Sample size
RECRUITMENT
As this trial is an early clinical trial with the aim to implement the novel method of 4D videostereophotogrammetry, sample size calculation was not based on a priori-hypothesis testing. Based on previous treatment numbers, in total 45 patients (1 skeletal class I, 21 skeletal class II, 23 skeletal class III) were operated in an interval similar to the scheduled recruitment phase of this study; a feasible sample size of 20 patients was planned for recruitment. The final sample size was 26 patients (13 skeletal class II, 13 skeletal class III) and a complete case analysis was performed.