Objective The study was designed to evaluate the comparison and correlation of soft and hard tissue profile changes in the extraction treatment using maximum anchorage in adolescent and adult cases. Methods Comparing 9 indicators about soft and hard tissues of those 13 adolescent and 14 adult cases between pre- and post- treatment with t-test respectively. After that, select some indicators and study the correlation of them. At last, a regression was deployed in this research. Results This study showed that: 1）In the adolescent group, U1- SN, U1-PM, the degree of crowding were changed significantly after the treatment. The decrease of the upper incisors and upper lip protrusion negatively correlated with the degree of crowding before the treatment, and positively correlated with the distance between the upper lip to E-line before the treatment. The linear regression equation between upper incisors and lip was y=-2.900+0.926x（y, changes of upper lip; x, changes of upper incisors）. 2）In the adult group, all of those indicators were significantly changed except SNA and Ls -PM. The decrease of the upper incisors positively correlated with the degree of incisor inclination on the lip before the treatment, and negatively correlated with the degree of crowding before the treatment. However, the decrease of the upper lip protrusion positively correlated with the degree of incisor inclination on the lip before the treatment. The linear regression equation was y =-1.027 +0.706x（y, changes of upper lip; x, changes of upper incisors）. Conclusion Extraction treatment with maximum anchorage has a good effect on correcting crowding and drawing back the position of upper incisors as well as upper lip. The decrease of upper incisors and lip protrusion is mainly influenced by the quantity of upper incisors′ protrusion and crowding in adults. But for adolescents, it will be complex, maybe growth is one of the important causes.
