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. 2021 Mar;159(3):321-332.
doi: 10.1016/j.ajodo.2019.12.028. Epub 2021 Jan 22.

Relative effectiveness of facemask therapy with alternate maxillary expansion and constriction in the early treatment of Class III malocclusion

Yuyao Liu  1 , Renya Hou  2 , Hairu Jin  1 , Xin Zhang  1 , Zuping Wu  1 , Zixuan Li  1 , Jie Guo  3
Affiliations

Relative effectiveness of facemask therapy with alternate maxillary expansion and constriction in the early treatment of Class III malocclusion

Yuyao Liu et al. Am J Orthod Dentofacial Orthop. 2021 Mar.

Abstract

Introduction: This study aimed to investigate the relative efficacy of maxillary protraction combined with a modified alternate rapid maxillary expansion and constriction (Alt-RAMEC) protocol compared with conventional protocols in the early orthopedic treatment of skeletal Class III malocclusion.

Methods: A sample of 39 patients was divided into 3 groups on the basis of different interventions. Conventional facemask (FM) with splint-type intraoral devices was performed in the FM group (7 males and 5 females; mean age, 9.53 ± 1.37 years). Maxillary expansion with an activation rate of 0.5 mm/d (twice a day) followed by FM therapy was applied in the rapid maxillary expansion group (RME/FM) (6 males and 6 females; mean age, 9.31 ± 1.60 years). In the Alt-RAMEC/FM group (7 males and 8 females; mean age, 10.01 ± 1.31 years), Alt-RAMEC was started simultaneously and throughout the entire course of maxillary protraction, with repetitive alternations between activation and deactivation of expanders (0.5 mm/d for 7 days). The patients in all groups were instructed to wear FMs for a minimum of 12 h/d. Pretreatment and posttreatment lateral cephalograms were all traced and measured.

Results: The Alt-RAMEC group showed statistically more significant maxillary advancement than other groups (A-VRP, 3.87 mm vs 3.04 mm [RME/FM], vs 2.04 mm [FM]; P <0.05). Analysis of variance did not reveal significant intergroup differences in palatal plane angulation changes (P >0.05). No pronounced mandibular clockwise rotations were noted in the Alt-RAMEC/FM group with distinct intergroup differences (P <0.05). There were more skeletal effects (88.7%) during overjet correction in the Alt-RAMEC/FM protocol.

Conclusions: A combination of the modified Alt-RAMEC protocol with FM revealed more favorable skeletal effects compared with FM and RME/FM protocols in treating prepubertal patients with maxillary deficiency.

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