Two thousand-two hundred-forty-three cases of various lesions of the oral and maxillofacial region in children under 16 years of age were reviewed. The lesions were classified by 10 groups; osteomyelitis, cysts, benign tumors, malignant tumors, fibro-osseous lesions, developmental disturbances, antral lesions, TMJ lesions, salivary gland lesions, and other lesions. The obtained results were as follows; 1. Developmental disturbances, especially cleft alveolus and palate, was the most common lesions (25.7％), followed by cysts (22.5％), antral lesions (12.7％), benign tumors (11.9％) and osteomyelitis (9.3％). 2. With the time, the incidence of osteomyelitis and malignant tumors has been decreased, but that of developmental disturbances, cysts and antral lesions has been increased. 3. The sex distribution was relatively equal for the entire series, with male predominence in cysts, malignant tumors, developmental disturbanes and salivary gland lesions and with female predominence in TMJ lesions. 4. Children with malignant tumors and osteomyelitis were somewhat younger and those with TMJ lesions were somewhat older. 5. Heading the list of each group except osteomyelitis was dentigerous cyst, odontoma, malignant lymphoma, fibrous dysplasia, cleft alveolus and palate, inflammatory change, degenerative change of condylar process, sialolithiasis and simple bone cyst respectively.