The developmental change in the occlusal contacts is one of the very important aspects, involved in clarifying the development of occlusal functions in children.
The purpose of this study was to improve the procedure for measuring the number of the occlusal contacts, the occlusal contact area, and the extent of occlusal force in growing children.
Pressure detecting sheets called “Occlusal Prescale” are produced by Fuji Photo Film Co.. The device to measure this consisted of light source, stereomicroscope, T. V. camera, image analyzer with 256 grades of density, and main computer.
To improve the accuracy for measuring the several variables related to the occlusal contacts, the following results were found to be important:
1. Measurement should be started at least 60 minutes after the devices were switched on.
2. The transmitted light, cross type, was the best way of illuminating the specimen.
3. The occlusal prescale should be laid at the center of the measuring field.
4. The third degree polynominal regression equation was the most useful califor estimating the pressure from the color density of occlusal prescales.
5. An attention was paid to the conditions at collection, preservation, and measurement of occlusal prescales. The coefficients of variation for the multiple measurements on the identical specimens under the above conditions were not more than 0.002 for the occlusal contact area and the degree of occlusal force. The occlusal contact area and the degree of the occlusal force were repeatedly measured on the samples consisting of three adults and three children to estimate the reproducibility. The coefficients of variation for both variables were not more than 0.08 in both the adult and child subjects. It could be stated that the measuring system of the occlusal contacts developed in this study might be useful enough to be applied in children.