Dentofacial orthopaedics in relation to chronological age, growth period and skeletal development. An analysis of 72 male patients with Class II division 1 malocclusion treated with the Herbst appliance

Mandibular skeletal and dental changes were related to chronological age and somatic maturation in 72 male patients with Class II division 1 malocclusion treated with the Herbst appliance for an average period of 7 months. Sagittal condylar growth and sagittal changes in incisor position were analysed by means of mouth-open profile radiographs taken at the start and end of treatment. The somatic maturity level of the subjects was assessed by means of longitudinal growth records of standing height, as well as radiographs of the right hand and wrist taken at the start and end of treatment. The findings support the view that there is a close relationship between maximum pubertal growth in standing height (PEAK) and maximum mandibular growth. Sagittal condylar growth in the patients treated at PEAK was twice that observed in patients treated 3 years before or 3 years after PEAK. In relation to skeletal maturation, patients treated at the initial closure of the middle phalanx Of the third finger (MP3-FG) had the greatest amount of sagittal condylar growth. Chronological age was an insufficient indicator of condylar growth capacity in the age range covered in this study. The amount of change in incisor position observed during the orthodontic treatment period seemed not to be closely related to any of the investigated variables, chronological age, growth period and skeletal development.