This study was performed to examine the relationships between lower lip and lower incisors. For the purpose of this study, cephalometric radiographs were taken from 54 males and 43 females of the Korean adults with normal occlusion, aged from 16.9 to 30.6 years old. Data obtained from measuring the cephalometric radiographs were analyzed by mean, standard deviation, minimum and maximun of the measurements, and correlations. The results were as follow:
1. Males were longer than females in the length of LIT-Sn, B'-Sn, and B-Sn.
2. There were no significant differences between males and females in each items of B-LIT, Pog'-Sn, FMIA, FLLA, and LI-Sn.
3. The lower incisors tended to be uprighted when the chin was projected anteriorly.