The challenge of ecological validity in temporomandibular disorders research.

OBJECTIVE: To review the ecological validity of outcomes from current research involving temporomandibular disorders (TMDs), with an emphasis on chronic myofascial pain and the precocious development of degenerative disease of the temporomandibular joint (TMJ). MATERIALS AND METHODS: Current approaches used to study TMDs in terms of neuromechanics, masticatory muscle behaviours, and the dynamics of the autonomic nervous system (ANS) were assessed for ecological validity in this review. In particular, the available literature was scrutinized regarding the effects of sampling, environmental and psychophysiological constraints and averaging data across biological rhythms. RESULTS: Validated computer-assisted numerical modelling of the neuromechanics used biological objective functions to accurately predict muscle activation patterns for jaw-loading tasks that were individual-specific. With respect to masticatory muscle behaviour, current findings refute the premise that sustained bruxing and clenching at high jaw-loading magnitudes were associated with painful TMDs such as myofascial pain. Concerning the role of the ANS in TMDs, there remains the need for personalized assessments based on biorhythms, and where the detection of dysregulated physiologic oscillators may inform interventions to relieve pain and restore normal function. CONCLUSIONS: Future human research which focuses on TMD myofascial pain or the precocious development and progression of TMJ degenerative joint disease requires experimental designs with ecological validity that capture objectively measured data which meaningfully reflect circadian and ultradian states.

Dental topographic proxies for ecological characteristics in carnivoran mammals.

Form-function relationships in mammalian feeding systems are active topics of research in evolutionary biology. This is due principally to their fundamental importance for understanding dietary adaptations in extinct taxa and macro-evolutionary patterns of morphological transformations through changing environments. We hypothesize that three-dimensional dental topographic metrics represent stronger predictors for dietary and other ecological variables than do linear measurements. To test this hypothesis, we measured three dental topographic metrics: Relief Index (RFI), Dirichlet Normal Energy (DNE), and Orientation Patch Count Rotated (OPCR) in 57 extant carnivoran species. Premolar and molar dental topographic indices were regressed against activity, diet breadth, habitat breadth, terrestriality, and trophic level variables within a phylogenetic framework. The results of this study showed significant correlations between RFI and the ecological variables diet breadth and trophic level. Weaker correlations are documented between OPCR and activity and between DNE and trophic level. Our results suggest that cusp height is strongly reflective of dietary ecology in carnivorans as a whole, and represents a proxy mainly for different degrees of hypercarnivory observed within this group of predatory mammals.

Is There an Association Between Temporomandibular Joint Effusion and Arthralgia?

PURPOSE: The literature on joint effusion (JE) and its association with clinical and radiologic variables in patients with temporomandibular disorders (TMDs) is inconsistent and is characterized by multiple methodologic limitations. The primary aim of this investigation was to evaluate the association between magnetic resonance imaging (MRI) identified JE and temporomandibular joint (TMJ) arthralgia. The secondary aim of this investigation was to determine the association between JE and other clinical and MRI-identified soft tissue characteristics. MATERIALS AND METHODS: A retrospective cohort study was conducted. Clinical and soft tissue imaging assessments were carried out according to the Diagnostic Criteria for Temporomandibular Disorders guidelines. The dependent variable was JE and the primary independent variable was arthralgia. The secondary independent variables were TMJ pain-associated characteristics and MRI-identified variables. When applicable, Pearson χ2 or t test was used to determine the statistical associations between JE and clinical characteristics and between JE and MRI-identified variables. Furthermore, generalized estimating equation (GEE) modeling was conducted to determine which of the independent clinical and MRI-identified variables were associated with JE. RESULTS: Data for 158 participants, representing 312 joints, were extracted. The mean age of the female sample (59.4%) was 31 ± 11.1 years and that of the male sample (40.6%) was 29.8 ± 9.7 years. No association was found between JE and arthralgia. However, statistically significant associations were found between JE and lateral disc rotation (P = .001) and between JE and disc position in the coronal and sagittal planes (P = .001). The GEE model suggested that disc displacement with reduction (odds ratio = 2.5) was a statistically relevant contributing factor for JE in the absence of degenerative joint disease. CONCLUSION: Results associated JE with the position of the disc in the sagittal plane. No association was found between JE and arthralgia or TMJ pain-associated clinical characteristics in patients with TMDs.

Reliability and diagnostic validity of a joint vibration analysis device.

BACKGROUND: This observational study was designed to evaluate the reliability and diagnostic validity of Joint Vibration Analysis (JVA) in subjects with bilateral disc displacement with reduction and in subjects with bilateral normal disc position. METHODS: The reliability of selecting the traces was assessed by reading the same traces at an interval of 30 days. The reliability of the vibrations provided by the subjects was assessed by obtaining two tracings from each individual at an interval of 30 min. The validity compared the Joint Vibration Analysis parameters against magnetic resonance imaging as the reference standard. The data were analyzed with exploratory factor analysis. RESULTS: The short- term reliability of the Joint Vibration Analysis outcome variables showed excellent results. Implementing factor analysis and a receiver operating characteristic as analytical methods showed that six items of the Joint Vibration Analysis outcome variables could be scaled and normalized to a composite score which presented acceptable levels of sensitivity and specificity with a receiver operating characteristic of 0.8. CONCLUSION: This study demonstrated that the composite score generated from the Joint Vibration Analysis variables could discriminate between subjects with bilateral normal versus bilateral displaced discs.

Goldenhar Syndrome and Pain-Related Temporomandibular Disorders. A Case Report.

Goldenhar syndrome (GS) is a development syndrome, characterized by incomplete development of the craniofacial region. The involvement is mainly unilateral; it varies from being mild to severe; and it can range from malocclusion and facial asymmetry to a more complex phenotype with complete absence of the mandibular ramus and temporomandibular joint. However, orthopedic symptoms of orofacial pain and dysfunction have not generally been considered as part of the symptom complex in GS cases. The case presented here is of a 15-year-old Caucasian patient, who was referred for evaluation because of bilateral pain in the masticatory muscles and temporomandibular joints.

Smoking cessation practices in the dental setting.

According to the US Centers for Disease Control, approximately 20.6% of the American adult population currently smokes cigarettes. There is no doubt that tobacco use has a negative effect on oral and general health. Dentists can be effective in assessing their patients' smoking status, health beliefs, and related behavior patterns. A total of 608 patients-smokers, former smokers, and nonsmokers-participated in this study. The Five A's protocol was utilized with follow-up interviews to assess smoking cessation (quit rates) among the patients. Of the 608 subjects, 170 (28%) were current smokers, 140 (23%) were former smokers, and 298 (49%) had never smoked. Females comprised 56% of the study group. Of the 170 smokers who were assessed at baseline, successful follow-ups were performed with 64 (38%). Based on a follow-up of these smokers, the 7-day abstinence quit rate was 22%. Among participants who received nicotine replacement therapy (NRT), 40% quit. Of the participants who did not receive NRT, 19% quit.

Systematic review of reliability and diagnostic validity of joint vibration analysis for diagnosis of 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.

The effect of oral motor exercises on patients with myofascial pain of masticatory system. Case series report.

Management of myofascial pain focuses on two goals: reducing pain and improving function in the muscles of mastication. A multidisciplinary treatment approach is typically used to help achieve these goals. The following case series report explores the impact of oral motor exercises on the management of myofascial pain when used in conjunction with other treatment modalities. Oral motor exercises are used by speech-language pathologists to improve the strength, range of movement and coordination of the oral musculature during non-speech movements. The findings of this case series report suggest an opportunity exists for collaboration between speech-language pathologists and the "traditional" TMD team.

Immediate Effect of Ultrasound on Bilateral Masseter Myalgia: A Randomized Dose-Response Clinical Trial.

AIMS: (1) To determine the dose-response relationship of therapeutic ultrasound for TMD-related pain in the masseter muscle among four doses comprised of two intensities (0.4 W/cm2 and 0.8 W/cm2) and two duty cycles (50% and 100%); and (2) to determine if therapeutic ultrasound applied to the masseter muscle would elicit a segmental effect on the ipsilateral temporalis muscle. METHODS: A total of 28 adult women with bilateral myalgia were randomly allocated to one of the four intervention doses. Therapeutic ultrasound was applied on each side of the masseter sequentially for 5 minutes. The following outcomes were measured before and immediately after each intervention: self-reported pain score, pressure pain thresholds for the masseter and temporalis muscles, and intraoral temperature adjacent to the treated masseter. RESULTS: Self-reported pain scores showed neither significant main effects nor significant interaction among the intensity or duty cycle doses (all P > .05). The change in the pressure pain threshold of the masseter showed a significant interaction (P = .02) attributed to the 0.4 W/cm2 and 100% duty cycle dose. Intraoral temperature was significantly increased and associated with the duty cycle (P = .01). A significant segmental effect of the pressure pain threshold of the temporalis was found for intensity (P = .01). CONCLUSION: There was an increase in the pressure pain threshold of the painful masticatory muscles and an increase in intraoral temperature adjacent to the treated area immediately after the use of ultrasound at 0.4 W/cm2 with a 100% duty cycle.

The Research Diagnostic Criteria for Temporomandibular Disorders. VI: future directions.

The Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) Validation Project has provided the first comprehensive assessment of reliability and validity of the original Axis I and II. In addition, Axis I of the RDC/TMD was revised with estimates of reliability and validity. These findings are reported in the five preceding articles in this series. The aim of this article is to present further revisions of Axis I and II for consideration by the TMD research and clinical communities. Potential Axis I revisions include addressing concerns with orofacial pain differential diagnosis and changes in nomenclature in an attempt to provide improved consistency with other musculoskeletal diagnostic systems. In addition, expansion of the RDC/TMD to include the less common TMD conditions and disorders would make it more comprehensive and clinically useful. The original standards for diagnostic sensitivity ( < or = 0.70) and specificity (< or = 0.95) should be reconsidered to reflect changes in the field since the RDC/TMD was published in 1992. Pertaining to Axis II, current recommendations for all chronic pain conditions include standardized instruments and expansion of the domains assessed. In addition, there is need for improved clinical efficiency of Axis II instruments and for exploring methods to better integrate Axis I and II in clinical settings.

The Research Diagnostic Criteria for Temporomandibular Disorders. V: methods used to establish and validate revised Axis I diagnostic algorithms.

AIMS: To derive reliable and valid revised Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) Axis I diagnostic algorithms for clinical TMD diagnoses. METHODS: The multisite RDC/TMD Validation Project's dataset (614 TMD community and clinic cases, and 91 controls) was used to derive revised algorithms for Axis I TMD diagnoses. Validity of diagnostic algorithms was assessed relative to reference standards, the latter based on consensus diagnoses rendered by two TMD experts using criterion examination data, including temporomandibular joint imaging. Cutoff points for target validity were sensitivity > or = 0.70 and specificity > or = 0.95. Reliability of revised algorithms was assessed in 27 study participants. RESULTS: Revised algorithm sensitivity and specificity exceeded the target levels for myofascial pain (0.82, 0.99, respectively) and myofascial pain with limited opening (0.93, 0.97). Combining diagnoses for any myofascial pain showed sensitivity of 0.91 and specificity of 1.00. For joint pain, target sensitivity and specificity were observed (0.92, 0.96) when arthralgia and osteoarthritis were combined as "any joint pain." Disc displacement without reduction with limited opening demonstrated target sensitivity and specificity (0.80, 0.97). For the other disc displacement diagnoses, osteoarthritis and osteoarthrosis, sensitivity was below target (0.35 to 0.53), and specificity ranged from 0.80 to meeting target. Kappa for revised algorithm diagnostic reliability was > or =0.63. CONCLUSION: Revised RDC/TMD Axis I TMD diagnostic algorithms are recommended for myofascial pain and joint pain as reliable and valid. However, revised clinical criteria alone, without recourse to imaging, are inadequate for valid diagnosis of two of the three disc displacements as well as osteoarthritis and osteoarthrosis.

A cross-sectional study of temporomandibular joint coronal plane disk position: imaging reliability and clinical utility.

OBJECTIVES: The aim of this study was to assess the reliability, frequency, and clinical significance of temporomandibular joint (TMJ) medial and lateral disk positions, observed in the coronal-oblique plane, to determine their importance in clinical diagnosis and for routine imaging. STUDY DESIGN: This cross-sectional study involved secondary data analysis (clinical and imaging) of 401 participants of the TMJ Impact Study. We used the χ2 statistic to evaluate the associations between coronal disk positions with (1) anterior disk displacements with reduction and without reduction; and (2) familiar TMJ pain resulting from excursive movements and palpation, range of motion, and joint sounds. RESULTS: Anterior disk displacements of any type occurred in 67.5% of joints; in contrast, medial and lateral disk positions occurred in 16% and 24% of joints, respectively. Radiologist reliability was as follows: sagittal posterior band position: right κ = 0.68, left κ = 0.60, average 84% agreement; and medial or lateral disk position: right κ = 0.36, left κ = 0.32, average 70% agreement. Medial and lateral disk positions were associated with sagittal displacements (P < .001). However, there were no associations between medial and lateral disk positions and familiar pain, range of motion, and joint sounds. CONCLUSIONS: Coronal disk position does not contribute to clinical symptomatology or findings and currently lacks sufficient evidence to support its inclusion into standard TMJ imaging protocols or into a clinical diagnostic category.

Mechanobehavior and mandibular ramus length in different facial phenotypes.

OBJECTIVES: To test the hypotheses that mechanobehavior scores (MBS) were correlated with mandibular ramus lengths (Co-Go) and differed between facial phenotypes. MATERIALS AND METHODS: Subjects gave informed consent to participate. Co-Go (mm), mandibular plane angles (SN-GoGn, °), and three-dimensional anatomy were derived from cephalometric radiography or cone beam computed tomography. Temporomandibular joint (TMJ) energy densities (ED) (mJ/mm3) were measured using dynamic stereometry and duty factors (DF) (%) were measured from electromyography, to calculate MBS (= ED2 × DF,) for each TMJ. Polynomial regressions, K-means cluster analysis, and analysis of variance (ANOVA) with Tukey post-hoc tests were employed. RESULTS: Fifty females and 23 males produced replete data. Polynomial regressions showed MBS were correlated with Co-Go (females, R2 = 0.57; males, R2 = 0.81). Cluster analysis identified three groups (P < .001). Dolichofacial subjects, with shorter normalized Co-Go, clustered into two subgroups with low and high MBS compared to brachyfacial subjects with longer Co-Go. SN-GoGn was significantly larger (P < .03) in the dolichofacial subgroups combined (33.0 ± 5.9°) compared to the brachyfacial group (29.8 ± 5.5°). CONCLUSIONS: MBS correlated with Co-Go within sexes and differed significantly between brachyfacial and dolichofacial subjects.

Smoking cessation practices in the dental profession.

AIM: The purpose of this review is to describe the current status of smoking cessation initiatives in the dental profession. REVIEW: A review of the initiatives undertaken by the dental profession to adopt smoking cessation recommendations as standard of care is presented. SUMMARY: Facts about the effects of smoking on the major oral diseases are stated and supported by national statistics. The barriers for compliance by dental professionals are described based on published research, but even more importantly, possible solutions are offered. CLINICAL SIGNIFICANCE: Awareness of the harmful effects of smoking tobacco can help dental professionals become more motivated to comply with current recommendations for smoking cessation in order to improve the oral and general health of the public.

Technological devices in the diagnosis of temporomandibular disorders.

Claims have been made that certain diagnostic devices should be routinely used to differentiate between jaw dysfunction and normal variation and between various pathologic conditions of the temporomandibular joint. The claims that jaw-tracking devices have diagnostic value for detecting TMD are not well supported by the scientific evidence. The clinical usefulness of electromyography devices is limited because of technical, methodologic, and data interpretation problems, as well as significant overlap between asymptomatic and symptomatic groups. Claims for the use of sonography and vibratography machines to discriminate between various intracapsular TMJ conditions have not been substantiated by well-designed research. Until acceptable levels of technical and diagnostic validity have been clearly established, these diagnostic devices cannot be relied on as aids in differential diagnosis or in clinical decision making in the TMD field.

Immediate Effect of Continuous Ultrasound vs Sham Ultrasound for Bilateral Masseter Myalgia: A Double-Blinded Trial.

AIMS: To investigate the local and segmental effects of therapeutic ultrasound at a dose of 0.4 w/cm2 with 100% duty cycle for 5 minutes compared to the effect of sham ultrasound on painful masticatory muscles. METHODS: A total of 20 adult female subjects with bilateral masseter myalgia diagnosed according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) were included. Each subject was randomized to either an active ultrasound group or a sham ultrasound group. The intervention was applied to each masseter muscle for 5 minutes. Measures included pre- and post-self-reported pain intensity recorded on a verbal rating scale (VRS), pressure pain thresholds for the masseter (PPT-M) and temporalis (PPT-T) muscles, and intraoral temperature for the masseter muscle. Preintervention score was subtracted from the postintervention score for all measures to calculate mean change in pain, and nonparametric Mann-Whitney test was used to compare the groups. Statistical significance was set at P < .05. RESULTS: Changes in VRS did not show a significant difference between groups (P > .05). There were significant increases in PPT-M and intraoral temperature in the ultrasound group compared to the sham group (P < .05). There was no significant difference in PPT-T (P > .05), suggesting no segmental effect. CONCLUSION: Therapeutic ultrasound produced an immediate increase in PPT-M and intraoral temperature compared to sham ultrasound in female subjects with bilateral masseter myalgia.

Psychosocial Scores and Jaw Muscle Activity in Women.

AIMS: To test whether women with temporomandibular disorder (TMD)-related pain showed higher psychosocial scores and higher awake- and sleep-time jaw muscle activities (characterized by duty factors) compared to pain-free controls and whether psychosocial scores and the jaw muscle duty factors were associated. METHODS: Subjects gave informed consent to participate. The Diagnostic Criteria for TMD (DC/TMD) were used for diagnosis of TMD pain, and 31 and 36 women were included in the TMD-related pain and control groups, respectively. DC/TMD Axis II instruments were used to determine psychosocial scores. Subjects self-recorded masseter and anterior temporalis electromyography (EMG) over 3 days and 3 nights. The duty factor (time of muscle activity/total recording time [%]) was quantified using subject-specific EMG/bite-force calibration via data recorded in the laboratory. Group differences (α = .05) were assessed for psychosocial scores and duty factors using chi-square and two-sample t tests. Linear regression assessed whether psychosocial scores were associated with duty factors. RESULTS: Average duty factors were ≤ 2.4% for awake and sleep times in both muscles, and between-group comparisons showed no significant differences. For physical symptom scores, there were significantly fewer TMD-related pain subjects in the normal category and significantly more in the moderate-severe category (all P < .01) compared to controls. Subjects with elevated compared to normal psychosocial scores showed significantly higher jaw muscle duty factors by ≥ 1.5-fold. CONCLUSION: A significantly larger proportion of TMD-related pain subjects compared to control subjects had moderate-severe physical symptom scores. Awake- and sleep-time jaw muscle duty factors were not different between groups and were generally low among all subjects. Additionally, higher than normal psychosocial scores were associated with significantly more low-magnitude jaw muscle activity.

Oral cancer screening, dental needs assessment and risk factors literacy in Hispanic population of western New York.

Thus far in 2007, 5370 people have died of oral cancer in the United States. While early detection is vital for most cancers, it is of utmost importance in the case of oral cancer, because most oral cancers are detected at advanced stages. It is important to focus on those groups at highest risk. In terms of oral cancer, men over the age of 40 in lower socio-economic groups who smoke, drink alcohol heavily and who have an unhealthy diet are at higher risk for developing oral cancer. Hispanics exhibit many of these high risk characteristics. Unfortunately, those at higher risk are also less likely to be screened for oral cancer than those at lower risk, because they make fewer regular dental visits. This paper presents the results from an ongoing outreach program developed by the School of Dental Medicine (SDM) at the University at Buffalo that was undertaken to assess the dental needs of and provide oral cancer screening and basic oral health instructions to the Hispanic community of Western New York. A total of 110 community members volunteered to participate in this program. The overall goal of the SDM is to increase its presence in the community in order to assist with treatment needs.

Assessment of knowledge on temporomandibular disorders among Mexican dental educators.

Temporomandibular disorders (TMDs) is an umbrella term that embraces a group of musculoskeletal and neuromuscular conditions that involve the temporomandibular joints, muscles and all associated tissues. Because of the relatively high number of patients with TMDs in the population, instruction in this area of health care should be included on all dental curricula. Although levels of knowledge among dentists have been evaluated in several countries, they have not been in Mexico. This study evaluates the dental faculty's range of knowledge about TMD at five dental schools in Puebla, Mexico. Using an observational design, a survey was administered to 161 educators in order to assess their knowledge of TMD. Four domains were assessed, including: a) pathophysiology; b) psychophysiology; c) psychiatric disorders; and d) chronic pain. Overall knowledge of TMD was measured using a consensus of TMD experts' answers as a reference standard1The results show that educators' overall knowledge had 55% agreement with the reference standard. Individually, the psychophysiological domain was correctly recognized by 77.7% of the educators; correct responses on the other domains ranged from 38% to 56%. This study demonstrates the need to incorporate standardized TMDs instruction into the dental curricula at Mexican Universities, without which graduating dentists will lack the necessary knowledge or experience to diagnose and manage their TMD patients.

Los Trastornos Témporomandibulares (TTM) incluyen un grupo de condiciones musculo-esqueléticas y neuromusculares que afectan a la Articulación Temporomandibular (ATM), los músculos masticadores y otros tejidos asociados. Debido al número relativamente alto de pacientes con TTM en la población, la educación en esta área de la salud debe ser incluida en las currículas de las escuelas de odontología. A pesar de que el nivel de conocimiento sobre TTM ha sido evaluado en diversos países, esto no ha sido realizado en México, por lo que el objetivo del presente estudio fue evaluar el nivel de conocimiento sobre los TTM de los profesores de odontología en cinco universidades de Puebla, México. Bajo un diseño observacional, se administró una encuesta a 161 docentes de odontología para evaluar el nivel de conocimiento sobre los TTM. La encuesta incluyó cuatro dominios: a) patofisiología; b) psicofisiología; c) trastornos psiquiátricos y d) dolor crónico. Se usaron las respuestas otorgadas con un consenso de expertos como estándar de referencia1 para evaluar el nivel global de conocimiento sobre los TTM. Los resultados mostraron que los docentes tuvieron un nivel global de conocimiento del 55% de acuerdo al estándar de referencia. El dominio psicofisiológico individualmente fue el mejor reconocido con el 77% de acuerdo con los expertos; las respuestas correctas en los otros dominios oscilaron entre el 38% y el 56%. El presente estudio demostró la necesidad de incorporar educación sobre los TTM estandarizada en la currícula de las escuelas o facultades de odontología en las universidades mexicanas. Hasta que esto suceda, las generaciones de odontólogos no tienen el conocimiento ni la experiencia necesarios para diagnosticar y manejar a los pacientes con Trastornos Temporomandibulares.

Association of Masseter Muscle Activities during Awake and Sleep Periods with Self-Reported Anxiety, Depression, and Somatic Symptoms.

AIM AND BACKGROUND: The objective of this study was to determine if duty factors (DF) of low-magnitude MMA during awake and sleep periods were associated with self-reports of anxiety, depression, and somatic symptoms, and if so, whether or not any associations were modified by gender or the presence of pain. Limited information is currently available in the literature regarding the association of low-magnitude masseter muscle activities (MMA) in habitual environmental settings and the presence of psychological symptoms. MATERIALS AND METHODS: Sixty-eight consenting participants were classified using the Diagnostic Criteria for Temporomandibular Disorders examination and validated self-reporting psychological symptom evaluation questionnaires. Each subject also had masseter electromyography recordings during standardized biting tasks in 2 laboratory sessions to calibrate the in-field MMA collected during 3 awake and 3 sleep periods. RESULTS: During awake periods, subjects with self-reported depression and somatic symptoms had statistically high odds of having higher DF of low-magnitude MMA (defined by ≥ 75th percentile of sample). The association between high DF of low-magnitude MMA and self-reported depression symptoms was significantly augmented among male participants, whereas, the association between high DF of low-magnitude MMA and self-reported somatic symptoms was significantly increased among female participants without pain. CONCLUSION: These pilot data support associations of low-magnitude masseter muscle activities with self-reported depression and somatic symptoms during awake periods.