial subtype of temporomandibular disorders completed a 4-day daily food intake diary, as well as self-report of pain severity, pain interference with eating, and depressive symptomatology. Nutrient intake for the MFP women was compared with a demographically-equivalent sample of community women participating in the federally-sponsored Continuing Survey of Food Intakes by Individuals (CFSII). Within the MFP sample, multiple linear regression analysis was used to test whether dietary fiber intake reduction was most likely due to pain adaptation, or to depressive symptomatology or associated appetite reduction. Results: Only the subgroup of MFP patients with above-average pain severity showed reduced dietary fiber intake compared with the community sample. MFP patients did not differ from the community sample on other nutrient intake measures (ie, total calories, protein, fat, carbohydrates and dietary fiber, calcium, and iron). Within the MFP sample, pain severity was significantly associated with reduced dietary fiber intake. This relationship persisted, after controlling for depressive symptomatology, appetite, and total calories. Conclusion: Myofascial face pain patients with more severe pain intensity are likely to reduce their intake of dietary fiber. This is likely due to an effort to decrease masticatory activity to avoid exacerbating facial pain. Since low dietary fiber, especially in combination with commonly prescribed medications for MFP, increases the risk of constipation and may exacerbate comorbid medical conditions, clinicians should recommend alternative dietary fiber sources for MFP patients. Keywords: myofascial face pain, temporomandibular disorders, quality of life, pain, nutrition

Aims: To carry out a randomized clinical trial (RCT) contrasting usual conservative treatment of TMD by clinical TMD specialists with a structured self-care intervention, targeted to clinic cases independent of TMD physical diagnosis, who were reporting minimal levels of psychosocial dysfunction; the intervention was delivered by dental hygienists in lieu of usual treatment. Methods: The Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) was used to target subjects who exhibited minimal TMD-related psychosocial interference. Criteria for study inclusion were: (1) self-report of facial and/or masticatory muscle pain discomfort for which usual care was prescribed by the clinic TMD specialist; (2) RDC/TMD Axis II graded scale of chronic pain (GCP) score of 0, I, or II-Low. (3) Age 18 to 70 years. Results: On 1-year follow-up, while both groups showed improvement in all clinical and self-report categories measured, patients in the tailored self-care treatment program compared to usual TMD treatment showed significantly: (a) decreased TMD pain, (b) decreased pain-related interference in activity; (c) reduced number of masticatory muscles painful; (d) fewer additional visits for TMD treatment. Groups were comparable with regard to measures of vertical range of motion. The self-care program was associated with consistent, but non-statistically significant, trends towards lower levels of depression and somatization. Ability to cope with TMD, knowledge concerning TMD and patient satisfaction was significantly enhanced for the self-care group. No participating patients experienced physical or personal adverse effects during the 1-year post-treatment follow-up period. Conclusion: Use of RDC/TMD psychosocial assessment criteria can contribute to successful clinical decision-making for the management of TMD. Keywords: Research Diagnostic Criteria for TMD, self-care, pain

Aims: To compare the relative effectiveness of a benzodiazepine (clonazepam), a muscle relaxant (cyclobenzaprine), and a placebo for the treatment of jaw pain upon awakening, when each is combined with the recommended nonpharmacological components of initial medical management. Methods: Forty-one subjects were recruited with a diagnosis of myofascial pain based on the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). All subjects were given education about TMD and a self-care program. Subjects were randomized into 1 of 3 groups: clonazepam (0.5 mg/night), cyclobenzaprine (10 mg/night), or placebo. The primary outcome measure was the subjects' average intensity of jaw pain upon awakening over the prior week. This was recorded with a visual analog scale at pretreatment and at the completion of the 3-week trial. A secondary outcome measure was sleep quality based on the Pittsburgh Sleep Quality Index. Results: Within-group changes showed a statistically significant (P .001) decrease in jaw pain upon awakening for all 3 groups. Betweengroup differences demonstrated a statistically significant difference (P .016) between cyclobenzaprine and placebo, and between cyclobenzaprine and clonazepam. There was no significant effect on sleep quality in any group. Conclusion: This study suggests that cyclobenzaprine is statistically superior to either placebo or clonazepam when added to self-care and education for the management of jaw pain upon awakening. Based on the subjects' report of sleep quality, these medications failed to significantly improve sleep in the short term. Keywords: temporomandibular joint, myofascial pain, clonazepam, cyclobenzaprine, randomized clinical trial (RCT)

Aims: To compare the effectiveness of dry needling in classically recognized acupuncture points ("acupuncture") with dry needling in skin areas not recognized as acupuncture points ("sham acupuncture") in reducing masseter muscle pain in a group of patients with myofascial pain of the jaw muscles. Methods: Eighteen patients were randomly assigned to 1 of 2 experimental groups: Ten patients received acupuncture and 8 received sham acupuncture. A visual analog scale (VAS) was used to measure changes in masseter muscle pain evoked by mechanical stimulation of the masseter muscle before and after the experiment. Results: Both groups showed a statistically significant reduction in VAS pain scores (P = .001). Seven out of 10 acupuncture subjects had a 10 mm or greater VAS reduction in pain, while 4 out of 8 of the sham acupuncture subjects had that great a pain reduction. There was no significant difference between the 2 groups. Conclusion: Both acupuncture and sham acupuncture reduced pain evoked by mechanical stimulation of the masseter muscles in myofascial pain patients. However, this reduction in pain was not dependent on whether the needling was performed in standard acupuncture points or in other areas of the skin. These results suggest that pain reduction resulting from a noxious stimulus (ie, needling) may not be specific to the location of the stimulus as predicted by the classical acupuncture literature. Keywords: acupuncture, VAS pain rating, dry needling, myofascial pain, masseter muscle