The Association Between the Central Sensitisation Inventory and Temporomandibular Disorders Is Confounded by Migraine, Depression, Widespread Pain and Parafunction. A Cross-Sectional Telehealth Study.

BACKGROUND: Temporomandibular disorders (TMDs) are conditions that involve the temporomandibular joints, masticatory muscles, and associated tissues, causing orofacial pain. Central sensitisation (CS) is a relevant part of the TMD pathophysiology. Migraine, psychological aspects, parafunctional oral habits and widespread pain are commonly associated with both TMD and CS and could confound the association between them. OBJECTIVES: To investigate the association between painful TMD and the Central Sensitisation Inventory (CSI) score, and to assess the presence of confounders in this association. METHODS: Cross-sectional study that assessed women with and without orofacial pain complaints using telehealth. The TMD Pain Screener and an online physical examination determined the presence of painful TMD. The following questionnaires were applied: CSI, Headache Screening Questionnaire, Generalized Anxiety Disorder-7, Patient Health Questionnaire-9, Oral Behavior Checklist, Jaw Functional Limitation Scale and the Nordic musculoskeletal questionnaire. A single regression investigated the association between the CSI score and TMD, and a multiple regression investigated the effect of the other outcomes as possible confounders. Confounding was considered present when the association between TMD and the CSI score changed more than 10% after adding a possible confounder to the regression model. RESULTS: Forty-two women with painful TMD and 53 without TMD were included. There was a significant association between the CSI score and the presence of painful TMD (R2 = 0.639; p < 0.001). This association changed when the following outcomes were added to the model: presence of migraine, symptoms of depression, widespread pain and parafunctional oral habits. CONCLUSION: The positive association between TMD and the CSI score was confounded by migraine, symptoms of depression, widespread pain and parafunctional oral habits.

Clinical features of chronic primary pain in individuals presenting painful temporomandibular disorder and comorbidities.

BACKGROUND: The diagnosis of chronic primary pain (CPP), according to the recently released International Classification of Disease (ICD-11) criteria, refers to conditions with complex aetiologies. CPP is characterized by specific clinical features such as generalized sensory hypersensitivity and widespread pain, and is associated with functional disability and emotional distress. OBJECTIVE: This study investigated clinical features of CPP in individuals with painful temporomandibular disorders (TMD) and comorbidities (fibromyalgia, migraine and/or tension-type headache). METHODS: This cross-sectional study was conducted with a sample of 129 individuals. Painful TMD, fibromyalgia and primary headaches were evaluated based on well-established international criteria. Generalized sensory hypersensitivity was assessed using psychophysical tests. Symptoms of anxiety and depression were assessed by the Generalized Anxiety Disorder-7 and Patient Health Questionnaire-9. The Central Sensitization Inventory was applied to assess central sensitization-related symptoms and the Pittsburg Sleep Quality Index to evaluate the quality of sleep. The presence of widespread pain was assessed using a body map. The sample was stratified into three groups: control (n = 25), TMD-painful TMD only (n = 35) and TMD + Cm-painful TMD and comorbidities (n = 69). Statistical analysis was performed using one-way ANOVA, chi-squared test and ANCOVA, considering gender as a covariate (α = .05). RESULTS: Compared to controls, individuals presenting painful TMD and comorbidities showed lower pressure pain thresholds in all evaluated areas (p ≤ .012) and a higher number of painful areas in the body (p = .001). They presented more symptoms of anxiety (p = .040) and depression (p = .018), and a higher score in the Central Sensitization Inventory (p ≤ .006) than the other groups. CONCLUSION: Individuals with painful TMD and comorbidities presented more clinical features of CPP compared to those affected by TMD only.

Are central sensitization symptoms and psychosocial alterations interfering in the association between painful TMD, migraine, and headache attributed to TMD?

OBJECTIVE: To determine if somatosensory function and symptoms related to central sensitization (CS) differed in individuals with painful temporomandibular disorders (TMD) according to the presence of migraine (MIG) or MIG + headache attributed to TMD (HAT). MATERIALS AND METHODS: This study evaluated 92 adults (20-65 years), presenting painful TMD. Standard diagnostic criteria were applied to classification of painful TMD, MIG, and HAT. CS was assessed through the central sensitization inventory (CSI), wind-up ratio (WUR), pressure pain thresholds (PPT), and the conditioned pain modulation test (CPM). Psychosocial factors were evaluated by validated instruments. RESULTS: There was a significant difference regarding gender, with more women in the group TMD + MIG + HAT (p = 0.028). TMD + MIG and TMD + MIG + HAT had significantly lower PPTs than the TMD group. No group differences were found for the WUR, CPM, or CSI. TMD + MIG + HAT had higher chronic pain intensity (p = 0.001), disability points (p = 0.045), graded chronic pain scale (p = 0.007), and higher somatization (NSPS) scores (p = 0.012), compared to the other groups. CONCLUSION: Mechanical hyperalgesia was more pronounced in the group with the highest pain and somatization scores, while CPM and WUR did not differ between groups. Altered somatosensory function and CS may partially underlie the pathophysiology of overlapping TMD pain conditions, pointing towards additive effects of comorbid head pains. CLINICAL RELEVANCE: Our results demonstrate the importance of considering the association of primary and secondary headaches during TMD assessment and its implications for maintaining the signs and symptoms of CS. This can influence the conduct of treatment, which must be multidisciplinary, and must include management of mechanisms related to CS.

Temporomandibular Disorders in a Young Adolescent Brazilian Population: Epidemiologic Characterization and Associated Factors.

AIMS: To carry out an epidemiologic characterization of the most common subtypes of temporomandibular disorders (TMD) and to identify associated factors in a Brazilian sample of young adolescents. METHODS: From a population of public schoolchildren (12 to 14 years of age), 3,117 students were randomly invited to participate in this study. TMD was assessed according to the Research Diagnostic Criteria for TMD (RDC/TMD) Axis I, in addition to some questions of the Axis II history questionnaire. The associated factors, ie, difficulty with concentration/attention, anger, sadness, anxiety, headache complaints, oral parafunctions, diurnal jaw clenching, tooth grinding at night, and parents not living together, were assessed based on the responses of the adolescents and their parents to structured questions. For the statistical analyses, descriptive statistics, chi-square tests, odds ratio, and logistic regression models were used, adopting a 95% confidence interval and 5% level of significance. RESULTS: The sample consisted of 1,307 individuals (response rate of 41.9%), 56.8% (n = 742) girls. Overall, 397 (30.4%) adolescents presented with TMD, of whom 330 (25.2%) had painful TMD diagnoses. The majority of these had painful TMD of muscular origin (13.1%) and comprised chronic cases (14.9%). Girls presented higher frequencies of TMD overall, painful TMD, painful combined TMD, and chronic painful TMD diagnoses The final multivariate logistic regression model revealed that headache complaints (odds ratio 2.87; confidence intervals 2.21-3.72), oral parafunctions (2.08; 1.26-3.44), tooth grinding at night (2.05; 1.56-2.70), diurnal jaw clenching (1.96; 1.50-2.55), and parents not living together (1.38; 1.07-1.80) were the factors significantly associated with a TMD (overall) diagnosis. CONCLUSION: About 25% of the adolescents evaluated presented painful TMD, and the majority of these comprised muscular and chronic cases. Some factors, such as reports of headache complaints, oral parafunctions, tooth grinding at night, and parents not living together, were associated with this condition among young Brazilian adolescents. Special attention should be given to these factors among adolescents with TMD.

Relationship between levels of neuropeptide Substance P in periodontal disease and chronic pain: a literature review.

The aim of the current review was to investigate the relationship between levels of neuropeptide Substance P in periodontal disease and chronic pain. Substance P is a neuropeptide that is directly related with pain. In periodontal disease, it is expressed during the inflammatory process, and is one of the factors responsible for bone resorption. Studies have shown that Substance P levels are highest in the gingival crevicular fluid from sites with active periodontal disease and bone loss. The persistence of these substances could be sufficient to stimulate neurogenic inflammation in susceptible tissues, and cause pain. The scientific literature shows that Substance P expressed during periodontal disease can be a risk factor for patients with systemic inflammatory pathologies, such as chronic arthritis or rheumatoid arthritis. Additional research is needed to confirm the participation of this substance in the origin of some types of chronic pain.