Evaluation of the stability of treatment with Herbst appliance associated with Hyrax expander and fixed orthodontics through counterpart analysis: A longitudinal follow‐up study

• Published in: Orthodontics & craniofacial research 2023-02, Vol.26 (1), p.27-36
• Main Authors: Arruda Aidar, Luís Antônio, Marchi, Luiz Carlos, Fuerte, Silvia, Yamashita, Hélio K., Dominguez, Gladys Cristina
• Format: Article
• Language: English
• Subjects: Adolescent; angle class II; Cephalometry; Dental occlusion; Facial Bones - diagnostic imaging; Follow-Up Studies; Humans; Longitudinal Studies; malocclusion; Malocclusion, Angle Class II - diagnostic imaging; Malocclusion, Angle Class II - therapy; Mandible; Mandible - diagnostic imaging; orthodontic appliances; Orthodontic Appliances, Functional - standards; Orthodontics; orthopaedics
• ISSN: 1601-6335; 1601-6343
• DOI: 10.1111/ocr.12574

Objective The aim of this study was to evaluate the stability of treatment with a Herbst appliance associated with Hyrax expander (Stage I), followed by fixed appliances (Stage II) and follow‐up for an average of 4 years after Stage II, on dentoskeletal facial structures. Methods This study involved 50 adolescents with Angle Class II division 1 malocclusion associated with mandibular retrognathism: Treated Group (TG‐25) and Control Group (CG‐25). Lateral cephalometric radiographs were taken: T1, immediately before Stage I (TG) or at the beginning of the follow‐up period (CG); T2, at the end of Stage I (TG) or the follow‐up period (CG); T3, at the end of Stage II (TG); and T4, on average, 4 years after Stage II (TG). Enlow's counterpart analysis and some cephalometric measurements were evaluated. Parametric and non‐parametric tests were used (P ≤ 0.05). Results The ramus alignment variables (P