Clinico-statistical observation was performed on the dental surgery in the Pedodontic Clinic of Niigata University Dental Hospital during the period from August 1979 to September 1989. 1. The number of surgical operations amounted to 656 cases (males 384 and female 272) and the highest age incidence was in the 6-8 year old range. 2. The incidence of the impacted teeth (62.8%) and the abnormality of the frenum (22.8%) occupied over 85% of all the cases. 3. Based on sex, the impacted supernumerary teeth and the abnormality of the buccal frenum, odotoma were more frequent in males, while the abnormality of the upper frenum and the mucous cysts were more frequent in females. 4. About 40% of the operative patients accepted were introduced from other medical institutions. 5. Regarding the methods of surgery, the impacted permanent teeth were frequent revealed by surgical exposure, while the diseases of salivary glands were revealed by extirpation. The benign tumors were removed by extirpation, the diseases of soft tissues by excision, cysts in the jaws were all surgically removed by marsupialization. 6. In regard to the age at the time of the operation, the abnormal frenum were often seen under 4 years of age but large increases were found in the impacted teeth from 4 to 8 years of age. The diseases of salivary glands and of soft tissues were seen more frequently under 10 years of age, and cysts in the jaws were noted after 7 years of age. 7. Children undergoing surgery who suffered from general diseases amounted to 31 cases and were found most commonly in cases of nervous mental diseases.(ABSTRACT TRUNCATED AT 250 WORDS)