Journal of Oral & Facial Pain and Headache, 03/2012

Aims: To estimate the contribution of various occlusal features of the natural dentition that may identify self-reported bruxers compared to nonbruxers. Methods: Two age- and sex-matched groups of self-reported bruxers (n = 67) and self-reported nonbruxers (n = 75) took part in the study. For each patient, the following occlusal features were clinically assessed: retruded contact position (RCP) to intercuspal contact position (ICP) slide length (< 2 mm was considered normal), vertical overlap (< 0 mm was considered an anterior open bite; > 4 mm, a deep bite), horizontal overlap (> 4 mm was considered a large horizontal overlap), incisor dental midline discrepancy (< 2 mm was considered normal), and the presence of a unilateral posterior crossbite, mediotrusive interferences, and laterotrusive interferences. A multiple logistic regression model was used to identify the significant associations between the assessed occlusal features (independent variables) and self-reported bruxism (dependent variable). Results: Accuracy values to predict self-reported bruxism were unacceptable for all occlusal variables. The only variable remaining in the final regression model was laterotrusive interferences (P = .030). The percentage of explained variance for bruxism by the final multiple regression model was 4.6%. This model including only one occlusal factor showed low positive (58.1%) and negative predictive values (59.7%), thus showing a poor accuracy to predict the presence of self-reported bruxism (59.2%). Conclusion: This investigation suggested that the contribution of occlusion to the differentiation between bruxers and nonbruxers is negligible. This finding supports theories that advocate a much diminished role for peripheral anatomical-structural factors in the pathogenesis of bruxism. Keywords: bruxism, occlusal features, predictive value

Aims: To test the hypothesis that the effects of an experimental occlusal interference differ between individuals reporting a high or low frequency of wake-time oral parafunctions. Methods: Study participants reporting very high (HFP group; n = 10) or very low (LFP group; n = 10) levels of oral parafunctions were selected by means of a questionnaire administered to 200 medical students. The selected participants wore an experimental occlusal interference in a single-blind longitudinal study, which comprised different occlusal conditions: interference free (IFC) and active occlusal interference (AIC). Assessments included clinical examination, measurements of nonfunctional tooth contacts, state and trait anxiety, and visual analog scale scores for occlusal discomfort, masticatory muscle pain, and headache. Data were analyzed by repeated measures twoway analysis of variance on ranked data, followed by calculation of within- and between-group differences using Friedman tests and Mann-Whitney tests, respectively. Results: During AIC, the frequency of nonfunctional tooth contacts significantly decreased in both groups (median [interquartile range, IQR]: in HFP from 55.3% [60.0%] to 31.1% [33.5%], P = .03; in LFP from 31.8% [32.4%] to 14.0% [22.8%], P < .01), the decrease being more pronounced in LFP than in HFP (P < .01). Trait anxiety was significantly higher (P = .01) in the HFP group (median, IQR = 22.5, 9.0) than in the LFP group (median, IQR = 19.0, 3.0). The interference caused more occlusal discomfort in the HFP group than in the LFP group (P = .02) and was associated with a significant increase of masticatory muscle pain (P = .05) and headache (P = .04) only in the HFP group. Conclusion: The application of an experimental occlusal interference has a different effect in individuals reporting a high or low frequency of oral parafunctions.

Aims: To test the hypothesis that estimates of time spent in tooth contact are significantly greater than estimates of time spent clenching, and to test the hypothesis that tooth contact is greater in pain patients, particularly those reporting facial or head pain, than those with pain elsewhere in the body. Methods: An anonymous, voluntary, confidential questionnaire was administered to 235 patients seeking care at a general medical clinic. The questionnaire assessed demographic variables, presence and location of pain, and percentage of time spent in tooth contact and in clenching. Analysis of variance was used to examine differences among groups of patients; logistic regression was used to identify significant predictors of pain. Results: All patients reported that the percentage of time spent in tooth contact was significantly greater than the time spent clenching. The same pattern of results emerged for those with and without head pain, and those with and without any chronic pain problem. Both tooth contact and clenching were significantly associated with head pain. Conclusion: Results from the logistic regressions provide convergent validity on the importance of oral parafunctions, specifically tooth contact and clenching, to facial/head pain. For assessment of oral parafunctional behaviors, inquiries that utilize clear behavioral referents (tooth contact versus clenching) are likely to result in more accurate estimates than behaviors with unclear definitions. Keywords: clenching, oral parafunction, pain, tooth contact

Aims: To test whether patients with temporomandibular disorder (TMD) pain differ from subjects from the general population with regard to their stress-related coping styles. Methods: Consecutive adult TMD patients (n = 70) and adult subjects of a regional general population sample (n = 868), examined according to the German version of the Research Diagnostic Criteria for TMD (RDC/TMD), were included in this study. The inclusion criterion for TMD patients was at least one pain-related diagnosis according to the RDC/ TMD, while general-population subjects were excluded if they had any pain-related TMD diagnosis. Coping styles were assessed using a common and well-accepted German 114-item stress-coping questionnaire ("Stressverarbeitungsfragebogen" SVF 114). The coping style-TMD pain relationship was investigated using logistic regression analyses adjusted for possible confounders (age, sex, level of education), as well as the influence of psychosocial measures (RDC/ TMD Axis II). Odds ratios (OR) with 95% confidence intervals (CI) were calculated. Results: Study participants who used fewer adaptive coping styles (OR = 0.47, CI: 0.26-0.83) and more maladaptive coping styles (OR = 1.55, CI: 1.05-2.29) were at greater risk for TMD pain. After adjustment for sociodemographic confounders, the coping style-TMD pain relationship changed only slightly in magnitude. In an analysis adjusted for sociodemographic confounders and psychosocial RDC/TMD Axis II measures, adaptive coping styles were even more profoundly related to TMD pain (OR: 0.27, 95 CI: 0.09-0.83), but maladaptive coping styles were less related to TMD pain (OR: 1.17, 95% CI: 0.51-2.72). Conclusion: Differences in the applied stress-related coping styles of TMD patients and subjects without TMD may have implications for clinical decisionmaking and choosing among treatment alternatives. Keywords: coping, stress, temporomandibular disorders

Aims: To test in a randomized controlled trial, if hypertonic saline (HS)-evoked pain and autonomic function are modulated by either a cold pressor test (CPT) or mental arithmetic stress induced by a paced auditory serial addition task (PASAT). Methods: Fourteen healthy women participated in three sessions. Pain was induced by two 5% HS infusions (5 minutes each, 30 minutes apart) infused into the masseter muscle. During the second HS infusion, pain was modulated by PASAT, CPT, or control (HS alone). HS-evoked pain intensity was scored on a 0 to 10 numeric rating scale (NRS). Heart rate variability (HRV) and hemodynamic measures were recorded noninvasively (Task Force Monitor). Data were analyzed using repeated measurements ANOVAs and Spearman correlation analysis. Results: HS-evoked pain was significantly and similarly reduced by both PASAT (30.8 ± 27.6%; P < .001) and CPT (35.8 ± 26.6%; P < .001) compared with the control session (9.0 ± 30.5%; P > .05). PASAT and CPT increased the heart rate compared with control (P .05). Conclusion: CPT and PASAT reduced HS-evoked masseter muscle pain and altered the autonomic response. The increase in heart rate following CPT and PASAT may be caused by different mechanisms. CPT reduced measures of efferent cardiac vagal (parasympathetic) activity, while the PASAT-induced increase in heart rate, but unchanged HRV, may suggest neurohumoral activation. Keywords: autonomic nervous system, cold pressor test, experimental muscle pain, mental stress, trigeminal nociception

Aims: To determine the contribution of a wide range of factors to care-seeking behavior in orofacial pain patients, expressed as (A) decision to seek care and (B) number of health care practitioners visited. Methods: Subjects with orofacial pain complaints were recruited in seven TMD clinics and from a nonclinical population sample. They received a questionnaire including a wide range of possible predictors. To study which predictive variables were associated with the decision to seek care and with the number of health care practitioners visited, multiple regression models were built. Results: Two hundred three persons with orofacial pain participated in the study. Of these participants, 169 (140 females) had visited at least one health care practitioner (care seekers), while the other 34 persons (25 females) did not (non-care seekers). The decision to seek care was not only associated with the pain intensity (P < .05), but, in women, also with fear of jaw movements (P < .01): Women with more fear of jaw movements were more likely to seek care. Pain intensity and disability were not associated with the number of health care practitioners visited. Instead, the main predictors were catastrophizing (P = .004) and the use of painkillers (P = .008). Conclusions: Pain intensity and fear of jaw movements play an important role in the decision to seek care for orofacial pain. The continuous search for help is associated with catastrophizing and the use of painkillers. Keywords: care seeking, health care utilization, orofacial pain, predictors

Aims: To analyze the influence of frequency, intensity, and duration of temporomandibular disorders (TMD), headaches, and neckshoulder pain (NSP) on Sami women's daily life. A further aim was to analyze the relationship between these symptoms and age. Methods: All 751 Sami women 21 to 70 years old registered in either the Swedish Sami Parliament's electoral register or registered as reindeer owners or herders and living north of the Arctic Circle in Sweden were sent a questionnaire regarding TMD symptoms, NSP, and headaches. In total, 487 women (65%) participated. The questionnaire focused on symptom frequency, duration, and intensity and whether these symptoms influenced activities of daily life. The symptom's interference with daily life activities was measured, respectively, with a numerical rating scale (NRS). The statistical analyses included multiple logistic regression analysis and Chi-square test. A P value < .05 was considered statistically significant. Results: Seventeen percent of the women reported that symptoms in the jaw-face region to some degree disturbed their daily life, and for 6%, the interference was significant (>= 5 on NRS). Duration of jaw pain, troublesome impaired jaw opening, and neck pain, together with a low education level, affected reports of whether symptoms of TMD influenced daily life. Almost half of the study population reported that headaches had a negative impact on their life. A similar pattern was reported for NSP. The prevalence of frequent and troublesome symptoms of TMD and headaches, but not NSP, showed a declining trend with age. Conclusion: TMD symptoms, headaches, and NSP negatively influence many Sami women's daily life. Factors related to pain had the greatest influence when these Sami women rated the related impairment. Keywords: headache, oral health, pain, quality of life, temporomandibular disorders

Aims: To determine whether a new palpometer and manual palpation can detect site-to-site differences in human craniofacial pain sensitivity in a similar pattern to that of an electronic pressure algometer and subsequently to compare between-session and within-session variability of palpometer and manual palpation. Methods: Sixteen volunteers participated. Experiment 1 was carried out in two sessions. In session 1, pressure pain thresholds (PPT) were determined with a pressure algometer at nine craniofacial sites. Manual palpation and the palpometer were then applied to all sites, and subjects scored perceived pressure/pain on a 0 to 100 numerical rating scale (NRS). Mean scores were compared using analysis of variance (ANOVA). Ten of the volunteers were recalled for a second session and the same protocol was carried out except for assessment of PPTs to establish between-session variability. In experiment 2, three craniofacial sites were examined using the palpometer and manual palpation. Both techniques were repeated 10 times at each site and coefficient of variation (CV) was compared to determine withinsession variability. Results: There were no significant differences in NRS scores evoked by manual palpation or palpometer at any test site between repeated sessions. The CV varied between techniques, with lower within-session variability for the palpometer compared with manual palpation (P = .03). Conclusion: The palpometer and manual palpation could detect differences in craniofacial sensitivity in healthy subjects, with no significant differences between repeated sessions. All techniques showed the highest sensitivity at the retromandibular site and the lowest at the temporalis muscle site. The palpometer had lower within-session variability compared with manual palpation. Keywords: algometer, numerical rating scale, palpation, palpometer, temporomandibular disorders

Aims: To determine the available evidence in the literature for whether hypoxia-reperfusion injury plays a role in the pathogenesis of joint diseases in general and of osteoarthritis (OA) of the temporomandibular joint (TMJ) in particular. Methods: The electronic databases CENTRAL, PubMed, and EMBASE were systematically searched. The search strategy combined thesaurus terms "reperfusion injury" and "joints" and excluded "tourniquet," which possibly induces iatrogenic reperfusion injury. Inclusion and exclusion criteria were applied, data were extracted, and quality was assessed. Results: Four studies could be included, investigating four different aspects of the hypoxia-reperfusion mechanism in joints. All studies investigated several arthritides in the knee or shoulder joint and were observational studies, except for one section of one of the studies, which was a randomized controlled trial. These studies do not provide any evidence to support or reject the hypothesis that hypoxia reperfusion occurs in TMJ OA. Positive but weak evidence is provided to support the hypothesis that hypoxia-reperfusion injury occurs in OA of the knee joint. Furthermore, some results of the included studies suggest differences between OA and other types of arthritis in relation to the hypoxia-reperfusion mechanism. Conclusion: There is no evidence to support or reject the hypothesis that hypoxia reperfusion occurs in TMJ OA, and limited evidence is provided to support that hypoxia-reperfusion injury occurs in OA of the knee joint. Since the studies suggest differences between OA and other types of arthritis in relation to hypoxia-reperfusion mechanisms, further research in this field needs to distinguish OA from other types of arthritis. Keywords: free radicals, osteoarthritis, reperfusion injury, temporomandibular joint

Orofacial pain bridges an important gap between medicine and dentistry. This article presents the case of a man who reported preauricular pain, tinnitus, and vertigo that began after extraction of an impacted third molar and who was sent for evaluation of a possible temporomandibular joint disorder. However, he was subsequently found to have markers and imaging results consistent with recurrent and more centralized lupus and/or multiple sclerosis. Keywords: lupus, multiple sclerosis, optic neuritis, temporomandibular disorders, tinnitus