Comparison of treatment effects after total mandibular arch distalization with miniscrews vs ramal plates in patients with Class III malocclusion.

INTRODUCTION

This study aimed to compare treatment effects after total mandibular arch distalization with buccal interradicular miniscrews vs ramal plates in patients with Class III malocclusion.

METHODS

The sample consisted of 40 patients with Class III malocclusion; 20 were treated with distalization via buccal miniscrews (age, 25.8 ± 7.9 years), whereas 20 were treated with ramal plates (age, 26.4 ± 6.1 years). Twenty-three linear and angular measurements were analyzed on pretreatment and posttreatment lateral cephalograms. The changes in each group and differences in treatment effects between the 2 groups were evaluated.

RESULTS

The mean amount of distalization at the crown and root levels of the mandibular first molars and the amount of distal tipping was 1.8 mm, 0.6 mm, and 5.4° in the buccal miniscrew group vs 3.6 mm, 2.0 mm, and 6.8° in the ramal plate group, respectively. In addition, 2.2° of counterclockwise rotation of the occlusal plane was observed in the buccal miniscrew group after 1.3 mm of molar intrusion (P <0.001). The distal movement of the lower lip was 0.6 mm in the buccal miniscrew group vs 2.3 mm in the ramal plate group.

CONCLUSIONS

The buccal miniscrew group showed more molar intrusion and counterclockwise rotation of the occlusal plane than in the ramal plate group. The ramal plate produced more distalization of the mandibular dentition with clockwise rotation of the mandible. Therefore, these results can be useful when selecting the type of temporary skeletal anchorage devices to treat patients with Class III malocclusion, depending on their vertical pattern.