Journal of Oral & Facial Pain and Headache, 01/2013

Aims: To build an understanding of the patient's experience and from this identify recurring themes that could form part of an item pool for further testing of persistent dentoalveolar pain disorder (PDAP). Methods: Proven cases of PDAP were identified from a clinical database, and a purposive maximum variation sample was drawn. Semi-structured interviews were conducted with the sample by a single trained interviewer. Interviews were digitally recorded and transcribed verbatim. Data collection and analysis occurred until data saturation (n = 20), with no new themes emerging. Analysis of the data was an iterative and inductive process broadly following the principles of the constant comparative method. Results: Recurrent themes emerging from the data were: difficulty in responding to history taking; duration and magnitude of pain; complex and confounding descriptors; common exacerbating factor; well-localized pain; deep pain; pressurized or pressure feeling. Conclusion: Several common experiences that can be considered items were identified in the data. These items will add to the limited pre-existing item pool in the literature and allow testing of this item pool to determine those items best suited to form an adjunctive self-report diagnostic instrument for PDAP. Keywords: atypical odontalgia, diagnosis, diagnostic instrument, persistent dentoalveolar pain, phantom tooth pain, qualitative

Aims: To investigate the association among temporomandibular disorders (TMD), sleep bruxism, and primary headaches, assessing the risk of occurrence of primary headaches in patients with or without painful TMD and sleep bruxism. Methods: The sample consisted of 301 individuals (253 women and 48 men) with ages varying from 18 to 76 years old (average age of 37.5 years). The Research Diagnostic Criteria for Temporomandibular Disorders were used to classify TMD. Sleep bruxism was diagnosed by clinical criteria proposed by the American Academy of Sleep Medicine, and primary headaches were diagnosed according to the International Classification of Headache Disorders-II. Data were analyzed by chisquare and odds ratio tests with a 95% confidence interval, and the significance level adopted was .05. Results: An association was found among painful TMD, migraine, and tension-type headache (P .01). The magnitude of association was higher for chronic migraine (odds ratio = 95.9; 95% confidence intervals = 12.51- 734.64), followed by episodic migraine (7.0; 3.45-14.22) and episodic tension-type headache (3.7; 1.59-8.75). With regard to sleep bruxism, the association was significant only for chronic migraine (3.8; 1.83-7.84). When the sample was stratified by the presence of sleep bruxism and painful TMD, only the presence of sleep bruxism did not increase the risk for any type of headache. The presence of painful TMD without sleep bruxism significantly increased the risk in particular for chronic migraine (30.1; 3.58-252.81), followed by episodic migraine (3.7; 1.46-9.16). The association between painful TMD and sleep bruxism significantly increased the risk for chronic migraine (87.1; 10.79-702.18), followed by episodic migraine (6.7; 2.79-15.98) and episodic tension-type headache (3.8; 1.38-10.69). Conclusion: The association of sleep bruxism and painful TMD greatly increased the risk for episodic migraine, episodic tension-type headache, and especially for chronic migraine. Keywords: facial pain, headache, migraine, sleep bruxism, tension-type headache

Aims: To determine whether an intervention reduces oromotor activity and masticatory muscle pain in myofascial temporomandibular disorder (M/TMD) patients with high levels of masticatory muscle activity associated with sleep bruxism. Methods: Fourteen women with M/TMD and prior polysomnographic evidence consistent with sleep bruxism participated in a 10-week single-group pre-test/ post-test mechanistic clinical trial. A 2-week period of baseline monitoring of individually biocalibrated electromyographic (EMG) events associated with sleep bruxism was followed by 6 weeks of EMGevent- contingent treatment via an innocuous electrical pulse to the skin overlying the temporalis muscle. Treatment was discontinued during 2-week follow-up monitoring. Each night before sleep, subjects recorded their average daily pain. Results: Mixed-model analysis of variance showed a reliable reduction of EMG events during contingent stimulation treatment periods, but frequency of EMG events returned to baseline levels during follow-up (linear term, P = .002; quadratic term, P = .001). In contrast, nightly pain reports failed to show any systematic changes during treatment (linear and quadratic trends, both P > .10). Conclusion: Spontaneous pain severity and nighttime oromotor activity vary independently over nights, even in M/TMD patients selected for relatively high levels of both characteristics. Keywords: bruxism, electromyography, orofacial pain, temporomandibular disorders

Aims: To evaluate the impact of smoking on pain severity, psychosocial impairment, depression, anxiety, and sleep disturbances in a large sample of patients with temporomandibular disorders (TMD). Methods: A retrospective database review was performed on data from 3,251 patients with TMD, diagnosed according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). Pain severity ratings and psychometric data regarding impairment, sleep disturbance, depression, and anxiety were obtained. Differences between smokers and nonsmokers were evaluated by means of chi-square tests and independent samples t tests. Logistic regression models were used to study the impact of smoking, pain severity, and psychometric variables. Results: Of the total population, 42.5% comprised RDC/TMD group I (muscle pain), 25.3% comprised RDC/TMD group III (joint pain), and 32.2% comprised a mixed RDC/TMD group consisting of patients with both a group I and a group III diagnosis. Of the entire population, 26.9% admitted they were smokers. Even after controlling for relevant covariates, smokers reported significantly higher pain severity, impairment, anxiety, depression, and sleep disturbances than nonsmokers. Conclusion: Smokers with TMD reported higher pain severity than nonsmokers with TMD. These patients are at higher risk for factors that may adversely affect treatment outcomes. Keywords: anxiety, depression, nicotine, sleep disturbance, temporomandibular disorders

Aims: To explore potential differences in characteristics of patients that might account for sex-specific differences in temporomandibular disorders (TMD). Methods: A total of 502 patients presenting with TMD during 2000 to 2002 at the Outpatient Unit for Functional Disorders of the Medical University of Vienna underwent detailed evaluation of their medical history and assessment of clinical findings. The data obtained were assessed for sex-specific differences by analysis of variance and multiple regression. Results: Overall, 404 females (mean age ± SD: 40 ± 16 years; range 12 to 96 years) and 98 males (mean age 41 ± 16 years; range 16 to 78 years) were included. Their rating of their pain on a visual analog scale (VAS) showed a significantly higher pain intensity for females than for males (P = .004). Clinical assessment showed a significantly lower degree of mouth opening for females than for males (P .001). While no sex-specific differences were noted for clicking phenomena of the temporomandibular joint (TMJ) and for the bite class of the patients, bite anomalies were significantly more frequent in male patients (P = .03). Palpation of masticatory muscles and the TMJ revealed significantly higher tenderness on palpation in female as compared to male patients (P = .001). Grouping by clicking, crepitation, and bruxism also showed greater pain (VAS) and more tenderness on palpation in females versus males. Females also showed peaks of prevalence of TMD in the age group below 25 years and in the group 55 to 60 years, whereas males had a more even age distribution. No external factors, such as exposure to stress, were found that moderated the sex difference. Conclusion: Female TMD patients showed greater pain and muscle tenderness on palpation as compared to male TMD patients. They also showed a different age distribution of prevalence of TMD. These results were independent of subjective symptoms, clinical findings, and external factors. Keywords: gender differences, muscle tenderness on palpation, orofacial pain, sex differences, temporomandibular disorders

Aims: To conduct a systematic review of papers reporting the reliability and diagnostic validity of the joint vibration analysis (JVA) for diagnosis of temporomandibular disorders (TMD). Methods: A search of Pubmed identified English-language publications of the reliability and diagnostic validity of the JVA. Guidelines were adapted from applied STAndards for the Reporting of Diagnostic accuracy studies (STARD) to evaluate the publications. Results: Fifteen publications were included in this review, each of which presented methodological limitations. Conclusion: This literature is unable to provide evidence to support the reliability and diagnostic validity of the JVA for diagnosis of TMD. Keywords: joint vibration analysis, temporomandibular disorders, temporomandibular joint, systematic review

Aims: To test the hypothesis that jaw muscles and specific neck muscles, ie, levator scapulae, trapezius, sternocleidomastoideus, and splenius capitis, co-contract at the different submaximum bite forces usually generated during jaw clenching and tooth grinding, and for different bite force directions. Methods: Bite-force transducers that measured all three spatial force components were incorporated in 11 healthy subjects. The test persons developed feedback-controlled submaximum bite forces in a variety of bite-force directions. The electromyographic (EMG) activity of the levator scapulae, splenius capitis, and trapezius muscles was recorded, at the level of the fifth cervical vertebra, by use of intramuscular wire electrodes. The activity of the sternocleidomastoideus and masseter muscles was recorded by surface electrodes. For normalization of the EMG data, maximum-effort tasks of the neck muscles were conducted in eight different loading directions by means of a special force-transducer system. Differences between neck-muscle activity during chewing, maximum biting in intercuspation, and the force-controlled motor tasks were compared with the baseline activity of the various muscles by one-way repeated-measures analysis of variance. Results: The results confirmed the hypothesis. Co-contractions of the neck muscles in the range of 3% to 10% of maximum voluntary contraction were observed. Significant (P .05) activity differences were recorded as a result of the different force levels and force directions exerted by the jaw muscles. Long-lasting action potential trains of single motor units triggered by jaw clenching tasks were also detected. Conclusion: The findings support the assumption of a relationship between jaw clenching and the neck muscle activity investigated. The low level of co-contraction activity, however, requires further study to elucidate possible pathophysiological interactions at the level of single motor units. Keywords: bruxism, electromyography, masticatory muscles, neck muscles

Aims: To develop and test labeled magnitude (LM) scales that are sensitive to variations in pain associated with dentin hypersensitivity (DH). Methods: Qualitative methods were used first to obtain words that describe the pain of DH. Magnitude estimation was then used to determine the position of these descriptive terms by relative magnitude along four vertical LM scales. To assess their DH, patients used the four LM scales following dentin stimulation with 4°C and 25°C water. The LM scales were then compared to visual analog scale (VAS) ratings by using eight pain scenarios of varying severity. Finally, participants with DH completed the four horizontal LM scales and VAS after dentin stimulation with 4°C and 25°C water. Within-subject t tests were used for comparisons between scales and water temperatures, and between-subject t tests were used for comparisons between participants with and without DH. Results: Participants showed comparable differentiation between 4°C and 25°C water on VAS and three of the LM scale measures. Responses on the fourth LM scale showed better differentiation than VAS between the two water temperatures. Participants used a greater portion of the LM scales than VAS when rating low-level pain scenarios. Conclusion: LM scales were shown to provide some advantages compared to standard VAS when used to evaluate DH-associated pain. These advantages may be generalized to other low-level pain conditions. Keywords: dentin hypersensitivity, labeled magnitude scales, pain assessment