LATE LOWER ARCH CROWDING IN RELATION TO THE DIRECTION OF ERUPTION

The change in lower arch crowding 3-4 years after second permanent mol ar eruption was examined in 85 subjects, in relation to the angulation and change in angulation of molars and incisors relative to the mandi bular plane using correlation and multiple regression analyses. Crowdi ng increased significantly during the observation periods. Changes in molar and incisor angulation in both mesial and distal directions were observed. The increase in crowding was not related to molar or inciso r angulation at 12 years, Some association between increase in crowdin g, reduction in arch depth and retroclination of incisors was found.