Purpose: To investigate the prevalence of osteoarthritic changes and condylar positioning of the temporomandibular joint (TMJ) in Korean children and adolescents with or without temporomandibular disorders (TMDs). Materials and Methods: A total of 101 asymptomatic and 181 symptomatic children and adolescents aged 10 to 18 years old were included in the study. Osteoarthritic changes such as flattening, sclerosis, osteophytes, or erosion, and the parasagittal positioning of the condyle were assessed using cone-beam computed tomography (CBCT) images. Results: The overall prevalence of osteoarthritic changes was higher in symptomatic (26.8%) than in asymptomatic adolescents (9.9%) (p<0.05). In the symptomatic group, the frequency was higher in males (33.3%) than in females (23.0%) (p<0.05). Erosion was the most common change for the symptomatic group (15.6%), whereas sclerosis was the most common change for the asymptomatic group (5.4%). Posterior condylar position was more frequently observed in the symptomatic group (p<0.05). Erosion was more common in the samples with TMJ pain or mouth opening limitations as compared to those without them (p<0.05). Conclusion: This study showed that osteoarthritic changes in TMJ were common in children and adolescents, with a much higher prevalence in symptomatic patients.