Efficiency of Class II Malocclusion Treatment With Extraction of 2 Maxillary Premolars and the First Class Appliance Anchored in Mini-Implants.

Abstract

Objectives: Treatment efficiency is considered an important clinical variable in orthodontic practice; therefore, the aim of this study was to compare the efficiency between different Class II compensatory treatment approaches. The extraction of 2 maxillary premolars was compared to molar distalization with the First Class distaliser indirectly anchored to mini-implants.

Materials and methods: A retrospective sample of 31 patients was divided into two groups. Group 1: Class II treatment with two premolar extractions; 18 patients with a mean initial age of 14.3 ± 1.3 years. Group 2: Distalization with the First Class appliance indirectly anchored to mini-implants; 13 patients with a mean initial age of 13.3 ± 1.3 years. The Peer Assessment Rating (PAR) and the Objective Grading System (OGS) were used to calculate the percentage of occlusal improvement (PcPAR), treatment time (TT) and treatment efficiency index (TEI). The occlusal indexes, TT and TEI between both groups were compared using t tests (p < 0.05).

Results: Similar occlusal outcomes were observed between the groups, with no statistically significant differences (F-PAR and OGS). The TT in Group 1 was significantly shorter compared to Group 2. As a result, treatment with extractions was significantly more efficient (TEI: 3.23) than the treatment with maxillary molar distalization anchored indirectly to mini-implants (TEI: 1.95).

Conclusions: Both treatment protocols showed similar occlusal results; however, Class II correction with two premolar extractions is significantly more efficient than molar distalization with indirect skeletal anchorage.