ABSTRACT
OBJECTIVE: The aim of this study was to introduce a new method for bilateral distal movement of the entire maxillary posterior segment. CASE REPORT: A 17-year-old girl with Class I skeletal malocclusion (end-to-end molar relationships, deviated midline and space deficiency for left maxillary canine) was referred for orthodontic treatment. She did not accept maxillary first premolars extraction. A modified Hyrax appliance (Dentaurum Ispringen, Germany) was used for bilateral distalization of maxillary posterior teeth simultaneously. Expansion vector was set anteroposteriorly. Posterior legs of Hyrax were welded to first maxillary molar bands. All posterior teeth on each side consolidated with a segment of 0.017 × 0.025-in stainless steel wire from the buccal side. Anterior legs of Hyrax were bent into eyelet form and attached to the anterior palate with two mini-screws (2 × 10 mm) (Jeil Medical Corporation Seoul, South Korea). Hyrax opening rate was 0.8 mm per month. Lateral cephalometric radiographs were used to evaluate the extent of distal movement. 3.5-mm distalization of posterior maxillary teeth was achieved in five months. RESULTS: A nearly bodily distal movement without anchorage loss was obtained. CONCLUSION: The mini-screw-supported modified Hyrax appliance was found to be helpful for achieving en-masse distal movement of maxillary posterior teeth.
Subject(s)
Malocclusion, Angle Class I/therapy , Orthodontic Anchorage Procedures , Tooth Movement Techniques , Adolescent , Cephalometry , Female , Humans , Malocclusion, Angle Class I/diagnostic imaging , Orthodontic Appliance Design , Radiography, Dental , Tooth Movement Techniques/instrumentationABSTRACT
ABSTRACT Objective: The aim of this study was to introduce a new method for bilateral distal movement of the entire maxillary posterior segment. Case report: A 17-year-old girl with Class I skeletal malocclusion (end-to-end molar relationships, deviated midline and space deficiency for left maxillary canine) was referred for orthodontic treatment. She did not accept maxillary first premolars extraction. A modified Hyrax appliance (Dentaurum Ispringen, Germany) was used for bilateral distalization of maxillary posterior teeth simultaneously. Expansion vector was set anteroposteriorly. Posterior legs of Hyrax were welded to first maxillary molar bands. All posterior teeth on each side consolidated with a segment of 0.017 × 0.025-in stainless steel wire from the buccal side. Anterior legs of Hyrax were bent into eyelet form and attached to the anterior palate with two mini-screws (2 × 10 mm) (Jeil Medical Corporation Seoul, South Korea). Hyrax opening rate was 0.8 mm per month. Lateral cephalometric radiographs were used to evaluate the extent of distal movement. 3.5-mm distalization of posterior maxillary teeth was achieved in five months. Results: A nearly bodily distal movement without anchorage loss was obtained. Conclusion: The mini-screw-supported modified Hyrax appliance was found to be helpful for achieving en-masse distal movement of maxillary posterior teeth.
RESUMO Objetivo: o objetivo do presente estudo foi apresentar um novo método para a distalização bilateral de todo o segmento posterior superior. Relato do caso: uma jovem de 17 anos de idade, com má oclusão esquelética de Classe I (relação de molares em topo a topo, linha média desviada e deficiência de espaço para o canino superior esquerdo) foi encaminhada para tratamento ortodôntico, mas recusou-se a autorizar a extração dos primeiros pré-molares superiores. Um aparelho Hyrax modificado (Dentaurum, Ispringen, Alemanha) foi utilizado para a distalização bilateral simultânea dos dentes posteriores superiores. O vetor de expansão foi definido no sentido anteroposterior. As barras de conexão posteriores do Hyrax foram soldadas às bandas dos primeiros molares superiores. Em cada um dos lados, todos os dentes posteriores foram agrupados com um segmento de fio de aço inoxidável de calibre 0,017" x 0,025" passando por vestibular. As barras de conexão anteriores do Hyrax foram dobradas em forma de loop e conectadas à região anterior do palato por meio de dois mini-implantes (2 x 10mm) (Jeil Medical Corporation, Seoul, Coreia do Sul). A taxa de abertura do Hyrax foi de 0,8mm / mês. Telerradiografias laterias foram usadas para avaliar a extensão dos movimentos de distalização. Resultados: em um prazo de cinco meses, foi obtida uma distalização de 3,5mm dos dentes posteriores superiores. O movimento realizado foi praticamente de corpo (translação), sem qualquer perda de ancoragem. Conclusão: o aparelho Hyrax modificado suportado por mini-implantes mostrou-se útil para efetuar o movimento de distalização em massa dos dentes posteriores superiores.