The purpose of this study was to determine the mean value of overbite and overjet, and to find the correlation among overbite, overjet and relative maxillofacial structures using the data from orthodontic casts and cephalometric films of. boys and girls aged from 9 to 18 years with normal occlusions. The results were obtained as follows: 1. Incisal overbite depth was decreased from Group I to Group 111. .2. The highest value of correlation coefficient with incisal overbite was 4.368 -of incisal angle *in Group III. 3. Overjet was not significantly correlated with the age and sex. 4. Ratio of mesiodistal diameters of upper and lower incisors was not significantly correlated with overbite and overjet.