LATE LOWER ARCH CROWDING IN RELATION TO SOFT-TISSUE MATURATION

Changes in lower arch space condition and incisor inclinations were me asured in relation to changes in the cross-sectional area and separati on of the lips in habitual posture in 23 boys and 23 girls between the ages of 12.5 and 15.5 years. Correlation analysis revealed no direct relationship between the increase in lower arch crowding and the chang es in lip size and position. In girls, the increase in lower arch crow ding was associated to some extent with retroclination of the upper in cisors and an increase in the interincisal angle. A very tenuous relat ionship was found between changes in the upper lip size and position a nd changes in incisor angulation.