Temporomandibular joint disorders (TMDs) can occur at any age, including childhood and adolescence, and pain-related TMDs can affect growth and quality of life. In the present study, recent trends in the diagnosis and treatment of TMDs in children and adolescents were analyzed over a 10-year period. Using 10 years of data from the Health Insurance Review and Assessment Service (HIRA) and Jeonbuk National University (JBNU) Dental Hospital, patients between 0 and 19 years of age diagnosed with K07.6 (temporomandibular joint disorders) were analyzed by 5-year bins. Both datasets indicated a higher prevalence in females (1.2-fold in HIRA, 1.5-fold in JBNU) and in ages 15 to 19 years (72.1% in HIRA, 74.7% in JBNU). HIRA reported a 42.3% increase in prevalence per 100,000 people, from 651.4 in 2011 to 927.0 in 2020. JBNU reported K07.66 (masticatory muscle disorders) as the most common diagnosis in subjects under 10 years of age and K07.60 (internal derangement of temporomandibular joint) in those over 10 years of age. In addition, both were treated mainly by a combination of physical therapy and medication, and the treatment rate increased in accordance with age. Because TMDs can affect various structures in the orofacial region and cause pain that tends to differ with age, an early and specific diagnosis appropriate for age is important for treatment. Therefore, pediatric dentists need to promptly recognize TMDs in children and adolescents and consult with specialists as the prevalence increases.