Journal of Oral & Facial Pain and Headache, 03/2011

Aims: To compare prevalences of self-reported comorbid headache, neck, back, and joint pains in respondents with temporomandibular joint and muscle disorder (TMJMD)-type pain in the 2000-2005 US National Health Interview Survey (NHIS), and to analyze these self-reported pains by gender and age for Non-Hispanic (NH) Whites (Caucasians), Hispanics, and NH Blacks (African Americans). Methods: Data from the 2000-2005 NHIS included information on gender, age, race, ethnicity, education, different common types of pain (specifically TMJMD-type, severe headache/migraine, neck, and low back pains), changes in health status, and health care utilization. Estimates and test statistics (ie, Pearson correlations, regressions, and logistic models) were conducted using SAS survey analysis and SUDAAN software that take into account the complex sample design. Results: A total of 189,977 people (52% female and 48% males, 73% NH Whites, 12% Hispanic, 11% NH Blacks, and 4% "Other") were included. A total of 4.6% reported TMJMD-type pain, and only 0.77% overall reported it without any comorbid headache/migraine, neck, or low back pains; also 59% of the TMJMD-type pain (n = 8,964) reported >= two comorbid pains. Females reported more comorbid pain than males (odds ratio [OR] = 1.41, P .001); Hispanic and NH Blacks reported more than NH Whites (OR = 1.56, P .001; OR= 1.38, P .001, respectively). In addition, 53% of those with TMJMD-type pain had severe headache/migraines, 54% had neck pain, 64% low back pain, and 62% joint pain. Differences in gender and race by age patterns were detected. For females, headache/migraine pain with TMJMD-type pain peaked around age 40 and decreased thereafter regardless of race/ethnicity. Neck pain continued to increase up to about age 60, with a higher prevalence for Hispanic women at younger ages, and more pronounced in males, being the highest in the non-Whites. Low back pain was higher in Black and Hispanic females across the age span, and higher among non-White males after age 60. Joint pain demonstrated similar patterns by race/ethnicity, with higher rates for Black females, and increased with age regardless of gender. Conclusion: TMJMD-type pain was most often associated with other common pains, and seldom existed alone. Two or more comorbid pains were common. Gender, race, and age patterns for pains with TMJMD-type pain resembled the specific underlying comorbid pain. Keywords: age, back pain, chronic pain, headache/migraine, neck pain, prevalence, race/ethnicity, sample survey, self-report, temporomandibular joint and muscle disorders

Aim: To determine whether patients with myogenous or mixed (ie, myogeneous plus arthrogeneous) temporomandibular disorders (TMD) had different head and cervical posture measured through angles commonly used in clinical research settings when compared to healthy individuals. Methods: One hundred fifty-four persons participated in this study. Of these, 50 subjects were healthy, 55 subjects had myogenous TMD, and 49 subjects had mixed TMD (ie, arthrogenous plus myogenous TMD). A lateral photograph was taken with the head in the self-balanced position. Four angles were measured in the photographs: (1) Eye-Tragus-Horizontal, (2) Tragus-C7-Horizontal, (3) Pogonion-Tragus-C7, and (4) Tragus-C7-Shoulder. Alcimagen software specially designed to measure angles was used in this study. All of the measurements were performed by a single trained rater, a dental specialist in orthodontics, blinded to each subject's group status. Results: The only angle that reached statistical significance among groups was the Eye-Tragus-Horizontal (F = 3.03, P = .040). Pairwise comparisons determined that a mean difference of 3.3 degrees (95% confidence intervals [CI]: 0.15, 6.41) existed when comparing subjects with myogenous TMD and healthy subjects (P = .036). Postural angles were not significantly related to neck disability, jaw disability, or pain intensity. Intrarater and interrater reliability of the measurements were excellent, with intraclass correlation coefficient (ICC) values ranging between 0.996-0.998. Conclusion: The only statistically significant difference in craniocervical posture between patients with myogenous TMD and healthy subjects was for the Eye-Tragus-Horizontal angle, indicating a more extended position of the head. However, the difference was very small (3.3 degrees) and was judged not to be clinically significant. Keywords: cervical posture, head posture, photographs, reliability, temporomandibular disorders

Aims: To develop and validate a short screening tool for temporomandibular disorders (TMD) from the comprehensive Research Diagnostic Criteria for TMD (RDC/TMD) assessment. Methods: Complete RDC/TMD assessments of four subject groups (96 TMD; 102 dental pain; 68 headache; 115 no-pain patients) were compared. Classification tree and multiple logistic regression analyses were utilized to develop the tool. To test external validity, a further 54 TMD and 51 non-TMD subjects whose diagnoses had been established by RDC/TMD assessment were reassessed with the new screening tool. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and likelihood ratios (LRs) were calculated for the screening tool in the validation set of subjects. Results: A short TMD checklist was developed. This screening instrument had sensitivity of 94.4% (95% confidence intervals [CI], 84.9% to 98.1%), specificity of 94.1% (95% CI, 84.1% to 98%), PPV of 94.4% (95% CI, 84.9% to 98.1%), NPV of 94.1% (95% CI, 84.1% to 98%), and positive and negative LRs of 16.056 (95% CI, 5.346 to 48.219) and 0.059 (95% CI, 0.02 to 0.178) in an independent validation set. Conclusion: A short TMD screening checklist with high validity has been developed. This checklist may have good utility in general practice as a primary screening tool for TMD. Keywords: Research Diagnostic Criteria for TMD, screening, temporomandibular disorders, validity

Aim: To assess whether changes in diagnoses and management of temporomandibular joint disorder (TMJD) patients are influenced by radiographic findings and if there is an association between specific radiologic alterations and management strategy changes. Methods: A total of 204 patients with TMJ symptoms were examined using the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). Diagnoses and management were first decided without the aid of radiographs. Management categories were: pharmacology, physiotherapy, counseling and behavioral treatment, occlusal stabilization, surgery, additional examinations, and referrals, each with subcategories. Sagittal TMJ tomograms were assessed for the presence of flattening, erosion, osteophyte, and sclerosis in the TMJ components. Diagnoses and management were reevaluated after gaining access to the radiographs and radiographic classifications. Logistic regression analyses were performed with changes in management as the dependent variable and age and radiographic findings as the independent variables. Results: Diagnosis was changed for 56 patients, mainly from arthralgia to osteoarthritis. Management was changed for 55 patients. Most changes occurred in pharmacology and physiotherapy followed by counseling and behavioral treatment, occlusal stabilization, referrals, additional examinations, and surgery. Changes were mostly within the categories, and the highest number of changes was seen in pharmacology, physiotherapy, and counseling and behavioral treatment. Radiographic degenerative findings increased the chance of change (any change) (odds ratio [OR] >= 2.03) and the chance of change in pharmacology (OR >= 2.56) and physiotherapy (OR = 2.48) separately. No other significant associations were found. Conclusion: Radiographic degenerative findings increased the chance of changes in management strategy. However, 73% of the TMJD patients had no changes in management after radiographic examination. In cases with changes, these were mainly adjustments within management categories. Keywords: clinical investigation, management, radiography, Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD), temporomandibular joint (TMJ), therapy

Aims: To determine whether patients with a painful myofascial temporomandibular disorder (TMD) have diminished nocturnal heart rate variability (HRV), a marker of autonomic nervous system (ANS) dysfunction, relative to healthy, pain-free controls. Methods: Participants with myofascial TMD and healthy, pain-free volunteers underwent nocturnal polysomnography studies during which HRV indices were measured. Multiple linear regression analyses were used to determine whether TMD status exerted unique effects on HRV. Results: Ninety-five participants (n = 37 TMD; n = 58 controls) were included in the analyses. The TMD group had a lower standard deviation of R-R intervals (89.81 ± 23.54 ms versus 107.93 ± 34.42 ms, P = .01), a lower root mean squared successive difference (RMSSD) of R-R intervals (54.78 ± 27.37 ms versus 81.88 ± 46.43 ms, P .01), and a lower high frequency spectral power (2336.89 ± 1224.64 ms2 versus 2861.78 ± 1319 ms2, P = .05) than the control group. The ratio of the low-frequency (LF) to the high-frequency (HF) spectral power was higher in the TMD group (2.47 ± 2 versus 1.38 ± 0.65, P .01). The differences in RMSSD (91.21 ms versus 112.03 ms, P = .05) and LF:HF ratio (0.71 versus 0.32, P .01) remained significant after controlling for age and psychological distress. Conclusion: Myofascial TMD patients revealed lower nocturnal HRV than healthy, pain-free controls. Further research should focus on processes that address this ANS imbalance, which may potentially lead to effective therapeutic interventions. Keywords: autonomic dysfunction, chronic pain syndrome, heart rate variability, sympathetic hyperactivity, temporomandibular disorder

Aims: To evaluate the influence of an oral appliance on morning headache and orofacial pain in subjects without reported sleep-disordered breathing (SDB). Methods: Twelve subjects aged 27.6 ± 2.1 (mean ± SE) years and suffering from frequent morning headache participated in this study. Each subject was individually fitted with a mandibular advancement appliance (MAA). The first two sleep laboratory polygraphic recording (SLPR) nights were for habituation (N1) and baseline (N2). Subjects then slept five nights without the MAA (period 1: P1), followed by eight nights with the MAA in neutral position (P2), ending with SLPR night 3 (N3). Subjects then slept five nights without the MAA (P3), followed by eight nights with the MAA in 50% advanced position (P4), ending with SLPR night 4 (N4). Finally, subjects slept 5 nights without the MAA (P5). Morning headache and orofacial pain intensity were assessed each morning with a 100-mm visual analog scale. Repeated measures ANOVAs and Friedman tests were used to evaluate treatment effects. Results: Compared to the baseline period (P1), the use of an MAA in both neutral and advanced position was associated with a >= 70% reduction in morning headache and >= 42% reduction in orofacial pain intensity (P = .001). During the washout periods (P3 and P5), morning headache and orofacial pain intensity returned to close to baseline levels. Compared to N2, both MAA positions significantly reduced (P .05) rhythmic masticatory muscle activity (RMMA). Conclusion: Short-term use of an MAA is associated with a significant reduction in morning headache and orofacial pain intensity. Part of this reduction may be linked to the concomitant reduction in RMMA. Keywords: mandibular advancement appliance, morning headache, oral appliance, orofacial pain, rhythmic masticatory muscle activity

Aims: To characterize the control of jaw-clenching forces by means of a simple force-matching exercise. Methods: Seventeen healthy subjects, provided with visual feedback of the exerted force, carried out a unilateral force-matching exercise requiring developing and maintaining for 7 seconds a jaw-clenching force at 10%, 30%, 50%, and 70% of the maximum voluntary contraction. The task was repeated three times in each of two sessions. Motor performance was assessed, for both left and right sides, by different indices quantifying mean distance (MD), offset error (OE), and standard deviation (SD). Their dependence on force intensity, side, and time was assessed by ANOVA. Results: All error indices increased with the intensity of contraction in absolute terms. After normalization with respect to force level, the average performance in the second session was characterized by MD of 8.1% ± 2.6, OE 4.8% ± 2.9, and SD 12.7% ± 6.7 (mean ± standard deviation). Assessment of performance exhibited good reliability for all indices (intraclass correlation coefficient ranging from 74% to 88%). The motor performance improved with repetition (P .01), varied considerably between subjects, was not correlated with gender or age (P > .05) but was highly correlated between left and right side (P .01). Conclusion: The adopted approach is adequate to provide for an objective assessment of individual force control, although the presence of a learning phase must be taken into account. Keywords: accuracy, force transducer, masseter muscle, motor control, precision

Aims: To examine the effect of decreased estrogen level and altered diet hardness on condylar cartilage morphology of the rat temporomandibular joint (TMJ) and on the expression of condylar cartilage estrogen receptor alpha (ERα) and matrix metalloproteinase-8 (MMP-8). Methods: A total of 36 female rats was divided into four groups: ovariectomized rats fed a normal diet, non-ovariectomized controls fed a normal diet, ovariectomized rats fed a soft diet, and non-ovariectomized controls fed a soft diet. Ovariectomy was performed at the age of 60 days. Seven days after the operation, the rats were sacrificed. Repeated measures ANOVA and Duncan's multiple comparison tests were used for statistical analysis. Results: The ovariectomized rats had thicker cartilage layers than the controls, both in the normal diet and soft diet groups. The thinnest cartilage layers were found in the control rats fed with the soft diet. The thickness of the chondroblastic layer was significantly higher (P .001) in the normal-diet rats than in the soft-diet rats in both ovariectomized and non-ovariectomized groups. The thickness of the proliferative layer was significantly higher (P .001) in the ovariectomized soft-diet rats than in the soft-diet control rats. The proportional amount of ERα was statistically significantly higher (P .001) in the condylar cartilage of the ovariectomized rats than in the non-ovariectomized control rats both in the normal- and soft-diet groups. The proportional amount of ERα was statistically significantly higher (P .001) in the ovariectomized normal-diet rats than in the ovariectomized soft-diet rats. The proportional number of MMP-8-positive cells was statistically significantly higher (P .001) in the condylar cartilage of ovariectomized rats fed the soft diet than in non-ovariectomized control rats fed the soft diet. Control rats fed with the normal diet had a higher proportional amount of MMP-8 positive cells than control rats fed with the soft diet (P .05). Conclusion: The rat TMJ condylar cartilage is sensitive to changes in estrogen levels and altered diet hardness. Keywords: ERα, estrogen, joint loading, mandibular condylar cartilage, MMP-8

An elongated styloid process is an unusual source of craniofacial and cervical pain. This condition is characterized by a dull, nagging pharyngeal pain and a palpatory finding in the tonsillar fossa. Eagle described it for the first time in 1937 as Eagle's Syndrome and divided it into two subtypes: the "classic syndrome" and the "stylo-carotid syndrome." The syndrome generally follows tonsillectomy or trauma. Diagnosis is confirmed by radiological findings. Palpation of the styloid process in the tonsillar fossa and infiltration with anesthetic are also used for making a diagnosis. This article presents a case report of a patient with a history of throat pain that was relieved after surgical treatment. Keywords: Eagle syndrome, neck pain, styloid process