Objectives: To estimate the cumulative incidence of arthritis-induced orofacial symptoms, dysfunctions, and dentofacial deformities in growing individuals with juvenile idiopathic arthritis (JIA) in a 36 month regional cohort study, and to identify predictors for the development of arthritis-induced dentofacial deformities.Methods: Data was retrieved from the Aarhus JIA TMJ cohort register, which contains standardized, longitudinal, observational data regarding orofacial conditions in patients with JIA (n=1040). This regional cohort represents the majority of all subjects with JIA from the western part of Denmark between 1990 and 2016, regardless of temporomandibular joint (TMJ) arthritis status. Cumulative incidences of orofacial conditions were reported using Kaplan-Meier methods and predictors for dentofacial deformity was identified using Cox proportional hazard analysis.Results: Follow-up data from 351 subjects over thirty-six months was included in this study.Median age at first clinical examination was 6.6 years (25/75 centiles: 4.9 and 9.9 years).Orofacial symptoms and dysfunction were common findings at 36 months after the first clinical examination and approximately five years after JIA onset, with a cumulative incidence of 38% and 53%, respectively. Dentofacial deformities were found in 35% of