Journal of Oral & Facial Pain and Headache, 04/2005

Aims: To determine the reliability and the validity of visual leg measurements used in dental kinesiology, which suggests that a masticatory dysfunction, such as occurs in temporomandibular disorders (TMD), can influence the length and the internal rotation of lower limbs. Methods: The leg-length inequality test and the internal foot-rotation test were performed independently by 3 different examiners on 41 subjects who were also screened for TMD. Data were analyzed by means of kappa statistics and by calculation of sensitivity and specificity values. Results: Chance-corrected reliability was generally poor for both the leg-length inequality test (0.33 = k = 0.39) and the internal foot-rotation test (0.15 = k = 0.27). Sensitivity and specificity values of the tests to differentiate TMD and healthy subjects were below acceptable thresholds; they ranged from 0.41 to 0.57. Conclusion: Visual evaluations of leg-length inequality and internal foot rotation were unreliable and are not valid for TMD diagnoses. The results of chiropractic visual leg measurement procedures in dentistry should be interpreted with caution, particularly when clinical decisions may lead to nonreversible dental treatment. Keywords: chiropractic, diagnostic tests, leg-length inequality, reliability, temporomandibular disorders

Aims: To examine whether catastrophizing is associated with clinical examination findings, pain-related activity interference, and health care use among patients with pain related to temporomandibular disorders (TMD). Methods: Patients with TMD (n = 338; 87% female; mean age, 37 years) completed measures of pain, pain-related activity interference, health care use, and depression, and received a Research Diagnostic Criteria/ Temporomandibular Disorders (RDC/TMD) clinical examination from an oral medicine specialist. Results: Catastrophizing was not significantly associated with the more objective clinical examination measures of maximum assisted jaw opening and jaw-joint sounds, but it was associated with the more subjective examination measures (unassisted opening without pain, extraoral muscle site palpation pain severity, joint site palpation pain severity) and with increased TMD-related activity interference and number of health care visits (P values for all .01). Even after controlling for demographic variables, pain duration, and depression severity, catastrophizing remained significantly associated with extraoral muscle and joint site palpation pain severity and with activity interference and number of health care visits. Conclusion: TMD patients who catastrophize have higher scores on clinical examination measures reflecting more widely dispersed and severe pain upon palpation of TMD-related facial muscle and joint sites, as well as greater TMD-related activity interference and health care use. Clinicians should consider screening patients with moderate or greater TMD pain and activity interference for catastrophizing. Cognitive-behavioral interventions may help reduce pain, disability, and health care use of patients who catastrophize. Keywords: activity interference, catastrophizing, chronic pain, Reasearch Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD), temporomandibular disorders

Aims: To outline the steps taken to conduct and to culturally adapt Dutch translations of the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) history questionnaire, clinical examination form, and verbal instructions to the patients, and to assess the reliability of the clinical examination. Methods: For the linguistic translation from English into Dutch, the forward and back-translation approach was followed. For cultural adaptation, an expert panel reviewed the translation, and a pretest was performed on a small clinical sample. Examiner training and calibration were carried out, and the clinical reliability of a "gold standard examiner" and 3 clinicians was assessed on 18 symptomatic TMD patients and 6 asymptomatic controls. The order of the examinations was based on a quasi-random Latin square design. Intraclass correlation coefficients (ICCs) were calculated to assess the overall interexaminer reliability of the clinical examination. Results: A linguistically valid and culturally equivalent translation of the RDC/TMD into Dutch resulted from the above-outlined procedure. As for the clinical reliability, the ICC values obtained could mostly be considered "excellent" or, less frequently, as "fair to good." Poor reliability was found only for some of the palpation tests. For uncommon diagnoses (disc displacement without reduction and without limited mouth opening; osteoarthritis), no reliable ICC value could be calculated. Conclusion: The mode described by the authors for preparing clinical sites for RDC/TMD-based research is a feasible one. Keywords: clinical examination, questionnaire, reliability, temporomandibular disorders, translation

Aims: To examine the presence and impact of post-traumatic stress disorder (PTSD) in a sample of patients seeking treatment for orofacial pain. Methods: One hundred forty-one consecutive patients with an array of orofacial pain conditions were screened using a structured clinical interview for PTSD and the PTSD Symptom Checklist-Civilian Version (PCL), a brief PTSD self-report inventory. Additionally, participants received a clinical examination and self-report questionnaires to assess pain, coping styles, and presence of post-traumatic symptoms. Results: Thirty-three (23%) patients received a full lifetime or current PTSD diagnosis, with an additional 11 patients receiving a partial PTSD diagnosis. Only 5 of these 44 patients had ever been previously diagnosed with PTSD. PTSD symptoms were associated with higher pain scores (P .05) and affective distress (P .01). Furthermore, discriminant function analyses suggested that the PCL accurately classified 89% of these cases (sensitivity = .85, specificity = .90, postive predictive power = 74%, negative predictive power = 95%). Conclusion: These results suggest that PTSD is prevalent in the orofacial pain setting and that PTSD symptomatology is associated with increased pain and affective distress that may complicate clinical presentation. Furthermore, PTSD can be accurately and efficiently assessed using a brief, self-report inventory. Keywords: orofacial pain, post-traumatic stress disorder, temporomandibular disorders

Aims: To compare pressure pain threshold (PPT) values for masticatory muscles in patients with signs and symptoms of myofascial pain and in asymptomatic individuals. Methods: Fifty women with masticatory myofascial pain comprised the symptomatic group (group 1), while 49 TMD symptom-free women were selected as controls (group 2). The PPT was obtained with the aid of an algometer by applying pressure to the masseter and to the anterior, middle, and posterior temporalis. A 90.8% specificity value was used to determine the appropriate PPT cutoff values for all 4 muscles studied. Receiver operator characteristic (ROC) curve areas and the likelihood ratio (LR) were also evaluated. Results: The 3-way ANCOVA test (group, muscle, and side) revealed a significantly lower PPT for all muscles in the symptomatic group (P .001). The lowest overall PPT was found for the masseter muscle, followed by the anterior, middle, and posterior temporalis (P .001). The 90.8% specificity was obtained with PPT values of 1.5 kgf/cm2 for the masseter, 2.47 kgf/cm2 for the anterior temporalis, 2.75 kgf/cm2 for the middle temporalis, and 2.77 kgf/cm2 for the posterior temporalis. The anterior temporalis had the highest LR. ROC curve areas of 0.84, 0.92, 0.90, and 0.90 were obtained for the masseter, anterior, middle, and posterior temporalis, respectively. Conclusion: The masseter and temporalis muscles require different pressures for distinguishing masticatory myofascial pain patients from asymptomatic individuals. Because the highest sensitivity (77%) and LR were found for the anterior temporalis, this muscle was considered to have the most suitable discriminative capacity. Keywords: masticatory muscle, myofascial pain, pressure pain threshold, sensitivity, specificity, temporalis muscle

Aims: To evaluate the distribution of mucopolysaccharides and glycoproteins in the articular discs of temporomandibular joints (TMJs) in human fetuses at different stages of development in order to test the hypothesis that the development and histological maturation of the articular disc has already begun by the 12th week of gestation. Methods: Eighteen human fetuses at gestational ages 12, 14, and 16 weeks were used (6 fetuses of each age). Sections (6 µm wide) of the articular discs were stained with trichromic stain for collagen fibers, Mayer's mucicarmine for mucopolysaccharides, and Schiff's periodic acid reaction for glycoproteins. The densities of the stained zones were measured by means of Image J software. The nonparametric Kruskal-Wallis test was used to evaluate the differences among stained zones in the 3 fetus groups. Results: TMJ tissues of four of the six 12-week-old fetuses were stained positive for collagen fibers, mucopolysaccharides, and glycoproteins. In these fetuses the stain was localized to the articular posterior area and was denser in that area than in the middle and anterior areas. The stained areas in the 14-week-old fetuses were distributed throughout the articular discs, with isolated clear unstained areas. The stained areas of all the articular discs of the 16-week-old fetuses were more compact than those of the 12-and 14-week-old fetuses. In all the fetuses examined, the collagen fibers along the articular disc had a wavy appearance. The fossa of the temporal bone was observed in all the fetuses as a straight structure that was similar in the 3 fetus groups. The densities (mean ± SD) of the stained zones were 38.36% ± 3.39%, 59.5% ± 1.56%, and 94.04% ± 2.04% for 12, 14, and 16 weeks of gestation, respectively; these densities were significantly different (x2 = 15.16; df = 2, P .001). Conclusion: This study indicates that mucopolysaccharides and glycoproteins as well as collagen fibers are present at 12, 14, and 16 weeks of gestation. This suggests that the histological maturation of the articular disc has already begun at the 12th week and is complete by the 16th week of gestation. Keywords: articular disc, collagen, human fetuses, mucopolysaccharides, temporomandibular joint

Aims: To evaluate how the frictional coefficient of the porcine temporomandibular joint (TMJ) is affected by an impairment of the synovial lubrication produced by an experimental abrasion of the articular cartilage and the application of hyaluronic acid (HA) with different molecular weights to the abraded cartilage surfaces. Methods: Erosion of the articular cartilage was produced by scouring it with sandpaper. Impairment and restoration of synovial lubrication were modeled by washing the joint space with phosphate-buffered saline (PBS) and by the application of HA with different molecular weights. After measuring the frictional coefficients in the intact TMJs (n = 10), the effects of washing with PBS, sandpaper scouring, and the application of HA were subsequently examined. Results: The mean frictional coefficient in the intact joint was 0.0154 (SD 0.0043). After PBS washing and sandpaper scouring, it increased significantly to 0.0235 (SD 0.0052) and 0.0520 (SD 0.0088), respectively. Subsequent application of HA resulted in a significant decrease (43% to 56%) of the frictional coefficient. Observations by scanning electron microscopy showed that after sandpaper scouring, the superficial cartilage layer was disrupted and inner layer was exposed, creating an irregular surface. Conclusion: Joint friction may increase by approximately 350% following an experimental scouring of the cartilage surface and impairment of synovial lubrication. Lubrication by means of HA decreased joint friction by approximately 50%. Keywords: frictional coefficient, hyaluronic acid, lubrication, osteoarthritis, temporomandibular joint

This article presents the case of a patient with an acute posterior disc displacement without reduction (PDDWR), whose temporomandibular joint (TMJ) showed, after physiotherapeutic manipulation, the characteristics of a posterior disc displacement with reduction (PDDR). Opto-electronic condylar movement recordings in both the PDDR state and the PDDWR state, and magnetic resonance imaging (MRI) scans of the TMJ in the PDDR state were carried out to document the case. The first 2 physiotherapeutic manipulations were initially successful in reducing the disc, but a few days later the joint showed a relapse to the PDDWR state. From the third manipulation on, now 12 months ago, the patient has been free of symptoms of the PDDWR state. Condylar movement traces of the joint in the PDDWR state indicated that the condyle was prevented from entering the fossa completely. The downward condylar movement deflections during the early phase of closing, recorded after the second manipulation, showed the reduction of the posteriorly displaced disc during closing. The movement recordings also showed that the PDDR could be eliminated by submaximal opening and closing movements. The MRI scans, taken after the third, successful manipulation, showed the disc to be in a normal position with respect to the condyle when the mouth was closed, and to be posteriorly displaced when the mouth was maximally opened. The case shows that manipulation techniques may successfully reverse an acute PDDWR into a PDDR. The technique of MRIs and condylar movement recordings show promise in further unraveling the morphological and clinical features of posterior disc displacements. Keywords: condylar movement recordings, internal derangement, magnetic resonance imaging, posterior disc displacement, temporomandibular joint