Heterotopic ossification of the temporomandibular joint in juvenile idiopathic arthritis

Cone beam computed tomography in the assessment of TMJ deformity in children with JIA: repeatability of a novel scoring system

BACKGROUND

The temporomandibular joint (TMJ) is frequently involved in juvenile idiopathic arthritis (JIA). Diagnostic imaging is necessary to correctly diagnose and evaluate TMJ involvement, however, hitherto little has been published on the accuracy of the applied scoring systems and measurements. The present study aims to investigate the precision of 20 imaging features and five measurements based on cone beam computed tomography (CBCT).

METHODS

Imaging and clinical data from 84 participants in the Norwegian study on juvenile idiopathic arthritis, the NorJIA study, were collected. Altogether 20 imaging features and five measurements were evaluated independently by three experienced radiologists for intra- and interobserver agreement. Agreement of categorical variables was assessed by Fleiss', Cohen's simple or weighted Kappa as appropriate. Agreement of continuous variables was assessed with 95% limits of agreement as advised by Bland and Altman.

RESULTS

"Overall impression of TMJ deformity" showed almost perfect intraobserver agreement with a kappa coefficient of 0.81 (95% CI 0.69-0.92), and substantial interobserver agreement (Fleiss' kappa 0.70 (0.61-0.78)). Moreover, both "flattening" and "irregularities" of the eminence/fossa and condyle performed well, with intra- and interobserver agreements of 0.66-0.82 and 0.55-0.76, respectively. "Reduced condylar volume" and "continuity" of the fossa/eminence had moderate intra- and interobserver Kappa values, whereas continuity of the condyle had Kappa values above 0.55. Measurements of distances and angles had limits of agreement of more than 15% of the sample mean.

CONCLUSIONS

We propose a CBCT-based scoring system of nine precise imaging features suggestive of TMJ deformity in JIA. Their clinical validity must be tested.

Complications following metal bar removal after Nuss repair are rare in a duocentric retrospective evaluation

PURPOSE

Minimally invasive pectus excavatum repair has gained widespread acceptance and its results and complications are well-described. However, there is a substantial debate on the risks and frequencies of complications following metal bar removal. We, therefore, aimed to analyse all complications that occurred during and after metal bar removal at our two paediatric surgical centres.

METHODS

Bar removal surgeries were identified via procedural codes and electronic records were reviewed using a pre-specified data extraction chart. Both intra- and postoperative complications were included and the latter scored according to Clavien-Dindo. We analysed the influence of the pre-specified potential predictors age, sex, and the number of implanted metal bars on the occurrence of complications using logistic regression.

RESULTS

We included 279 patients with a median age of 19 years (interquartile range 17-20 years). 15 patients experienced 17 complications. Of 11 postoperative complications, only an enlarging pleural effusion required a chest drain in local anaesthesia, resulting in a Claven-Dindo grade IIIa, whereas the remainder were classified as grade I. Neither age (adjusted odds ratio (aOR) 0.97, 95% confidence interval (CI) 0.84-1.13, P = 0.73), nor sex (aOR 0.88, 95% CI 0.19-4.07, P = 0.87) or the number of bars (aOR 0.64, 95% CI 0.15-2.71, P = 0.547) did influence the occurrence of complications.

CONCLUSION

Complications following metal bar removal were scarce in our duocentric retrospective series and usually of minor relevance. However, to address the perceived paucity of data on the frequency and severity of complications following metal bar removal, further studies, including large database research is necessary.

2021 American College of Rheumatology Guideline for the Treatment of Juvenile Idiopathic Arthritis: Therapeutic Approaches for Oligoarthritis, Temporomandibular Joint Arthritis, and Systemic Juvenile Idiopathic Arthritis

OBJECTIVE

To provide updated guidelines for pharmacologic management of juvenile idiopathic arthritis (JIA), focusing on treatment of oligoarthritis, temporomandibular joint (TMJ) arthritis, and systemic JIA with and without macrophage activation syndrome. Recommendations regarding tapering and discontinuing treatment in inactive systemic JIA are also provided.

METHODS

We developed clinically relevant Patient/Population, Intervention, Comparison, and Outcomes questions. After conducting a systematic literature review, the Grading of Recommendations Assessment, Development and Evaluation approach was used to rate the quality of evidence (high, moderate, low, or very low). A Voting Panel including clinicians and patients/caregivers achieved consensus on the direction (for or against) and strength (strong or conditional) of recommendations.

RESULTS

Similar to those published in 2019, these JIA recommendations are based on clinical phenotypes of JIA, rather than a specific classification schema. This guideline provides recommendations for initial and subsequent treatment of JIA with oligoarthritis, TMJ arthritis, and systemic JIA as well as for tapering and discontinuing treatment in subjects with inactive systemic JIA. Other aspects of disease management, including factors that influence treatment choice and medication tapering, are discussed. Evidence for all recommendations was graded as low or very low in quality. For that reason, more than half of the recommendations are conditional.

CONCLUSION

This clinical practice guideline complements the 2019 American College of Rheumatology JIA and uveitis guidelines, which addressed polyarthritis, sacroiliitis, enthesitis, and uveitis. It serves as a tool to support clinicians, patients, and caregivers in decision-making. The recommendations take into consideration the severity of both articular and nonarticular manifestations as well as patient quality of life. Although evidence is generally low quality and many recommendations are conditional, the inclusion of caregivers and patients in the decision-making process strengthens the relevance and applicability of the guideline. It is important to remember that these are recommendations. Clinical decisions, as always, should be made by the treating clinician and patient/caregiver.

Controversial Aspects of Diagnostics and Therapy of Arthritis of the Temporomandibular Joint in Rheumatoid and Juvenile Idiopathic Arthritis-An Analysis of Evidence- and Consensus-Based Recommendations Based on an Interdisciplinary Guideline Project

Introduction: Due to potentially severe sequelae (impaired growth, condylar resorption, and ankylosis) early diagnosis of chronic rheumatic arthritis of the temporomandibular joint (TMJ) and timely onset of therapy are essential. Aim: Owing to very limited evidence the aim of the study was to identify and discuss controversial topics in the guideline development to promote further focused research. Methods: Through a systematic literature search, 394 out of 3771 publications were included in a German interdisciplinary guideline draft. Two workgroups (1: oral and maxillofacial surgery, 2: interdisciplinary) voted on 77 recommendations/statements, in 2 independent anonymized and blinded consensus phases (Delphi process). Results: The voting results were relatively homogenous, except for a greater proportion of abstentions amongst the interdisciplinary group (p < 0.001). Eighty-four percent of recommendations/statements were approved in the first round, 89% with strong consensus. Fourteen recommendations/statements (18.2%) required a prolonged consensus phase and further discussion. Discussion: Contrast-enhanced MRI was confirmed as the method of choice for the diagnosis of TMJ arthritis. Intraarticular corticosteroid injection is to be limited to therapy-refractory cases and single injection only. In adults, alloplastic joint replacement is preferable to autologous replacement. In children/adolescents, autologous reconstruction may be performed lacking viable alternatives. Alloplastic options are currently still considered experimental.

2021 American College of Rheumatology Guideline for the Treatment of Juvenile Idiopathic Arthritis: Therapeutic Approaches for Oligoarthritis, Temporomandibular Joint Arthritis, and Systemic Juvenile Idiopathic Arthritis

OBJECTIVE

To provide updated guidelines for pharmacologic management of juvenile idiopathic arthritis (JIA), focusing on treatment of oligoarthritis, temporomandibular joint (TMJ) arthritis, and systemic JIA with and without macrophage activation syndrome. Recommendations regarding tapering and discontinuing treatment in inactive systemic JIA are also provided.

METHODS

We developed clinically relevant Patient/Population, Intervention, Comparison, and Outcomes questions. After conducting a systematic literature review, the Grading of Recommendations Assessment, Development and Evaluation approach was used to rate the quality of evidence (high, moderate, low, or very low). A Voting Panel including clinicians and patients/caregivers achieved consensus on the direction (for or against) and strength (strong or conditional) of recommendations.

RESULTS

Similar to those published in 2019, these JIA recommendations are based on clinical phenotypes of JIA, rather than a specific classification schema. This guideline provides recommendations for initial and subsequent treatment of JIA with oligoarthritis, TMJ arthritis, and systemic JIA as well as for tapering and discontinuing treatment in subjects with inactive systemic JIA. Other aspects of disease management, including factors that influence treatment choice and medication tapering, are discussed. Evidence for all recommendations was graded as low or very low in quality. For that reason, more than half of the recommendations are conditional.

CONCLUSION

This clinical practice guideline complements the 2019 American College of Rheumatology JIA and uveitis guidelines, which addressed polyarthritis, sacroiliitis, enthesitis, and uveitis. It serves as a tool to support clinicians, patients, and caregivers in decision-making. The recommendations take into consideration the severity of both articular and nonarticular manifestations as well as patient quality of life. Although evidence is generally low quality and many recommendations are conditional, the inclusion of caregivers and patients in the decision-making process strengthens the relevance and applicability of the guideline. It is important to remember that these are recommendations. Clinical decisions, as always, should be made by the treating clinician and patient/caregiver.

The Temporomandibular Joint in Juvenile Idiopathic Arthritis

Patients with juvenile idiopathic arthritis (JIA) often have involvement of the temporomandibular joint (TMJ) during their disease course. Active arthritis of the TMJ remains difficult to assess. Clinical signs and symptoms alone are unreliable, and active TMJ arthritis needs confirmation by gadolinium-enhanced MRI. In recent years, changes in treatment approach have occurred. This article discusses the latest evidence on diagnosis and treatment of JIA-associated TMJ arthritis.

Comprehensive Management of Rheumatic Diseases Affecting the Temporomandibular Joint

The temporomandibular joint (TMJ) is a synovial joint and thus is vulnerable to the afflictions that may affect other joints in the fields of rheumatology and orthopedics. Too often temporomandibular complaints are seen strictly as dental or orofacial concerns. Similarly, patients with known rheumatic disease may not have their TMJs included in routine screening and monitoring protocols. The purpose of this review is to highlight the rheumatic conditions likely to affect the TMJ and outline medical and surgical management in these patients with a focus on the need for continued patient reassessment and monitoring.

Efficacy and safety of intraarticular corticosteroid injections in adolescents with juvenile idiopathic arthritis in the temporomandibular joint: a Norwegian 2-year prospective multicenter pilot study

BACKGROUND

Intraarticular corticosteroids (IACs) have been used to treat temporomandibular joint (TMJ) arthritis. However, prospective clinical studies with magnetic resonance imaging (MRI) scoring are lacking. The aim of this study was to examine efficacy and safety of a single IAC in the TMJ in adolescents with juvenile idiopathic arthritis (JIA) in a clinical setting.

METHODS

In this Norwegian prospective multicenter pilot study 15 patients with JIA (mostly persistent oligoarthritis or RF negative polyarthritis categories) and a clinically and MRI-verified diagnosis of TMJ arthritis were treated with IACs and followed for 2 years. Demographics, systemic medication, general disease activity and outcome measures were recorded including a pain-index score and maximal incisal opening (MIO). Inflammation and bone damage scores were assessed, using two recently published MRI scoring systems with masked radiological evaluation.

RESULTS

Among the 15 patients, 13 received a single IAC (5 bilateral), and 2 repeated IACs once unilaterally. Thus, the total number of IACs was 22. Median age was 15 years and the majority had an age not thought of as critical regarding mandibular growth retardation due to steroid injection. During the 2-year observation period systemic medication with disease modifying antirheumatic drugs (DMARDs) including biologics was initiated or adjusted in 10/15 (67%) patients. At the 2-months study visit after injection we observed a minimal improvement in MIO from median 44 (1st, 3rd quartiles; 36, 48) mm to 45 (43, 47) mm, p = 0.045 and decreased MRI mean additive inflammatory score from 4.4 ± 1.8 standard deviations (SD) to 3.4 ± 2.0, p = 0.040. From baseline to the 2-months follow-up pain improved in 6/11 patients but pain scores were not significantly improved. MRI-assessed damage increased in two patients with repeated IACs, and decreased in 3 patients but most of the patients were stable over the 2-year follow-up. Intra-rater repeatability of the MRI scoring system domains varied from poor to excellent.

CONCLUSIONS

In this pilot study of predominately single IACs to the TMJ in combination with systemic treatment we observed improvement in MRI-assessed inflammation, mostly stable condylar bone conditions and minimal clinical improvement in adolescents with JIA and TMJ arthritis. No severe side effects were seen.

Limited Mandibular Movements as a Consequence of Unilateral or Asymmetrical Temporomandibular Joint Involvement in Juvenile Idiopathic Arthritis Patients

This study aimed to assess the asymmetry of the lower face and motor dysfunction of the masticatory system resulting from unilateral or asymmetrical bilateral temporomandibular joint (TMJ) involvement in juvenile idiopathic arthritis (JIA) patients. The study consisted of clinical examination and cone beam computed tomography (CBCT) of TMJs. Statistical analysis showed correlations between several factors: facial asymmetry and mandibular lateral deviation; the direction of mandibular deviation and the degree of radiological deformities in TMJs; the child's age at the time of the onset and the range of lateral movement towards the healthy or less destructed joint. In addition, there was a significant difference in ranges of lateral movements; a significantly smaller range was observed for the joint with fewer condylar abnormalities compared to the range in the opposite direction. In JIA children, among the clinical markers of unilateral or asymmetrical TMJ involvement, the asymmetry of the lower face, deviation of the mandible on opening, and an uneven range of mandibular lateral movements deserve attention. The obtained results do not show a relationship between the degree of condylar changes and the asymmetry of the lower face and the presence and degree of mandibular motor dysfunction.

Role of alloplastic reconstruction of the temporomandibular joint in the juvenile idiopathic arthritis population

We present outcomes following total joint replacement of the temporomandibular joint (TMJ) in adolescent and young adult patients with juvenile idiopathic arthritis (JIA), and discuss a multidisciplinary treatment model. A retrospective review was performed of patients presenting to the University of North Carolina Oral and Maxillofacial Surgery Service (Chapel Hill, NC) from 2016- 2018 who underwent unilateral or bilateral total replacement of the TMJ for a diagnosis of end-stage joint disease secondary to JIA. Inclusion criteria included diagnosis by a rheumatologist, presentation to our department in adolescence (under 18 years of age), surgical intervention in adolescence or young adulthood (under 25 years of age), and documentation of preoperative and postoperative pain, maximum incisal opening (MIO), and quality of life measures. A database was created and data were then analysed both qualitatively and quantitatively. Five patients met the inclusion criteria. All achieved MIO of more than 35mm with a mean improvement of 24mm, and were able to tolerate a regular diet. All preoperative pain had essentially been eliminated. All patients reported a considerable improvement in quality of life. To our knowledge, this is the first report to document a series of paediatric and young adult patients with JIA who required total replacement of the joint for end-stage joint disease. To our knowledge, it is also the first to describe the use of a collaborative clinic of oral and maxillofacial surgeons, neuroradiologists, dental radiologists, orofacial pain specialists, paediatric rheumatologists, and paediatric nurse practitioners, to care for these patients.

Intra-articular calcifications of the temporomandibular joint and associations with degenerative bone alterations

Purpose

The purpose of this study was to use cone-beam computed tomography (CBCT) images to determine the prevalence of calcifications in the temporomandibular joint (TMJ) and to evaluate any associations between the presence of such calcifications and degenerative bone alterations of the TMJ, sex, or age.

Materials and Methods

In this retrospective study, 1,058 CBCT exams were analyzed, and data regarding the presence and quantity of calcifications, the affected side, any degenerative alterations of the condyle, sex, and age were collected. To evaluate associations between the presence of calcifications and sex or age, the Fisher exact test or the Spearman correlation coefficient, respectively, was used. To assess the association between the presence of calcifications and joint bone alterations, the chi-square and Fisher exact tests were used. The significance level adopted was 5% (P<0.05).

Results

Twenty-eight patients (2.7%) presented with TMJ calcifications, including 23 women (82.1%) and 5 men (17.9%). Significant correlations were found between the presence of calcifications and age (P<0.05) and between the presence of calcifications and the presence of condylar alterations (P<0.05), with 73.2% of patients with bone alterations having TMJ calcifications.

Conclusion

It may be concluded that, although rare (with a prevalence of only 2.7%), intra-articular calcifications are associated with both degenerative bone alterations and age.

Levels of Selected Matrix Metalloproteinases, Their Inhibitors in Saliva, and Oral Status in Juvenile Idiopathic Arthritis Patients vs. Healthy Controls

Aims

Matrix metalloproteinases (MMPs) are a group of calcium-dependent zinc-containing proteinases acting both physiologically and in pathological conditions. The aim of this study was to evaluate the concentration of MMP-2, MMP-8, and MMP-9 and their inhibitors TIMP-1 and TIMP-2 of unstimulated whole saliva (UWS) in correlation with the oral health in juvenile idiopathic arthritis (JIA) children.

Methods

The study population comprised 34 JIA patients and 34 age- and sex-matched controls (C). They were divided into two groups: with mixed dentition (MD) and with permanent dentition (PD). Dental caries (DMFT/dmft), unstimulated salivary flow rate (SF), and gingival inflammation (Gingival Index (GI) and Papilla Bleeding Index (PBI)) and oral hygiene (Simplified Oral Hygiene Index (OHI-S)) indices were evaluated. Saliva samples were tested with the enzyme-linked immunosorbent assay (ELISA) for MMP-2, MMP-8, MMP-9, TIMP-1, and TIMP-2. Data were statistically analysed with the Mann–Whitney U test and Spearman's rank correlation (p < 0.05).

Results

There were no differences in dental hygiene or dental and periodontal status between the JIA and C groups. The MMP-9 concentration was higher in the whole JIA group compared with C (p=0.005) and JIA MD groups (p=0.038). A positive correlation of MMP-2 with the OHI-S index and a negative correlation of MMP-2 with SF were found in JIA. MMP-9 and its tissue inhibitor TIMP-1 had a positive mean correlation with the GI. A high correlation of MMP-8 with the number of decayed teeth (D) in JIA MD patients (p=0.037) was revealed. In the JIA-PD patients, there was a positive correlation of MMP-2, -8, and -9 levels with gingival inflammation indices and a negative correlation of MMP-2 and 8 with the SF.

Conclusions

Despite a comparable clinical oral status of affected and unaffected children, in the JIA patients, a statistically significantly increased level of MMP-9 was found. In reference to the periodontal status, the role of MMPs increased in children with permanent dentition, whereas in reference to dental caries, the period of mixed dentition (MD) was critical.

Risk Factors for Intraarticular Heterotopic Bone Formation in the Temporomandibular Joint in Juvenile Idiopathic Arthritis

Objective.

Intraarticular corticosteroid (IAC) injections are often used to treat temporomandibular joint (TMJ) arthritis associated with juvenile idiopathic arthritis (JIA). One potential complication of IA therapy is heterotopic bone formation (HBF). The purpose of our study was to evaluate risk factors for HBF development in children with JIA who received IA therapy for TMJ arthritis.

Methods.

This was a retrospective study of children with JIA who had received ≥ 1 IAC injection into the TMJ. Survival regression analysis was performed to identify risk factors for the development of HBF.

Results.

There were 238 children included, of whom 33 (14%) developed HBF. No cases of HBF were diagnosed prior to the initial injection. Univariate analysis revealed that the risk factors for development of HBF were the total number of injections received into the TMJ and age at diagnosis of JIA, while the length of time from diagnosis of JIA to the first injection was inversely associated with the risk of HBF formation. The total number of injections was no longer significant following adjusted survival models. Children with HBF had increased physical examination evidence of acute or chronic changes, namely decreased maximal incisal opening and increased likelihood of jaw deviation.

Conclusion.

HBF within the TMJ is relatively common in patients with JIA receiving IAC injections for TMJ arthritis. Future prospective studies are required to delineate the risks posed by the injections themselves as opposed to the underlying disease activity, as well as to evaluate alternative forms of local therapy to the TMJ.

Acquired heterotopic ossification of the temporomandibular joint

Although the risk factors and diagnosis of heterotopic ossification (HO) are discussed in the orthopedics literature, the etiology of HO, as well as its prevention and management, remain theoretical. Furthermore, there is a lack of information in the literature regarding HO in temporomandibular joint replacement (TMJR). This article provides a qualitative review of information relative to the etiology, diagnosis, and management of HO to inform and encourage further investigation in TMJR. The orthopedic HO literature considered for this qualitative review was drawn from a comprehensive examination of the subject published previously by one of the authors. Using the key words "heterotopic ossification" or "heterotopic bone", citations in the PubMed database from both the dental and oral and maxillofacial surgery literature were reviewed. Based on this, it appears that the etiology, diagnosis, imaging, laboratory testing, risk factors, prophylaxis, and non-surgical and surgical options available for the management of TMJR-related HO are similar to those for orthopedic HO, but further elucidation is required for TMJR. There is a lack of published information in the literature on TMJR. Therefore, using the literature from this review as a foundation, studies should be developed and reported so that alloplastic TMJ surgeons have evidence-based protocols that will lead to the early detection and potential prevention of HO.

Quantifying Temporomandibular Joint Synovitis in Children With Juvenile Idiopathic Arthritis

OBJECTIVE

Juvenile idiopathic arthritis (JIA) frequently affects the temporomandibular joints (TMJs) and is often undetected by history, examination, and plain imaging. Qualitative assessment of gadolinium-enhanced magnetic resonance images (MRIs) is currently the standard for diagnosis of TMJ synovitis associated with JIA. The purpose of this study is to apply a quantitative analysis of synovial enhancement to MRIs of patients with and without JIA to establish a disease threshold and sensitivity and specificity for the technique.

METHODS

This is a retrospective case-control study of children (age ≤16 years) who had MRIs with gadolinium including the TMJs. Subjects were divided into a JIA group and a control group. From a coronal T1-weighted image, a ratio (enhancement ratio [ER]) of the average pixel intensity within three 0.2-mm² regions of interest (ROIs) in the TMJ synovium to that of a 50-mm² ROI of the longus capitis muscle was calculated. Receiver operating characteristic curves were used to determine the sensitivity and specificity. The inter- and intraexaminer reliability was evaluated with Bland-Altman plots and 2-way mixed, absolute agreement intraclass correlation coefficients.

RESULTS

There were 187 and 142 TMJs included in the JIA and control groups, respectively. An ER threshold of 1.55 had a sensitivity and specificity for detecting synovitis of 91% and 96%, respectively. The inter- and intraexaminer reliability was excellent.

CONCLUSION

Calculating a ratio of pixel intensity between the TMJ synovium and the longus capitis muscle is a reliable way to quantify synovial enhancement. An ER of 1.55 differentiates normal TMJs from those affected by inflammatory arthritis.

Unstimulated salivary flow, pH, proteins and oral health in patients with Juvenile Idiopathic Arthritis

Background

There have been inconsistent conclusions regarding salivary abnormalities and their effect on oral health of Juvenile Idiopathic Arthritis (JIA) patients. The purpose of the study was to evaluate the flow rate and selected biochemical parameters of unstimulated whole saliva in correlation to oral health in JIA children.

Methods

Thirty-four JIA patients and 34 age- and sex-matched controls not affected by JIA (C) were divided into two groups: with mixed and permanent dentition. DMFT/dmft, gingival and simplified oral hygiene indices were evaluated. Salivary flow rate, pH, lysozyme, lactoferrin, salivary protein concentrations and peroxidase activity were assessed.

Results

The salivary flow rate was significantly lower in the total JIA group (0.41 ml/min) as compared with the C (0.51 ml/min) and in the permanent dentition of JIA children (0.43 ml/min) as compared with the C (0.61 ml/min). A significantly lower pH was observed in total (6.74), mixed (6.7) and permanent (6.76) dentition of JIA groups in comparison to the C (7.25, 7.21, 7.28 respectively). The specific activity of peroxidase was significantly higher in JIA patients (total 112.72 IU/l, mixed dentition 112.98 IU/l, permanent dentition 112.5 IU/l) than in the C group (total 70.03 IU/l, mixed dentition 71.83 IU/l, permanent dentition 68.61 IU/l). The lysozyme concentration in JIA patients (total and permanent dentition groups) was significantly higher than in the C group. There were no significant differences in lactoferrin and salivary protein concentrations. There were no statistically significant differences in oral status between JIA patients and C, respectively: DMFT = 5.71, dmft = 3.73, OHI-S = 0.95, GI = 0.25 and DMFT 5.71, dmft = 3.73, OHI-S = 0.85, GI = 0.24. The specific activity of peroxidase in the unstimulated whole saliva was inversely correlated with the GI index, whereas the salivary lysozyme concentration was inversely correlated with the dmft index in JIA patients.

Conclusion

In the course of JIA occur a reduction of the resting salivary flow rate and a decrease of saliva pH. In spite of this, no differences in the clinical oral status between the JIA children population and the control group were found. The mobilisation of salivary peroxidase and lysozyme contributes to the maintenance of healthy oral tissues.

Clinical Orofacial Examination in Juvenile Idiopathic Arthritis: International Consensus-based Recommendations for Monitoring Patients in Clinical Practice and Research Studies

OBJECTIVE

To develop international consensus-based recommendations for the orofacial examination of patients with juvenile idiopathic arthritis (JIA), for use in clinical practice and research.

METHODS

Using a sequential phased approach, a multidisciplinary task force developed and evaluated a set of recommendations for the orofacial examination of patients with JIA. Phase 1: A Delphi survey was conducted among 40 expert physicians and dentists with the aim of identifying and ranking the importance of items for inclusion. Phase 2: The task force developed consensus about the domains and items to be included in the recommendations. Phase 3: A systematic literature review was performed to assess the evidence supporting the consensus-based recommendations. Phase 4: An independent group of orofacial and JIA experts were invited to assess the content validity of the task force's recommendations.

RESULTS

Five recommendations were developed to assess the following 5 domains: medical history, orofacial symptoms, muscle and temporomandibular joint function, orofacial function, and dentofacial growth. After application of data search criteria, 56 articles were included in the systematic review. The level of evidence for the 5 recommendations was derived primarily from descriptive studies, such as cross-sectional and case-control studies.

CONCLUSION

Five recommendations are proposed for the orofacial examination of patients with JIA to improve the clinical practice and aid standardized data collection for future studies. The task force has formulated a future research program based on the proposed recommendations.

Quantifying the Effect of Temporomandibular Joint Intra-Articular Steroid Injection on Synovial Enhancement in Juvenile Idiopathic Arthritis

PURPOSE

To quantify the effect of intra-articular steroid injections (IASIs) on temporomandibular joint (TMJ) synovitis in children with juvenile idiopathic arthritis (JIA) using gadolinium-enhanced magnetic resonance imaging (MRI).

MATERIALS AND METHODS

The present study was a retrospective study of children with JIA who had undergone TMJ IASIs at Boston Children's Hospital. The patients were included if they had undergone contrast-enhanced MRI both before and after IASI and if the pre-IASI MRI had demonstrated synovitis (enhancement ratio [ER] >1.55). Patients with TMJ pathology or pain unrelated to JIA or a history of facial trauma were excluded. The predictor variables were age, gender, JIA subtype, exposure to medications for arthritis, and a family history of autoimmune disease. The primary outcome variable was the ER. Additional outcome variables included patient-reported pain and the maximal incisal opening (MIO).

RESULTS

Twenty-nine subjects (83% female) with a total of 50 injected TMJs were included. The average age at JIA diagnosis and at IASI was 6.8 ± 1.7 years and 12.1 ± 1.9 years, respectively. The mean follow-up period was 22.9 ± 4.3 months (range 5 to 48). The ER decreased in all injected joints, with a mean reduction of 1.05 ± 1.01 (P < .001). The post-IASI ER was less than the normal threshold (1.55) in 18% of the injected TMJs. IASI was associated with an elimination of pain in 89% of the subjects (P < .001) and in augmentation of the MIO by 5.8 ± 2.6 mm (P < .001).

CONCLUSIONS

In children with JIA and TMJ synovitis, TMJ IASI was associated with a reduction in synovial enhancement, decreased pain, and an increased MIO. Only 18% of injected joints, however, experienced complete resolution of synovitis. These results support the use of IASI in the management of the pain and dysfunction associated with TMJ synovitis. Further study is required to determine the efficacy of IASI in limiting inflammation and future joint destruction.

Contemporary management of TMJ involvement in JIA patients and its orofacial consequences

Juvenile idiopathic arthritis is the most common chronic rheumatic condition during childhood. Temporomandibular joint arthritis is frequently asymptomatic. When it takes place during childhood, it may affect condylar growth; therefore, these children are at risk of unfavorable long-term outcomes from the associated joint damage. The etiology is not completely understood, but it is considered as multifactorial with both genetic and environmental factors involved.

The standardized examination and imaging protocols serve important purpose to diagnose temporomandibular joint (TMJ) arthritis not only to establish an early interventional strategy but also to assess craniofacial growth and the progression of signs and symptoms in those patients. Although the treatment of juvenile idiopathic arthritis (JIA) has changed dramatically over the last decades due to new therapeutic options, TMJ arthritis still can develop during the course of the disease. In clinical experience, TMJs appear to respond less well to the standard of care used to treat other joints. More individualized approach to the patient’s treatment serves as the main goal of personalized medicine. It could be achieved by adopting new methods of medical imaging such as conebeam computer tomography as well as developing reliable biomarkers which may assist with predicting disease type, course, or severity and predicting response to medication.

This article provides an overview of current information on orofacial complications in JIA and its management. Based on information provided in this review, more precise diagnosis, proper tools for recognizing people at risk, and more efficient treatment approaches could be implemented. This may lead to more personalized treatment management strategies of TMJ complications of JIA patients.

Juvenile arthritis: current concepts in terminology, etiopathogenesis, diagnosis, and management

The latest change in terminology from juvenile rheumatoid arthritis (JRA) to juvenile idiopathic arthritis (JIA), established by the International League of Associations for Rheumatology (ILAR), has resulted in some confusion for OMFS and other treating clinicians. JIA comprises a group of systemic inflammatory diseases that result in the destruction of hard and soft tissues in a single or multiple joints. In a significant number of patients, one or both temporomandibular joints (TMJ) are also involved. TMJ disease may be accompanied by pain, swelling, and limitation of motion, as well as mandibular retrognathism, open bite, and asymmetry. The purpose of this article is to provide a review, for the oral and maxillofacial surgeon, of the terminology, etiopathogenesis, diagnosis, and management of children with JIA.

Quantifying Synovial Enhancement of the Pediatric Temporomandibular Joint

PURPOSE

The purposes of this study were to assess a novel method for quantifying temporomandibular joint (TMJ) synovial enhancement on gadolinium-enhanced magnetic resonance imaging (MRI) and to establish normative values to allow early detection of synovitis.

MATERIALS AND METHODS

This is a retrospective cohort study of pediatric patients (aged 0 to 16 years) without jaw pathology who underwent MRI scans with contrast that included the TMJs. From a coronal T1-weighted image, the signal intensity within the superior and inferior joint spaces was divided by the signal intensity of the longus capitis muscle to establish a ratio by age. Intrarater reliability and inter-rater reliability were assessed. A mixed-model regression analysis was used to determine the 95% specificity threshold for normal ratios.

RESULTS

Temporal and optic nerve MRI scans of 158 patients were included. Normative synovial enhancement ratios (95% specificity) thresholds were established: 1.52, 1.68, and 1.55 for superior joint space, inferior joint space, and average of both joint spaces, respectively. Intrarater and inter-rater agreement was excellent.

CONCLUSIONS

A ratio of signal intensity of the TMJ synovium to the longus capitis is a reliable method to quantify enhancement controlling for time after contrast infusion and may be useful for diagnosis of TMJ synovitis.

Juvenile idiopathic arthritis and the temporomandibular joint: A comprehensive review

Juvenile idiopathic arthritis is the most common inflammatory rheumatic disease of childhood and represents a series of chronic inflammatory arthritides of unknown cause. Involvement of the temporomandibular joint has been reported in up to 87% of children with juvenile idiopathic arthritis when based on magnetic tomography imaging; it can be asymptomatic and may lead to severe long term complications. In this review a summary of the contemporary literature of imaging of the temporomandibular joint in children with juvenile idiopathic arthritis will be provided, including ultrasound which is a valuable method for guided joint injections, but does not necessarily allow detection of acute inflammation, cone beam computed tomography, which has emerged as a feasible and accurate low-dose alternative as compared to conventional computed tomography to detect destructive change, and magnetic resonance imaging which is considered the method of choice for assessing acute, inflammatory change, although the lack of normative standards remains a challenge in children.

Excess BMP Signaling in Heterotopic Cartilage Forming in Prg4-null TMJ Discs

Heterotopic cartilage develops in certain pathologic conditions, including those affecting the human temporomandibular joint (TMJ), but the underlying molecular mechanisms remain obscure. This is in part due to the fact that a reliable animal model of such TMJ diseases is not available. Here, we show that aberrant chondrocyte differentiation and ectopic cartilage formation occur spontaneously in proteoglycan 4 (Prg4) mutant TMJ discs without further invasive procedure. By 2 mo of age, mutant disc cells displayed chondrocyte transdifferentiation, accompanied by strong expression of cartilage master gene Sox9 and matrix genes aggrecan and type II collagen. By 6 mo, heterotopic cartilage had formed in the discs and expressed cartilage hypertrophic markers Runx2 and ColX. The ectopic tissue grew in size over time and exhibited regional mineralization by 12 mo. Bone morphogenetic protein (BMP) signaling was activated with the ectopic chondrogenic cells and chondrocytes, as indicated by phosphorylated Smad 1/5/8 nuclear staining and by elevated expression of Bmp2, Bmpr1b, Bmpr2, and BMP signaling target genes. Likewise, we found that upon treatment with recombinant human BMP 2 in high-density micromass culture, mutant disc cells differentiated into chondrocytes and synthesized cartilage matrix more robustly than control cells. Importantly, a specific kinase inhibitor of BMP receptors drastically attenuated chondrogenesis in recombinant human BMP 2-treated mutant disc cultures. Unexpectedly, we found that Prg4 was expressed at joint-associated sites, including disc/muscle insertion and muscle/bone interface, and all these structures were abnormal in Prg4 mutants. Our data indicate that Prg4 is needed for TMJ disc integrity and function and that its absence leads to ectopic chondrogenesis and cartilage formation in conjunction with abnormal BMP signaling. Our findings imply that the BMP signaling pathway could be a potential therapeutic target for prevention or inhibition of ectopic cartilage formation in TMJ disease.

Therapy. Intra-articular steroids for TMJ arthritis--caution needed

In the past decade, the consequences of temporomandibular joint arthritis in patients with juvenile idiopathic arthritis have received increasing attention. Intra-articular corticosteroid injections have been suggested as a treatment option, but concerns that this treatment could reduce mandibular growth have been raised and are supported by new data published in The Journal of Rheumatology.

Magnetic Resonance Imaging Assessment of Temporomandibular Joint Involvement and Mandibular Growth Following Corticosteroid Injection in Juvenile Idiopathic Arthritis

OBJECTIVE

To assess whether intraarticular corticosteroid injection (CSI) reduces inflammation of the temporomandibular joint (TMJ), prevents growth disturbances of the mandibular condyle, and restores normal growth of the mandibular ramus.

METHODS

Retrospective longitudinal magnetic resonance imaging (MRI) evaluation of inflammatory activity, TMJ deformity, and mandibular ramus height in 33 children (23 girls, median age 5.2 yrs) over a median period of 5 years following repetitive CSI to the TMJ.

RESULTS

Intraarticular location of CSI led to inflammatory grade improvement in 53% at first MRI followup compared to 20% with extraarticular location (p = 0.005), with more improvement of the mean inflammatory grade after intraarticular CSI (p = 0.001). Rate of osseous deformities of the TMJ deteriorated from 51% at study inclusion to 62% at end of observation period, with progression to severe condylar destruction in 26% of joints including 24% with development of intraarticular calcifications/ossifications. Mean short-term growth rates of the mandibular ramus were negative for intraarticular CSI while positive for extraarticular CSI (p = 0.036). Mean longterm mandibular ramus growth rate (0.7 ± 0.8 mm/yr) after CSI was significantly lower than reported normal mean age- and sex-matched growth rate (1.4 ± 0.1 mm/yr, p < 0.0001).

CONCLUSION

Despite improving the inflammatory activity as seen on MRI, repetitive CSI to the TMJ does not reach the treatment goals to prevent progressive osseous deformation and to normalize mandibular ramus growth in children with juvenile idiopathic arthritis.

Soft tissue ossification and condylar cartilage degeneration following TMJ disc perforation in a rabbit pilot study

OBJECTIVE

There are limited clinical treatments for temporomandibular joint (TMJ) pathologies, including degenerative disease, disc perforation and heterotopic ossification (HO). One barrier hindering the development of new therapies is that animal models recapitulating TMJ diseases are poorly established. The objective of this study was to develop an animal model for TMJ cartilage degeneration and disc pathology, including disc perforation and soft tissue HO.

METHODS

New Zealand white rabbits (n = 9 rabbits) underwent unilateral TMJ disc perforation surgery and sham surgery on the contralateral side. A 2.5 mm defect was created using a punch biopsy in rabbit TMJ disc. The TMJ condyles and discs were evaluated macroscopically and histologically after 4, 8 and 12 weeks. Condyles were blindly scored by four independent observers using OARSI recommendations for macroscopic and histopathological scoring of osteoarthritis (OA) in rabbit tissues.

RESULTS

Histological evidence of TMJ condylar cartilage degeneration was apparent in experimental condyles following disc perforation relative to sham controls after 4 and 8 weeks, including surface fissures and loss of Safranin O staining. At 12 weeks, OARSI scores indicated experimental condylar cartilage erosion into the subchondral bone. Most strikingly, HO occurred within the TMJ disc upon perforation injury in six rabbits after 8 and 12 weeks.

CONCLUSION

We report for the first time a rabbit TMJ injury model that demonstrates condylar cartilage degeneration and disc ossification, which is indispensible for testing the efficacy of potential TMJ therapies.

Imaging of the temporomandibular joint in juvenile idiopathic arthritis

OBJECTIVE

Temporomandibular joint (TMJ) arthritis in children with juvenile idiopathic arthritis (JIA) is extremely common but frequently asymptomatic. Magnetic resonance imaging (MRI) with contrast remains the gold standard for identifying TMJ arthritis in JIA. A reliable scoring system with published MRI examples of typical acute and chronic TMJ arthritis changes will be invaluable for future prospective treatment trials of TMJ arthritis in JIA.

METHODS

MRIs were collected from routine clinical studies assessing TMJ arthritis in JIA. Representative images were selected for publication to depict acute (synovial fluid, bone marrow edema, and synovial enhancement) and chronic (pannus, disc derangement, and condylar head flattening and erosions) TMJ arthritis findings. A preliminary MRI-based scoring system for assessing degrees of acute and chronic TMJ arthritis was developed and tested for inter- and intrareader reliability.

RESULTS

TMJ MRIs representative of acute and chronic TMJ arthritis in JIA were selected from among thousands taken (>500 TMJ MRI studies annually at Children's of Alabama) since September 2007. Moreover, computed tomography scans depicting select bony changes (osteophyte formation, micrognathia) were chosen for publication. A description of the MRI protocol for assessing TMJ arthritis is included. A preliminary scoring system weighted for degree of acute and chronic TMJ arthritis MRI findings was found to have substantial inter- and intrareader reliability.

CONCLUSION

A published set of MRIs depicting representative acute and chronic changes will help establish a standardized scoring system to assess TMJ arthritis in children with JIA. Future validation will aid in assessing improvement during treatment trials of TMJ arthritis.

Intra-articular steroid injection for temporomandibular joint arthritis in juvenile idiopathic arthritis: A systematic review on efficacy and safety

OBJECTIVE

To determine the current level of evidence for the use of intra-articular corticosteroid injections (IACI) against temporomandibular joint (TMJ) arthritis in patients with juvenile idiopathic arthritis (JIA) with a particular focus on clinical and radiological improvements and safety profile.

METHODS

A comprehensive electronic search strategy was performed in all major medical databases in February 2012. Studies were selected independently by two reviewers in accordance with a pre-specified protocol and a risk of bias assessment for all included studies.

RESULTS

Ninety-four unique citations were identified of which seven remained after the inclusion criteria were applied and all of these were assessed to have a high risk of bias. The current limited level of evidence suggests potential beneficial properties of IACI in patients with TMJ arthritis-related symptoms and/or MRI-verified signs of TMJ inflammation. Currently, no scientific evidence substantiates the effect of IACI in terms of (I) improving maximal mouth opening capacity significantly, (II) reducing radiological disease progression, (III) normalising/improving mandibular growth, and (IV) increasing efficacy upon repeated injections.

CONCLUSION

The current level of evidence allows only very limited conclusions on the effect of IACI therapy in patients with TMJ arthritis. Knowledge on the long-term impact of IACI on mandibular growth is not available. Future studies designed in accordance with evidence-based standards are needed to allow a more general conclusion on efficacy and safety of this treatment modality in patients with TMJ arthritis.