Magnetic resonance imaging assessment of juvenile idiopathic arthritis using OMERACT and EuroTMjoint classifications

Developing standards for MRI evaluation of joints in children with juvenile idiopathic arthritis utilizing the temporomandibular joint as a model

The treatment of a patient with juvenile idiopathic arthritis (JIA) is best monitored with standardized and validated tools to measure joint changes over time. Treatment approaches are best indicated if the clinicians are aware of the structural status of the joint at a given time, especially in anatomically deep joints for which clinical assessment is limited. Magnetic resonance imaging (MRI) is of utmost importance for assessment of deep joints and extra-articular soft tissue of the entire body for which ultrasound may be suboptimal. Because the distinction between pathologic and physiologic joint changes on MRI is key for proper diagnosis and treatment of patients with arthropathies, a comprehensive standardized approach is needed to effectively measure outcomes of growing joints of children with JIA. Such an approach is essential for both clinical assessment and to conduct clinical trials in patients with JIA treated in different centers around the world. To meet this need, several international imaging collaborative research groups have been developing MRI scales over the past years, including the MRI in JIA (JAMRI) special interest group within the Outcome Measures in Rheumatology (OMERACT) research network. This manuscript reviews the efforts of the OMERACT JAMRI working group to generate and validate pediatric MRI scoring systems for different joints in children with JIA that can have ubiquitous utilization anywhere in the world. In particular, it describes the different steps of development and validation of an MRI scale using the TMJ as a model.

Management of temporomandibular joint arthritis in children and adolescents: An introduction for orthodontists

Juvenile idiopathic arthritis (JIA) is the most common inflammatory rheumatic disease of childhood. JIA can affect any joint and the temporomandibular joint (TMJ) is one of the joints most frequently involved. TMJ arthritis impacts mandibular growth and development and can result in skeletal deformity (convex profile and facial asymmetry), and malocclusion. Furthermore, when TMJs are affected, patients may present with pain at joint and masticatory muscles and dysfunction with crepitus and limited jaw movement. This review aims to describe the role of orthodontists in the management of patients with JIA and TMJ involvement. This article is an overview of evidence for the diagnosis and treatment of patients with JIA and TMJ involvement. Screening for the orofacial manifestation of JIA is important for orthodontists to identify TMJ involvement and related dentofacial deformity. The treatment protocol of JIA with TMJ involvement requires an interdisciplinary collaboration including orthopaedic/orthodontic treatment and surgical interventions for the management of growth disturbances. Orthodontists are also involved in the management of orofacial signs and symptoms; behavioural therapy, physiotherapy and occlusal splints are the suggested treatments. Patients with TMJ arthritis require specific expertise from an interdisciplinary team with members knowledgeable in JIA care. Since disorders of mandibular growth often appear during childhood, the orthodontist could be the first clinician to see the patient and can play a crucial role in the diagnosis and management of JIA patients with TMJ involvement.

MRI of the temporomandibular joint in children with juvenile idiopathic arthritis: protocol and findings

Contrast-enhanced magnetic resonance imaging (MRI) is the technique of choice for diagnosis and monitoring of temporomandibular joint (TMJ) disorders in patients with juvenile idiopathic arthritis (JIA), as it is able to visualize both soft tissue and osteochondral changes. Approximately 40% of children with JIA develop inflammatory and chronic osteochondral changes observable on imaging, which if left untreated can lead to significant facial growth impairment, including facial asymmetry and retrognathia. MRI of the TMJ plays a paramount role in diagnosis and treatment monitoring in JIA since early signs of TMJ involvement are difficult to detect clinically and with physical examination. Findings of TMJ arthritis may be classified into acute and chronic domains. Early or acute manifestations include joint effusion, bone marrow edema, synovial thickening, and increased joint enhancement. With disease progression, there are characteristic osteochondral changes, including deformity of the mandibular condyle with shortening of the mandibular ramus, bone erosions, and disk abnormalities. In this pictorial essay, we describe a consensus MRI protocol for the study of the TMJ and illustrate the degree of normal and pathological MRI findings using currently available MRI scoring systems of the TMJ developed for JIA.