Multiple diagnoses, increased kinesiophobia? - Patients with high kinesiophobia levels showed a greater number of temporomandibular disorder diagnoses.

OBJECTIVES: The aim of this study was to empirically derive subgroups according to pain-related fear of movement beliefs using cluster analysis within a sample of TMD patients and asymptomatic volunteers. METHODS: 129 volunteers participated in this cross-sectional study (34.78, standard deviation [SD]: 12.49 years; 92 TMD patients and 37 symptom-free volunteers). Mechanical pain sensitivity through pressure pain threshold (PPT) on orofacial and remote sites, kinesiophobia, pain catastrophizing, anxiety and depression were assessed. A cluster analysis was used to derive subgroups according to kinesiophobia scores (TSK/TMD). RESULTS: Three subgroups were derived: cluster 1 (high kinesiophobia [n = 53], TSK score: 33, SD[standard deviation] = 2.9), cluster 2 (moderate kinesiophobia [n = 50], TSK score: 26.2, SD = 2.14) and cluster 3 (no/low kinesiophobia [n = 26], TSK score 12.12, SD = 2.08) which included patients with higher overall PPT and lower scores on psychosocial variables. The group with high kinesiophobia showed high levels of pain catastrophizing, anxiety, and orofacial pain-related disability compared to the other subgroups and mechanical pain hyperalgesia in remote site compared to the low-kinesiophobia group. Also, we found a greater prevalence of triple diagnosis for the high-kinesiophobia subgroup compared to the moderate kinesiophobia group - odds ratio: 12.6 (95% confidence interval [CI]: 3.31-43.52, p < 0.01). CONCLUSION: These results suggested that patients with TMD and higher levels of kinesiophobia beliefs may show a more complex clinical feature, with high psychosocial distress, widespread mechanical pain sensitivity, and a more complex TMD disorder. In this way, we suggest a relationship between the number of TMD diagnoses and kinesiophobia severity.

Brazilian Portuguese Version of the Craniofacial Pain and Disability Inventory: Cross-Cultural Reliability, Internal Consistency, and Construct and Structural Validity.

AIMS: To culturally adapt the Craniofacial Pain and Disability Inventory (CF-PDI) for a Brazilian population and to assess its psychometric properties, including internal consistency, reliability, and construct and structural validity. METHODS: A total of 100 female and male TMD patients with temporomandibular disorders (TMD), with or without headaches, were included. Participants were assessed based on the Research Diagnostic Criteria for TMD and the International Headache Society criteria. For statistical analyses, intraclass correlation coefficient (ICC) was used for assessing reliability (test-retest), Cronbach's alpha for internal consistency, Pearson rank correlation for construct validity, and confirmatory factor analysis (CFA) for structural validity. RESULTS: The CFA provided the following three factors/domains for the Brazilian CF-PDI (CF-PDI/Br): (1) functional and psychosocial limitation; (2) pain; and (3) frequency of comorbidities. Scores for test-retest reliability and internal consistency in each domain were acceptable (ICC > 0.9; Cronbach's α > 0.77). Correlations between CF-PDI scores and jaw functional limitation, pain-related disability, pain catastrophizing, depression, neck pain-related disability, and kinesiophobia scores were confirmed in 89% (50/56) of the comparisons. CONCLUSION: The CF-PDI/Br with three factors had sound psychometric properties. Therefore, the Brazilian Portuguese version can be used in clinical settings and for research purposes.

Electromyographic ratio of masseter and anterior temporalis muscles in children with and without temporomandibular disorders.

OBJECTIVE: This study investigated differences in surface electromyography (sEMG) activity of the masseter and anterior temporalis muscles in children with and without temporomandibular disorders (TMD). PARTICIPANTS: Thirty-four children aged 8-12 years were recruited, comprising 17 children with TMD and 17 without TMD (control group [CG]). The children were quasi-matched for sex, age, weight, and height. sEMG data were obtained using Myosystem® Br-1 equipment with 12 channels to evaluate the bilateral masseter, anterior temporalis, and suprahyoid muscles. For sEMG analysis, raw and normalized root mean square (RMS) values were obtained at rest and during maximum clenching. The sEMG ratios of the raw RMS data of the bilateral masseter in relation to the anterior temporalis muscles (sEMG-M/AT ratio) were also assessed. Mann-Whitney tests (p ≤ 0.05) were used to compare sEMG ratio between TMD group and CG. RESULTS: Significant prevalences of pain during chewing (53% vs. 0%, X2 = 5.87, p = 0.01), TMJ pain (58% vs. 0%, X2 = 6.67, p = 0.01), neck pain (58% vs. 18%, X2 = 3.77, p = 0.05) and pain in the temples (47% vs. 6%, X2 = 5.44, p = 0.02) were identified in the TMD group compared to CG. Our results revealed lower sEMG-M/AT ratios during maximum clenching (p = 0.01) in children with TMD compared to those in the asymptomatic CG. CONCLUSION: The results showed that children with TMD preferentially used their temporalis muscles during maximum voluntary clenching, probably as a consequence of nociceptive inputs in order to obtain pain relief.