Psychometrics in temporomandibular disorders. An overview

Coronavirus Lockdown as a Major Life Stressor: Does It Affect TMD Symptoms?

Temporomandibular disorders are multi-factorial conditions that are caused by both physical and psychological factors. It has been well established that stress triggers or worsens TMDs. This paper looks to present early research, still unfolding, on the relationship between COVID-19 as a major life stressor and TMDs. The main aims of this study were to: investigate the presence of symptoms related to TMDs and the time of onset and the worsening of painful symptoms in relation to the changes in social life imposed by the coronavirus pandemic; and to evaluate the perception of COVID-19 as a major stressful event in subjects who report worsening of painful TMD symptoms. One hundred and eighty-two subjects answered questionnaires-Axis II of the RDC/TMD, the PSS, and specific items about coronavirus as a stressful event-during the lockdown period for COVID-19 in Italy to evaluate the presence of reported symptoms of TMD and the level of depression, somatization, and stress perceived. The results showed that 40.7% of subjects complained about TMD symptoms in the past month. Regarding the time of onset, 60.8% of them reported that facial pain started in the last three months, while 51.4% of these subjects reported that their symptoms worsened in the last month and were related to the aggravation of pain due to the coronavirus lockdown as a major life event and to the stress experienced. The results of this study seem to support the hypothesis that stress during the pandemic lockdown influenced the onset of temporomandibular joint disorders and facial pain, albeit with individual responses.

Associations between symptoms of temporomandibular disorders, quality of life and psychological states in Asian Military Personnel

BACKGROUND

Symptoms of Temporomandibular Disorders (TMD) could affect oral health-related quality of life (OHRQoL) and psychological distress.

OBJECTIVE

This study aims to determine the prevalence of TMD symptoms, and impact of type and number of TMD symptoms on OHRQoL and psychological states among Asian military personnel.

METHOD

The study was conducted across 12 military dental centres using self-administered questionnaire comprising demographical data, DC/TMD symptom questionnaire, OHIP-14 and DASS-21. A total of 3028 personnel, aged between 18-65 years old, were invited to participate with an acceptance rate of 90.5%. Data analysis was done using non-parametric tests, regression analysis and Spearman correlation (P < 0.05).

RESULTS

Out of 2043 subjects (1998 males; 45 females, mean age 24.18 ± 7.18 years), 36.32% (n = 742) reported at least one TMD symptom. Significant differences in summary OHIP-14, depression, anxiety and stress scores were observed between subjects with and without TMD symptoms. Significant differences in OHIP-14 and DASS-21 scores were observed between dissimilar type and number of TMD symptoms in the TMD group. Those with headaches and 2-3 symptoms have substantially poorer OHRQoL and greater psychological distress. Associations between number of TMD symptoms, quality of life, depression, anxiety and stress were significant but weak (r = 0.19-0.40).

CONCLUSIONS

Symptoms of Temporomandibular Disorders were prevalent among Asian military population. Significant differences in OHRQoL and psychological states were observed between subjects with and without TMD symptoms. Specific type and number of TMD symptoms impacted OHRQoL and psychological states differently. Associations between number of TMD symptoms and quality of life, depression, anxiety and stress were significant but weak.

The Role of Stress in the Etiology of Oral Parafunction and Myofascial Pain

Oral parafunction during waking comprises possible behaviors that can be measured with a comprehensive checklist or behavioral monitoring. Multiple studies lead to largely consistent findings: stressful states can trigger parafunctional episodes that contribute to myofascial pain. However, this simple causal pathway coexists with at least 3 other pathways: anxiety and stress are potent direct contributors to pain, pain results in maladaptive behaviors such as parafunction, and parafunction may be a coping response to potential threat coupled with hypervigilance and somatosensory amplification. Awake parafunction remains an important risk factor for myofascial pain onset and overuse models alone of causation are insufficient.

Review of aetiological concepts of temporomandibular pain disorders: towards a biopsychosocial model for integration of physical disorder factors with psychological and psychosocial illness impact factors

Several studies have reported that musculoskeletal disorders of the stomatognathic system, commonly known as temporomandibular disorders (TMD) resemble musculoskeletal disorders and chronic pain disorders in general. There is also general consensus that combined biomedical and biopsychosocial methods best support the assessment and management of the cardinal features of TMD, i.e., pain and dysfunction or physical (peripheral) and psychosocial (central) factors. This overview of the aetiology of TMD will outline conceptualizations of past models and present the current view that patients with TMD should be assessed according to both the physical disorder and the psychosocial illness impact factors. The conceptual theories outlined in this review include biomedical models related to temporomandibular joints, muscles of mastication and occlusal factors, psychological models and the biopsychosocial models. An integrated and multidimensional approach concerning physical and psychosocial factors in temporomandibular pain and dysfunction is presented as an example of how the biopsychosocial model and information processing theory may apply in the conceptualization and management of TMD for various health care professionals.

The impact of stress and anxiety on the pressure pain threshold of myofascial pain patients

The purpose of this study was to evaluate the influence of stress and anxiety on the pressure pain threshold (PPT) of masticatory muscles and on the subjective pain report. Forty-five women, students, with mean age of 19.75 years, were divided into two groups: group 1:29 presenting with masticatory myofascial pain (MFP), according to the Research Diagnostic Criteria for Temporomandibular Disorders and group 2: 16 asymptomatic controls. An electronic algometer registered the pain thresholds on four different occasions throughout the academic year. To measure levels of stress, anxiety and pain, the Beck Anxiety Inventory, Lipp Stress Symptoms Inventory and Visual Analog Scale (VAS) were used. Three-way anova and Tukey's tests were used to verify differences in PPT between groups, times and sites. Levels of anxiety and VAS were compared using Mann-Whitney test, while Friedman's test was used for the within-groups comparison at different times (T1 to T4). The chi-squared and Cochran tests were performed to compare groups for the proportion of subjects with stress (alpha = 0.05). Differences in PPT recordings between time (P = 0.001) and sites (P < 0.001) were detected. Higher levels of anxiety and lower PPT figures were detected at T2 (academic examination) (P = 0.001). There was no difference between groups for anxiety and stress at any time (P > 0.05). The MFP group also has shown significant increase of VAS at the time of academic examination (P < 0.001). External stressors such as academic examinations have a potential impact on masticatory muscle tenderness, regardless of the presence of a previous condition such as masticatory myofascial pain.

The lateral pterygoid muscle, a heterogeneous unit implicated in temporomandibular disorder: a literature review

Based on its anatomical relationships, the lateral pterygoid muscle is strongly linked with the temporomandibular joint (TMJ). It plays a major role in mastication. Embryological, histological, and anatomical knowledge define the lateral pterygoid muscle as a single muscle with a penniform structure. The various results of electromyographic (EMG) studies describe a complex physiology with a chronological contraction of the layers during the masticatory cycle. The sequential contraction of the layers of the lateral pterygoid muscle is the result of a selective neuronal activation induced by the masticatory Central Pattern Generator (mCPG). This neurophysiological theory highlights the essential role of the reticular formation in oral motor control. The sensitivity of those neurological structures to chronic emotional stress is one of the possible explanations for the appearance of oral parafunctions accompanied by a modification of pain perception and a disorganized muscular activation, determining factors in temporomandibular disorders.

Psychological factors and responses to artificial interferences in subjects with and without a history of temporomandibular disorders

OBJECTIVE

It has often been suggested that psychological factors play a role in temporomandibular disorders (TMD). However, reports on psychological factors in TMD patients and controls have been equivocal. In a previous double-blind randomized controlled study, subjects with a TMD history showed more clinical signs and subjective symptoms and adapted less well to the artificial interferences than subjects without an earlier TMD history. In the present study, we analyzed the associations of psychological factors with symptom responses and adaptation to interferences.

MATERIAL AND METHODS

Before the intervention, the subjects filled in questionnaires dealing with personality traits, level of psychological and somatic stress symptoms, coping strategies, and health beliefs. Every day during the 2-week follow-up period, the subjects rated the intensity of their symptoms on 9 modified visual analog scales (VAS).

RESULTS

Health hardiness, positive socialization history and inhibition of aggression were associated with weaker symptom responses and better adaptation to true artificial interferences. Some personality characteristics in subjects with an earlier TMD history tended to associate with higher symptom reporting despite the type of intervention.

CONCLUSIONS

Psychological factors appeared significant for the symptom responses to artificial interferences, and they seem to play a different role in responses in subjects with an earlier TMD history compared to those without.

The influence of war stress on the prevalence of signs and symptoms of temporomandibular disorders

The aim of this study was to determine the prevalence of signs and symptoms of temporomandibular disorders in patients with post-traumatic stress disorder (PTSD) occurring as a consequence of exposure to war stress. The examined group consisted of 100 male subjects, aged from 25 to 50 years, who had taken part in the War in Croatia, and in whom PTSD had previously been diagnosed. The control group comprised 100 subjects, without PTSD, of the same sex and age group, who had not taken part in the War. A functional evaluation of the stomatognathic system was performed using the Helkimo Anamnestic and Clinical Dysfunction Index. Eighty-two per cent of the group with PTSD had at least one symptom, and 98% at least one sign of dysfunction. Eight per cent reported mild symptoms and 74% severe symptoms. Twenty-eight per cent showed mild clinical signs, 22% had signs of moderate, and 48% of severe dysfunction. Twenty-four per cent of the control group of subjects had at least one symptom, and 52% at least one clinical sign of dysfunction. Twenty-two per cent reported mild and 2% severe symptoms. Mild clinical signs of dysfunction were found in 50% of subjects in the control group, moderate in 2% and none exhibited severe clinical signs. It is concluded that correlation exists between war stress and temporomandibular disorders.

Systematic review of population-based epidemiological studies of oro-facial pain

OBJECTIVES

To conduct a systematic review of epidemiological literature in order to determine the prevalence and associated risk factors of oro-facial pain.

DATA

Population based observational studies (cohorts, cross-sectional and case-control studies) of oro-facial pain, published in the English language, prior to 1999 were included.

SOURCES

Electronic databases (Medline, Embase, Cinahl, BIDS and Health CD) were searched. Reference lists of relevant articles were examined, and the journals "Pain" and "Community Dentistry and Oral Epidemiology" were handsearched for the years 1994-1998.

RESULTS

The results of the search strategy were screened for relevance. A standardised checklist was used to assess the methodological quality of each study by two reviewers before an attempt was made to summarise the results. The median quality score was 70% of the maximum attainable score. Due to methodological issues, it was not possible to pool the data on the prevalence of oro-facial pain. Age, gender and psychological factors were found to be associated with OFP, however there was not enough information on other factors such as local mechanical and co-morbidities to draw any reliable conclusions. None of the factors fully fulfilled criteria for causality.

CONCLUSIONS

There is a need for good quality epidemiological studies of oro-facial pain in the general population. To enable comprehensive examination of the aetiology of oro-facial pain, it is necessary to address a broad range of factors including demography and life-style, local mechanical factors, medical history and psychological factors. Future studies should recruit adequately sized samples for precise determination of the prevalence and detection of important associated factors. Data on potential confounders and effect modifiers should also be collected and adjusted for in the statistical analysis.

The role of psychosocial factors in temporomandibular disorders

The temporomandibular disorders (TMDs) comprise a constellation of symptoms affecting the joints and muscles involved in jaw movement. Patients complain of orofacial pain, limited jaw opening, and clicking or popping sounds. Although pain is generally the defining characteristic of TMD, patients often report marked degrees of stress and interference in daily life. This article reviews recent studies on epidemiology, sex differences, pediatric TMD, classification systems, comparisons to other chronic pain disorders of uncertain etiology, psychological assessment, depression, central modulation and hypervigilance, sleep disturbances, stress, and the management of TMD by conservative physical interventions and cognitive behavioral therapy. Both the assessment and the management of TMD requires a multidisciplinary perspective with strong emphasis on psychosocial variables.

Depression, pain, exposure to stressful life events, and long-term outcomes in temporomandibular disorder patients

PURPOSE

This study investigated the role of psychological factors in temporomandibular disorders (TMD). Orofacial pain patients' pretreatment levels of depression, disability caused by pain, and exposure to stressful life events were measured, and differences on these variables between temporomandibular joint (TMJ) disease patients and patients whose pain was of muscular origin (MPD) were evaluated. The use of these variables and patient diagnostic status in predicting response to treatment in a subsample of these patients was also evaluated.

PATIENTS AND METHODS

Before undergoing treatment, 258 patients were administered the Beck Depression Inventory (BDI), the Pain Disability Index (PDI), and the Social Readjustment Rating Scale (SRRS). Follow-up data on pain disability, current level of pain, depression, and satisfaction with treatment were obtained on 48 of these patients who were contacted at varying intervals after completing treatment.

RESULTS

BDI scores obtained at the outset of treatment were significantly elevated and were positively correlated with SRRS and PDI scores. MPD patients had higher SRRS, BDI depression, and PDI pain disability scores than TMJ patients, and differences between the 2 groups in pain disability were greatest in areas that are often sources of interpersonal stress. Among follow-up patients, PDI scores declined after treatment, with MPD patients showing greater decreases than TMJ patients. Independent of patients' diagnostic status, their pretreatment PDI scores were predictive of their pain level at follow-up and were inversely related to their degree of satisfaction with treatment at follow-up; their pretreatment BDI scores were predictive of their depression level at follow-up.

CONCLUSIONS

The findings are consistent with previous research indicating a link between emotional dysfunction and TMD and are largely supportive of the conclusion that psychological factors play a more pronounced role when pain is of muscular origin. Promising behavioral interventions are available for TMD patients in whom psychological factors appear to be playing a significant role.

Psychological distress in chronic craniomandibular and cervical spinal pain patients

Recent studies to chronic pain have shown that the number of painful body areas is related to the level of psychological distress. Therefore, the first aim of this study was to analyse differences in level of psychological distress between craniomandibular pain patients with or without cervical spinal pain. In this analysis, the number of painful body areas below the cervical spine was also taken into account. The second aim was to determine psychological differences between subgroups of craniomandibular pain patients. In this study, 103 out of 250 persons with or without craniomandibular pain were included in the final analyses. Patients who suffered from both craniomandibular and cervical spinal pain showed higher levels of psychological distress, as measured with the Symptom Checklist 90 (SCL-90) than patients with local craniomandibular pain and persons without pain. Further, a positive relationship was found between the number of painful body areas below the cervical spine, as measured on a body drawing, and the SCL-90 scores. No psychological differences were found between myogenous and arthrogenous craniomandibular pain patients. In conclusion, chronic craniomandibular pain patients with a coexistent cervical spinal pain showed more psychological distress compared to patients with only a local craniomandibular pain and asymptomatic persons.

Smallest detectable difference in outcome variables related to painful restriction of the temporomandibular joint

The smallest detectable difference is the smallest statistically significant change in measurement results. In the field of temporomandibular disorders, the smallest detectable difference is not a commonly used concept. Most outcome studies are based on comparisons of group means, although this does not provide information about individual changes or about the clinical relevance thereof. The smallest detectable difference for maximal mouth opening was calculated from previously published reliability coefficients and the standard deviations of different samples of healthy subjects and patients with complaints of the temporomandibular joint. The smallest detectable difference of pain intensity measured with different visual analogue scales was calculated from the reliability coefficients and standard deviations of a heterogeneous group of pain patients. The smallest detectable difference of function impairment was calculated for a group of patients with complaints of the temporomandibular joint. For maximal mouth opening in healthy subjects, the smallest detectable difference was 5 mm. Repeated measurements improved it to 3 mm. The smallest detectable difference on a visual analogue scale was 28 mm for actual pain intensity and 22 mm for minimal pain as well as for maximal pain intensity. For total function impairment of patients with complaints of the temporomandibular joint, the smallest detectable difference was 8 units on a 0 to 68 scale.

Anticipatory stress reduction among chronic pain patients

Stress has long been viewed as a contributor to the pain experienced by chronic pain patients. The purpose of this research was to study the relationship between anticipated and experienced stress and anticipated and experienced pain levels among three patient groups: chronic pain patients, patients about to receive molar extraction (acute pain group), and a no-pain comparison group. Results showed that chronic pain patients anticipated significantly more stress than did an acute pain or a non-pain comparison patient group but reported non-significant differences in the actual level of stress experienced. A secondary purpose of this study was to examine cognitive factors, such as perceived daily hassles, which may contribute to this increased anticipatory stress. Results showed that there was consistency among the chronic pain patients as to the types of anticipated stressors, which were similar to those previously reported by chronic headache sufferers. The chronic pain group had significantly higher scores than the two remaining groups on the stress they anticipated from hassles related both to practical considerations (F2.45 = 3.5, p < 0.05) and to health (F2.45 = 9.37, p < 0.001). Strategies the dentist can use in combination with dental therapy to reduce cognitive-based anticipatory stress as well as strategies for collaboration with the patient and a mental health therapist are discussed.