Journal of Oral & Facial Pain and Headache, 02/2023

Aims: To describe how some management practices in the field of orofacial musculoskeletal disorders (also described as temporomandibular disorders [TMDs]) are based on concepts about occlusal relationships, condyle positions, or functional guidance; for some patients, these procedures may be producing successful outcomes in terms of symptom reduction, but in many cases, they can be examples of unnecessary overtreatment. Methods: The authors discuss the negative consequences of this type of overtreatment for both doctors and patients, as well as the impact on the dental profession itself. Special focus is given to trying to move the dental profession away from the old mechanical paradigms for treating TMDs and forward to the more modern (and generally more conservative) medically based approaches, with emphasis on the biopsychosocial model. Results: The clinical implications of such a discussion are apparent. For example, it can be argued that the routine use of Phase II dental or surgical treatments for managing most orofacial pain cases represents overtreatment, which cannot be defended on the grounds of symptom improvement (ie, "successful" outcomes) alone. Similarly, there is enough clinical evidence to conclude that complex biomechanical approaches focusing on the search for an ideal specific condylar or neuromuscular position for the management of orofacial musculoskeletal disorders are not needed to produce a positive clinical result that is stable over time. Conclusion: Typically, overtreatment successes cannot be easily perceived by the patients or the treating dentists because the patients are satisfied and the dentists feel good about those outcomes. However, neither party knows whether an excessive amount of treatment has been provided. Therefore, both the practical and ethical aspects of this discussion about proper treatment vs overtreatment deserve attention. Keywords: orofacial musculoskeletal disorders, overtreatment, success, temporomandibular disorders, temporomandibular joint

Aims: To systematically review the literature assessing associations between TMDs and primary headaches. Methods: Using validated clinical criteria, studies on TMDs and primary headaches published up to January 10, 2023 were identified using six electronic databases. This review adhered to the PRISMA 2020 guidelines and 27-item checklist and is registered on PROSPERO (CRD42021256391). Risk of bias was evaluated using the National Institutes of Health Quality Assessment Toolkits for Observational Cohort and Cross-Sectional Studies. Results: Two independent investigators rated 7,697 records against the primary endpoint and found 8 records meeting the eligibility requirements. Migraine was found to be the most common primary headache related to TMDs (61.5%), followed by episodic tension-type headache (ETTH; 38.5%). A moderate association was found for mixed TMDs with migraine and ETTH, with a large sample size and multiple studies included (n = 8). A very low-quality association was found for myalgia-related TMDs with migraine and ETTH (included studies, n = 2). Conclusion: The association between TMDs and primary headaches is of great interest given the possible effectiveness of TMD management in reducing headache intensity/frequency in patients with TMDs and headache comorbidity. A moderate association was found for mixed TMDs with primary headaches, in particular migraine and ETTH. However, owing to the overall moderate certainty of evidence of the present findings, further longitudinal studies with larger samples investigating possible associated factors and using accurate TMD and headache category assignment are needed. Keywords: episodic tension-type headache, headache, orofacial pain, migrain, temporomandibular joint dysfunction

Aims: To examine the effect of manual therapy applied to the cervical joint for reducing pain and improving mouth opening and jaw function in people with TMDs. Methods: A systematic review of randomized controlled trials was performed. Participants were adults diagnosed with TMDs. The experimental intervention was manual therapy applied to the cervical joint compared to no intervention/placebo. Outcome data relating to orofacial pain intensity, pressure pain threshold (PPT), maximum mouth opening, and jaw function were extracted and combined in meta-analyses. Results: The review included five trials involving 213 participants, of which 90% were women. Manual therapy applied to the cervical joint decreased orofacial pain (mean difference: -1.8 cm; 95% CI: -2.8 to -0.9) and improved PPT (mean difference: 0.64 kg/cm2; 95% CI: 0.02 to 1.26) and jaw function (standardized mean difference: 0.65; 95% CI: 0.3 to 1.0). Conclusion: Manual therapy applied to the cervical joint had short-term benefits for reducing pain intensity and improving jaw function in women with TMDs. Further studies are needed to improve the quality of the evidence and to investigate the maintenance of benefits beyond the intervention period. Keywords: manipulation, mobilization, massage, pain, rehabilitation, temporomandibular joint

Aims: To identify the range of patient-reported outcome measures (PROMs) used in TMD studies, summarize the available evidence for their psychometric properties, and provide guidance for the selection of such measures. Methods: A comprehensive search was conducted to retrieve articles published between 2009 and 2018 containing a patient-reported measure of the effects of TMDs. Three databases were searched: MEDLINE, Embase, and Web of Science. Results: A total of 517 articles containing at least one PROM were included in the review, and 57 additional studies were also located describing the psychometric properties of some tools in a TMD population. A total of 106 PROMs were identified and fell into the following categories: PROMs describing the severity of symptoms; PROMs describing psychologic status; and PROMs describing quality of life and general health. The most commonly used PROM was the visual analog scale. However, a wide range of verbal descriptors was employed. The Oral Health Impact Profile-14 and Beck Depression Inventory were the most commonly used PROMs describing the effect of TMDs on quality of life and psychologic status, respectively. Additionally, the Oral Health Impact Profile (various versions) and the Research Diagnostic Criteria Axis ll questionnaires were the instruments most repeatedly tested in a TMD population, and these instruments have undergone cross-cultural validation in several languages. Conclusion: A wide range of PROMs have been used to describe the impact of TMDs on patients. Such variability may limit the ability of researchers and clinicians to evaluate the efficacy of different treatments and make meaningful comparisons. Keywords: patient-reported outcome measures, psychometric properties, quality of life, review, temporomandibular disorders

Aims: To assess differences in biopsychosocial factors between participants with masticatory myofascial pain with referral (MFPwR), with myalgia without referral (Mw/oR), and community controls without TMDs. Methods: Study participants were diagnosed with MFPwR (n = 196), Mw/oR (n = 299), or as a non-TMD community control (n = 87) by two calibrated examiners at each of three study sites. Pain chronicity, pain on palpation of masticatory muscle sites, and pressure pain thresholds (PPT) at 12 masticatory muscle, 2 trigeminal, and 2 nontrigeminal control sites were recorded. Psychosocial factors assessed included anxiety, depression, and nonspecific physical symptoms (Symptom Checklist-90 Revised); stress (Perceived Stress Scale); and health-related quality of life (Short Form Health Survey). Comparisons among the three groups were adjusted for age, sex, race, education, and income using multivariable linear regression. The significance threshold was set at P = .017 (.05 / 3) for subsequent pairwise comparisons. Results: Compared to the Mw/oR group, the MFPwR group had significantly greater pain chronicity, number of painful muscle sites, anxiety, depression, nonspecific physical symptoms, and impaired physical health (P < .017). The MFPwR group also had significantly lower PPTs for masticatory sites (P < .017). Both muscle pain groups differed significantly from the non-TMD community control group for all outcome measures (P < .017). Conclusion: These findings support the clinical utility of separating MFPwR from Mw/oR. Patients with MFPwR are more complex from a biopsychosocial perspective than Mw/oR patients, which likely affects prognosis and supports consideration of these factors in case management. Keywords: biopsychosocial, diagnosis, myofascial, pain, pain referral, temporomandibular disorders

Aims: To measure brain activity in patients with bruxism and temporomandibular disorder (TMD)-related pain in comparison to controls using functional magnetic resonance imaging (fMRI) and to investigate whether modulations in jaw clenching led to different pain reports and/or changes in neural activity in motor and pain processing areas within and between both groups. Methods: A total of 40 participants (21 patients with bruxism and TMD-related pain and 19 healthy controls) performed a tooth-clenching task while lying inside a 3T MRI scanner. Participants were instructed to mildly or strongly clench their teeth for brief periods of 12 seconds and to subsequently rate their clenching intensity and pain experience after each clenching period. Results: Patients reported significantly more pain during strong clenching compared to mild clenching. Further results showed significant differences between patients and controls in activity in areas of brain networks commonly associated with pain processing, which were also correlated with reported pain intensity. There was no evidence for differences in activity in motor-related areas between groups, which contrasts with findings of previous research. Conclusions: Brain activity in patients with bruxism and TMD-related pain is correlated more with pain processing than with motoric differences.