BILATERAL SYMMETRY OF DENTAL CARIES

¹ Naval Medical Research Institute, Bethesda, Md.

1. When the caries experience for each groove is sumed up over all the individuals of a group, a high degree of association has been found between the bilaterally paired grooves of the molar teeth of the white rats in this study. In the individual case, however, the degree of bilateral symmetry is subject to great variation.

2. In approximately 75 per cent of the cases, the condition of caries or noncaries in one of the bilaterally paired grooves will be duplicated in the other member of the pair.

3. The average incidence of caries varies from groove to groove and appears to be related to groove position.

4. An appreciable degree of asymmetry exists which would materially affect any conclusions of experiments based upon the hypothesis of perfect symmetry.

5. A method has been demonstrated by means of which it is possible to determine the degree of symmetry present between bilaterally paired grooves.

6. Incidental findings show sex differences existing in caries incidence. Bilateral quadrant differences between the maxilla and mandible were obscured by summation of total caries incidence without regard to groove.