Correlation of RDC/TMD axis I diagnoses and axis II pain-related disability. A multicenter study

As part of an ongoing multicenter investigation involving four highly specialized tertiary clinics for temporomandibular disorders (TMD) treatment, retrospective analysis of Research Diagnostic Criteria for TMD (RDC/TMD) axis I and axis II data gathered on clinic and community cases were assessed with a twofold aim: (1) to search for a correlation between axis I diagnoses and axis II pain-related disability, and (2) to identify clinical (axis I) and psychosocial (axis II) predictors of high pain-related disability. Two samples of patients seeking treatment for TMD (clinic cases, N = 1,312) and a sample of general population subjects (community cases, N = 211) underwent a thorough assessment in accordance with the RDC/TMD version 1.0 [1] guidelines to receive both axis I and axis II diagnoses. Spearman’s test was performed to assess the level of correlation between axis I diagnoses and Graded Chronic Pain Scale (GCPS) pain-related disability. A stepwise multiple logistic regression model was used to identify the significant associations between 12 clinical and psychosocial predictors and the presence of high pain-related disability. Axis I findings were related with pain-related impairment (GCPS scores) in the overall study sample including both clinic community cases (Spearman correlation = 0.129, p = 0.000), but the results of the correlation analyses performed on the clinic sample alone were not significant (Spearman correlation = −0.018, p = 0.618). Predictors for high disability were related to axis II findings (severe depression and somatization) or psychosocial aspects related to the pain experience (pain lasting from more than 6 months; treatment-seeking behavior), while none of the axis I diagnoses remained in the final logistic regression model. The final model predicted the level of pain-related impairment at a fair level (R ² = 26.7%). The correlation between axis I diagnoses and pain-related impairment is not significant in the patients populations. Treatment-seeking behavior and other factors related with the pain experience are likely to be more important than the physical findings to determine the degree of psychosocial impairment.     

Radiographic measurement of the cervical spine in patients with temporomandibular dysfunction

Aim

To compare the craniocervical angles and distances between temporomandibular dysfunction (TMD) and free TMD subjects.

Casuistic and methods

The sample consisted of young adults, of both genders, with age ranging between 18 and 30 years. TMD diagnosis was based on the clinical criteria of the Research Diagnostic Criteria for TMD (RDC/TMD), associated with self-reported symptoms of TMD. For radiological analysis we measured three angles and two distances of craniocervical region.

Results

Of the 56 subjects, only 23 completed all stages of research, which were divided into two groups: (1) free TMD group - composed of 11 individuals; (2) TMD group - constituted of 12 subjects. The most common clinical diagnosis of TMD was arthralgia (75.0%) followed by myofascial pain without limited mouth opening (58.4%). Among the self-reported symptoms of TMD, the most frequents were facial (83.4%) and neck (66.6%) pain. Of radiological measurement, only plane atlas angle (APA) (p = 0.026) and anterior translation distance (Tz C₂-C₇) (p = 0.045) showed statistical difference between groups TMD (APA = 16.7 ± 1.63; Tz C₂-C₇ = 28.7 ± 2.58) and free TMD (APA = 21.64 ± 1.24; Tz C₂-C₇ = 19.82 ± 3.29).

Conclusion

It could be verified that the symptomatic TMD patients presented a flexion of the first cervical vertebra associated with an anteriorization of the cervical spine (hyperlordosis).     

Key factors associated with oral health-related quality of life (OHRQOL) in Hong Kong Chinese adults with orofacial pain

Objectives

To investigate key factors associated with oral health-related quality of life (OHRQOL) of Hong Kong Chinese adults with orofacial pain (OFP) symptoms.

Methods

A cross-sectional study was conducted amongst a random sample of registered patients at a primary medical care teaching clinic in Hong Kong. Patients who were aged 35-70 years and had experienced OFP symptoms in the past 1 month were included. The OHRQOL was assessed by the Chinese version of the Oral Health Impact Profile (OHIP-14). A structured questionnaire on OFP symptoms and characteristics in the past 1 month, the depression and non-specific physical symptoms (NPS) scale in the research diagnostic criteria for temporomandibular disorders (RDC/TMD) questionnaire, and questions about professional treatment and dental attendance were administered before a standard clinical assessment. Negative binomial regression with forward stepwise selection was used to investigate key factors associated with the OHIP-14 additive score.

Results

The mean OHIP-14 additive score of the 200 participants was 10.1 (SD 9.4). Regression analysis revealed that five independent factors were significantly associated with higher OHIP-14 additive scores (indicating a poorer OHRQOL): a higher pain scale rating in the past 1 month (p = 0.001), OFP clinical classification as musculoligamentous/soft tissue (MST) or dentoalveolar (DA) instead of neurological/vascular (NV) (p < 0.001), more frequent dental attendance (p = 0.008), moderate/severe RDC/TMD depression (p = 0.005) and moderate/severe RDC/TMD NPS with pain (p = 0.003).

Conclusion

Various factors were associated with OHRQOL and could have implications for the improvement of OHRQOL in people in the community who have OFP symptoms.     

Social impairment of individuals suffering from different types of chronic orofacial pain

Background

The daily life of patients suffering from orofacial pain is considerably impaired as compared to healthy subjects. The aim of this study was to investigate the influence of different categories of orofacial pain on the habitual life of adult individuals.

Methods

Seven hundred eighty-one individuals with orofacial pain were recruited from an initial sample of 1,058 patients. All the individuals were allocated to groups according to their diagnosis: myofascial pain (group A, 676 subjects, 525 females and 151 males; mean age ± SD = 35.2 ± 12.6), migraine (group B, 39 subjects, 29 females and 10 males; mean age ± SD 36.0 ± 10.7), and both myofascial pain and migraine (group C, 66 subjects, 56 females and 10 males, mean age ± SD = 35.6 ± 10.8). Characteristic pain intensity (CPI), disability days (DD), disability score (DS), and graded chronic pain intensity (GCPS) were calculated according to Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) axis II. Depression and somatization (nonspecific physical symptoms) scores were also calculated.

Results

A significant association between groups and GCPS categories was found (p < 0.0001). Post hoc tests showed a significant difference between groups A and B and between A and C, but not between B and C. In group A, the most frequent GCPS score was grade II. The most frequent GCPS score in groups B and C was grade III, indicating a moderate limiting impairment. This score was more frequent in group B (41%) than in the other groups (group A = 20.6%, group C = 34.8%). GCPS grade IV was more frequent in group C (19.7%) than in the other groups. Group C had significantly higher scores for nonspecific physical symptoms than group A (p < 0.05).

Conclusions

Myofascial pain and migraine sensibly affect the common daily life of adult individuals. The comorbidity of both conditions determines a major impairment.     

Correlation of somatization,depression, and chronic pain with clinical findings of the temporomandibular disorders in asymptomatic women

ABSTRACT

Objective: The aim of this study was to correlate degree of depression, somatization, and chronic pain in asymptomatic women with clinical findings, using Research Diagnostic Criteria/Temporomandibular disorders (RDC/TMD).

Methods: A total of 200 female participants, ages 18–65, filled out a standard RDC/TMD axis II form for the assessment of chronic pain, disability, depression, and non-specific physical symptoms and underwent clinical examination of the temporomandibular joint. Correlation of clinical findings (axis I) and axis II assessment was performed using Spearman’s correlation test, with significance set at p < 0.05.

Results: There was a significant correlation between depression scores (p < 0.04), chronic pain (p < 0.001), and non-specific physical symptoms without questions about pain (p = 0.008).

Discussion: The highest scores on the Graded Chronic Pain Scale were observed in patients with arthralgia, while patients with myofascial pain scored higher on depression and somatization tests.     

Assessment of thickness and function of masticatory and cervical muscles in adults with and without temporomandibular disorders

Objective

The aim of this study was to evaluate the maximal bite force (MBF), electromyographic (EMG) activity and thickness of the masseter, anterior part of the temporalis and sternocleidomastoid (SCM) muscles in a group of young adults with and without temporomandibular disorders (TMDs).

Design

Nineteen individuals comprised the TMD group (6 males/13 females, aged 25.4 ± 3.8 years), classified based on the Research Diagnostic Criteria for TMD (RDC/TMD), and 19 comprised the control group (6 males/13 females, aged 24.1 ± 3.6 years). The MBF was determined with a transducer placed between the dental arches at the first molars level (N). The muscles were evaluated bilaterally at rest and during maximal voluntary clenching (MVC) by assessing EMG activity and performing ultrasonography (USG). The mean values of these measures for both sides of the mouth were used. The normality of the distributions was assessed by the Shapiro–Wilks test. Variables between groups and genders were compared using two-way factorial ANOVA test and correlated using the Spearman coefficient (α = 0.05). Unpaired t test was used to compare variables between TMD subgroups. Logistic regression analysis was used to identify the variables associated with the presence of TMD.

Results

MBF, EMG and USG data were similar among clinical groups and among TMD subgroups. The thickness of masseter and SCM muscles in the relaxed and clenching states were significantly higher in males than females. On the other hand, the EMG of the temporalis muscle in the rest state was significantly higher in females than males. Additionally, the MBF was positively correlated with the USG characteristics of masseter and SCM muscles, as well as with the EMG activity of masseter and temporalis muscles in the TMD group. In this group, there was also a positive correlation between the thickness of the masseter muscle and its activity. On the other hand, the thickness of the SCM muscle was negatively correlated with its activity. A lower MBF was independently associated with the presence of TMD.

Conclusions

Subjects with TMD exhibited similar values of MBF, thickness and electrical activity of masticatory and cervical muscles when compared with controls; positive correlations observed between these variables may suggest a muscular alteration in TMD patients and a co-activation of masticatory and cervical muscles during mandibular movement. This fact may also be confirmed by the negative association between bite forces and presence of TMD.     

Does adolescent self-reported TMD pain persist into early adulthood? A longitudinal study

Abstract

Objective: To follow up 2209 individuals in a longitudinal study and assess self-reported TMD pain, painful and non-painful comorbid conditions, and pain-related disability.

Material and methods: During 2012–2014, questionnaires were sent to 2209 eligible individuals who had been screened for TMD pain each year during 2000–2003. The two screening questions were (1) Do you have pain in the temple, face, jaw joint, or jaws once a week or more often? and (2) Do you have pain when you open your mouth wide or chew once a week or more often? If the patient answered ‘yes’ to one or both of the questions, TMD pain was recorded. Non-respondents received reminders; telephone interviews were offered a randomised group. The questionnaire queried TMD pain, and painful and non-painful comorbid conditions.

Results: The overall response rate was 36.5%. Individuals were placed into one of four pain groups defined by their pain experience at baseline and at the follow-up: no TMD pain (69.0%), new TMD pain (13.0%), previous TMD pain (9.9%), and persistent TMD pain (8.1%). Based on the self-report surveys, significantly more responders with TMD pain at follow-up had had pain as adolescents than not. Of adolescents with TMD pain, 45.1% had pain at follow-up as young adults, while 15.8% had pain at follow-up without a previous history of TMD pain. Individuals with persistent TMD pain had high frequencies of comorbid pains (p?<?.001), 45.2% reported moderate-severe depression scores (p?<?.001), and 13.0% had moderate pain-related disability (GCPS).

Conclusions: Based on self-report surveys, TMD pain in adolescence appears to triple the risk of TMD pain in young adulthood, and persistent pain increased comorbid pain and psychosocial distress.     

Painful temporomandibular disorders (TMD) and comorbidities in primary care: associations with pain-related disability

Objective: We studied whether primary care temporomandibular disorder (TMD) patients reporting different levels of pain-related disability differ in terms of comorbid pains, general health conditions and quality of life.

Material and methods: Consecutive TMD pain patients (n?=?399) seeking treatment in primary care completed a questionnaire on comorbid pains and their interference and the Finnish version of the RAND-36-item quality of life questionnaire. Medical diagnoses confirmed by doctors were recorded. The patients were classified according to the Graded Chronic Pain Scale (GCPS) of the Research Diagnostic Criteria for TMD (RDC/TMD). The patients were classified: no disability group (0 disability points), low disability group (1–2 disability points) and high disability group (3–6 disability points).

Results: Compared to patients in the no-disability group, patients in the high- and low-disability groups reported more comorbid pain conditions (p?<?.001), and experienced these as more intense and interfering more with daily life (p?<?.05). Patients in the high-disability group reported more general health-related medical diagnoses than patients in the no-disability group (p?<?.05). Furthermore, patients with low or high pain-related disability indicated poorer quality of life in all RAND-36 subscales than those with no disability (p?<?.05).

Conclusions: The findings suggest that GCPS-related disability scoring can be used as a simple screening instrument to identify TMD patients with different degrees of health burdens.     

Relationship between impacts of removable prosthodontic rehabilitation on daily living,satisfaction and personality profiles

Objectives

To investigate dental impacts on daily living and satisfaction with removable complete and partial prosthodontic rehabilitations, and to identify their relationship with personality profiles.

Methods

Sixty-eight patients (38 males and 30 females; mean age = 53.2 ± 11.8 years) received removable prostheses (32 complete dentures and 36 removable partial dentures). Clinical success of prostheses was assessed according specific criteria. The Dental Impact on Daily Living (DIDL) questionnaire was utilized to assess satisfaction with prostheses and impacts on daily living. NEO Five Factor Inventory (NEO-FFI) was utilized to assess patients’ personality profiles.

Results

Participants’ total satisfaction and satisfaction with appearance, pain tolerance, oral comfort, and eating improved after treatment (p < .05). Position of prosthesis and age had no significant relationships with satisfaction or personality scores (p > .05). Females were less satisfied with appearance (p < .05). Patients who received partial dentures were more satisfied with eating and scored higher total satisfaction scores than those who had complete dentures (p < .05). Before treatment; Neuroticism and Openness scores were associated with dental satisfaction and impacts (p < .05). After treatment, Conscientiousness and Extraversion scores were associated with dental satisfaction and impacts (p < .05).

Conclusions

Patients satisfaction with oral condition improved following using removable prosthetic rehabilitation with RPD having better impacts than CD. Psychological profiles (e.g. Neuroticism, Extraversion, Openness and Conscientiousness) might play a role and explain prosthetic impacts on daily living and patients’ satisfaction with prostheses.     

Axis II psychosocial findings predict effectiveness of TMJ hyaluronic acid injections

The objective was to investigate the correlation between levels of depression, somatization, and pain-related impairment, as assessed by the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMDs) axis II, and the treatment outcome of a cycle of five weekly injections of hyaluronic acid immediately following arthrocentesis. 57 consecutive patients with a diagnosis of temporomandibular joint (TMJ) osteoarthritis according to the RDC/TMD underwent the treatment protocol and a follow-up assessment at 6 months. Axis II findings were assessed as potential predictors of improvement in visual analogue scale (VAS) values at the end of the observation period with respect to baseline. The percentage of VAS improvement at the end of treatment was inversely related to all the psychosocial variables. The best fitting model identified pain-related impairment (p < 0.001) and disability points (p < 0.001) as the most significant predictors of VAS changes. The percentage of variance in the outcome variable explained by the significant predictors was high (R² 70.5%). All the RDC/TMD axis II psychosocial scores (depression, somatization, and pain-related impairment levels) were inversely correlated with therapeutic outcome. The clinical relevance of these findings is important, since psychosocial diagnosis may be even more important than physical evaluation in terms of prognostic impact.     

Psychosocial factors associated with pain outcomes in patients with painful temporomandibular disorders and headaches

The objective of this study was to assess the association between psychosocial factors (in terms of anxiety, somatization, depression, and optimism) and pain (in terms of headache pain intensity and pain-related disability), in patients with a painful temporomandibular disorder (TMD) and one of the following headache types: migraine, tension-type headache (TTH), or headache attributed to TMD, corrected for the influence of bruxism. A retrospective study was conducted at an orofacial pain and dysfunction (OPD) clinic. Inclusion criteria were painful TMD, with migraine, TTH, and/or headache attributed to TMD. Linear regressions were performed to assess the influence of psychosocial variables on pain intensity and on pain-related disability, stratified per headache type. The regression models were corrected for bruxism and the presence of multiple headache types. A total of 323 patients (61% female; mean age 42.9, SD 14.4 years) were included. Headache pain intensity only had significant associations in TMD-pain patients with headache attributed to TMD, and anxiety showed the strongest relation (β = 0.353) with pain intensity. Pain-related disability was most strongly associated with depression in TMD-pain patients with TTH (β = 0.444), and with somatization in patients with headache attributed to TMD (β = 0.399). In conclusion, the influence of psychosocial factors on headache pain intensity and pain-related disability depends on the headache type presenting.     

Psychosocial profiles of painful TMD patients

Summary  The aim of the present investigation is to test the null hypothesis that the presence of psychopathology in patients with temporomandibular disorders (TMD) is related to the presence of pain, independent of its location [(i.e. myofascial and/or temporomandibular joint (TMJ) pain]. Ninety-six ( n  = 96) patients affected by painful TMD underwent a clinical assessment in accordance with the research diagnostic criteria for TMD (RDC/TMD) guidelines and filled out the Symptoms Check List – Revised (SCL-90-R) instrument to investigate the presence of symptoms of psychopathology. Patients with myofascial pain, alone or combined with TMJ pain, endorsed the highest scores in all SCL-90-R scales and showed the highest percentage of abnormal values in the depression (DEP) and somatization (SOM) scales for the assessment of depressive and somatization symptoms. Nonetheless, anova revealed no significant differences between groups in any of the SCL-90-R scales, except than in the Positive Symptom Total Index ( F  = 3·463; P  = 0·035), and the chi-squared test did not detect any significant differences between groups for the prevalence of abnormal scores in the DEP and SOM scales. The existence of a close association between pain and psychosocial disorders in TMD patients was supported by the present study. The null hypothesis is that no differences exist between patients with different painful TMD cannot be fully accepted for the presence of psychosocial disorders because of the trend evidencing higher SCL-90-R scores for myofascial pain patients, alone or combined with TMJ pain, with respect to TMJ pain alone.     

Changes in oral health related quality of life after dental bleaching in a double-blind randomized clinical trial

Objectives

This study aimed to assess changes in oral health-related quality of life (OHRQoL) in individuals enroled in a double-blind randomized clinical trial conducted to evaluate the efficacy and safety of two carbamide peroxide concentrations used in at-home vital bleaching in the city of Pelotas, Southern Brazil.

Methods

Ninety-two volunteers with a shade mean of C1 or darker for the six maxillary anterior teeth were randomized into two balanced groups (n = 46) according to bleaching agent concentration: 10% or 16% carbamide peroxide. The patients were instructed to use the whitening agent in a tray for 2 h once a day for three weeks. To assess changes in OHRQoL, participants completed the oral impact on daily performance (OIDP) at the start and one week after the completion of treatment. Because there was no difference with regard to whitening effect or tooth sensitivity during or after treatment the two groups were merged for the analyses of the current article. Before-and-after changes in OIDP scores were assessed by chi-square and McNemar tests (p < 0.05).

Results

Mean pre- and post-treatment OIDP scores varied from 0.42 to 0.60. When the frequency of impacts for different activities were compared, there was an increase in difficulty in cleaning teeth (p = 0.02) and a significant reduction in smiling and showing teeth with embarrassment (p = 0.03). Regarding the symptoms and main oral conditions that generated impact, there was higher number of participants reporting pain (p = 0.05) after treatment. In opposite, significant decrease was observed in individuals reporting being unhappy with their appearance (p = 0.03). On the contrary, it was showed a decrease in impacts resulting from dental colour was observed after bleaching (p = 0.03).

Conclusion

Quality of life is complex and encompasses different domains. Although positive impact of the dental bleaching was detected, with patients showing more their teeth without embarrassment, difficult in dental hygiene and pain resulting from the treatment were also reported, and this can negatively impact daily performances. Dentists must consider these aspects when performing aesthetics procedures.     

TMD in class III patients referred for orthognathic surgery: Psychological and dentition-related aspects

ObjectiveTo investigate temporomandibular disorders (TMD), psychosocial, and occlusal variables in class III orthognathic surgery patients with respect to the control subjects, and to compare psychosocial and occlusal features in class III patients with different Research Diagnostic Criteria for TMD (RDC/TMD) diagnoses.Materials and methodsThe study enrolled 44 class III patients referred for orthognathic surgery and 44 individuals without a malocclusion. TMD, depression and somatization were assessed by RDC/TMD. Occlusal analysis included Helkimo's Occlusal Index items, overjet and overbite.ResultsIn the controls, patients with class III deformities had higher prevalence of myogenic TMD, increased grade of chronic pain, and more occlusal deviations. Within the study group, TMD patients reported higher depression score (P < 0.01), myofascial pain was related to higher depression and somatization grades (P < 0.01, P < 0.05 respectively), and disc displacement showed relation with RCP-ICP slide interferences (P < 0.05).ConclusionWith respect to subjects without a malocclusion, TMD in class III dentofacial deformities is similar in prevalence, but differs in clinical appearance. Occlusal, but not psychosocial features deviate from those in the controls. While psychosocial variables accompanied TMD and myofascial pain, increased RCP-ICP slide was related to disc displacement in class III patients.     

Effects of xylitol mouthrinse on Streptococcus mutans

Objectives

This study aimed to measure the effect of xylitol mouthrinse on salivary Streptococcus mutans counts.

Methods

Subjects in the study group (n = 25) used xylitol mouthrinse for 4 weeks, while another group (n = 25) used saccharine mouthrinse. S. mutans were measured before and after intervention.

Results

At the baseline the mean S. mutans scores were 3.9 (SE = 0.03) and 3.9 (0.04) for the xylitol group and control group respectively, while the scores were 2.8 (0.13) and 3.9 (0.07) after the intervention. Significant reductions (p < 0.01) in the scores of S. mutans were found after the four week use of xylitol mouthrinse.

Conclusions

Significant reductions in the scores of S. mutans were found after the four week use of 20% xylitol mouthrinse. The bacteriostatic effect of xylitol mouthrinse on S. mutans may be comparable to other xylitol products. Further studies are needed to confirm both the short and long term effects of xylitol mouthrinse.     

Identification of psychological comorbidity in TMD-patients

Objectives: The aim of the current study was to access the prevalence of depression among patients with Temporomandibular Joint Disorder (TMD) compared to patients with no current TMD.

Method: Patients (92) and controls (90) answered questionnaires on subjective pain, severity of chronic pain, jaw disability, emotional well-being and depression, and a clinical examination was performed.

Results: Temporomandibular Joint Disorder patients reported higher disability of jaw function, compared to controls (p<0.001). The myoarthopathy subgroup (67.4%) had slightly more jaw disability than the myopathy subgroup (p>0.05). While 51% of TMD patients reported poor emotional well-being, only 7.8% of controls were affected (p<0.001). Clinical symptoms of depression were reported by 16% of TMD patients and not in the controls (p<0.001). Among TMD patients, a higher prevalence of depression was observed in the myopathy subgroup.

Discussion: A regular screening for psychological problems, using standardized questionnaires, should be integrated in clinical examination of TMD patients.     

Long-term results and complications after treatment of bilateral fractures of the mandibular condyle

The purpose of this study was to investigate the long-term results of conservative treatment of bilateral condylar fractures and to study the influence of possible functional impairment on intensity of pain and associated disability. We studied 71 patients (mean (SD) age 33 (14) years) with conservatively treated bilateral condylar fractures. Traffic crashes (n = 42, 59%) and falls (n = 20, 28%) were the main cause of the fractures. Forty-one patients (58%) were re-examined after about 90 months (mean 86, range 3–193). Five of the 41 (12%) had developed malocclusion, but did not experience any pain in the temporomandibular joint according to the Research Diagnostic Criteria for Temporomandibular Disorders. There was a significant negative relation between the presence of pain and the duration of follow up (p = 0.02). Increasing age was significantly related to reduction in the intensity of pain (p = 0.03). Of the remaining 30 patients who were not followed up, 2 had had bilateral sagittal split osteotomy and 1 a Le Fort I osteotomy. One patient had had orthodontic correction for a malocclusion. Including the five malocclusion patients, at least 9 of the total of 71 (13%) developed a malocclusion after conservative treatment. Functional impairment had no influence on the intensity of pain or pain-related disability in the patients with malocclusion after conservatively treated bilateral condylar fractures. This report may therefore be of value in the debate about whether open or closed treatment is better for bilateral mandibular condylar fractures.     

Women with more severe degrees of temporomandibular disorder exhibit an increase in temperature over the temporomandibular joint

Aim

The purpose of the present study was to correlate the degree of temporomandibular disorder (TMD) severity and skin temperatures over the temporomandibular joint (TMJ) and masseter and anterior temporalis muscles.

Materials and methods

This blind cross-sectional study involved 60 women aged 18–40 years. The volunteers were allocated to groups based on Fonseca anamnestic index (FAI) score: no TMD, mild TMD, moderate TMD, and severe TMD (n = 15 each). All volunteers underwent infrared thermography for the determination of skin temperatures over the TMJ, masseter and anterior temporalis muscles. The Shapiro–Wilk test was used to determine the normality of the data. The Kruskal–Wallis test, followed by Dunn’s test, was used for comparisons among groups according to TMD severity. Spearman’s correlation coefficients were calculated to determine the strength of associations among variables.

Results

Weak, positive, significant associations were found between FAI score and skin temperatures over the left TMJ (rs = 0.195, p = 0.009) and right TMJ (rs = 0.238, p = 0.001). Temperatures over the right and left TMJ were significantly higher in groups with more severe TMD (p < 0.05).

Conclusion

FAI score was associated with skin temperature over the TMJ, as determined by infrared thermography, in this sample. Women with more severe TMD demonstrated a bilateral increase in skin temperature.