Abstract
The incidence of approximal caries in the deciduous molars in which no approximal caries were detected by inspection and probing, was investigated using the bitewing dental X-ray. The comparison was made between the two groups which were classified according to the severity of the occlusal caries. The low incidence group consisted of no caries and the degree of C1 on the occlusal surface and the high incidence group consisted of the degrees of C2-C3 on the occlusal surface.2The difference of the incidence in proximal caries was statistically examined between the right and left sides, upper and lower jaws, and examined as to whether or not the approximal caries will be more frequently and deeply affected in the high incidence group of occlusal caries than in the low incidence group. The results were as follows:21) There was no significant difference between the right and left side in the incidence of approximal dental caries.22) When we compared the incidence of approximal caries between the upper and lower jaw, the higher incidence was found on the distal surface of the 1st deciduous molar and the mesial surface of the 2nd deciduous molar in the lower jaw.23) The higher incidence group in regard to occlusal caries showed the higher incidence of approximal caries on the distal surface of the 1st deciduous molar and the mesial surface of the 2nd deciduous molar in both jaws in comparison with the low incidence group.24) There was no significant trend towards deeper caries in the approximal surface in relation to the severity of occlusal caries.
