Abstract
Objective. To propose multidisciplinary, consensus-based, standardization of operational terminology and method of assessment for temporomandibular joint (TMJ) involvement in juvenile idiopathic arthritis (JIA).
Methods. Using a sequential expert group–defined terminology and methods-of-assessment approach by (1) establishment of task force, (2) item generation, (3) working group consensus, (4) external expert content validity testing, and (5) multidisciplinary group of experts final Delphi survey consensus.
Results. Seven standardized operational terms were defined: TMJ arthritis, TMJ involvement, TMJ arthritis management, dentofacial deformity, TMJ deformity, TMJ symptoms, and TMJ dysfunction.
Conclusion. Definition of 7 operational standardized terms provides an optimal platform for communication across healthcare providers involved in JIA-TMJ arthritis management.
Temporomandibular joint (TMJ) arthritis is common in juvenile idiopathic arthritis (JIA)1,2. TMJ arthritis may impair joint mobility and masticatory function, cause TMJ degeneration, lead to reduced dentofacial growth, create orofacial pain, and affect general quality of life3,4,5,6,7,8. Treatment is complex and multidisciplinary, involving pediatric rheumatologists, maxillofacial surgeons, orthodontists, radiologists, pediatric dentists, occupational and physiotherapists, and orofacial pain specialists9.
Research in TMJ arthritis has increased exponentially over the last decade. As this field has grown, so has confusion over terminology. Recent systematic reviews have highlighted the need for a standardized set of JIA-associated TMJ arthritis definitions6,7,8. Standardization is critical to enhance research comparability and care provider communication.
The objectives of our study were to use a consensus-based approach to propose the following: (1) a standardized terminology for JIA-associated TMJ arthritis; and (2) methods of assessment of TMJ arthritis in patients with JIA.
MATERIALS AND METHODS
This study was conducted using a series of sequential iterations including the following: (1) establishment of task force and item generation; (2) working group consensus meeting and drafting of provisional recommendations; (3) content validity testing of provisional recommendations by external experts; and (4) Delphi survey to reach final consensus (Figure 1).
Flowchart of consensus process. * Response rate. TMJaw: Temporomandibular joint Juvenile Arthritis Working Group.
Task force assembly, item generation, consensus meeting
The task force was assembled with members of the TMJ Juvenile Arthritis Working group (TMJaw; formerly known as euroTMjoint research network), an international, multidisciplinary, open group studying TMJ arthritis in JIA, and includes researchers from all specialties involved in JIA-related TMJ arthritis management. Members of the terminology task force were identified based on clinical experience and scientific contributions. The task force included 1 pediatric rheumatologist (MT), 2 oral maxillofacial surgeons (SA, CR), and 2 orthodontists (TKP, PS), and represents 1 European and 3 North American centers.
For item generation, the task force identified TMJ arthritis–related terms used in existing JIA literature7,8. In February 2017, those terms were distributed to all members of TMJaw by e-mail, with an invitation to participate in an online questionnaire. The participants were asked to report their understanding of these terms and the role of different specialties involved in TMJ arthritis management.
Based on the results of the online questionnaire, the terminology task force generated 6 provisional terms for discussion at the TMJaw meeting in Rostock, Germany, in March 2017. The provisional terms were adjusted and definitions for each term were established based on consensus from the group.
Test of face validity
In April 2017, 16 external experts were invited to assess the validity of the provisional terms and definitions generated at the Rostock consensus meeting. The external experts were identified based on TMJ arthritis clinical expertise and scientific merit. The external experts were asked to assess validity, suggest improvements, and address redundancies for the provisional terms. The task force then adjusted the provisional terms and definitions accordingly.
Delphi survey
In September 2017, participants from the Rostock consensus meeting (n = 18) and external experts (n = 16) were invited to participate in an online Delphi survey to assess agreement with the provisional terms. Participants were asked to respond to each term and definition with “agree,” “agree with minor changes,” or “do not agree.” Participants were also asked to suggest improvements to the terms and definitions, and to define methods of assessment for each term from the following options: (1) contrast-enhanced magnetic resonance imaging (MRI); (2) MRI without contrast; (3) 3-D imaging [e.g., computed tomography (CT) or cone-beam CT]; (4) conventional radiology (e.g., cephalograms and panoramic radiographs); (5) ultrasonography; (6) clinical examination; (7) patient-reported outcomes; and (8) other (e.g., 3-D photographs and scintigraphy). Participants could select multiple options.
The provisional terms and definitions were adjusted based on the results of this Delphi survey. These results were provided to participants before initiation of the next iteration in December 2017. In this final Delphi round, participants could “agree” or “disagree” with each term and definition. Only terms and definitions that received “agreement” by > 80% of participants were included in the final recommendations. The results were summarized, and final consensus was reached in February 2018.
RESULTS
Thirty experts participated in the final Delphi survey (Figure 1). The following specialties were represented: pediatric rheumatology (n = 10), maxillofacial surgery (n = 5), orthodontics (n = 8), pediatric dentistry (n = 3), radiology (n = 3), and orofacial pain (n = 1). Based on results of the first round of the Delphi survey, the number of terms was expanded from 6 to 7; the term TMJ disability was divided into TMJ symptoms and TMJ dysfunction. All 7 provisional terms received a Delphi survey agreement score > 80% (Table 1).
Recommended standardized operational terminology, definitions, and agreement with definitions in patients with JIA.
TMJ arthritis
Arthritis is defined as “inflammation in a joint.” The term TMJ arthritis, therefore, is intended to indicate the presence of active TMJ inflammation, and is independent of signs and symptoms; hence it can be present with or without any signs or symptoms. To add the qualifier “active” to the definition was considered redundant by some, but this word was ultimately included to highlight the strict characteristics of the term, which refers only to inflammation and not joint damage per se. The term chronic TMJ arthritis has been used in literature, but the task force recommends avoiding it because of imprecision, and chronic but not active TMJ arthritis falls under the term TMJ involvement.
Contrast-enhanced MRI is the current method for assessment of active inflammation in TMJ arthritis7. Other methods (e.g., clinical examination and patient reporting) may suggest the presence of TMJ arthritis but cannot confirm the presence of inflammation. Contrast-enhanced MRI was the only method of assessment that received a recommendation score > 80%. A recently published MRI scoring system is recommended10,11.
TMJ involvement and TMJ arthritis management
TMJ involvement is defined as “abnormalities presumed to be the result of TMJ arthritis.” This term is less restrictive than TMJ arthritis. The presence of active TMJ inflammation (TMJ arthritis) is not a prerequisite for TMJ involvement, but TMJ arthritis implies the presence of TMJ involvement. The term TMJ involvement is intended for the following: (1) clinical situations in which no contrast-enhanced MRI verification of active TMJ inflammation has occurred but where signs, symptoms, and/or radiological findings suggest the presence of actual or former TMJ arthritis; (2) patients with no current MRI evidence of active TMJ inflammation (TMJ arthritis) but with abnormalities indicating previous TMJ arthritis. Once the TMJ has been inflamed, it is prospectively considered “involved” regardless of the current inflammatory state.
By definition, TMJ arthritis management embraces diagnosis, treatment, and monitoring of TMJ arthritis and involvement. Methods of assessment include contrast-enhanced MRI, 3-D imaging, clinical examination, and patient-reported outcomes.
Dentofacial deformity and TMJ deformity
Dentofacial deformity refers to growth deviation that occurs as a result of TMJ arthritis in patients with JIA. Growth deviation may affect the morphology and position of the mandible, maxilla, and/or dental occlusion12,13. The recommended assessment of dentofacial deformity includes 3-D imaging, conventional radiography, clinical examination, and photographs. Recent recommendations are available13.
TMJ deformity indicates arthritis-related alteration of the anatomy of the TMJ. This term does not cover signs and symptoms (which are considered in another term, TMJ dysfunction), but rather is limited to anatomic deformities. Conventional radiographs and 3-D imaging are used to assess osseous TMJ deformities, with the caveat that soft tissue changes, which are often present in TMJ deformities, will not be visible with these imaging techniques but would require MRI evaluation.
TMJ symptoms and TMJ dysfunction
TMJ symptoms refers to patient/parent-reported measures. In contrast, the term TMJ dysfunction addresses clinical examination signs of abnormal mandibular function believed to be related to TMJ involvement. Recent recommendations for clinical orofacial examination in JIA are available8. The final recommendations for standardized terminology and definitions are presented in Table 1. The final recommendations for methods of assessment are shown in Table 2.
Standardized terminology and method of assessment in patients with juvenile idiopathic arthritis.
DISCUSSION
In our study, the TMJaw group has described and defined the most common terms used in TMJ arthritis research and is uniquely positioned to provide these recommendations for standardization of terminology representing multiple specialties and many North American and European TMJ arthritis research centers. Consensus-based standardization of terminology provides an optimal platform for communication across healthcare providers involved in research and management of TMJ arthritis in JIA. An important qualifier is that these terms apply only to patients with JIA. It must be noted that TMJ symptoms and/or TMJ dysfunction may not be directly attributable to JIA, as in a patient with myofascial pain disorder. To date, no reliable diagnostic method exists to distinguish between JIA-related orofacial symptoms/dysfunction and similar findings due to other etiologies. This project did not intend to define terms applicable to other temporomandibular dysfunction; further studies are required.
Additionally, the methods of assessment that received recommendation scores > 80% represent the most frequent diagnostic measures used to assess each term and serve as a guide. Methods of assessment with a recommendation score < 80% should not be discounted, however, because they may still be useful in special clinical scenarios.
The unequal numbers of participating experts representing different specialties may be a limitation to our study; however, we are convinced that it strengthens the recommendations that so many different experts agree on the proposed standardized terminology.
We encourage investigators and clinicians to use the recommended terms and definitions in future publications as a reference standard. We suggest including the following text: “terminology adheres to JIA-TMJaw consensus-based standardized terminology.”
Acknowledgment
We acknowledge Drs. Bernd Koos, Rotraud Saurenman, Tore A. Larheim, Nikolay Tzaribachev, Severine Cuillaume-Czitrom, and Zane Krisjane for their contribution to this project.
- Accepted for publication September 24, 2018.
