Abstract
The degree of tooth formation were studied quantitatively way using 11,200 orthopantomograms (5,700 males and 5,500 females) obtained from Japanese children aged 2 to 14.
The assessment was based on a slight of modification Moorrees, et al. tooth formation stages. They were divided into 14 stages for the molars and 13 for the premolars. Each stage consisted of points ranging from 0 to 14.
The results obtained were as follows:
1. The formation was faster in all teeth for female than for male, this tendency being especially true during middle stages of tooth development.
2. Statistically a tooth on one side developed at the same rate as its counterpart on the other side regardless of sex, or arch differences.3. The norms of the formation for Japanese permanent molars may be applied to daily dental practice.
