SOME CHARACTERISTICS OF CARIES ON THE PROXIMAL SURFACES OF THE TEETH

¹ Department of Medicine, University of Texas School of Dentistry, Houston, Tex.

From a study of 20,816 proximal surfaces of teeth from mixed and permanent dentitions, of which 9,018 showed evidence of various attack, it was found that:

1. The pattern of proximal caries attacks on individual teeth displayed a striking measure of bilateral symmetry for the aggregate experience of whole groups of cases, but that this bilateral symmetry of the total proximal caries pattern was seldom encountered in individual cases.

2. (a) There was high correlation between total maxillary and total mandibular proximal caries incidence in posterior teeth of individual cases. (b) In the presence of maxillary anterior proximal caries, there was a significant correlation between its total frequency and that for all posterior surfaces in individuals. Absence of maxillary anterior proximal caries was not, however, associated with any particular level of posterior proximal caries. (c) Presence or absence of mandibular anterior proximal caries showed no significant interregional correlations.

3. Approximation of surfaces was obviously a factor in proximal caries incidence, and a consistently high percentage of proximal attacks occurred as adjacent pairs of approximated attacks.

4. No clear picture emerged related to age or sex factors.

5. There are important difficulties to be overcome in selecting a basis for assessment of proximal surfaces as various, under such circumstances as when teeth are missing or have been lost from the dentition.

6. By study of the total and incremental patterns of proximal carious attack, it was possible to rank the various proximal surfaces according to their relative caries susceptibility.

7. Essentially similar patterns of tooth susceptibility were characteristic in both slowly and rapidly developing carious attack on proximal surfaces.

8. Simple spot proximal fillings appeared to have become defective with five times the frequency of conventional occlusal-proximal two-surface restorations.