Clinically Established Temporomandibular Involvement in Adults With Juvenile Idiopathic Arthritis.

OBJECTIVE: To study clinical variables defining temporomandibular function in adults with juvenile idiopathic arthritis (JIA) and healthy controls. METHODS: In this cross-sectional study, the temporomandibular joint (TMJ) screening protocol, mandibular range of motion (MROM), and anterior maximum voluntary bite force (AMVBF) were compared between adults with JIA and healthy controls. Unadjusted and adjusted models with corrections for sex and disease duration were constructed for active maximum interincisal mouth opening (AMIO) and AMVBF. RESULTS: A total of 100 adults with JIA and 59 healthy adults were included in this study. In adults with JIA, 56% had clinically established TMJ involvement. AMIO was the MROM variable most reduced by TMJ involvement; AMIO was 8.8 mm (95% CI -11.40 to -6.12; P < 0.001) less in adults with JIA with TMJ involvement compared to JIA without TMJ involvement. No differences of AMIO were found between healthy adults and adults with JIA without TMJ involvement (-2.52, 95% CI -5.13 to 0.10; P = 0.06). Male sex was associated with a higher AMIO, and disease duration was associated with a decreased AMIO. Collinearity between the subtype prebiologic era and disease duration was found. AMVBF did not differ between adults with JIA and healthy adults. CONCLUSION: The high prevalence of clinically established TMJ involvement in adults with JIA indicates the need for awareness of TMJ problems in adults with JIA. TMJ involvement negatively influenced AMIO and should therefore be part of the TMJ screening in adults with JIA. AMVBF seems to have less utility for TMJ screening in adult populations.

Reliability and measurement error of anterior maximum voluntary bite force in children with juvenile idiopathic arthritis and healthy children.

In children with juvenile idiopathic arthritis (JIA) the temporomandibular joint (TMJ) can be involved. As a consequence, the oral function can be impaired due to joint and/or muscle involvement of the masticatory system with a negative influence on the maximum bite force. The aim of this cross-sectional study was to establish the reliability of AMVBF in children with JIA and healthy children. Children with JIA and healthy children conducted three attempts of AMVBF. The reliability of AMVBF measurement was determined by the intra-class correlation coefficient (ICC) by age, standard error of measurement (SEM), smallest detectable change (SDC), and limits of agreement (LoA). A total of 298 children with JIA and 168 healthy children were examined. The AMVBF measurements showed an good to excellent reliability in children with JIA based on the ICCs corrected for age (0.782-0.979). In healthy children, the reliability was moderate to excellent (0.546-0.999). The SDC in our study indicated that values above 11.4N might be a clinical relevant change over time in children with JIA. The LoA showed a wide spread of variability in both children with JIA (-72.6-44.4N) and healthy children (-79.9-72.8N). The Bland-Altman plots indicated that the differences between the test and retest increased in value proportionally to the biteforce value.

Growth curves for mandibular range of motion and maximum voluntary bite force in healthy children.

Mandibular range of motion and bite force are indispensable variables for the evaluation of mandibular function. There are a variety of medical and dental conditions that can negatively affect mandibular function. Values for mandibular range of motion (i.e., active and passive maximum interincisal mouth opening, protrusion, and laterotrusion) and anterior maximum voluntary bite force (AMVBF) in healthy children and adolescents can help in recognizing temporomandibular dysfunction. In this longitudinal study, 169 healthy children aged 6-18 years were included. They were examined at four time points over 1 year. Mixed model analysis was performed to produce growth curves of mandibular range of motion and AMVBF. Average active maximum interincisal mouth opening was significantly higher in boys with 50.0 mm compared to 47.8 mm in girls. Boys also had a significantly higher AMVBF than girls with an average of 169.0 N versus 140.0 N, respectively. Growth curves of active and passive maximum interincisal mouth opening showed an increase with age, albeit levelling off through puberty. The growth curves of AMVBF in girls reach a plateau phase at ages 12-14 years, after which the curve descends; in boys, the AMVBF tended to increase up to 18 years of age, although a slow-down after 14 years of age was noted.

Mandibular range of motion in children with juvenile idiopathic arthritis with and without clinically established temporomandibular joint involvement and in healthy children; a cross-sectional study.

BACKGROUND: Recognition of temporomandibular joint (TMJ) involvement in children with juvenile idiopathic arthritis (JIA) has gained increasing attention in the past decade. The clinical assessment of mandibular range of motion characteristics is part of the recommended variables to detect TMJ involvement in children with JIA. The aim of this study was to explore explanatory variables for mandibular range of motion outcomes in children with JIA, with and without clinically established TMJ involvement, and in healthy children. METHODS: This cross-sectional study included children with JIA and healthy children of age 6-18 years. Mandibular range of motion variables included active and passive maximum interincisal opening (AMIO and PMIO), protrusion, laterotrusion, dental midline shift in AMIO and in protrusion. Additionally, the TMJ screening protocol and palpation pain were assessed. Adjusted linear regression analyses of AMIO, PMIO, protrusion, and laterotrusion were performed to evaluate the explanatory factors. Two adjusted models were constructed: model 1 to compare children with JIA and healthy children, and model 2 to compare children with JIA with and without TMJ involvement. RESULTS: A total of 298 children with JIA and 169 healthy children were included. Length was an explanatory variable for the mandibular range of motion excursions. Each centimeter increase in length increased AMIO (0.14 mm), PMIO (0.14 mm), and protrusion (0.02 mm). Male gender increased AMIO by 1.35 mm. Having JIA negatively influenced AMIO (3.57 mm), PMIO (3.71 mm), and protrusion (1.03 mm) compared with healthy children, while the discrepancy between left and right laterotrusion raised 0.68 mm. Children with JIA and TMJ involvement had a 8.27 mm lower AMIO, 7.68 mm lower PMIO and 0.96 mm higher discrepancy in left and right laterotrusion compared to healthy children. CONCLUSION: All mandibular range of motion items were restricted in children with JIA compared with healthy children. In children with JIA and TMJ involvement, AMIO, PMIO and the discrepancy between left and right laterotrusion were impaired more severely. The limitation in protrusion and laterotrusion was hardly clinically relevant. Overall, AMIO is the mandibular range of motion variable with the highest restriction (in millimeters) in children with JIA and clinically established TMJ involvement compared to healthy children.

Maximum bite force in children with juvenile idiopathic arthritis with and without clinical established temporomandibular joint involvement and in healthy children: a cross-sectional study.

BACKGROUND: In children with juvenile idiopathic arthritis (JIA), the temporomandibular joint (TMJ) can be involved, resulting in dysfunction of the masticatory system. Bite force is one of the variables that reflects the function of the masticatory system. The aim of this study was to compare maximum bite force in children with JIA, with and without TMJ involvement and with healthy children. METHODS: Children with JIA and healthy children between the ages 6 and 18 were included in this cross-sectional study. The clinical examination consisted of measuring the anterior maximum voluntary bite force (AMVBF), assessment of the TMJ screening protocol items and TMJ, masseter and temporal muscle palpation pain. Unadjusted linear regression analyses were performed to evaluate the explanatory factors for AMVBF. Two adjusted models were constructed with corrections for age and gender differences: model 1 to compare children with JIA and healthy children and model 2 to compare children with JIA with and without TMJ involvement. RESULTS: In this cross-sectional study, 298 children with JIA and 169 healthy children participated. AMVBF was 24 Newton (N) lower in children with JIA, when compared with healthy children (95%CI: -35.5--12.4, p = .000). When children with JIA also had clinically established TMJ involvement, AMVBF was reduced 42 N (component JIA:-16.78, 95% CI -28.96--4.59, p = .007 and component TMJ involvement:-25.36, 95% CI -40.08--10.63, p = .001). Age and male gender increased AMVBF. CONCLUSION: Children with JIA had a reduction in the AMVBF compared with healthy children. In children with JIA and clinically established TMJ involvement, AMVBF was more reduced.

Reliability and Validity of the Diagnostic Criteria for Temporomandibular Disorders Axis I in Clinical and Research Settings: A Critical Appraisal.

The recently published Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) Axis I, which is recommended for use in clinical and research settings, has provided an update of the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). The authors of the DC/TMD based their publication on the results of a Validation Project (2001-2008) and consecutive workgroup sessions held between 2008 and 2013. The DC/TMD represents a major change in both content and procedures; nonetheless, earlier concerns and new insights have only partly been followed up when drafting the new recommendations. Moreover, the emphasis on immediate implementation in clinical and research settings is not in line with the provided external evidence on which the DC/TMD is based. This Focus Article describes these concerns with regard to several aspects of the DC/TMD: the additional classification categories; the high dependency on pressure-pain results from use of the recommended palpation technique; the TMD pain screening instrument; the test population characteristics; the utility of additional subgroups; the use of a reference standard; the dichotomy between pain and dysfunction; and the DC/TMD algorithms. Thus, although the DC/TMD represents an improvement over the RDC/TMD, its immediate implementation in research and clinical care does not yet appear to be adequately substantiated.

Authors' Response to Critical Commentaries: Reliability and Validity of the DC/TMD Axis I.

No abstract available.

Temporomandibular Joint Involvement in Association With Quality of Life, Disability, and High Disease Activity in Juvenile Idiopathic Arthritis.

OBJECTIVE: To evaluate the demographic, disease activity, disability, and health-related quality of life (HRQOL) differences between children with juvenile idiopathic arthritis (JIA) and their healthy peers, and between children with JIA with and without clinical temporomandibular joint (TMJ) involvement and its determinants. METHODS: This study is based on a cross-sectional cohort of 3,343 children with JIA and 3,409 healthy peers, enrolled in the Pediatric Rheumatology International Trials Organisation HRQOL study or in the methotrexate trial. Potential determinants of TMJ involvement included demographic, disease activity, disability, and HRQOL measures selected through univariate and multivariable logistic regression. RESULTS: Clinical TMJ involvement was observed in 387 of 3,343 children with JIA (11.6%). Children with TMJ involvement, compared to those without, more often had polyarticular disease course (95% versus 70%), higher Juvenile Arthritis Disease Activity Score (odds ratio [OR] 4.6), more disability, and lower HRQOL. Children with TMJ involvement experienced clearly more disability and lower HRQOL compared to their healthy peers. The multivariable analysis showed that cervical spine involvement (OR 4.6), disease duration >4.4 years (OR 2.8), and having more disability (Childhood Health Assessment Questionnaire Disability Index >0.625) (OR 1.6) were the most important determinants for TMJ involvement. CONCLUSION: Clinical TMJ involvement in JIA is associated with higher disease activity, higher disability, and impaired HRQOL. Our findings indicate the need for dedicated clinical and imaging evaluation of TMJ arthritis, especially in children with cervical spine involvement, polyarticular course, and longer disease duration.

Mandibular dysfunction as a reflection of bulbar involvement in SMA type 2 and 3.

OBJECTIVE: In a cross-sectional study, we aimed to determine (1) the effect of spinal muscular atrophy (SMA) type 2 and 3 on mandibular function reflected as masticatory performance, mandibular range of motion, and bite force and (2) the predictors of mandibular dysfunction. METHODS: Sixty patients with SMA type 2 and 3 (mean age 32.3 years, SD 17.4 years) and 60 age-matched controls filled out questionnaires about impairments of mandibular function. All participants underwent detailed clinical examination to document the mandibular range of motion including maximal mouth opening, bite force, and masticatory function. RESULTS: All mandibular movements, including mouth opening, lateral range of motion, and protrusion of the mandible, were reduced in patients with SMA type 2 and 3 compared to healthy controls (p < 0.001). Maximal bite force was 19% lower in patients than controls, and more in patients with SMA type 2 than type 3. The strongest predictive factor was SMA type for impairment of mandibular range of motion (R(2) = 0.82) and weakness of neck muscles for bite force (R(2) = 0.47). CONCLUSIONS: Reduced mandibular mobility and bite force are common complications in SMA. SMA type and neck muscle strength are important correlates of these complications. We provide further evidence for clinically relevant bulbar involvement in patients with SMA.

Temporomandibular joint involvement in Juvenile Idiopathic Arthritis: reliability and validity of a screening protocol for the rheumatologist.

BACKGROUND: In Juvenile Idiopathic Arthritis (JIA) the temporomandibular joint (TMJ) can be involved leading to pain, dysfunction and growth disturbances of the mandible and associated structures. There may be value to a three minute screening protocol allowing the rheumatologist to detect TMJ involvement systematically. Reliability and validity of the TMJ protocol for detecting TMJ co-morbidity were determined in 74 consecutive JIA patients. METHODS: The assessments of the rheumatologist and of a reference examiner (RE) were compared and validity of the TMJ protocol was established using the disease activity (JADAS-27) as an external reference. RESULTS: The internal consistency of the protocol was 0.73 (Cronbach's alpha). The inter-examiner agreement between the rheumatologist and the RE varied between 0.25 and 0.87 (Cohen's Kappa). Sensitivity and specificity, with the JADAS "3.8" indicating minimal disease activity, were 0.57 and 0.77 respectively. The area under the curve (AUC) was 0.70. A cut-off value of two positive items was found to be an optimal threshold to select the patients with likely TMJ involvement. CONCLUSIONS: The use of the protocol is feasible in everyday clinical practice. Reliability and validity aspects were satisfactory. The screening protocol for TMJ involvement provides the rheumatologist with systematic and focused TMJ information which relates to the JIA disease activity (JADAS-27).

Fighting Against Disuse of the Masticatory System in Duchenne Muscular Dystrophy: A Pilot Study Using Chewing Gum.

Duchenne muscular dystrophy patients report masticatory problems. The aim was to determine the efficacy of mastication training in Duchenne muscular dystrophy using chewing gum for 4 weeks. In all, 17 patients and 17 healthy age-matched males participated. The masticatory performance was assessed using a mixing ability test and measuring anterior bite force before, shortly after and 1 month after the training. In the patient group the masticatory performance improved and remained after 1-month follow-up, no significant changes in anterior maximum bite force was observed after mastication training. In the healthy subject the bite force increased and remained at the 1-month follow-up; no significant differences in masticatory performance were observed. Mastication training by using sugar-free chewing gum in Duchenne muscular dystrophy patients improved their masticatory performance. Since bite force did not improve, the working mechanism of the improvement in chewing may relate to changes of the neuromuscular function and coordination, resulting in improvement of skills in performing mastication.

Bulbar muscle MRI changes in patients with SMA with reduced mouth opening and dysphagia.

OBJECTIVE: We performed a study in patients with proximal spinal muscular atrophy (SMA) to determine the prevalence of reduced maximal mouth opening (MMO) and its association with dysphagia as a reflection of bulbar dysfunction and visualized the underlying mechanisms using MRI. METHODS: We performed a cross-sectional study of MMO in 145 patients with SMA types 1-4 and 119 healthy controls and used MRI in 12 patients to visualize mandibular condylar shape and sliding and the anatomy of muscle groups relevant for mouth opening and closing. We analyzed associations of reduced MMO with SMA severity and complaints of dysphagia. RESULTS: Reduced MMO was defined as an interincisal distance ≤ 35 mm and was found in none of the healthy controls and in 100%, 79%, 50%, and 7% of patients with SMA types 1, 2, 3a, and 3b/4, respectively. MRI showed severe fatty degeneration of the lateral pterygoid muscles that mediate mouth opening by allowing mandibular condylar sliding but relatively mild involvement of the mouth closing muscles in patients with reduced MMO. Reduced MMO was associated with SMA type, age, muscle weakness, and dysphagia (p < 0.05). CONCLUSIONS: Reduced MMO is common in SMA types 1-3a and is mainly caused by fatty degeneration of specific mouth opening muscles. Reduced MMO is a sign of bulbar dysfunction in SMA.

Evaluation of the short-term effectiveness of education versus an occlusal splint for the treatment of myofascial pain of the jaw muscles.

BACKGROUND: The authors conducted a clinical trial to compare the effectiveness of an education program with that of an occlusal splint in treating myofascial pain of the jaw muscles across a short period. METHOD: The authors assigned 44 patients randomly to two treatment groups; 41 patients completed the study. The first group (four male, 19 female; mean [standard deviation {SD}] age, 31.4 [14.0] years) received information regarding the nature of temporomandibular disorder (TMD) and self-care measures, whereas the second group (five male, 13 female; mean [SD] age, 31.1 [8.8] years) received an occlusal splint. One of the authors evaluated each patient every three weeks during a three-month treatment period. Treatment outcomes included pain-free maximal mouth opening, spontaneous muscle pain, pain during chewing and headache. RESULTS: After three months, changes in spontaneous muscle pain differed significantly between the education and occlusal splint groups (P = .034; effect size = 0.33). Changes in pain-free maximal mouth opening did not differ significantly between groups (P = .528; effect size = 0.20). Changes of headache and pain on chewing did not differ significantly between groups (P ≥ .550, effect size ≤ 0.10). CONCLUSIONS: During a short period, education was slightly more effective than an occlusal splint delivered without education in reducing spontaneous muscle pain in patients with TMD. Pain-free mouth opening, headache and pain during chewing were not significantly different between the two treatments.

Impaired mandibular function in spinal muscular atrophy type II: need for early recognition.

The aim of the study is to assess mandibular function in young patients with spinal muscular atrophy type II. A total of 12 children and young adults with spinal muscular atrophy type II and 12 healthy matched controls participated. The mandibular function impairment was moderate to severe in 50% of patients. A limited mouth opening (≤30 mm) was observed in 75% of the patients. In patients with a severe reduction of the mandibular range of motion the temporomandibular joint mainly rotated during mouth opening instead of the usual combination of rotation and sliding. The severity of the limited active mouth opening correlated with the severity of the disease (motor function measure scores). This study shows that mandibular dysfunction is common among young patients with spinal muscular atrophy type II. Early recognition of mandibular dysfunction may help to prevent complications such as aspiration as a result of chewing problems.

Validity of the Research Diagnostic Criteria for Temporomandibular Disorders Axis I in clinical and research settings.

The lack of standardized diagnostic criteria for defining clinical subtypes of temporomandibular disorders (TMD) was the main motive to create the Research Diagnostic Criteria for TMD (RDC/TMD), which were provided to allow standardization and replication of research into the most common forms of muscle- and joint-related TMD. The RDC/TMD offered improvement compared to the older literature: the use of one system classifying TMD subgroups and the introduction of a dual-axis classification. The aim of this Focus Article is to appraise the RDC/TMD Axis I (physical findings). Since the original publication in 1992, no modification of the RDC/TMD has taken place, although research has yielded important new findings. The article outlines several concerns, including diagnostic issues in Axis I, classification criteria, feasibility of palpation sites, the myofascial diagnostic algorithm, the lack of joint tests (compression, traction), and missing subgroups. Using a gold standard examiner may improve calibration and offer better reliability; it does not improve any of the diagnostic validity issues. It is also noted that in the 2004 mission statement of the International Consortium For RDC/TMD-Based Research, the RDC/TMD are also advocated for clinical settings. Clinicians may eagerly embrace the RDC/TMD, believing that the clinical use of the RDC/TMD as a diagnostic procedure is already supported by evidence, but its application is not indicated in clinical settings. The article concludes that given the research developments, there is a need to update the RDC/TMD Axis I in the clinical research setting.

The additional value of a home physical therapy regimen versus patient education only for the treatment of myofascial pain of the jaw muscles: short-term results of a randomized clinical trial.

AIMS: To compare the short-term efficacy of patient education only versus the combination of patient education and home exercises for the treatment of myofascial pain of the jaw muscles. MATERIALS AND METHODS: Seventy myogenous temporomandibular disorder patients were assigned to 2 treatment groups. One group received patient education supplemented by general information about self-care of the jaw musculature. The other group received both education and a home physical therapy program. Treatment contrast, calculated from the mean normalized relative changes in anamnestic and clinical scores, was used to determine treatment success. Clinical outcome measures included pressure pain threshold (PPT) of the masseter, anterior temporalis, and Achilles tendon; pain-free maximal jaw opening; and pain on chewing, spontaneous muscle pain, and headache as rated on visual analog scales. RESULTS: After 3 months the success rate was 57% for the group that received education only and 77% for the group that received both education and home physical therapy (P = .157). The patients were then redivided into 2 groups: successfully treated patients and unsuccessfully treated patients. In the unsuccessfully treated group, pain-free maximal jaw opening increased significantly more among those who had been in the education and physical therapy group than among those who had been in the education-only group (P = .019). The change in PPT was significantly greater in successfully treated patients than in unsuccessfully treated patients (.009 < P < .039), independent of the treatment modality, with higher PPTs among successful patients. There were no significant differences between the successfully and unsuccessfully treated groups or between treatment modalities for any other variable. CONCLUSION: Over a period of 3 months, the combination of education and a home physical therapy regimen, as used in this protocol, is slightly more clinically effective than education alone for the treatment of myofascial pain of the jaw muscles.

Mandibular condyle osteochondroma. Review of the literature and report of a misdiagnosed case.

Temporomandibular disorders can usually be diagnosed on the basis of a thorough history and a comprehensive examination of the patient. Additional diagnostic tests, such as imaging of the temporomandibular joint (TMJ) area, are mandatory and must be flawless in case of atypical findings. The aim of this report is to illustrate pitfalls in clinical reasoning and in imaging procedures in the diagnosis of temporomandibular pain and dysfunction. A case report of a patient with osteocartilaginous exostosis of the mandibular condyle, which was erroneously diagnosed and treated as an internal derangement of the TMJ for half a year, is presented.