Comparison of anterior retraction and anchorage control between en masse retraction and two-step retraction: A randomized prospective clinical trial

Abstract

Objectives: The purpose of this two-arm parallel trial was to compare en masse (ER) and two-step retraction (TSR) during space closure. Materials and Methods: Forty-eight adult patients with bimaxillary protrusion who were planned for treatment with extraction of four first premolars were enrolled. All patients were randomly allocated in a 1:1 ratio to either the ER (n = 24) group or the TSR (n = 24) group. The main outcome was the amount of posterior anchorage loss in the molars and the retraction of the incisors between ER and TSR; the difference in incisor and molar inclination was a secondary outcome. Lateral cephalometric radiographs and oblique cephalometric radiographs at 45° were taken before retraction (T1) and after space closure (T2). Cephalograms were digitized and superimposed on the anatomic best fit of the maxilla and mandible by one operator who was blinded to the treatment group. Results: Neither incisor nor molar crown movements showed any significant differences between the ER and TSR. There were no significant differences in the tipping of incisors and molars between the two groups. Conclusions: No significant differences existed in the amount of retraction of incisors and anchorage loss of molars between ER and TSR. Changes in incisor and molar tipping were similar, with the crowns showing more movement than the apex.

Effectiveness of orthodontic temporary anchorage devices in canine retraction and anchorage preservation during the two-step technique: a systematic review and meta-analysis

“…Substantial clinical heterogeneity existed in the meta-analysis because the included studies varied significantly in the use of osseointegrated and nonosseointegrated implants, study type, bracket slot sizes, archwires and measurement methods. Canine retraction is the first step of the two-step technique for space closure [20]. Clinically, the extent of canine movement is of great importance for subsequent incisor retraction, especially for patients with dentoalveolar protrusion.…”

“…Currently, there exists little research on two-step retraction with TADs, and whether it can lead to the same outcome or an even better outcome than en masse retraction with TADs remains inconclusive. Canine retraction is the first step of the two-step retraction method [20], the completion of which is crucial for subsequent incisor retraction.…”

“…Two-step retraction and en masse retraction are two methods for achieving extraction space closure [ 18 , 19 ]. Both techniques are efficient for space closure, and there is no significant difference between the two methods in the extent of anterior tooth retraction or molar anchorage loss [ 5 , 18 , 20 ]. However, it takes more time to achieve space closure with two-step retraction than with en masse retraction [ 5 , 21 ].…”

Effectiveness of orthodontic temporary anchorage devices in canine retraction and anchorage preservation during two-step technique: A systematic review and meta-analysis

“…Canine retraction is the first step of the two-step technique for space closure 17 . Clinically, the extent of canine movement is of great importance for subsequent incisor retraction, especially for patients with dentoalveolar protrusion.…”

“…Two-step retraction and en masse retraction are two methods for achieving extraction space closure 15,16 . Both techniques are efficient for space closure, and there is no significant difference between the two methods in the extent of anterior tooth retraction or molar anchorage loss 5,15,17 .…”