Persistent Temporomandibular Disorders Research Articles

Filling in the Gaps. Making Sense of Living with Temporomandibular Disorders: A Reflexive Thematic Analysis.

Persistent, painful temporomandibular disorders (TMDs) are challenging to manage and usually require the active engagement of patients. To achieve this, it is necessary to understand the complex and multifactorial nature of persistent pain. Many dental professionals have little education about persistent pain and may prefer to offer structural management and advice. This research aims to explore how people understand their persistent TMD and how this understanding has been influenced by their treatment providers. Twenty-one people were recruited to represent a diversity of experience with persistent TMD. Interviews followed a semistructured topic guide. Themes were constructed through reflexive thematic analysis to represent how people made sense of their symptoms and the messages that they had picked up through their treatment journey. Participants described examples of conflicting opinions and inconsistent management recommendations. They rarely recalled collaborative discussions about the nature and complexity of their symptoms and different options for treatment. This experience is represented by a single theme, "a medical merry-go-round." Subthemes of "a medical journey to nowhere-participants' frustrated attempts to find medical management that will end their pain" and "is it me?-participants' questioning their role in persisting pain" kept participants on the merry-go-round, while symptom resolution and participants' emerging development of a holistic understanding of their TMD pain provided exit points. Understanding pain holistically tended to be helpful and typically occurred despite rather than because of the advice given in routine treatment settings. Participants in this study had not typically found their pain management within dental and medical settings to have helped them to construct meaning and understand their experiences of painful TMD. However, understanding symptoms holistically was experienced as beneficial. This study suggests that improved communication and signposting within services for persistent TMD may be beneficial to patients with TMD pain. Results of this study confirm that being offered a series of anatomically based, singular-cause explanations for persisting pain symptoms had been experienced as unhelpful by the participants who had sought help for their TMD. Participants highlighted the importance of accurate and collaborative communication and of dental professionals explicitly adopting and communicating a biopsychosocial understanding of pain to their patients who have TMD. Results highlight that some people can struggle to manage persisting pain with minimal support. Signposting patients to appropriate services and resources may help them to understand more about the nature of persistent pain and methods of managing it.

The Contribution of Insomnia and Obstructive Sleep Apnea on the Transition from Acute to Chronic Painful Temporomandibular Disorders and their Persistence: A Prospective 3-Month Cohort Study

ABSTRACT Background Insomnia, and Excessive Daytime Sleepiness (EDS), a surrogate marker of Obstructive Sleep Apnea (OSA), are common sleep-related conditions among painful temporomandibular disorders (TMD) patients. OSA was found to increase the risk of chronic painful TMD. Aims This prospective cohort study aims to determine the contribution of insomnia and EDS on acute to chronic painful TMD transition as well as its persistence when chronic pain is defined by: (i) duration (> 3 months), and (ii) dysfunction (Graded Chronic Pain Scale [GCPS II-IV]). Methods From 456 patients recruited between 2015 to 2021, through four locations in Canada, 378 completed the follow-up. A diagnosis was obtained using the Research Diagnostic Criteria or the Diagnostic Criteria for TMD. Insomnia was assessed with the Insomnia Severity Scale (ISS), and OSA was assessed using the Epworth Sleepiness Scale (ESS) which measures EDS, both at baseline. Patients completed the GCPS form at baseline and 3-month follow-up. Results Borderline associations were found between EDS and the transition or persistence of chronic painful TMD when chronic pain was defined by pain duration (RR adjusted_duration = 1.11, P = 0.07) and dysfunction (RRadjusted_dysfunction =1.40, P = 0.051). Furthermore, EDS was specifically associated with persistent painful TMD when chronic pain was defined by pain duration (RR = 1.13, 95%CI: 1.00-1.26, P = 0.04). Insomnia was not related to the study outcomes (RRadjusted_duration = 0.94, P = 0.27, RRadjusted_dysfunction =1.00, P = 0.99). Conclusion Results indicate that EDS contrary to insomnia predicted the persistence of chronic painful TMD at a 3-month follow-up.

COMPARING SHORT- AND LONG-TERM TMD PAIN COMORBIDITIES: A CROSS-SECTIONAL STUDY AMONG ADOLESCENTS

<h3>Objectives</h3> The primary aim of this study was to compare painful and nonpainful comorbidities between short- and long-term temporomandibular disorder (TMD) pain. The secondary aim was to assess the impact of persistent TMD pain on school absence. <h3>Study Design</h3> Adolescents were enrolled in Montreal (Canada), Nice (France), and Arceburgo (Brazil). The presence of TMD pain, comorbidities (i.e., asthma, allergies, back pain, neck pain, stomach pain, and headache), and school absence were assessed using reliable and validated questionnaires. TMD pain lasting <6 months was considered short-term, and that lasting ≥6 month was deemed long-term. Chi-square tests and analysis of variance were used to test statistical differences between adolescents with short- and long-term TMD pain and those without (controls). Univariate and multivariate unconditional nominal logistic regression analyses were used to assess the association between TMD pain (dependent variable) and the independent variables. <h3>Results</h3> This study enrolled 1400 adolescents with short-term (n = 312, 22.29%) and long-term (n = 139, 9.93%) TMD pain and controls (n = 949, 67.79%). The number of comorbidities was associated with short-term (odds ratio [OR] = 1.71; 95% confidence interval [CI], 1.53-1.90) and long-term (OR = 1.79; 95% CI, 1.55-2.08) TMD pain compared with controls. Allergies were only associated with short-term TMD pain (OR = 1.54; 95% CI, 1.13-2.10). In comparison to controls, adolescents with long- and short-term TMD pain were more likely to have frequent headaches (≥once a week; OR short-term = 4.39; 95% CI, 3.23-5.98; OR long-term = 3.69; 95% CI, 2.45-5.57) and frequent back pain (OR short-term = 1.46; 95% CI, 1.06-2.03; OR long-term = 1.69; 95% CI, 1.11-2.59). Frequent stomach pain was only associated with long-term TMD pain (OR = 2.01; 95% CI, 1.35-3.26), whereas frequent neck pain was only associated with short-term TMD pain (OR = 2.23; 95% CI, 1.53-3.26). Adolescents with long-term TMD pain had higher rates of missing school than those with short-term TMD pain (n long-term = 39, 28.26%; n short-term = 48, 15.43%; <i>P</i> = .0015). <h3>Conclusions</h3> Frequent headache and back pain are very common among adolescents with both short- and long-term TMD pain. The specific association between stomach pain and long-term TMD pain suggests a central dysregulation mechanism.

Pharmacological interventions for painful persistent temporomandibular disorders (TMD)

Objectives This is a protocol for a Cochrane Review (intervention). The objectives are as follows: To assess the efficacy and adverse effects of pharmacological interventions for reducing pain and the impact of pain in people aged 18 years or older with painful persistent temporomandibular disorders (TMD).

Is jaw muscle activity impaired in adults with persistent temporomandibular disorders? A systematic review and meta-analysis.

Understanding jaw muscle activity changes in temporomandibular disorders (TMD) is crucial to guide clinical management. The nature of these changes is currently unclear. Explore changes in jaw muscle activity in TMD. Electronic databases (PubMed, EMBASE, CINAHL, Scopus, Web of Science, Cochrane) and bibliographies were searched from inception to 9 July 2020 for eligible studies, including grey literature. Case-control and interventional studies reporting time-domain and frequency-domain electromyographic measures of jaw muscle activity in TMD and control groups were included. SIGN checklist for case-control studies was used to evaluate risk of bias. Results were pooled for meta-analysis using random-effects model. Confidence in cumulative evidence was established using American Academy of Neurology guidelines. Forty-five studies were included. Most were rated moderate risk of bias. Activity of four muscles (masseter, temporalis, lateral pterygoid, suprahyoids) was assessed across six domains (resting, clenching, chewing, swallowing, concentrating, resisted mandibular movements), with partial meta-analysis scope. Masseter and temporalis activity were significantly higher at rest (P=.05, P<.0001), but lower during brief maximal clenching (P=.005, P=.04) in TMD vs controls. Insufficient data precluded meta-analysis of remaining outcomes and subgroup analysis. Confidence in cumulative evidence ranged from moderate to very low. Changes in jaw muscle activity exist in TMD, which are both task-specific and muscle-specific. It remains unclear whether jaw muscle activity changes vary between TMD subgroups. Muscle function should be considered in clinical management of TMD. Insufficient subgroup data highlight future direction for research.

Are jaw range of motion, muscle function and proprioception impaired in adults with persistent temporomandibular disorders? A systematic review and meta-analysis.

The nature of certain musculoskeletal impairments associated with temporomandibular disorders (TMD) is unclear. Understanding impairments within TMD subgroups is important to guide management. Characterise local musculoskeletal impairments in adults with persistent TMD. PubMed, EMBASE, CINAHL, Scopus, Web of Science and Cochrane databases were searched from inception to 12 January 2020. Bibliographies were searched for additional articles, including grey literature. Case-control and interventional studies reporting temporomandibular range of motion (ROM), muscle function (MF) or proprioception in TMD and control groups were included. Risk of bias was assessed using SIGN checklist for case-control studies. Results were pooled using random-effects model. Confidence in cumulative evidence was determined using American Academy of Neurology guidelines. Sixty-six studies were included, most rated moderate risk of bias. Twelve primary outcomes were assessed, with partial scope for meta-analysis. Significant reductions were found for active maximal mouth opening (P<.00001, MD=-4.65mm), protrusion (P<.0001, MD=-0.76mm) and maximum bite force (P<.00001) in TMD versus controls. Subgroup analysis scope was limited. Reduced AMMO was found in myogenic TMD subgroups versus controls (P=.001, MD= -3.28mm). Few studies measured proprioception, with high methodological variability. Confidence in cumulative evidence ranged from high to very low. ROM and bite force impairments accompany TMD. Insufficient data were available to investigate impairments within TMD subgroups. Several musculoskeletal impairments have been identified, which may guide clinical management of TMD. Lack of subgroup data, and data for proprioception and MF, highlights future direction for research. CRD42020150734.

Neuroplasticity and Central Sensitization in Orofacial Pain and TMD

Temporomandibular disorders (TMD) are a group of musculoskeletal and neuromuscular conditions that involve the temporomandibular joint (TMJ), the masticatory muscles, and branches of the trigeminal nerve. TMD is the most common chronic oral facial pain disorder. Pain associated with TMD can be clinically expressed as myogenous or arthrogenous in etiology. The myogenous variant of TMD is characterized by pain in the muscles of mastication. The arthrogenous form of TMD is caused by pain in the joint leading to synovitis, capsulitis, or arthritis. Classically, mastication activity aggravates musculoskeletal pain. TMD pain is frequently associated with biomechanical dysfunction of the temporomandibular joint. This includes clicking or locking of the TMJ due to an anterior displaced disk, resulting in limited range of motion of the mandible. The diagnosis is based on the presence of symptoms such as periauricular pain related to mastication, joint noises (popping/clicking), limited mandible opening, jaw locking, and headaches. Orofacial pain includes several diagnoses: odontogenic, musculoskeletal, neurovascular, persistent idiopathic facial pain (PIFP), neuropathic pain, neuralgia, TMD, and headache. When there is a persistent and intense nociceptive input in a sensitized central nervous system, the patient becomes more reactive and experiences more pain with less provocation. Practitioners should have knowledge of this type of heterotopic pain when determining the origins of orofacial pain. Without deep understanding of the trigeminal system and mechanisms differentiating nociceptive and non-nociceptive pain, clinicians will most likely treat the reported symptoms instead of the underlying cause.

Premorbid and concurrent predictors of TMD onset and persistence.

Multiple risk factors predict temporomandibular disorders (TMD) onset, but temporal changes in risk factors and their contribution to risk of TMD have not been evaluated. The study aims were to (a) describe changes occurring in premorbid TMD risk factors when re-measured at TMD onset and 6months later, and (b) determine if measures of change improve accuracy in predicting TMD incidence compared to premorbid measures alone. In this observational prospective cohort study at four university research clinics, 3,258 community-based, 18- to 44-year-olds without TMD were enrolled. During the 3-year median follow-up, 260 incident cases of first-onset TMD were identified, and 196 TMD-free subjects were selected as matched controls. Six-months later, 147 of 260 incident cases (56.6%) were re-examined revealing 72 (49%) with 'persistent TMD' and 75 (51%) whose condition had resolved ('transient TMD'). Virtually all (126) of the 127 re-examined controls remained without TMD. Questionnaires and clinical measurements evaluated risk factors from clinical, health, psychological and behavioural and neurosensory domains. Most risk factors across all four domains increased with TMD onset, remained elevated in the persistent group and declined in the transient group (i.e., significant ANOVA interactions, p<.05). Accuracy in predicting first-onset TMD, quantified as area under the receiver operating characteristic curve was 0.71 (95% CL 0.68, 0.73) using only premorbid measures of risk factors, which increased to 0.91 (95% CL 0.89, 0.94) after addition of change measures. TMD pain onset and persistence appear to be determined by enduring characteristics of the person as well as mutually interactive with temporally evolving variables. TMD is known to be a complex disorder, in which onset and persistence are associated with disease-related variables in multiple domains, including environmental exposure, clinical, psychological, health status, and pain processing variables. Using a more dynamic approach in order to capture change across time, many aspects of those domains were found to worsen prior to the reporting of pain, with bidirectional influences between domains and pain emergence likely. TMD onset appears to represent the cumulative effect of multiple system dysregulation.

Clinical predictors of persistent temporomandibular disorder in people with first-onset temporomandibular disorder: A prospective case-control study

BackgroundWhen patients first develop a painful temporomandibular disorder (TMD) and seek care, 1 priority for clinicians is to assess prognosis. The authors aimed to develop a predictive model by using biopsychosocial measures from the Diagnostic Criteria for Temporomandibular Disorders (DC-TMD) to predict risk of developing TMD symptom persistence. MethodsAt baseline, trained examiners identified 260 participants with first-onset TMD classified by using DC-TMD–compliant protocols. After follow-up at least 6 months later, 72 (49%) had examiner-classified TMD (persistent cases), and 75 (51%) no longer had examiner-classified TMD (transient cases). For multivariable logistic regression analysis, the authors used blocks of variables selected using minimum redundancy maximum relevance to construct a model to predict the odds of TMD persistence. ResultsAt onset, persistent cases had multiple worse TMD clinical measures and, among Axis II measures, only greater baseline pain intensity (odds ratio [OR], 1.5; 95% confidence interval [CI], 1.04 to 2.2; P = .030) and more physical symptoms (OR, 1.8; 95% CI, 1.2 to 2.9; P = .004) than did transient cases. A multivariable model using TMD clinical measures showed greater discriminative capacity (area under the receiver operating characteristic curve, 0.74; 95% CI, 0.73 to 0.75) than did a model involving psychosocial measures (area under the receiver operating characteristic curve, 0.63; 95% CI, 0.62 to 0.64). ConclusionsClinical measures that clinicians can assess readily when TMD first develops are useful in predicting the risk of developing persistent TMD. Psychosocial measures are important predictors of onset but do not add meaningfully to the predictive capacity of clinical measures. Practical ImplicationsWhen TMD first develops, clinicians usefully can identify patients at higher risk of developing persistence by using clinical measures that they logically also could use in treatment planning and for monitoring outcomes of intervention.

MR-guided navigation for botulinum toxin injection in the lateral pterygoid muscle. First results in the treatment of temporomandibular joint disorders

IntroductionHyperactivity of the lateral pterygoid muscle (LPM) is one of the presumed mechanisms of the onset of temporomandibular disorders (TMD) and explains why intramuscular injection of botulinum toxin (BT) may be indicated for treatment. Intramuscular injection without guidance is difficult because of its deep location. The objectives of this study were to determine the feasibility of MR-guided navigation for BT injection in the LPM in TMD and to report about our first results. Patients and methodsSix patients suffering from persistent myogenic TMD were enrolled in a prospective study and treated with intramuscular injection of BT A: 20 UI in each LPM with MR-guided navigation using the Brainlab plateform (Kolibri®, Brainlab®, Munich, Germany) the target being the center of the upper head, 30 UI in each masseter and 20 UI in each temporal with clinical guidance. The investigated outcomes were: pain intensity, maximum interincisal opening and joint sounds. ResultsMR-guided navigation could be used in all patients and the target could constantly be reached. Pain improvement [mean reduction of 4.4 on a numeric scale (p = 0.0579)] was observed in 66.7% of the patients. Significant improvement of maximum interincisal opening was found (p = 0.0360) and joint sounds tend to disappear (p = 0.5594). DiscussionMR-guided navigation is an effective method for tracking the upper head of the LPM and allows for a precise injection of BT. Injection of BT in the upper head of the LPM, the masseter and the temporal muscles is effective in refractory TMD. A combination of this morphologic guidance with electromyographic tracking would allow to select more carefully the muscles to be injected.

Benefits of implementing pain-related disability and psychological assessment in dental practice for patients with temporomandibular pain and other oral health conditions

BackgroundEvidence in the field of dentistry has demonstrated the importance of pain-related disability and psychological assessment in the development of chronic symptoms. The Diagnostic Criteria for Temporomandibular Disorders offer a brief assessment for the diagnostic process in patients with orofacial pain (Axis II). The authors describe relevant outcomes that may guide general oral health care practitioners toward tailored treatment decisions and improved treatment outcomes and provide recommendations for the primary care setting. MethodsThe authors conducted a review of the literature to provide an overview of knowledge about Axis II assessment relevant for the general oral health care practitioner. ResultsThe authors propose 3 domains of the Axis II assessment to be used in general oral health care: pain location (pain drawing), pain intensity and related disability (Graded Chronic Pain Scale [GCPS]), and psychological distress (Patient Health Questionnaire-4 [PHQ-4]). In the case of localized pain, low GCPS scores (0-II), and low PHQ-4 scores (0-5), patients preferably receive treatment in primary care. In the case of widespread pain, high GCPS scores (III-IV), and high PHQ-4 scores (6-12), the authors recommend referral to a multidisciplinary team, especially for patients with temporomandibular disorder (TMD) pain. ConclusionsThe authors recommend psychological assessment at first intake of a new adult patient or for patients with persistent TMD pain. The authors recommend the pain-related disability screening tools for all TMD pain symptoms and for dental pain symptoms that persist beyond the normal healing period. Practical ImplicationsA brief psychological and pain-related disability assessment for patients in primary care may help the general oral health care practitioner make tailored treatment decisions.

Clinical phenotype of South-East Asian temporomandibular disorder patients with upper airway resistance syndrome.

Clinical and radiographic characteristics of a subset of South East Asian temporomandibular disorder (TMD) patients with comorbid upper airway resistance syndrome (UARS) were documented in a multi-center prospective series of 86 patients (26 men and 60 women / mean age 35.7 years). All had excessive daytime sleepiness, high arousal index and Apnoea-Hypopnoea Index (AHI) <5. The mean body mass index was 20·1, mean arousal index 16·2, mean respiratory disturbance index 19·6, mean AHI 3·9 while the mean Epworth Sleepiness Scale was 14·8. Many had functional somatic complaints; 66·3% headaches, 41·9% neck aches, 53·5% masticatory muscle myalgia, 68·6% temporomandibular joint (TMJ) arthralgia while 90·7% reported sleep bruxism (SB). Unlike patients with obstructive sleep apnoea (OSA), hypertension was uncommon (4·7%) while depression was prevalent at 68·6% with short REM latency of <90min and an increased REM composition >25% documented in 79·6% and 57·6% of these depressed patients, respectively. 65·1% displayed a posteriorly displaced condyle at maximum intercuspation with or without TMJ clicking. Mostexhibited a forward head posture (FHP) characterised by loss of normal cervical lordosis (80·2%), C0-C1 narrowing (38·4%) or an elevated hyoid position (50%), and 91·9% had nasal congestion. We postulate the TMD-UARS phenotype may have originally developed as an adaptive response to 'awake' disordered breathing during growth. Patients with persistent TMD and/or reporting SB should be screened for UARS and chronic nasal obstruction, especially when they also present with FHP. The lateral cephalogram is a useful tool in the differentiation of UARS from other OSA phenotypes.

The Effectiveness of Noninvasive Interventions for Temporomandibular Disorders: A Systematic Review by the Ontario Protocol for Traffic Injury Management (OPTIMa) Collaboration.

To determine the effectiveness and cost-effectiveness of noninvasive interventions for temporomandibular disorders (TMD). We systematically searched MEDLINE, EMBASE, CINAHL, PsycINFO, and Cochrane Central register from 1990 to 2014 for effectiveness studies and the Cochrane Health Technology Assessment Database, EconLit, NHS Economic Evaluation Database, and Tufts Medical Center Cost-Effectiveness Analysis Register from 1990 to 2014 for cost-effectiveness studies. Random pairs of independent reviewers critically appraised eligible studies using the Scottish Intercollegiate Guidelines Network criteria. Evidence from eligible studies was synthesized using best-evidence synthesis methodology. Our search for effectiveness studies yielded 16,995 citations; 31 were relevant and 7 randomized controlled trials (published in 8 articles) had a low risk of bias. We found no relevant cost-effectiveness studies. The evidence suggests that for persistent TMD: (1) cognitive-behavioral therapy and self-care management lead to similar improvements in pain and disability but cognitive-behavioral therapy is more effective for activity interference and depressive symptoms; (2) cognitive-behavioral therapy combined with usual treatment provides short-term benefits in pain and ability to control pain compared with usual treatment alone; (3) intraoral myofascial therapy may reduce pain and improve jaw opening; and (4) structured self-care management may be more effective than usual treatment. The evidence suggests that occlusal devices may not be effective in reducing pain and improving motion for TMD of variable duration. Evidence on the effectiveness of biofeedback is inconclusive. The available evidence suggests that cognitive-behavioral therapy, intraoral myofascial therapy, and self-care management are therapeutic options for persistent TMD.

Pressure pain thresholds fluctuate with, but do not usefully predict, the clinical course of painful temporomandibular disorder

Central sensitization elicits pain hypersensitivity and is thought to be causally implicated in painful temporomandibular disorder (TMD). This causal inference is based on cross-sectional evidence that people with TMD have greater sensitivity than controls to noxious stimuli. We tested this inference in the Orofacial Pain: Prospective Evaluation and Risk Assessment (OPPERA) prospective cohort study of 3258 adults with no lifetime history of TMD when enrolled (visit 1). During 5years of follow-up, 1 group labeled “persistent TMD cases” (n=72) developed first-onset TMD by visit 2 that persisted ⩾6months until visit 3. Another group labeled “transient TMD cases” (n=75) developed first-onset TMD at visit 2, which resolved by visit 3. Randomly sampled “controls” (n=126) remained TMD-free throughout all 3 visits. At each visit, pressure pain thresholds (PPTs) were measured by algometry at 10 cranial and bodily sites. In persistent TMD case patients, mean PPTs reduced 43kPa (P<.0001) between visits 1 and 2 and thereafter did not change significantly. In transient TMD case patients, mean PPTs reduced 41kPa (P<.001) between visits 1 and 2, and then increased 20kPa (P<.001) by visit 3. These patterns were similar after excluding cranial sites symptomatic for TMD. Importantly, visit 1 PPTs had no clinically useful prognostic value in predicting first-onset TMD (odds ratio [OR]=1.07, P=.15). Among first-onset case patients, visit 2 PPTs were modest predictors of persistent TMD (OR=1.36, P=.002). In this longitudinal study, PPTs reduced when TMD developed then rebounded when TMD resolved. However, premorbid PPTs poorly predicted TMD incidence, countering the hypothesis that PPTs signify mechanisms causing first-onset TMD.

Differential diagnosis of facial pain and guidelines for management

The diagnosis and management of facial pain below the eye can be very different dependant on whether the patient visits a dentist or medical practitioner. A structure for accurate diagnosis is proposed beginning with a very careful history. The commonest acute causes of pain are dental and these are well managed by dentists. Chronic facial pain can be unilateral or bilateral and continuous or episodic. The commonest non-dental pains are temporomandibular disorders (TMDs), especially musculoskeletal involving the muscles of mastication either unilaterally or bilaterally; they may be associated with other chronic pains. A very wide range of treatments are used but early diagnosis, reassurance and some simple physiotherapy is often effective in those with good coping strategies. Dentists will often make splints to wear at night. Neuropathic pain is usually unilateral and of the episodic type; the most easily recognized is trigeminal neuralgia. This severe electric shock like pain, provoked by light touch, responds best to carbamazepine, and neurosurgery in poorly controlled patients. Trauma, either major or because of dental procedures, results in neuropathic pain and these are then managed as for any other neuropathic pain. Red flags include giant cell arteritis which much be distinguished from temporomandibular disorders (TMD), especially in >50 yr olds, and cancer which can present as a progressive neuropathic pain. Burning mouth syndrome is rarely recognized as a neuropathic pain as it occurs principally in peri-menopausal women and is thought to be psychological. Chronic facial pain patients are best managed by a multidisciplinary team.

Efficacy of botulinum toxin type A for treatment of persistent myofascial TMD pain: A randomized, controlled, double-blind multicenter study

Evidence of an effect by botulinum toxins is still lacking for most pain conditions. In the present randomized, placebo-controlled, crossover multicenter study, the efficacy of botulinum toxin type A (BTX-A) was investigated in patients with persistent myofascial temporomandibular disorders (TMD). Twenty-one patients with myofascial TMD without adequate pain relief after conventional treatment participated. A total of 50 U of BTX-A or isotonic saline (control) was randomly injected into 3 standardized sites of the painful masseter muscles. Follow-up was performed after 1 and 3 months, followed by a 1-month washout period, after which crossover occurred. Pain intensity at rest was the primary outcome measure, while physical and emotional function, global improvement, side effects, and clinical measures were additional outcome measures. There was no main difference between drugs (ANOVA; P = .163), but there was a significant time effect ( P < .001), so BTX-A reduced mean (SD) percent change of pain intensity by 30 (33%) after 1 month and by 23 (30%) after 3 months compared to 11 (40%) and 4 (33%) for saline. The number of patients who received a 30% pain reduction was not significantly larger for BTX-A than after saline at any follow-up visit. The number needed to treat was 11 after 1 month and 7 after 3 months. There were no significant changes after treatment in any other outcome measures, with the exception of pain on palpation, which decreased 3 months after saline injection ( P < .05). These results do not indicate a clinical relevant effect of BTX-A in patients with persistent myofascial TMD pain. Botulinum toxin type A is not an effective adjunct to conventional treatment in persistent myofascial temporomandibular disorders.

Editor's Summary and Q&A: Twenty-year cohort study of health gain from orthodontic treatment: Temporomandibular disorders

Introduction Temporomandibular disorder (TMD) is a common condition. Studies of TMD in relation to orthodontic treatment did not show an association, but longitudinal studies from adolescence to adulthood are lacking. The aim of this study was to investigate the relationship between orthodontic treatment and TMD with a longitudinal study design. Methods This prospective cohort study was conducted in South Wales, United Kingdom. The baseline investigation was carried out in 1981 and involved children aged 11 to 12 years (n = 1018). Follow-up investigations were done in 1984 (n = 792), 1989 (n = 456), and 2000 (n = 337). Results Overall TMD prevalence increased from the baseline (3.2%) to age 19 to 20 (17.6%) and decreased by age 30 to 31 (9.9%). TMD prevalence was higher in females at all follow-up points, except the baseline. Overall, incidences of TMD were 11.9%, 11.5%, and 6.0% at the first, second, and last follow-ups, respectively. Females were more likely to develop TMD than males (hazard ratio [HR], 2.1; 95% CI, 1.3 and 3.3), and those with high self-esteem were less likely to develop TMD (HR, 0.6; 95% CI, 0.4 and 0.8). There was no association between orthodontic treatment and new TMD onset. The incidences of persistent TMD were 20.0%, 34.9%, and 28.0% at the first, second, and last follow-ups, respectively. Females were more likely to have persistent TMD than males (HR, 2.5; 95% CI, 1.0 and 6.1). There was no association between orthodontic treatment and persistent TMD. The only significant predictors of TMD in adults aged 30 to 31 were female sex (odd ratio, 3.0; 95% CI, 1.1 and 8.2) and TMD in adolescence (odds ratio, 4.5; 95% CI, 2.0 and 10.0). Conclusions Orthodontic treatment neither causes nor prevents TMD. Female sex and TMD in adolescence were the only predictors of TMD in young adulthood. Temporomandibular disorder (TMD) is a common condition. Studies of TMD in relation to orthodontic treatment did not show an association, but longitudinal studies from adolescence to adulthood are lacking. The aim of this study was to investigate the relationship between orthodontic treatment and TMD with a longitudinal study design. This prospective cohort study was conducted in South Wales, United Kingdom. The baseline investigation was carried out in 1981 and involved children aged 11 to 12 years (n = 1018). Follow-up investigations were done in 1984 (n = 792), 1989 (n = 456), and 2000 (n = 337). Overall TMD prevalence increased from the baseline (3.2%) to age 19 to 20 (17.6%) and decreased by age 30 to 31 (9.9%). TMD prevalence was higher in females at all follow-up points, except the baseline. Overall, incidences of TMD were 11.9%, 11.5%, and 6.0% at the first, second, and last follow-ups, respectively. Females were more likely to develop TMD than males (hazard ratio [HR], 2.1; 95% CI, 1.3 and 3.3), and those with high self-esteem were less likely to develop TMD (HR, 0.6; 95% CI, 0.4 and 0.8). There was no association between orthodontic treatment and new TMD onset. The incidences of persistent TMD were 20.0%, 34.9%, and 28.0% at the first, second, and last follow-ups, respectively. Females were more likely to have persistent TMD than males (HR, 2.5; 95% CI, 1.0 and 6.1). There was no association between orthodontic treatment and persistent TMD. The only significant predictors of TMD in adults aged 30 to 31 were female sex (odd ratio, 3.0; 95% CI, 1.1 and 8.2) and TMD in adolescence (odds ratio, 4.5; 95% CI, 2.0 and 10.0). Orthodontic treatment neither causes nor prevents TMD. Female sex and TMD in adolescence were the only predictors of TMD in young adulthood.

Twenty-year cohort study of health gain from orthodontic treatment: Temporomandibular disorders

Temporomandibular disorder (TMD) is a common condition. Studies of TMD in relation to orthodontic treatment did not show an association, but longitudinal studies from adolescence to adulthood are lacking. The aim of this study was to investigate the relationship between orthodontic treatment and TMD with a longitudinal study design. This prospective cohort study was conducted in South Wales, United Kingdom. The baseline investigation was carried out in 1981 and involved children aged 11 to 12 years (n = 1018). Follow-up investigations were done in 1984 (n = 792), 1989 (n = 456), and 2000 (n = 337). Overall TMD prevalence increased from the baseline (3.2%) to age 19 to 20 (17.6%) and decreased by age 30 to 31 (9.9%). TMD prevalence was higher in females at all follow-up points, except the baseline. Overall, incidences of TMD were 11.9%, 11.5%, and 6.0% at the first, second, and last follow-ups, respectively. Females were more likely to develop TMD than males (hazard ratio [HR], 2.1; 95% CI, 1.3 and 3.3), and those with high self-esteem were less likely to develop TMD (HR, 0.6; 95% CI, 0.4 and 0.8). There was no association between orthodontic treatment and new TMD onset. The incidences of persistent TMD were 20.0%, 34.9%, and 28.0% at the first, second, and last follow-ups, respectively. Females were more likely to have persistent TMD than males (HR, 2.5; 95% CI, 1.0 and 6.1). There was no association between orthodontic treatment and persistent TMD. The only significant predictors of TMD in adults aged 30 to 31 were female sex (odd ratio, 3.0; 95% CI, 1.1 and 8.2) and TMD in adolescence (odds ratio, 4.5; 95% CI, 2.0 and 10.0). Orthodontic treatment neither causes nor prevents TMD. Female sex and TMD in adolescence were the only predictors of TMD in young adulthood.

Glutamate-evoked jaw muscle pain as a model of persistent myofascial TMD pain?

Objective Compare pain-related measures and psychosocial variables between glutamate-evoked jaw muscle pain in healthy subjects (HS) and patients with persistent myofascial temporomandibular disorder (TMD) pain. Design Forty-seven female HS and 10 female patients with persistent myofascial TMD pain participated. The HS received an injection of glutamate into the masseter muscle to model persistent myofascial TMD pain. Participants filled out a coping strategies questionnaire (CSQ), the symptom checklist 90 (SCL-90) and McGill pain questionnaire (MPQ). Pain intensity was assessed on an electronic visual analogue scale (VAS). Pain-drawing areas, numerical rating scale (NRS) scores of unpleasantness, pressure pain thresholds (PPTs) and pressure pain tolerance (PPTOL) were measured. Unpaired t-tests and correlation tests were used for analyses. Results The groups were significantly different when comparing the CSQ scores of control, decrease, diverting attention, increase of behavioural activities and somatization. The peak VAS pain, NRS of unpleasantness and MPQ scores were not significantly different between groups, but PPT and PPTOL were significantly lower in the TMD patients. Significant positive correlations were found in the TMD patients between peak VAS pain and CSQ catastrophizing score and SCL-90 somatization. The scores of PPTs and PPTOLs, in patients showed positive correlations with CSQ reinterpreting pain sensations scores and PPTs correlated with CSQ praying/hoping scores. Conclusions Glutamate-evoked pain responses in HS and persistent myofascial TMD pain have similar sensory-discriminative and affective-unpleasantness components but differ in psychosocial features. This study suggests that experimental designs based on glutamate injection into muscle can provide an appropriate model for elucidating persistent myofascial pain conditions.

Adaptive psychophysical methodology applied to sensory-discriminative tests of pain perception

Compare pain-related measures and psychosocial variables between glutamate-evoked jaw muscle pain in healthy subjects (HS) and patients with persistent myofascial temporomandibular disorder (TMD) pain.Forty-seven female HS and 10 female patients with persistent myofascial TMD pain participated. The HS received an injection of glutamate into the masseter muscle to model persistent myofascial TMD pain. Participants filled out a coping strategies questionnaire (CSQ), the symptom checklist 90 (SCL-90) and McGill pain questionnaire (MPQ). Pain intensity was assessed on an electronic visual analogue scale (VAS). Pain-drawing areas, numerical rating scale (NRS) scores of unpleasantness, pressure pain thresholds (PPTs) and pressure pain tolerance (PPTOL) were measured. Unpaired t-tests and correlation tests were used for analyses.The groups were significantly different when comparing the CSQ scores of control, decrease, diverting attention, increase of behavioural activities and somatization. The peak VAS pain, NRS of unpleasantness and MPQ scores were not significantly different between groups, but PPT and PPTOL were significantly lower in the TMD patients. Significant positive correlations were found in the TMD patients between peak VAS pain and CSQ catastrophizing score and SCL-90 somatization. The scores of PPTs and PPTOLs, in patients showed positive correlations with CSQ reinterpreting pain sensations scores and PPTs correlated with CSQ praying/hoping scores.Glutamate-evoked pain responses in HS and persistent myofascial TMD pain have similar sensory-discriminative and affective-unpleasantness components but differ in psychosocial features. This study suggests that experimental designs based on glutamate injection into muscle can provide an appropriate model for elucidating persistent myofascial pain conditions.