Abstract
The purpose of this study was to evaluate the changes of the dental arch from the pre-dental to the primary dentition.
Materials were 52 longitudinal dental casts taken from 22 boys and 30 girls. Dental arch length, anterior dental arch length, posterior dental arch length were measured at each dental stages using 3dimesional digitizer, while dental arch width were measured as the distance between left and right canines, first and second molars etc.
The results were as follows;
1) Dental arch length showed gradually increased in the maxilla, while there was remarkable increase in the mandible after beginning of the eruption of the deciduous canines.
2) Inter canine width increased at the eruption of the deciduous canine in the maxilla, however it decreased at the eruption of the deciduous first molar in the mandible.
3) The differences were observed in the growth timing of anterior and posterior part of the dental arch length and most posterior part of the dental arch width between boys and girls
4) The advanced growth took place in posterior section of the dental arch, and then the dental arch width showed tendency to increase of the eruption of the deciduous canine.
