Improved nutrition, disease and environments have generated substantial change in human body over recent centuries. Occlusal pattern also follows secular trend. The earlier studies found the tooth sizes and dental arch dimensions reduction, which can be defined as the new trend in Thai population.
Objectives:
The purposes of this study were to determine the dental arch dimensions and tooth size in patients born in the 1970s and the 1990s, and to compare the dental arch dimensions and tooth sizes between two generations.
Methods:
The 142 dental casts of the patients from the Department of Orthodontics at Mahidol University were selected. The dental arch dimensions were measured to the nearest 0.01 millimeter with digital sliding calipers. The difference in dental arch dimensions and tooth sizes of the patients who born in the 1970s and the 1990s was analyzed by using T-test (P < .05).
Results:
There were significant differences in the dental arch depth and dental arch length between the two subjects at the 95% confidence level (P<.05). Although, significant differences in the arch width and the tooth sizes were not found between the 2 groups.
Conclusions:
The present generation has the secular trend toward the reduction of the dental arch width and length. This showed a grater probability of developing a malocclusion in the new generation.