Edition V14N05 | Year 2015 | Editorial TMD and Orofacial Pain | Pages 20 to 23
Juvenile idiopathic arthritis (JIA) is the name given to an heterogeneous group of inflammatory chronic diseases which have chronic arthritis in common and affect approximately 1 in a group of 1,000 children not older than 16 years of age. It is the most common chronic pediatric rheumatologic disease.1 JIA is groups in at least six subgroups, according to the International League Against Rheumatism (ILAR). Major JIA subtypes are: systemic (inflammation in any number of joints), polyarticular (inflammation in five or more of joints) and oligoarticular (inflammation in four or fewer joints).2 A few subtypes present with articular cartilage severe destruction, which might lead to severe decreased functional ability within a short period of time. Nevertheless, a few other subtypes, as it is the case of the oligoarticular one, even in more severe cases, might present with minimal or nonexistent arthralgia. The etiology of JIA is not yet fully understood; however, it is believed it might be triggered in genetically predisposed children under psychological stress, hormonal changes, articular trauma and viral or bacterial infection.