Two hundred and thirty five children enrolled in kindergarden of Araraquara public school system were evalueted and cast models were obtained. For this purpose a special apparatus was confeccioned with utility wax and exam stick following the dental arch form. After an year same children were evaluated again in order to observe possible changes in the primary dental arches. Using the cast models some measurements were acquired by a tridimensional digitalizer, MicroScribe-3DX, on the first and after one year cast models. Second molars, first molars and canine width, arch perimeter, arch length and primate space were evaluated. Gender dimorphism, arch type and finger or pacifier sucking habits were also considered. It was concluded that the transverse measurements showed a significant increase in primary dentition, while the perimeter, arch length and primate spaces were stable. The first and second molars width presented gender dimorphism, with higher values in the females. Considering the perimeter, arch length and primate spaces there were no significant differences according to gender. The arch length dimensions were not different between Baume Type I and II arches, althougth Baume Type I arch width were larger than Type II. Finger and pacifier sucking habits had no effect on primary dentition dimensions during the observed period of one year.
Primary dentition; Malocclusion; Dimensions changes
