Mandibular Cervical Headgear vs Rapid Maxillary Expander and Facemask for Orthopedic Treatment of Class III Malocclusion

Abstract

Objective:To compare the effectiveness of the rapid maxillary expander and facemask (RME/ FM) and mandibular cervical headgear (MCH) protocols when followed by fixed appliances and evaluated at a postpubertal observation in patients with dentoskeletal Class III malocclusion. Materials and Methods: The sample treated with the RME/FM followed by fixed appliances included 32 patients (12 boys and 20 girls). The sample treated with the MCH followed by fixed appliances included 26 patients (eight boys and 18 girls). Cephalometric analysis was performed at T 1 (before treatment) and T 2 (after the first phase of orthopedic therapy and the second phase of fixed appliances). T 1 -T 2 changes were evaluated by means of t-tests. Results: Midfacial length, mandibular length, and the sagittal position of the chin all showed significantly smaller increases in the MCH group than in the RME/FM group. The amount of increase in the overjet was also significantly smaller in the MCH group, whereas the amount of molar correction was greater. The upper incisors were significantly less proclined and the lower incisors were significantly less retroclined in the MCH group when compared with the RME/FM group. Conclusions: RME/FM therapy appears to be indicated in Class III patients with a component of maxillary retrusion, whereas MCH therapy is preferable in patients with mandibular prognathism.

O tratamento da Classe III: revisão sistemática - Parte I. Magnitude, direção e duração das forças na protração maxilar

“…A magnitude média determinada no presente trabalho foi de 447,8g, estando condizente com a maioria das recomendações dos demais estudos 2,3,5,6,9,10,19,21,23,32,33,35,42 .…”

“…MacDonald, Kapust e Turley 24 utilizaram uma força entre 200g e 450g (média 325g) e diversos autores afirmaram utilizar uma força entre 300g e 500g (média 400g) 5,6,10,41,43 , próxima da empregada nos estudos que usaram 500g de força 2,19,23,32,33 .…”

“…pois a força foi direcionada paralelamente ao Plano de Frankfurt. Alguns estudos [3][4][5][6][9][10][11][12]43 foram desconsiderados para a realização das médias e desvios-padrão, por não apresentarem o valor em graus dos vetores. Os autores relataram apenas o vetor para frente e para baixo em relação ao Plano Oclusal.…”

“…Outros trabalhos 2,3,5,9,10,34,[43][44][45][46] relataram o uso de, no mínimo, 14 horas por dia, semelhante à média de 14 horas relatada em outros estudos 8,13,30 . Para Pangrazio-Kulbersh, Berger, Kersten 32 e Pangrazio-Kulbersh et al 33 , as horas mínimas de uso variaram entre 14h e 16h (média 15h) por dia.…”

Effect of face mask therapy on mandibular rotation considering initial and final vertical growth pattern: A longitudinal study

“…Wolfe et al reported that, compared with a Class I control group, patients with Class III malocclusion display hyperdivergent jaws and increased inferior facial height (Wolfe, Araujo, Behrents, & Buschang, ). Treatment has been aimed at maxillary advancement and/or control of jaw growth, and several devices have been designed for this purpose such as protraction face masks (FMs), chincups, mandibular cervical hedgear, and functional orthopedic appliances (Baccetti, Rey, Angel, Oberti, & McNamara, ; Baccetti, Rey, Oberti, Stahl, & McNamara, ; Baik, Jee, Lee, & Oh, ; Rey, Angel, Oberti, & Baccetti, ; Zhang et al, ).…”