Incisor and profile alterations in extraction cases treated with standard Edgewise and pre-adjusted appliances: A controlled before-and-after study

Spyridon N Papageorgiou,Chiara Cassina,Vaska Vandevska-Radunovic,Theodore Eliades

doi:10.1016/j.ejwf.2021.04.001

Spyridon N Papageorgiou, Chiara Cassina + Show 2 more

Open Access

https://doi.org/10.1016/j.ejwf.2021.04.001

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Abstract

Even though treatment of Class II malocclusion with premolar extractions and incisor retraction might affect incisor inclination and soft tissue profile, the effects of bracket prescription on this have not been thoroughly assessed. Fifty patients (mean age: 13.6 years; 34% male) receiving extraction-based treatment with either standard Edgewise or pre-adjusted appliances were included. Between-group differences in the incisor inclination assessed with lateral cephalograms were analyzed statistically with linear/logistic regression at 5%. Treatment-induced changes included retroclination of the upper/lower incisors (-3.0° and -2.0°, respectively), retraction of the upper/lower incisors (-3.4 mm and -1.5 mm, respectively), retraction of the upper/lower lip (-2.1 mm and -2.0 mm, respectively), and enlargement of the nasolabial angle (+1.6°). Analysis of the data adjusting for confounders indicated that the pre-adjusted group, after treatment, had larger inclination of the upper or lower incisors (+3.2° and +4.5°, respectively), more prominent upper incisors relative to the facial plane (+1.3 mm), and smaller interincisal angle (-7.3 or -7.7°). Post-treatment upper incisor inclination fell within the cephalometric norm significantly more in the pre-adjusted than in the standard Edgewise group (odds ratio 4.3; 95% confidence interval 1.1-16.6). No differences were found in lower incisor prominence, upper/lower lip prominence, or nasolabial angle. Pre-adjusted appliances were associated with increased inclination of the upper and lower incisors, with more prominent upper incisors, and with more acute interincisal angle after retraction compared with standard Edgewise appliances. However, such differences did not translate in greater retraction of the upper/lower lips and greater nasolabial angle.

Highlights

The effectiveness of orthodontic treatment with fixed appliances in establishing a well-balanced occlusion has been well documented over the past century
Analysis of the data adjusting for confounders indicated that the pre-adjusted group, after treatment, had larger inclination of the upper or lower incisors (+3.2° and +4.5°, respectively), more prominent upper incisors relative to the facial plane (+1.3 mm), and smaller interincisal angle (−7.3 or −7.7°)
Post-treatment upper incisor inclination fell within the cephalometric norm significantly more in the preadjusted than in the standard Edgewise group

Summary

Introduction

The effectiveness of orthodontic treatment with fixed appliances in establishing a well-balanced occlusion has been well documented over the past century. Long-term changes in the occlusion of orthodontically treated patients seem to be more favorable in terms of improved settling and reduced tendency for anterior crowding relapse [4] as the finishing quality of orthodontic treatment increases [5]. Such evidence highlights the importance that well-finished postorthodontic occlusion plays and the care with which orthodontists should strive to achieve optimal results. Even though treatment of Class II malocclusion with premolar extractions and incisor retraction might affect incisor inclination and soft tissue profile, the effects of bracket prescription on this have not been thoroughly assessed

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