Cases six years postretention.

1. The cuspid width is most likely to decrease after treatment (9 of 11) although on occasion a slight increase (2 of 11) was maintained. 2. The molar width is apt to decrease from the beginning of treatment through the postretention period. 3. The cephalometric measurements studied in this sample of good stable occlusions coincided with with the norms and ranges as used by R.M. 4. The age changes of the various cephalometric measurements also agreed with the age changes that R.M. utilize. 5. Lower arch crowding may be due to multiple factors of expanded cuspids, protrusive and labially inclined mandibular incisors, and late skeletal growth changes.