Introduction
malocclusion, occlusion, Class II malocclusion, malocclusions, orthodontic, trauma
ANGLE CLASS I, CLASS I MALOCCLUSION, ERUPTION
The occlusion and dental arches change dynamically throughout the human lifespan. Dental arches develop and expand from childhood to adolescence, along with craniofacial growth, dentoalveolar growth, and eruption of primary and permanent teeth. Transversal growth of the dental arches is finished before 15 years of age [Angle Class II malocclusion is one of the most prevalent malocclusions worldwide after Class I malocclusion and dental crowding [The aim of orthodontic treatment is to normalize occlusion and enable normal dentofacial growth and development. Cervical headgear (CHG) is a well-known and reported orthodontic appliance to correct Class II malocclusion and dental crowding [Wider and longer dental arches are known outcomes of CHG treatment, and especially in the molar region, expansion is shown to be stable [The appropriate timing of Class II treatment remains controversial. The early timing of orthodontic treatment reduces the risk of incisal trauma in children with Class II malocclusion [The aim of this study was to analyse the long-term influences of the timing of CHG treatment on the development of dental arches in a randomized setting. The hypothesis was that timing of the CHG treatment affects dental arch dimensions and stability of the outcome in long-term follow-up.