Use of a structural equation model for prediction of pain symptoms in patients with orofacial pain and temporomandibular disorders.

AIMS: To develop and test a biopsychosocial model using structural equation modeling for predicting orofacial pain symptoms in a sample of patients with masticatory muscle pain (MMP). METHODS: Data were collected from clinic records of 251 adult patients who presented for initial evaluation to the Orofacial Pain Center at the University of Kentucky College of Dentistry and were subsequently diagnosed with MMP. Data were used to fit a model relating stressors, psychological distress, arousal, sleep problems, oral parafunction, and pain symptoms. Items from the Multidimensional Pain Inventory (MPI) and the IMPATH:TMJ, a comprehensive biopsychosocial assessment of patients with temporomandibular disorders (TMD), were used to construct a measurement model of five latent variables. RESULTS: Estimation of the model indicated a good fit to the data and significant associations between stressors, psychological distress, arousal, sleep problems, and pain symptoms. Sleep problems partially mediated the relation between arousal and pain symptoms. Contrary to hypotheses, no association occurred between oral parafunction and pain symptoms, possibly indicating that any relationship between oral parafunction and pain symptoms may not exist. CONCLUSION: Results from the model tested in the present study are an additional step toward developing a more comprehensive biopsychosocial model explaining the nature and etiology of MMP in orofacial pain and TMD. With additional development and testing, it may also serve as an aid to planning interventions, especially psychosocial interventions targeting stress management, psychophysiological regulation, psychological distress, and sleep problems.

Ecological momentary assessment of fatigue following breast cancer treatment.

Fatigue is a common and debilitating symptom often experienced during and following cancer treatment. An Ecological Momentary Assessment (EMA) approach was used to examine the diurnal pattern of off-treatment fatigue in breast cancer survivors. Twenty-five breast cancer (BC) survivors 6-26 months posttreatment and age-matched groups of healthy women (HC; n = 25) and women with benign breast problems (BBP; n = 24) completed four daily diary measures of fatigue, pain, and mood for 5 consecutive days. Type of activity engaged in at the time of the diary assessments, as well as daily pedometer activity level, and nightly sleep duration were also assessed. While BC survivors reported greater levels of fatigue relative to BBP anid HC groups, no group differences in mood, activity type or level, sleep duration, or diurnal pattern of fatigue were evident. The results confirm that fatigue mav continue to be experienced long after conclusion of cancer treatment while questioning its clinical significance, provide insight into potential etiological mechanisms underlying off-treatment fatigue in, and demonstrate the value of EMA approaches to the study of cancer-related fatigue.

Psychological and physiological parameters of masticatory muscle pain.

The objective of this research was to identify the psychological and physiological variables that differentiate persons reporting masticatory muscle pain (MMP) from normal controls (NC). This study examined the characteristics of 35 MMP patients in comparison to 35 age-, sex-, and weight-matched NCs. All subjects completed a series of standardized questionnaires prior to undergoing a laboratory evaluation consisting of a psychosocial stressor and pressure pain stimulation at multiple body sites. During the evaluation, subjects' emotional and physiological responses (heart rate, blood pressure, respiration, skin temperature, and muscle activity) were monitored. Results indicated that persons with MMP reported greater fatigue, disturbed sleep, depression, anxiety, menstrual symptoms, and less self-deception (P's < 0.05) than matched controls. At rest, MMPs had lower end tidal carbon dioxide levels (P < 0.04) and lower diastolic blood pressures than the NCs (P < 0.02). During laboratory challenge, both groups responded to the standard stressor with significant physiological activity and emotional responding consistent with an acute stress response (P < 0.01), but there were no differences between the MMPs and NCs. Muscle pain patients reported lower pressure pain thresholds than did NCs at the right/left masseter and right temporalis sites (P's < 0.05); there were no differences in pressure pain thresholds between MMPs and NCs for the left temporalis (P < 0.07) and right/left middle finger sites (P's > 0.93). These results are discussed in terms of the psychological and physiological processes that may account for the development of muscle pain in the masticatory system.