Comparative study between conventional en-masse retraction (sliding mechanics) and en-masse retraction using orthodontic micro implant

Abstract

Purpose: The purpose of this study was to measure and compare the difference between rate of en-masse retraction with mini-implant and molar anchorage.

Patients and method: A comparative study consisting of 14 patients (all females) randomized into 2 groups. Seven in group I (nonimplant) molar was used as anchor for en-masse retraction of anterior teeth (mean age 16 years SD +/- 1.41). In group II (implant), mini-implant was used as anchorage to retract the anterior teeth (mean age 17.36 SD +/- 1.35). In both groups, all first premolars were extracted. After leveling and aligning, surgical steel mini-implant of 1.3 mm in diameter and 8 mm in length were placed between the roots of second premolar and first molar in the maxilla in the implant group. Implants were immediately loaded with 2 N of force. In nonimplant group molar was used as anchorage. The retraction and postretraction lateral cephalograms were taken. Rate of retraction and anchor loss were measured by using pterygoid vertical in maxilla.

Results: Four implants became loose during the treatment, which were subsequently replaced. The stability of surgical steel in this study was 71.4%. Student t test were used to analyze the treatment charges in 2 groups. Mean anchor loss in maxilla in nonimplant group. No differences in the mean rate of retraction time were noted in both groups.

Conclusion: Mini-implants provided absolute anchorage in patients requiring maximum anterior retraction. No differences in the mean retraction time were noted between 2 groups.