Journal of Oral & Facial Pain and Headache, 02/2008

Aims: To determine the prevalence of treatment need for temporomandibular disorders in adult populations by meta-analysis of nonpatient studies and to investigate factors influencing temporomandibular disorder treatment-need estimates. Methods: Population-based and nonpatient studies of adult subjects with temporomandibular disorders published in the English language prior to July 2006 were systematically reviewed. Electronic databases (MEDLINE, CINAHL, and Science Citation Index Expanded) were searched (n = 641). To combine data, fixed- and random-effects meta-regression models were used. Subgroup analyses were performed to assess factors influencing treatment need estimates. Results: Of 676 articles identified, 17 (9,454 subjects) met the study criteria. The prevalence of treatment need for TMD in adults (95% confidence interval) was estimated to be 15.6% (10.0, 23.6) for the fixed effect model and 16.2% (11.2, 21.1) for the random-effects model. Criteria of estimating treatment need and place of study strongly influenced summary estimates of treatment need (P .001). Need estimates derived from clinical TMD signs were higher than estimates based on subject-reported symptoms (P = .010). Estimates for younger subjects (19 to 45 years) were higher than for older subjects (46+ years; P = .013). Conclusion: The treatment need for TMD in the general adult population is substantial and varies according to definition, criteria, and age. Findings of this meta-analysis can be used for planning and allocating health-care resources. Keywords: epidemiology, temporomandibular disorders, temporomandibular joint dysfunction, treatment need

Aims: To use data from a large health maintenance organization to specifically investigate dental utilization rates among patients with and without temporomandibular disorders (TMD). Methods: Subjects were enrolled in Kaiser Permanente Northwest between 1998 and 2003. Two age- and gender-matched controls were selected for each subject who had a TMD diagnosis during the study period. Dental treatment was categorized using Current Dental Terminology (CDT) codes. Overall dental utilization rates were calculated, as well as rates based on age, gender, categories of treatment, and periods before and after TMD diagnoses. These rates were analyzed with t tests. Results: TMD subjects utilized significantly more dental services than comparison subjects overall and for several dental categories. The difference was between 10% to 20%, or about 1 additional dental procedure per year. A positive linear relationship existed between dental utilization rates and age, with a significant increase in utilization for each ascending age cohort. Females had higher dental utilization rates than males in TMD and non-TMD groups and in all categories of dentistry. After a TMD diagnosis, major differences in utilization were not found when compared to patterns of treatment prior to the diagnosis. Conclusion: TMD subjects utilized 10% to 20% more dental services than non-TMD subjects. Gender and age were important factors with increased utilization in females and older patients. TMD diagnoses did not affect dental utilization patterns, indicating that most TMD patients continue to seek routine dental care. Keywords: age groups, dental care, dental insurance, dental utilization, temporomandibular disorders

Aims: To test the hypothesis that temporomandibular disorder (TMD) patients have characteristic diurnal patterns of pain that are associated with diurnal or nocturnal parafunctions. Methods: Experience sampling methods were used to obtain information on pain from subjects (n = 84) diagnosed, according to the Research Diagnostic Criteria for TMD, with myofascial pain, myofascial pain and arthralgia, disc displacement, and from non-TMD controls. Variations in pain as reported on the pager questionnaire form were modeled as linear, exponential, and quadratic effects. Results: Between 8.7% and 23.8% of TMD subjects with pain showed significant patterns to their daily pain reports, compared to 4.5% of non-TMD controls. Groups did not differ significantly in the proportions of those with increasing (59.5%) vs. decreasing (40.5%) pain levels. Self-reported clenching during the day and grinding at night were weakly associated with an increasing or decreasing pattern of pain during the day (P .10). Pain levels during weekends were significantly lower for all groups. Conclusions: Strongly linear or curvilinear patterns of pain were not characteristic of this sample of subjects. More than half the subjects reported slightly increasing pain during the day, but the variability within groups was considerable. Increasing and decreasing patterns of pain were independent of self-reported daytime and nighttime clenching and grinding. Self-reported pain patterns may not be used to reliably infer the times when parafunctional activities occur. The presence of lower pain levels during the weekend probably reflects reduction in psychosocial stressors associated with the work week. Keywords: diurnal variation, experience sampling, modeling, pain, temporomandibular disorders

Aims: To investigate the effects of local intramuscular injection of the N-methyl-D-aspartate (NMDA) receptor antagonist ketamine on chronic myofascial pain and mandibular function in temporomandibular disorder patients. Methods: Fourteen myofascial temporomandibular disorder pain patients (10 women and 4 men) were recruited. The subjects completed 2 sessions in a double-blinded randomized and placebo-controlled trial. They received a single injection of 0.2 mL ketamine or placebo (buffered isotonic saline [NaCl], 155 mmol/L) into the most painful part of the masseter muscle. The primary outcome parameters were spontaneous pain assessed on an electronic visual analog scale and numeric rating scale. In addition, numeric rating scale of unpleasantness, numeric rating scale of pain relief, pressure pain threshold, pressure pain tolerance, completion of a McGill Pain Questionnaire and pain drawing areas, maximum voluntary bite force and maximum voluntary jaw opening were obtained. Paired t tests and analysis of variance were performed to compare the data. Results: There were no main effects of the treatment on the outcome parameters except for a significant effect of time for maximum voluntary bite force (analysis of variance; P = .030) and effects of treatment, time, and interactions between treatment and time for maximum voluntary jaw opening (analysis of variance; P .047). Conclusion: These results suggest that peripheral NMDA receptors do not play a major role in the pathophysiology of chronic myofascial temporomandibular disorder pain. Although there was a minor effect of ketamine on maximum voluntary jaw opening, local administration may not be promising treatment for these patients. Keywords: experimental pain, glutamate, ketamine, muscle pain, orofacial pain, temporomandibular disorders, trigeminal physiology

Aims: To develop a Malay-language version of the Axis II Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) through a formal translation/back-translation process and to summarize available data about the psychometric properties of the translated scales. Methods: To cross-culturally adapt the instrument, the RDC/TMD underwent translation using a forward-backward method. Subjects were recruited to test the congruency between translated and original versions of the RDC/TMD. The psychometric properties of 3 domains (Graded Chronic Pain Scale, Nonspecific Physical Symptoms, and Depression) of the RDC/TMD were examined, and the literature on this topic was reviewed. Results: All the items scored 93% to 100% congruency. Cronbach's alphas for Graded Chronic Pain Scale, Nonspecific Physical Symptoms, and Depression were 0.77, 0.71, and 0.88, respectively (n = 40). The test-retest reliability of scores (intraclass correlation coefficient [ICC]) and levels (Spearman's rho) for these domains showed ICCs of 0.97, 0.94, and 0.95, respectively, with a lowest ICC value of 0.84 (n = 40); the Spearman's rho values were 0.93, 0.74, and 0.74, respectively. The discriminant validity between patients with pain symptoms (n = 40) and normal pain-free controls (n = 40) were statistically significant (P .001). These correlations provide support for the internal consistency and validity of the Graded Chronic Pain Scale, Nonspecific Physical Symptoms, and Depression domains of the translated version of the RDC/TMD, which were found to be comparable to the psychometric properties of the original and other international translated versions. Conclusion: The cross-cultural adaptation of the RDC/TMD into the Malay language is suitable for use in Malaysia. Keywords: cross-cultural adaptation, internal consistency, temporomandibular disorders, translation, validity

Aims: To compare the tactile detection threshold, the filament-prick pain detection threshold, the pressure pain threshold, and the pressure pain tolerance detection threshold at multiple measuring points in the orofacial region and at the thenar muscle of symptom-free subjects and patients with myofascial pain of the masticatory muscles. Methods: Twenty patients (age range: 25 to 55 years) and 20 healthy subjects (age range: 25 to 55 years) were recruited. The tactile detection threshold and the filament prick-pain detection threshold were measured at the cheek skin overlying the central part of the left and right masseter muscles, at the right thenar muscle and at the tip of the tongue, using Semmes-Weinstein monofilaments. The pressure pain threshold and the pressure pain tolerance threshold were measured at the central part of the masseter muscle and on the thenar muscle, using a pressure algometer. The intensity of pain perceived during the assessment of filament prick-pain detection threshold, pressure pain threshold, and the pressure pain tolerance threshold was scored on visual analog scales. Results: The tongue tip had the lowest filament prick-pain detection thresholds as compared to the other sites. Filament prick-pain detection thresholds of the tongue and thumb sites were significantly lower in myofascial pain patients than in controls. Pressure pain thresholds of the masseter and thenar muscles were significantly lower in patients with myofascial pain than in control subjects whereas pressure pain tolerance thresholds did not differ significantly between patients and controls. Conclusions: The findings of the present study show topographic variations in the pain responses to different stimulus modalities. Different pain responses were also found between patients with myofascial pain and control subjects and were interpreted to support theories of centrally mediated pain for temporomandibular disorders. Keywords: jaw muscles, pain thresholds, temporomandibular disorders, trigeminal sensory testing, Von Frey hairs

Aims: To compare burning mouth syndrome (BMS) patients with age- and gender-matched controls for psychologic conditions, to analyze the effect of menstrual state on the intensity of burning, and to assess the efficacy of an antidepressant medication on the burning pain and psychologic status. Methods: Ninety-four patients with BMS and 94 matched control subjects participated in the study. Anxiety and depression were analyzed by means of the Spielberger State-Trait Anxiety Inventory and Zung Self-Rating Depression Scale, and the severity of the burning sensation was measured by means of a visual analog scale (VAS). In female BMS patients and controls, the menstrual state was noted (menstruating, menopausal, or postmenopausal). BMS patients were treated with the antidepressant moclobemide (150 mg 2 times daily) for 3 months. Thereafter, anxiety, depression, and burning pain intensity were reassessed. Patient-perceived satisfactory improvement for burning sensation was assessed using a 5-point categorical rating of change scale. Results: BMS patients had significantly higher anxiety and depression scores than controls (P .05). After treatment, anxiety and depression scores as well as the VAS values for burning pain decreased significantly (P .001). Thirty-seven patients reported good to very good improvement, and 44 reported satisfactory improvement. No adverse reactions were reported. Conclusions: The study confirmed earlier reports that BMS patients have higher anxiety and depression levels than controls. An antidepressant medication may be effective in alleviating the burning pain, at least in the short term. Keywords: anxiety, burning mouth syndrome, depression, moclobemide, pain measurement, treatment

Aims: To examine the effect of mechanical loading on the induction of temporomandibular joint osteoarthrosis (TMJ OA). Methods: Mechanical stress was applied to the rat TMJ by forced jaw opening of 3 hours a day for 5 days. The electromyographic (EMG) activity of the masseter and digastric muscles was continuously monitored by radio-telemetry. It was characterized by the total time each muscle was active (duty time), the number of bursts, and the average burst length. For histologic analysis, rats were sacrificed before, immediately after, and 3 weeks after the period of forced jaw opening. Results: The condylar cartilage revealed OA-like lesions with a decrease in the number of chondrocytes immediately after forced jaw opening. Three weeks later, the OA-like lesions were repaired to some extent. After the forced jaw opening, the duty time of the masseter increased, whereas the duty time of the digastric decreased significantly (P .01) at the 5% activity level. Three weeks later, the masseter duty time had decreased and the digastric duty time had slightly increased, returning to the levels observed before forced jaw opening. Conclusion: These results suggest that mechanical overloading of the TMJ induced OA-like lesions with a simultaneous influence on jaw muscle activity, especially at the low activity level. This might imply that muscle activity adapted to reduce the effects of (forced) joint overloading. Keywords: electromyography, jaw muscle, mechanical stress, osteoarthrosis, temporomandibular joint

25th Scientific Meeting of the French National College of Gnathology Collège National d'Occlusodontie (CNO) March 13-14, 2008 Brest, France