A comparative study on anterior teeth retraction-related hard and soft tissue changes with physiologic anchorage control technique.

Aim of this comparative cross-sectional study was to evaluate the effect of anterior teeth retraction and related hard and soft tissue change under physiologic anchorage control in patients with chief complain of protrusive teeth. 68 Class I or II orthodontic patients undergoing four-premolar extraction and requiring maximum or medium anchorage were included. Patients were treated with physiologic anchorage control technique (PASS group, n = 34, 18.6 +/- 7.7 years, 10 male and 24 female) and self-ligation technique (Damon group, n = 34, 17.5 +/- 5.4 years, 13 male and 21 female), respectively. TADs were used for anchorage reinforcement in Damon group. Pre- and post-treatment cephalograms were collected. Twenty-six skeletal, dental and soft tissue items were measured and analyzed using a blinded method. T test and paired rank-sum test were used for statistical analysis. The baseline characteristics were similar between groups (P > 0.05). After treatment, inter-group comparison showed statistically significant differences in the decrease of skeletal measurements angleANB (- 0.73 +/- 1.05 degrees in PASS group and - 0.25 +/- 0.84 degrees in the Damon group), Wits value (- 2.56 +/- 2.29 mm in PASS group and - 0.47 +/- 2.15 mm in Damon group) and soft tissue measurement UL-E (- 2.75 +/- 1.36 mm in PASS group and - 2.03 +/- 1.30 mm in Damon group) and the increase of FCA and Z angle, which was 2.03 +/- 2.12 degrees and 9.52 +/- 4.78 degrees in PASS group and 0.97 +/- 2.12 degrees and 6.96 +/- 4.43 degrees in Damon group, respectively (P < 0.05). Our results indicated that significant anterior teeth retraction and profile improvement could be achieved with PASS technique without additional anchorage devices. Appropriate application of physiologic anchorage control could reduce the dependence of TADs for anterior teeth retraction.