The purpose of this study was to examine the constituents of crowding permanent dentition by longitudinal changes from stage II C of Hellman's dental age to stage IV A of the dental arch form and craniofacial morphology. The dental arch form was analyzed using dental casts, and the craniofacial morphology was analyzed using the roentgenocephalometric films. The subjects were divided into two groups by the level of arch length discrepancy of permanent dentition at stage IV A of Hellman's dental age. The two groups were classified into the normal dentition group (NDG) and the crowding dentition group (CDG). The NDG was comprised of 15 subjects, and the CDG of 11 subjects. The findings were as follow; 1) The mesio-distal lengths of maxillar or mandibular in the CDG tended to be short in comparison with the length in the NDG after stage III A.2) The axial inclination of the incisor in the CDG tended to be small in comparison with the axial inclination in the NDG after stage III A.3) There was a significant positive correlation between the arch length discrepancy and dental arch width at stage II C. The dental arch length and arch perimeter after stage III A related to the arch length discrepancy with a significant positive correlation. In contrast, there was a significant negative correlation between crown width and arch length discrepancy at stages III A and IV A.