Student Number : 0204056G - MD research report - School of Oral Health Science - Faculty of Health Sciences / Evaluating facial profiles and facial balance is a continuous learning process for orthodontists. Hence, the importance of studying the intermediate and long term effects of treatment on soft tissues cannot be overemphasized. The objective of this study was to evaluate the lip changes occuring in response to tooth movement, not only immediately post-treatment but also to following the long-term monitoring when cranio-facial growth has ceased. The lip changes were measured relative to the Burstone (B-line) line. The sample was taken from the records successfully treated orthodontic cases in the Department of Orthodontics at the University of the Witwatersrand, Johannesburg. This sample comprised 18 Caucasoid females (14 extracttion, 4 non-extraction). Pre-treatment, post-treatment, and long term follow-up lateral cephalometric radiographs were evaluated. Statistical evaluation of the lips in the long term follow-up records revealed no statistically significant changes. The lips remained, relatively, in a similar position to that which had been attained immediately post-treatment. This was the case for both the extraction and non-extraction groups. The general lack of consistency in post-treatment correlations between dental variables and the soft tissue form supports the hypothesis that the soft tissues, having their own inherent architecture, respond independently. This varied response to tooth movement makes lip movement difficult to predict on a reliable basis. The concept that is better to finish the cases slightly more protrusive because the lips tend to lose elasticity with age and, as a result, become more retrusive, is therfore supported by these observations.