In school dentistry it is important to understand the incidence of dental caries and the level of treatment and to discover problems in dental care. A dental survey of 458, 040 school children of elementary and junior high schools in Kanagawa Prefecture was made in 1969, and the results were as follows.
1. The DMF possesor rate in elementary school children was generally higher in higher grade children and in females. The DMF possesor rate in junior high school children was also higher in females.
2. The Mean number of DMF teeth per person in elementary school children generally showed a linear increase from lower to higher grades, and it was greater in females and in central geographicol areas. In junior high school children it was greater in females. and in outlying area.
3. The rate of treated teeth in elementary school children generally showed a rapid increase with grade in the first, second, third and fourth grade children, and a slow increase thereafter.
The rate in junior higher school children was higher in females and in central areas.
4. The possesor rate of untreated teeth in elementary school children generally showed an increase with grade; in the three lower grades it showed a rapid increase and a slow one thereafter. The rate in junior high school children also showed a general increase with grade. And it was higher in outlying than in central areas.