Comparison of Rate of En masse Retraction and Anchorage Loss in Conventional Labial Appliance with Labial and Lingual Force: A Clinical Study

Abstract

Aims: The rate of en masse retraction and anchorage loss were compared between labial appliance with lingual force and conventional labial appliance. Subjects and Methods: The sample consists of 14 patients and they were divided into two groups. In Group 1 – labial appliance with lingual force, elastomeric chain was placed from the palatal surface of the canines to the palatal surface of the molars. In Group 2 – labial appliance with labial force, elastomeric chain was placed from the crimpable hook distal to lateral incisor to the molar tube hooks. The rate of en masse retraction and anchorage loss was calculated for both the groups during retraction in dental casts (R 0 , initial; R 1 , 4 weeks; R 2 , 8 weeks; and R 3 , 12 weeks). Statistical Analysis Used: Student's paired t -test. Results: The rate of retraction was faster and anchorage loss was lower with labial appliance with lingual force, i.e., Group 1. The difference of anchorage loss in Group 1 and Group 2 shows t = 4.824 and P value= 0.000, which is statistically highly significant. The difference of rate of retraction in Group 1 and Group 2 shows t = 3.573 and P value = 0.004, which is statistically signifcant. Conclusions: The rate of retraction was faster and anchorage loss was lower with labial appliance with lingual force, thus indicating that this new technique of space closure utilizes biomechanical advantage of lingual force in conventional labial appliance.