The Potential of Percent Agreement as an Adjunctive Diagnostic Tool for Acute Temporomandibular Disorder

Keela W., Itthikul T., Mitrirattanakul S., Pongrojpaw S.

The aim of this research was to explore the oral behaviours exhibited by individuals with and without temporomandibular disorders (TMD) pain, and with various pain characteristics; and to determine which oral behaviour is correlated with painful TMD. 328 patients with TMD who visited Orofacial Pain Clinic were included in this retrospective cross-sectional study. The patients were categorised into 2 groups—painful TMD and non-painful TMD—based on pain status; their other pain characteristics were recorded. To evaluate oral behaviours, researchers utilised the Oral Behaviors Checklist (OBC) and categorised into 3 levels based on the Diagnostic criteria for TMD scoring manual. To investigate the associations amongst demographic information, oral behaviour levels, and TMD pain status and characteristics, logistic regression was employed, whilst t tests were used to analyse OBC scores. Logistic regression was also used to examine individual oral behaviours in relation to specific pain characteristics. Age and marital status were associated with TMD pain status. Significantly higher OBC scores were observed in chronic pain compared to acute pain group, but the scores were not significantly different for pain status and other pain characteristics. OBC score and level were associated solely with TMD pain chronicity. According to multivariate logistic regression, “clench or grind teeth when sleeping” was the strongest predictor of TMD pain and “place tongue forcibly against teeth” was the strongest predictor of chronic painful TMD. High oral behaviour level and OBC scores were associated with chronic painful TMD. Sleep bruxism was the strongest predictor of TMD pain. Age and marital status were correlated with TMD pain status. In the treatment of TMD, there can be potential benefits in addressing and managing oral parafunctional behaviours.

Elbarbary M., Goldberg M., Tenenbaum H.C., Lam D.K., Freeman B.V., Pustaka D.J., Mock D., Beyene J., Azarpazhooh A.

Masticatory myofascial pain is a musculoligamentous syndrome that can mimic odontogenic pain. Pain referral to odontogenic structures can be traced to hyperirritated myofascial trigger points (MTrPs). This pragmatic study evaluated the concordance between ultrasonography and palpation in detecting MTrPs in the masseter and temporalis muscles.Fifty-seven patients suspected to have temporomandibular disorder were included. MTrPs were palpated manually by expert clinicians. Ultrasonography was then performed by a blind sonographer. The quantity of MTrPs and the involved muscle sections, the pain occurrence, and the location of the MTrPs within the muscle sections were compared using the mean difference (MD) and concordance statistics (Cohen κ and the interclass correlation coefficient [ICC]) as applicable.Ultrasonography located MTrPs as 2.1 ± 1.3 mm2 hypoechoic nodules at a depth of 7 ± 3.3 mm. Ultrasonography moderately agreed with palpation on the quantity of MTrPs per patient (MD = 1; 95% confidence interval [CI], 0.06-1.9; ICC = 0.56; 95% CI, 0.32-0.72). Palpation detected marginally more involved muscle sections per patient (MD = 0.7; 95% CI, 0.06-1.34.05; ICC = 0.64; 95% CI, 0.44-0.77) with more pain occurrence per patient (MD = 1.4; 95% CI, 0.56-2.28; ICC = 0.13; 95% CI, -0.26 to 0.41). There was a discordance in the location of the MTrPs within the muscle sections per patient (κ = -0.46; 95% CI, -0.77 to -0.14).Ultrasonography and palpation concurred moderately to substantially on the quantity of MTrPs and the involved muscle sections but disagreed on the location of the MTrPs within the muscle sections. Ultrasonography has the potential as a chairside diagnostic aid to help clinicians determine an accurate diagnosis, enhance patient experience during examination, and avoid unnecessary treatments that can mitigate the risk of iatrogenic damage.

Wieckiewicz M., Jenca A., Seweryn P., Orzeszek S., Petrasova A., Grychowska N., Winocur-Arias O., Emodi-Perlman A., Kujawa K.

BackgroundThere is a need to assess a relationship between the psychoemotional state of patients and the occurrence and the intensity of pain and temporomandibular disorders (TMD) in relation to a Polish population. There are no such precision data in the literature relating to the population of big Eastern European country. The study conducted by the authors refer to a large group of male and female adult patients of the Polish population in a different age profile. As a result, this study provides a picture of the situation that also takes into account population characteristics that may affect the clinical situation of patients.ObjectiveThe aim of the study was to assess the pain intensity, pain-related disability, anxiety, depression, and perceived stress among Polish adults with TMD as well as the association between psychosocial impairment and TMD.Materials and methodsThis prospective cohort study included 219 adult patients from the Outpatient Clinic for Temporomandibular Disorders at the Academic Dental Polyclinic in Wroclaw. The patients completed validated questionnaires, and received a TMD diagnosis based on a standardized examination (Diagnostic Criteria for Temporomandibular Disorders) performed by a qualified dentist. A statistical analysis was carried out on the collected data.ResultsMyalgia was the most commonly diagnosed condition among the TMD patients. Furthermore, the prevalence of perceived stress, anxiety, and depression was high in the studied sample. Females showed more depression symptoms than males, while the level of anxiety and stress was similar in both groups. The most statistically significant correlation was observed between the group of masticatory muscle disorders and the level of depression, stress, pain intensity, and pain-related disability.ConclusionDue to the high prevalence of increased levels of anxiety, depression, and perceived stress, it is essential to screen the psychosocial status of Polish TMD adult patients. Psychosocial status may have an impact on a studied patient’s response to treatment and pain intensity, and pain-related disability. Therefore, Polish TMD adult patients should be provided with management based on an interdisciplinary approach.Clinical trial registration[https://clinicaltrials.gov/], identifier [NCT05183503].

Bortsov A.V., Parisien M., Khoury S., Martinsen A.E., Lie M.U., Heuch I., Hveem K., Zwart J., Winsvold B.S., Diatchenko L.

Nickel J.C., Gonzalez Y.M., Wu Y., Liu Y., Liu H., Iwasaki L.R.

Chronic pain associated with temporomandibular disorders (TMDs) may reflect muscle mechanoreceptor afferent barrage and dysregulated sensory processing. This observational study tested for associations between Characteristic Pain Intensity (CPI), physical symptoms (Patient Health Questionnaire–15 [PHQ-15]), and cumulative jaw muscle motor load (mV*s). In accordance with institutional review board oversight and Strengthening the Reporting of Observational Studies in Epidemiology guidelines, adult subjects gave informed consent and were identified via Diagnostic Criteria for TMD (DC-TMD) examination and research protocols. Subjects were assigned to ±Pain groups using DC-TMD criteria for myalgia. CPI scores characterized pain intensity. PHQ-15 scores were surrogate measures of dysregulated sensory processing. Laboratory tests were performed to quantify masseter and temporalis muscle activities (mV) per bite force (N) for each subject. In their natural environments, subjects recorded day- and nighttime electromyography from which cumulative jaw muscle motor loads (mV*s) were determined for activities consistent with bite forces of >1 to ≤2 and >2 to ≤5 N. Data were assessed using univariate analysis of variance, simple effects tests, K-means cluster classification, and 3-dimensional regression analyses. Of 242 individuals screened, 144 enrolled, and 125 with complete data from study protocols, there were 35 females and 15 males for +Pain and 35 females and 40 males for −Pain. Subjects produced 324 daytime and 341 nighttime recordings of average duration 6.9 ± 1.7 and 7.6 ± 1.7 h, respectively. Overall, +Pain compared to −Pain subjects had significantly higher (all P ≤ 0.002) CPI and PHQ-15 scores. Cumulative jaw muscle motor loads showed significant between-subject effects for time, diagnostic group, and sex (all P < 0.003), where motor loads tended to be higher for daytime versus nighttime, +Pain versus −Pain groups, and males versus females. Two clusters were identified, and regression relations showed associations of low-magnitude daytime masseter motor load, PHQ-15, and CPI scores for cluster 1 ( n = 105, R2 = 0.44) and cluster 2 ( n = 18, R2 = 0.80). Furthermore, these regression relations showed thresholds of motor load and PHQ-15 scores, above which there were nonlinear increases in reported pain.

Winocur-Arias O., Friedman-Rubin P., Abu Ras K., Lockerman L., Emodi-Perlman A., Greenbaum T., Reiter S.

The Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) categorized TMD muscle disorders into 3 subgroups: local myalgia, myofascial pain with spreading and myofascial pain with referral. However, the rationale for such division into subgroups and the pathogenesis and prognosis of muscle-related TMD are still poorly understood. The aim of this study was to explore the differences between local myalgia and myofascial pain with referral by means of a biopsychosocial model based on the DC/TMD. This retrospective study included all consecutive TMD patients who were diagnosed according to the DC/TMD in our institution between 2015 and 2018. The Axis I and II findings of patients diagnosed with local myalgia were compared to those of patients with myofascial pain with referral. A p value < 0.05 was considered statistically significant. A total of 255 patients (61 men and 194 women, mean age 37.8 ± 15.34 years) were enrolled into the study, 114 in the local myalgia group and 83 in the myofascial pain with referral group. The levels of depression and nonspecific physical symptoms, headache attributed to TMD (HAattrTMD), and characteristic pain intensity (CPI) were significantly higher in the latter group. The significant differences for depression and nonspecific physical symptoms persisted after excluding patients diagnosed with HAattrTMD, however, the levels of significance were lower (p = 0.006 compared to p = 0.033 for depression total score, and p = 0.001 compared to p = 0.046 for nonspecific physical symptoms total score). CPI levels, extent of disability, and pain duration were similar for both groups when excluding for HAattrTMD. The current study findings highlight the importance of differentiating between subgroups of myalgia according to the DC/TMD. The diagnosis of myofascial pain with referral may point to a significant Axis II component.

Sabsoob O., Elsaraj S.M., Gornitsky M., Laszlo E., Fricton J.R., Schiffman E.L., Velly A.M.

The aims of this critical review were to: (i) assess the factors that differentiate acute from chronic temporomandibular disorders (TMD) pain; (ii) assess the risk factors associated with the transition from acute to chronic TMD pain; and (iii) summarize and appraise the studies.The databases used were MEDLINE, Embase, and Cochrane Database of Systematic Reviews. Eligible studies included articles comparing acute to chronic TMD pain, and cohort studies assessing the risk factors implicated in the transition from acute to chronic TMD pain.Seven articles were selected: one case-control study, three cross-sectional studies, and three cohort studies. These studies found that psychological factors were more common in chronic than acute TMD pain patients; however, these factors did not increase the transition risk in the multivariable model. Myofascial and baseline pain intensity were associated with the transition from acute to chronic TMD pain at a 6-month follow-up. Due to methodological weaknesses in the available literature, more research is required to establish the risk factors implicated in the transition from acute to chronic TMD pain.This review found some evidence that myofascial pain is associated with the transition risk from acute to chronic TMD pain at a 6-month follow-up and that pain intensity at baseline is associated with more intense TMD pain 6 months later. There is insufficient evidence to draw conclusions about the role of demographics and psychological disorders as independent risk factors.

Barjandi G., Kosek E., Hedenberg-Magnusson B., Velly A.M., Ernberg M.

The impact of comorbidities in fibromyalgia (FM) and temporomandibular disorders (TMD) have been well documented, but whether TMD sub-diagnoses myalgia (MYA) and myofascial pain with referral (MFP) differ regarding comorbidity is unclear. We aimed to elucidate this by studying the presence and associations of comorbidities in FM, MFP and MYA. An extended version of the Diagnostic Criteria for TMD axis II questionnaire was used to examine demographics, pain and comorbidities in 81 patients with FM, 80 with MYA, and 81 with MFP. Patients with MFP and FM reported a higher percentage of irritable bowel syndrome (IBS), depression, anxiety, somatic symptoms, perceived stress, and insomnia compared to MYA. Patients with FM had more IBS, depression, and somatic symptom disorder versus MFP. After adjusting for confounding variables, participants with anxiety, somatic symptoms disorder, pain catastrophizing, and perceived stress, as well as a greater number of comorbidities, were more likely to have MFP than MYA, whereas FM participants were more associated with IBS, somatic symptoms and insomnia compared to MFP. The number of comorbidities was significantly associated with widespread pain but not pain duration, body mass index or being on sick leave. In conclusion, patients with MFP were more similar to those with FM regarding comorbidity and should be differentiated from MYA in clinical settings and pain management.

Kuć J., Szarejko K.D., Gołȩbiewska M.

Background: The temporomandibular joint is the one of the most important joints in the human body. It enables numerous orofacial functions such as mastication, swallowing, breathing, speech, emotional communication, and facial expressions. The aim of the study was to evaluate the prevalence of jaw functional limitations and oral behaviors with respect to general health status in patients with temporomandibular joint disorders—myofascial pain with referral.Materials and methods: The study group consisted of 50 individuals (37 females and 13 males) with complete natural dentition. The average age was 23.36 years with ± 0.30 as a standard error. All subjects underwent clinical examination and were diagnosed with myofascial pain with referral according to the Diagnostic Criteria for Temporomandibular Disorders. The survey was conducted in connection with the Jaw Functional Limitation Scale-8 (JFLS-8), Jaw Functional Limitation Scale-20 (JFLS-20), Patient Health Questionnaire-4 (PHQ-4), Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder-7 (GAD-7), Patient Health Questionnaire-15 (PHQ-15), and Oral Behaviors Checklist (OBC).Results: The most common functional problems in the entire study group were chewing tough food and yawning. In terms of gender, statistically significant differences were noted for chewing tough food and smiling (p = 0.015451; p = 0.035978, respectively). With respect to Bonferroni correction and Benjamini-Hochberg procedure, the observed differences were not statistically significant. There were no statistically considerable differences in mastication, mandibular mobility, verbal and emotional communication, or global limitations (p &gt; 0.05). Over half (56%) of the respondents had depression of varying severity. Somatic symptoms of different severity were found in 78% of the patients, and 44% of the respondents declared anxiety disorders. The score of the Oral Behavior Checklist (OBC = 27.18) highlighted a high tendency for developing craniomandibular disorders.Conclusion: Patients with myofascial pain with referral, demonstrated a disturbed biopsychosocial profile. The restrictions in yawning and smiling as well as limitations in mastication, mobility, verbal and emotional communication, and global limitations appear to be significant predictors of craniomandibular dysfunction. Depression, stress, and somatic disorders are important factors predisposing patients to the occurrence of myofascial pain with referral. The progression of oral behaviors may indicate the role of somatosensory amplification.

Cao Y., Yap A.U., Lei J., Zhang M., Fu K.

Objectives To determine the differences in psychological states and sleep quality in patients with various temporomandibular disorder (TMD) subtypes, and to ascertain the relationships between TMD duration with psychological and sleep impairments. Methods A total of 830 TMD patients were recruited categorized into pain-related (PT), intra-articular (IT), and combined (CT) TMD groups. Each group was further divided into acute and chronic subtypes. The Depression, Anxiety, and Stress Scales-21 (DASS-21), and Pittsburgh Sleep Quality Index (PSQI) were used to assess emotional states and sleep problems. Results Although chronic TMDs generally had higher levels of anxiety, depression, stress, and sleep impairments than acute TMDs, significant differences were only observed for the PT group. Ranking of the mean depression, anxiety, and stress scores was as follows: acute TMDs: CT > PT > IT; chronic TMDs: PT > CT > IT. For both acute and chronic TMDs, the ranking of mean PSQI global and component scores was PT ≥ CT ≥ IT. Logistic regression analyses indicated that stress (ORs = 4.40) and depression (ORs = 2.82) increased the risks of chronic pain-related TMDs (p < .05). Conclusions Chronic pain-related TMDs are associated with high levels of psychological distress and poorer sleep, while chronic intra-articular TMDs are not. Stress and depression increased the probability of chronic pain-related TMDs.

Marchevsky A.M., Walts A.E., Lissenberg-Witte B.I., Thunnissen E.

Kappa statistics have been widely used in the pathology literature to compare interobserver diagnostic variability (IOV) among different pathologists but there has been limited discussion about the clinical significance of kappa scores. Five representative and recent pathology papers were queried using clinically relevant specific questions to learn how IOV was evaluated and how the clinical applicability of results was interpreted. The papers supported our anecdotal impression that pathologists usually assess IOV using Cohen's or Fleiss' kappa statistics and interpret the results using some variation of the scale proposed by Landis and Koch. The papers did not cite or propose specific guidelines to comment on the clinical applicability of results. The solutions proposed to decrease IOV included the development of better diagnostic criteria and additional educational efforts, but the possibility that the entities themselves represented a continuum of morphologic findings rather than distinct diagnostic categories was not considered in any of the studies. A dataset from a previous study of IOV reported by Thunnissen et al. was recalculated to estimate percent agreement among 19 international lung pathologists for the diagnosis of 74 challenging lung neuroendocrine neoplasms. Kappa scores and diagnostic sensitivity, specificity, positive and negative predictive values were calculated using the majority consensus diagnosis for each case as the gold reference diagnosis for that case. Diagnostic specificity estimates among multiple pathologists were > 90%, although kappa scores were considerably more variable. We explain why kappa scores are of limited clinical applicability in pathology and propose the use of positive and negative percent agreement and diagnostic specificity against a gold reference diagnosis to evaluate IOV among two and multiple raters, respectively.

Chung M.K., Wang S., Yang J., Alshanqiti I., Wei F., Ro J.Y.

Craniofacial muscle pain is highly prevalent in temporomandibular disorders but is difficult to treat. Enhanced understanding of neurobiology unique to craniofacial muscle pain should lead to the development of novel mechanism-based treatments. Herein, we review recent studies to summarize neural pathways of craniofacial muscle pain. Nociceptive afferents in craniofacial muscles are predominantly peptidergic afferents enriched with TRPV1. Signals from peripheral glutamate receptors converge onto TRPV1, leading to mechanical hyperalgesia. Further studies are needed to clarify whether hyperalgesic priming in nonpeptidergic afferents or repeated acid injections also affect craniofacial muscle pain. Within trigeminal ganglia, afferents innervating craniofacial muscles interact with surrounding satellite glia, which enhances the sensitivity of the inflamed neurons as well as nearby uninjured afferents, resulting in hyperalgesia and ectopic pain originating from adjacent orofacial tissues. Craniofacial muscle afferents project to a wide area within the trigeminal nucleus complex, and central sensitization of medullary dorsal horn neurons is a critical factor in muscle hyperalgesia related to ectopic pain and emotional stress. Second-order neurons project rostrally to pathways associated with affective pain, such as parabrachial nucleus and medial thalamic nucleus, as well as sensory-discriminative pain, such as ventral posteromedial thalamic nuclei. Abnormal endogenous pain modulation can also contribute to chronic muscle pain. Descending serotonergic circuits from the rostral ventromedial medulla facilitate activation of second-order neurons in the trigeminal nucleus complex, which leads to the maintenance of mechanical hyperalgesia of inflamed masseter muscle. Patients with temporomandibular disorders exhibit altered brain networks in widespread cortical and subcortical regions. Recent development of methods for neural circuit manipulation allows silencing of specific hyperactive neural circuits. Chemogenetic silencing of TRPV1-expressing afferents or rostral ventromedial medulla neurons attenuates hyperalgesia during masseter inflammation. It is likely, therefore, that further delineation of neural circuits mediating craniofacial muscle hyperalgesia potentially enhances treatment of chronic muscle pain conditions.

Simoen L., Van den Berghe L., Jacquet W., Marks L.

The objective of this study was to compare levels of depression and anxiety of a group of patients with orofacial pain attributed to a temporomandibular disorder (TMD) to the general population. Diagnosis of orofacial pain attributed to a TMD was given according the DC/TMD classification system. PHQ-9 and GAD-7 questionnaires were used to respectively screen for depression and anxiety. Scores of these two questionnaires in the study group were compared to the scores of two large population samples representing normative data in the general population. Two hundred forty-three patients (191 females and 52 males) were included in the study. Both Kolmogorov-Smirnov and chi-square testing showed statistically significant higher scores (p ≤ 0.05) for both PHQ-9 and GAD-7 in the study group in comparison with the general population and PHQ-9 and GAD-7 scores were strongly correlated. The results of this study indicate that screening for depression and anxiety should be considered in the diagnosis of patients with orofacial pain attributed to a TMD. PHQ-9 and GAD-7 could be used to assist clinicians, without specific training in mental health, to screen for potential signs of existing comorbidity of depression or anxiety disorders in patients with orofacial pain attributed to TMD.

Von Korff M., DeBar L.L., Krebs E.E., Kerns R.D., Deyo R.A., Keefe F.J.

Sperry M.M., Kartha S., Winkelstein B.A., Granquist E.J.

Temporomandibular joint (TMJ) osteoarthritis (OA) is a degenerative disease of the joint that can produce persistent orofacial pain as well as functional and structural changes to its bone, cartilage, and ligaments. Despite advances in the clinical utility and reliability of the Diagnostic Criteria for Temporomandibular Disorders, clinical tools inadequately predict which patients will develop chronic TMJ pain and degeneration, limiting clinical management. The challenges of managing and treating TMJ OA are due, in part, to a limited understanding of the mechanisms contributing to the development and maintenance of TMJ pain. OA is initiated by multiple factors, including injury, aging, abnormal joint mechanics, and atypical joint shape, which can produce microtrauma, remodeling of joint tissues, and synovial inflammation. TMJ microtrauma and remodeling can increase expression of cytokines, chemokines, and catabolic factors that damage synovial tissues and can activate free nerve endings in the joint. Although studies have separately investigated inflammation-driven orofacial pain, acute activity of the trigeminal nerve, or TMJ tissue degeneration and/or damage, the temporal mechanistic factors leading to chronic TMJ pain are undefined. Limited understanding of the interaction between degeneration, intra-articular chemical factors, and pain has further restricted the development of targeted, disease-modifying drugs to help patients avoid long-term pain and invasive procedures, like TMJ replacement. A range of animal models captures features of intra-articular inflammation, joint overloading, and tissue damage. Although those models traditionally measure peripheral sensitivity as a surrogate for pain, recent studies recognize the brain’s role in integrating, modulating, and interpreting nociceptive inputs in the TMJ, particularly in light of psychosocial influences on TMJ pain. The articular and neural contributors to TMJ pain, imaging modalities with clinical potential to identify TMJ OA early, and future directions for clinical management of TMJ OA are reviewed in the context of evidence in the field.