DOES A SECULAR TREND EXIST IN THE DISTRIBUTION OF OCCLUSAL PATTERNS

The existence of a secular trend in the distribution of occlusal patte rns was studied in two generations of children. Study models and demog raphic data of a sample of 265 childen from the previous generation (g roup A) and recordings of clinical examinations of 988 children from t he present generation (group B) served as the data base for this study . Children in whom caries affected the occlusion and those in the deci duous dentition stage were excluded. Thus, occlusal analysis was perfo rmed for 102 children in group A and 703 in group B. A dramatic decrea se was found in the prevalence of caries affecting the occlusion. No d ifference existed between the two groups with respect to molar and can ine anteroposterior relationships. However, there was a decrease in th e prevalence of normal occlusion accompanied by an increase of Class I malocclusion.