Me. Richardson, LATE LOWER ARCH CROWDING IN RELATION TO SOFT-TISSUE MATURATION, American journal of orthodontics and dentofacial orthopedics, 112(2), 1997, pp. 159-164
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.