Effect of Juvenile Idiopathic Arthritis on the Temporomandibular Joint and Occlusion in Children and Young Adolescents: A Descriptive Cross-sectional Study

Juvenile Idiopathic Arthritis (JIA) is a chronic rheumatic disease, with a prevalence of 1 in 1000 children under the age of 16 years. The clinical symptoms include inflammation of joints, swelling of synovial membrane resulting in growth disturbances and loss of bone density. Aim: To assess the effect of JIA on the development of Temporomandibular Joint (TMJ) and occlusion in children and young adolescents in the age group of 8-16 years and to evaluate the effect of TMJ arthritis on the growth of maxilla and mandible. Materials and Methods: This is a descriptive cross-sectional study with a study and control group. A total of 44 children with JIA attending the Department of Rheumatology, Nizam Institute of Medical Sciences (NIMS), within the age group of 8-16 years were screened and enrolled in study from May-July 2014. A gender and sex-matched healthy control group were enrolled from Paediatric Dentistry outpatient specialty. For the measurement and comparison of arch perimeters of mandible and maxilla, the JIA and control group were divided into sub-groups 1 (8-10 y), 2 (11-13 y), and 3 (14-16 y). All the parameters were recorded and subjected to statistical analysis. An Independent sample t-test was used to find a significant difference for maxillary and mandibular arch perimeters among both the groups. Chi-square test was used to know the difference for TMJ parameters, occlusion and occlusal abnormalities. The level of significance was set at p<0.05 for all tests. Results: Children in the JIA group had reported TMJ pain on movement (40.9%), clicking sounds (36.4%), and dislocation (22.7%). Angle’s class II malocclusion was seen in 36.4% compared to the control group (4.5%). The mean arch perimeter of the mandible was significantly less among JIA children in subgroups 2 (73.00±3.03 mm), and 3 (71.77±6.27 mm) when compared to healthy controls. Other occlusal abnormalities such as increased overjet (34.1%), decreased overbite (31.8%), and crowding (54.5%) were reported in significant percentages compared to healthy controls. Conclusion: The mean arch perimeter of the mandible in the JIA group is less when compared to children of the same age in the control group. There is increased predilection of developing Angle’s class II Malocclusion in the JIA group. From a paediatric dentist perspective, it’s important to understand the overall impact of JIA on stomatognathic system, and an early intervention is recommended.