Chronic Temporomandibular Joint Disorder Research Articles

Dietary supplementation with grape seed extract from Vitus vinifera prevents suppression of GABAergic protein expression in female Sprague Dawley trigeminal ganglion in a model of chronic temporomandibular joint disorder

ObjectiveTo investigate cellular changes in protein expression in the trigeminal ganglion in an established preclinical chronic model of temporomandibular joint disorder (TMD) in response to grape seed extract (GSE) supplementation based on its beneficial use in preclinical chronic orofacial pain models. DesignThree experimental conditions included female Sprague-Dawley rats as naïve controls, and animals subjected to neck muscle inflammation and prolonged jaw opening with and without daily supplementation of GSE in the drinking water prior to inflammation. Changes were evaluated in mechanical sensitivity to von Frey filaments and protein expression in the trigeminal ganglion of animals 14 days post jaw opening. ResultsCalcitonin-gene related peptide and protein kinase A, proteins positively associated with peripheral sensitization and enhanced nociception, did not show elevated expression at day 14 in the model compared to naïve or GSE supplemented animals. However, neuronal levels of glutamate decarboxylase (GAD) 65/67, which are enzymes responsible for the synthesis of the inhibitory neurotransmitter GABA that functions to suppress neuronal excitability, were significantly decreased on day 14 post jaw opening. Similarly, a significant decrease in neuronal expression of the GABA receptor subunits GABAB1 and GABAB2, but not GABAA, was observed in the TMD model. Importantly, GSE prevented suppression of GAD 65/67 and GABAB subunits, maintaining levels similar to naïve animals. ConclusionResults from our study provide evidence of the downregulation of inhibitory GABAergic proteins in trigeminal ganglion neurons in a preclinical chronic TMD model and the benefits of GSE supplementation in preventing their suppression and maintaining normal levels.

Estrogen Status and Trigeminal Ganglion Responses to Jaw Movement

Chronic temporomandibular joint disorders (TMDs) present with pain in the temporomandibular joint (TMJ) and muscles of mastication. Risk factors for TMD include localized joint/muscle inflammation and estrogen status. This study determined whether mild tissue inflammation and estrogen status influenced the responses of trigeminal ganglion neurons to jaw palpation or jaw movement, 2 key diagnostic features of clinical TMD, in adult rats. Neuronal activity was recorded from male rats, ovariectomized (OvX) female rats, and OvX female rats injected with 17β-estradiol 24 h prior to testing (OvXE). Neurons were tested for responses to deep press over the TMJ region and jaw movement in 3 directions (open, protrusion, lateral) 10 d after intra-TMJ injection of a low dose of complete Freund’s adjuvant (CFA) or vehicle (sham). Deep press evoked similar responses in all treatment groups. The response magnitude to jaw opening and protrusion was significantly greater for neurons recorded from OvXE CFA-treated rats than from OvX CFA-treated or OvXE sham rats. The responses to lateral movement of the jaw were similar across all treatment groups. Most neurons (70% to 90%) displayed a static response pattern to jaw movement independent of direction. Estradiol treatment also increased the proportion of neurons that were excited by jaw movement in >1 direction as compared with untreated OvX females or males. These results suggest that mild localized inflammation in the TMJ region during periods of elevated estrogen were sufficient to increase the peripheral driving force for jaw movement–evoked hyperalgesia.

Inhibition of Nociception in a Preclinical Episodic Migraine Model by Dietary Supplementation of Grape Seed Extract Involves Activation of Endocannabinoid Receptors.

Migraine is associated with peripheral and central sensitization of the trigeminal system and dysfunction of descending pain modulation pathways. Recently, dietary inclusion of grape seed extract (GSE) was shown to inhibit mechanical nociception in a preclinical model of chronic temporomandibular joint disorder, a condition often comorbid with migraine, with the antinociceptive effect mediated, in part, by activation of 5-HT3/7 and GABAB receptors. This study further investigated the mechanisms by which GSE inhibits mechanical nociception in a preclinical model of episodic migraine. Hyperalgesic priming of female and male Sprague Dawley rats was induced by three consecutive daily two-hour episodes of restraint stress. Seven days after the final restraint stress, rats were exposed to pungent odors from an oil extract that contains the compound umbellulone, which stimulates CGRP release and induces migraine-like pain. Some animals received dietary supplementation of GSE in their drinking water beginning one week prior to restraint stress. Changes in mechanical sensitivity in the orofacial region and hindpaw were determined using von Frey filaments. To investigate the role of the endocannabinoid receptors in the effect of GSE, some animals were injected intracisternally with the CB1 antagonist AM 251 or the CB2 antagonist AM 630 prior to odor inhalation. Changes in CGRP expression in the spinal trigeminal nucleus (STN) in response to stress, odor and GSE supplementation were studied using immunohistochemistry. Exposure of stress-primed animals to the odor caused a significant increase in the average number of withdrawal responses to mechanical stimulation in both the orofacial region and hindpaw, and the effect was significantly suppressed by daily supplementation with GSE. The anti-nociceptive effect of GSE was inhibited by intracisternal administration of antagonists of CB1 and CB2 receptors. GSE supplementation inhibited odor-mediated stimulation of CGRP expression in the STN in sensitized animals. These results demonstrate that GSE supplementation inhibits trigeminal pain signaling in an injury-free model of migraine-like pain via activation of endocannabinoid receptors and repression of CGRP expression centrally. Hence, we propose that GSE may be beneficial as a complementary migraine therapeutic.

Thermal ultrasound, manipulation and exercise on pain and mouth opening in Chronic temporomandibular joint disorder

A 60-year-old female patient reported with a chief complaint of pain in bilateral temporomandibular joints (TMJ) region since 11/2 years. The pain was initially reported to be insidious in onset, moderate in intensity, aggravated on chewing food and during excessive mouth opening. On examination her mouth opening was found to be less than 8mm and standard head and neck examination showed grade 2 tenderness with swelling on bilateral TMJ and forward neck posture with rounded shoulders. The patient reported her pain to be 6 at rest in NPRS (with 0 being no pain and 10 being maximum) and 8 out of 10 on mouth opening. A 4-week Physiotherapy Intervention program, which consisted of Ultrasound Therapy at varying intensity, TMJ manipulation, Cervical Range of Motion Exercises and Manual Cervical traction was administered. Repeated evaluation of pain and other functional outcomes were done on a weekly basis. There was significant improvement in her mouth opening (41mm), restoration of masticatory functions, complete resolution of pain and overall improvement in quality of life after the 4weeks intervention program. A structured Physiotherapy intervention program consisting of Non-thermal Ultrasound, Manipulation and exercise targeting TMJ and Upper quarter, proved to be highly effective in increasing functions and reducing signs and symptoms in Chronic TMJ Dysfunction which can be highly disabling. The recovery observed in this patient, who was not on any standard treatment for almost 18months, hence the severe limitations she encountered, is a testament to the need of designing individualized treatment protocols addressing the many facets of impairment in TMJ Disorders.

Asymmetry of dental or joint anatomy or impaired chewing function contribute to chronic temporomandibular joint disorders

IntroductionThe etiologies of most chronic temporomandibular joint disorders are unknown. However, an association between habitual chewing on a particular side and chronic temporomandibular joint disorders has been reported.The aim of this study was to investigate the differences between sides (affected vs unaffected) of biodynamic factors (including lateral dental guidance determined by dental anatomy) or condylar path angles (determined by temporomandibular joint morphology) and chewing function (physiological alternate chewing vs single habitual chewing side). The study scope was to investigate possible etiological factors to improve the understanding of temporomandibular joint disorders.The null hypothesis was that no difference would be found between sides that are or are not affected by chronic temporomandibular joint disorders in chewing function or in levels of dental or temporomandibular joint remodeling. MethodsThis cross-sectional, double-blind study involved 24 adults with substantial, chronic, unilateral symptoms diagnosed as temporomandibular joint disorders. Chewing function, temporomandibular joint remodeling (using axiography) and dental anatomy (lateral guidance angles using kinesiography) were assessed. ResultsHabitual chewing on one particular side was observed in 17 of 24 participants; significantly more (n=15) chewed on the affected side than on the unaffected side (P=0.002 in a two-tailed Fisher’s exact test; risk estimate=4.5; 95% CI 1.326–15.277). The condylar path (CP) angle was steeper on the affected side than on the unaffected side (mean (standard deviation)=50.52° (9.98°) versus 45.50° (7.98°); P=0.002 in a two-tailed t-test). The lateral guidance (LG) angles were flatter on the affected side in all 24 participants. ConclusionOur results suggest that habitual chewing on one side may be associated with increasing condylar path, with flattening lateral guidance angles, and also with chronic temporomandibular joint disorder on the habitual chewing side.

Occlusal Adjustment vs Placebo for Chronic Temporomandibular Disorders. The MAP Randomized Clinical Trial

Importance: Evidence regarding effective treatments for temporomandibular joint disorders (TMDs) is limited. Objective: To determine whether occlusal adjustment may reduce the pain intensity of patients with chronic TMD. Design: The MAP study was a phase 3 randomized, participant- and assessor-blinded, placebo-controlled trial of a novel occlusal therapy for chronic TMD over the course of 6 months. It was carried out from August 4, 2014 to October 25, 2018 (last 6-month follow-up). Setting: Single referral tertiary care hospital. Therapies were performed in a University Clinic in a different city. Participants: From 924 adult patients screened diagnosed as TMD, 820 were excluded (partial tooth loss, no chronic condition, malocclusion); 27 declined to participate. Seventy-seven participants underwent randomization; all but one female participant completed the analysis. Interventions: Participants were randomly (1:1) assigned to occlusal adjustment therapy (N=39) or similar placebo (N=38) that did not remove any enamel. Main Outcome and Measure: Primary outcome (before data collection began): change in pain score (in a 0-10 points visual analogue scale) from baseline to the 3- and 6-month assessments. Because one majority of the 1-month therapy visits (carried out in a city 70 km away) were delayed nearest the 3-month visit, the actual primary outcome was the average pain intensity improvement at 6 months in respect of the baseline scores (05/05/2016 ISRCTN amendment). Clinical important difference 1.5 points. Results: The trial was stopped early for efficacy. This report includes all randomized participants in their originally assigned group: 39 to occlusal adjustment and 38 to placebo therapy. Both groups were balanced regarding baseline characteristics. As compared with the placebo, occlusal adjustment reduced jaw pain intensity (adjusted mean difference, -1.54; 95% confidence interval [CI] -.5 to -2.6; P=0.004; ANCOVA model). Conclusions and Relevance: The occlusal adjustment was effective in treating chronic TMD pain and improved limited mouth opening in comparison with the placebo over a 6-month period. The results of this trial are provisional and should not be generalized to patients with different dental conditions, or if the therapies are provided by less experienced dental professionals.

Standardized mastication increases the coordination in masticatory activity in women with chronic temporomandibular joint disorders: a case control study.

Background: The effects of jaw movement pattern on masticatory activity during chewing remains unclear in chronic temporomandibular joint disorders individuals. Objective: to assess the effect of habitual and non-habitual mastication patterns based upon the activation of the masseter and temporalis muscles in individuals with or without temporomandibular joint disorder (TMJD). Methods: Fifty-four participants (age: 18–44 years) were divided into two groups: the TMJD (n=27) and control (n=27) groups. TMJD was identified using the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). Electromyographic activity of the masticatory muscles was measured during 2 tasks: habitual mastication with parafilm (HM) and non-habitual mastication with parafilm (NHM). MATLAB software was used to process electromyography (EMG) signals. The root mean square, symmetry index (SI%), anteroposterior coefficient (APC%) and torque coefficient (TC%) were determined from the processed EMG signal. Results: Reduced right masseter activation was observed for the TMJD group (p<0.05) during jaw agonist phase. During the jaw agonist phase, all muscles presented with more activation during NHM. Symmetry of temporalis (ST%) and APC% were the lowest for HM. TC% was increased for HM. Conclusion: Habitual and non-habitual mastication differ in masticatory activity during jaw agonist and antagonist phase and TMJD individuals presented a different way to recruit muscles under these circumstances. Non-habitual mastication has a more coordinating and stable motor pattern in masticatory activity and has less variability than habitual mastication to assess masticatory activity.

The current referral patterns for temporomandibular joint disorders (TMD) in Greater Manchester.

Temporomandibular joint disorders (TMD) affect up to 50% of the population. Chronic TMD may have a significant impact on patients' quality of life and is associated with a significant cost burden to health services. The aim of this study was to investigate the incidence of TMD in Greater Manchester and to determine the most appropriate setting for its management. Data were retrospectively collected on the demographics, symptoms and management provided to patients referred for TMD. There were 789 referrals analysed; 616 to a Tertiary Centre and 173 to a District General Hospital (DGH). The most common reason for referral was pain (82%), followed by limitation in opening (55%) and clicks or sounds (44%). 27% of referrals were managed with a splint and 12% were provided with advice or a patient information leaflet prior to referral. The effect of chronic pain on patients' quality of life and the cost burden of its management compels us to review current practices in referral and management of TMD. Barriers to provision of treatment in primary care may include a lack of training, remuneration or confidence. These may be overcome with the development of self-care plans for patients and a care pathway for practitioners. Based on existing evidence, timely and conservative management of TMD should be encouraged in primary care, enabling better outcomes to be achieved for patients and the maintenance of the experience and skill level of specialist services in secondary care.

Cross-cultural adaptation, reliability and validity of the Italian version of the craniofacial pain and disability inventory in patients with chronic temporomandibular joint disorders

BackgroundTo develop an Italian version of the Craniofacial Pain Disability Inventory (CFPDI-I) and investigate its psychometric abilities in patients with temporomandibular disorders (TMD).MethodsThe CFPDI was translated following international standards. The psychometric analyses included reliability by internal consistency (Cronbach’s alpha) and test/retest stability (intraclass correlation coefficient, ICC); construct validity was investigated by matching (a priori hypotheses) the CFPDI-I with the Italian Neck Disability Index (NDI-I), a pain intensity numerical rating scale (NRS), the Italian Pain Catastrophising Scale (PCS-I), the Italian Tampa Scale of Kinesiophobia (TSK-I), and the Italian Migraine Disability Assessment Score Questionnaire (MIDAS) (Pearson’s correlation). Alpha was set at 0.05.ResultsTwo hundred and twelve patients with chronic TMD completed the tool. The questionnaire was internally consistent (α = 0.95) and its stability was good (ICCs = 0.91). As hypothesised, validity figures showed CFPDI-I strongly correlated with the NDI-I (r = 0.66, p < 0.05) and moderately correlated with the NRS (r = 0.48, p < 0.05), PCS (r = 0.37, p < 0.05), TSKI (r = 0.35, p < 0.05) and MIDAS (r = 0.47, p < 0.05). Similar estimates were shown by CFPDI-I subscales.ConclusionsThe cross-culturally adapted version of the Craniofacial Pain and Disability Inventory (CFPDI-I) showed satisfactory psychometric properties that replicate those of the original version and, therefore, can be implemented in the clinical assessment of Italian people affected by TMD.

“Evaluation of frequency of anxiety and depression among patients with chronic temporomandibular disorder.”

Temporomandibular Disorder (TMD) has been considered as one of the commonest disorder in Pakistan. In this disorder, the patient complains of pain in Temporomandibular joint and associated anatomical muscles. This research study has been performed to evaluate the frequency of Anxiety and Depression in patients with Chronic Temporomandibular Disorder (CTMD). Objectives: The objective of this research study is to evaluate the frequency of Anxiety and Depression among patients with Chronic Temporomandibular joint Disorder. Study Design: A Cross-sectional Descriptive research study. Setting: This research study was conducted in the Department of Oral and Maxillofacial Surgery at Dr. Ishrat-ul-Ebad Khan Institute of Oral and Health sciences, Dow University of Health Sciences and Dr. Ruth K.M. Pfau Civil Hospital, Karachi, Pakistan. Period: This research study was conducted for a respective period of 1 year from 1st March 2018 to 1st March 2019. Materials and Methods: A total of 213 patients having persisting Temporomandibular joint pain for more than 6 months were included in this study. The diagnosis of Temporomandibular Disorder (TMD) was established if the patient demonstrated pain/discomfort in the Temporomandibular Joint (TMJ) and muscles of mastication and masticatory dysfunction for a period, exceeding 6 months. After demographic questions, Hospital Anxiety and Depression Scale (HADS) was administered to each patient and the intensity and severity of Anxiety and Depression were recorded and documented by the Operator. Results: The percentage of Anxiety and Depression among patients with Chronic Temporomandibular Disorder (TMD) was 31.46% (67/213) and 36.15% (77/213). Conclusion: In our respective study, the Frequency of psychological disorders like Anxiety and Depression were significantly high. Our results showed that an adequate and profound diagnosis and treatment planning is very necessary for all patients suffering from Chronic Temporomandibular Disorder (CTMD) so that both physical and psychological factors of patients with Chronic Temporomandibular Disorder (CTMD) should be taken into primary foremost consideration prior to the decision pertaining to its management respectively.

A Phenomenologic Study About the Dietary Habits and Digestive Complications for People Living with Temporomandibular Joint Disorders

To better understand the experiences of individuals who must alter the types of food they eat because of having a chronic temporomandibular joint disorder (TMD) and the digestive issues that these alterations produce. Six participants answered open-ended questions during semi-structured interviews about their experiences with TMD-related changes in diet and digestion. These interviews, held face-to-face with the participants in a nonclinical environment, were recorded and transcribed. Interpretive phenomenology was used to arrange and analyze the narrative data collected. The authors identified three common themes among the participants: (1) constipation and bloating; (2) loss of chewing function; and (3) weight change. For each of these themes, participants expressed physiologic and psychologic complications, which were largely unaddressed by their health care providers. These findings highlight the need for health care providers to establish nutritional guidelines for TMD individuals at risk of physiologic and psychologic comorbidities. Health care intervention programs to treat people living with chronic TMD pain and that provide nutritional guidance will help decrease medical crises and the need for expensive interventions and will better assist these patients.

Anterior joint space narrowing in patients with temporomandibular disorder.

The aim of this work is to investigate changes in the anterior joint space (AJS) and the relationship of such changes to clinical symptoms in chronic temporomandibular joint disorder (TMD) patients, and to compare symptoms between chronic and acute TMD patients. Data from 100 TMD patients diagnosed based on the Diagnostic Criteria for Temporomandibular Disorders (55women; mean age 34.34 ± 14.88 years) including 50patients with acute TMD (aTMD) and 50patients with chronic TMD (cTMD) were analyzed. The AJS was calculated based on cone-beam computed tomography images analyzed using AutoCAD software (Autodesk Inc., San Francisco, CA, USA). The presence of osteoarthritis (OA) in the temporomandibular joint (TMJ) was evaluated using bone scintigraphy. Bilateral OA was significantly more frequent in patients with cTMD than in those with aTMD (50% vs. 30%; p < 0.05). Significant differences in the AJS of the TMJs were found between patients with cTMD and those with aTMD. AJS values of both right and left TMJs were significantly smaller in the patients with cTMD than in those with aTMD (4.18 ± 1.71 mm2 vs. 7.35 ± 1.71 mm2, and 6.20 ± 2.88 mm2 vs. 7.34 ± 2.47 mm2, respectively; p < 0.05). In patients with cTMD, narrowed AJS was correlated with increased dysfunction index (r = -0.373, p < 0.01). Over time, AJS of the TMJ can be narrowed in TMD patients, causing aggravation of TMJ dysfunction.

Prevalence of Depression, Anxiety and Stress in Chronic Temporomandibular Joint Disorders Patients.

Introduction: Temporomandibular disorders (TMD), defined as a collection of medical and dental conditions affecting the Temporomandibular joints (TMJs) and/or masticatory muscles and associated structures, have an estimated prevalence in the adult population of around 10%. Symptoms of depression and anxiety have also been considered as risk factors for TMD. Aims and objective: To evaluate the prevalence of depression, anxiety and stress in patients with a chronic Temporomandibular disorder. Materials and methods: The sample consisted of 100 patients diagnosed with muscle or joint pain, consistent with the Research Diagnostic Criteria for TMD (RDC/TMD) and was assigned to one of three groups: Muscle pain (MM) group, joint pain (TMJ) group, and mixed group. Variable of interest were derived from the Depression Anxiety Stress Scale (DASS)-42 questionnaire. Results: The mean (± standard deviation) age for the whole sample was 37.74 ±11.3 years; 86% were women. The overall prevalence of depression was 48.1% and overall prevalence of anxiety was 74%. Patients in the MM group reported the highest prevalence of Depression and Anxiety. Patients in the MM group were significantly more likely to be depressed and anxious compared to patients in the TMJ and Mixed groups. Conclusion: Elevated levels of stress, depression, and anxiety were reported in a chronic TMD population, especially in those with chronic muscle pain, compared to the general population. These findings emphasize the need for screening for depression, anxiety and other comorbidities in TMD patients suffering from chronic pain.

Effectiveness of vitamin b complex in reducing chronic temporomandibular joint disorder pain — double blind randomised clinical trial

Background: Chronic temporomandibular joint disorder (TMD) pain management has always been challenging and usually requires long-term analgesics. Commonly used analgesics have a potential for adverse effects in long-term usage, thus there is a need to look for a safer alternative analgesic option. Objectives: To evaluate efficacy of vitamin B complex (VBC) [B1, B6, B12] in reducing chronic TMD pain. Methods: 26 patients with chronic TMD pain secondary to arthralgia, osteoarthritis and disc displacement were included. The patients were allocated randomly into two groups and received either VBC tablet (B1: 242.5 mg, B6: 250 mg, B12: 1 mg) or placebo once per day for six weeks. Clinical measurements were recorded at week 0 and week 2, week 4, and week 6 to evaluate the efficacy of the treatment. Pain intensity was measured by visual analogue score (VAS) and mandibular range of movement was measured by maximal comfortable mandibular opening and lateral excursion. Adverse effects and compliance rate towards treatment were also assessed. Findings: In this 6-week clinical trial, both groups showed significant VAS pain reduction (VBC 2.49 ± 1.71; placebo 1.41 ± 1.53; P < 0.05). The amount of VAS pain reduction in the VBC group was significantly higher than in the Placebo group at week 2 (1.19 ± 1.28 versus 0.23 ± 0.90) and week 4 (2.32 ± 1.42 versus 1.25 ± 0.75; P < 0.05). No statistically significant difference was noted in mouth opening improvement. Both VBC and placebo medications were well tolerated with minimal adverse effects. Conclusion: In this study a dose of VBC (B1: 242.5 mg, B6: 250 mg, B12: 1 mg) was significantly better than placebo in reducing chronic TMD pain at week two and week four.

Diagnostic efficiency of high-resolution ultrasonography in patients with chronic temporomandibular disorders

Purpose Temporomandibular disorders (TMDs) affect 8–12 % of the adolescent and adult population, resulting in patient discomfort and affecting quality of life. Despite the growing incidence of these disorders, an effective screening modality to detect TMDs is still lacking. Although magnetic resonance imaging is the gold standard for imaging of the temporomandibular joint (TMJ), it has a few drawbacks such as cost and its time-consuming nature. High-resolution ultrasonography is a non-invasive and cost-effective imaging modality that enables simultaneous visualization of the hard and soft tissue components of the TMJ. This study aimed to evaluate the correlations between the clinical signs and symptoms of patients with chronic TMJ disorders and their ultrasonographic findings, thereby enabling the use of ultrasonography as an imaging modality for screening of TMDs.

Influência de abordagens biopsicossociais e autocuidados no controle das disfunções temporomandibulares crônicas

JUSTIFICATIVA E OBJETIVOS: A disfunção temporomandibular (DTM), condição musculoesquelética do sistema mastigatório, pode se tornar crônica, causando maior comprometimento na qualidade de vida (QV) dos pacientes. Devido à inter-relação entre sintomas físicos e emocionais, há uma crescente busca pelo modelo integrativo, o qual inclui abordagens psicossociais para o tratamento de condições dolorosas. O objetivo deste estudo foi realizar uma revisão de literatura sobre o impacto da educação e modalidades simples de autocuidados podem ter na dor e na disfunção relacionadas à DTM dolorosa crônica. CONTEÚDO: Os fatores psicossociais estão frequentemente envolvidos na cronificação da dor, tornando as abordagens biocomportamentais cada vez mais indicadas para mudar a percepção da dor, reduzir o sofrimento e as alterações psicossociais que acompanham as dores persistentes. CONCLUSÃO: A literatura existente, apesar de não ser vasta, indica resultados positivos da aplicação de métodos de educação e autocuidados em DTM dolorosa crônica. Mais estudos são necessários para reforçar tais achados e disseminar a aplicação de tais abordagens no controle da dor crônica e da DTM.

Sleep continuity and architecture: Associations with pain-inhibitory processes in patients with temporomandibular joint disorder

Recent research suggests bi-directional interactions between the experience of pain and the process of sleep; pain interferes with the ability to obtain sleep, and disrupted sleep contributes to enhanced pain perception. Our group recently reported, in a controlled experimental study, that sleep fragmentation among healthy adults resulted in subsequent decrements in endogenous pain inhibition. The present report follows up that observation by extending this line of research to a sample of patients experiencing persistent pain. Patients with chronic temporomandibular joint disorder (TMD) pain were studied using polysomnography and psychophysical evaluation of pain responses. We assessed whether individual differences in sleep continuity and/or architecture were related to diffuse noxious inhibitory controls (DNIC), a measure of central nervous system pain inhibition. Among 53 TMD patients, higher sleep efficiency and longer total sleep time were positively associated with better functioning of DNIC ( r = 0.42–0.44, p < 0.01; ps < 0.05 for the multivariate analyses). These results suggest the possibility that disrupted sleep may serve as a risk factor for inadequate pain-inhibitory processing and hint that aggressive efforts to treat sleep disturbance early in the course of a pain condition might be beneficial in reducing the severity or impact of clinical pain.

Assessment of pain in temporomandibular disorders: the bio-psychosocial complexity

Temporomandibular joint disorders (TMD) affect the joint, the masticatory muscles, or are expressed as a clinical combination of these two factors. The aims of this study were to: (i) identify the clinical and psychosocial factors that aid in the diagnosis and classification of acute and chronic TMD, (ii) determine specific initiating and perpetuating factors which may act as a guide to differentiate between acute and chronic TMD, (iii) identify factors which might predispose to conversion from acute to chronic TMD. Twenty-two patients were examined in the pain clinics at the Eastman Dental Institute. The assessment technique incorporated questionnaires, clinical history and examination including dental panoramic tomography. The results of this pilot study show a significant correlation between mood and enjoyment of life in both groups, mood and relationships in the chronic group, average pain and sleep in the chronic group, average pain and eating–chewing in the chronic group, and phobia for physical disease with trust in clinicians in the chronic group. The bio-psychosocial model of pain is an important appraisal tool. The newly designed TMD Pain Assessment is described with good results.