Quality of orthodontic care—A multicenter cohort study in Germany: Part 1: Evaluation of effectiveness of orthodontic treatments and predictive factors

AIMS: Orthodontic care and its effectiveness have increasingly become the focus of political and public attention in the recent past. Therefore, this multicenter cohort study aimed to report about the effectiveness of orthodontic treatments in Germany and to identify potential influencing factors. METHODS: A total of 586 patients from seven German study centers were screened for this cohort study, of which 361 patients were recruited at the end of their orthodontic treatment. Of these, 26 patients had missing study models and/or missing treatment information. Thus, 335 participants were included. The severity of malocclusion was rated using the Peer Assessment Rating (PAR) Index at baseline (T0) retrospectively and—prospectively—after the retention period (T1). Practitioner-, treatment- and patient-related information were analyzed in order to detect potential predictive factors for treatment effectiveness. RESULTS: Study participants (202 female and 133 male) were on average 14.8 (standard deviation [SD] ± 6.1) years old at start of active treatment. Average PAR score at T0 was 25.96 (SD ± 10.75) and mean posttreatment PAR score was 3.67 (SD ± 2.98) at T1. An average decrease of total PAR score by 22.30 points (SD ± 10.73) or 83.54% (SD ± 14.58; p < 0.001) was detected. Furthermore, 164 treatments (49.1%) were categorized as ‘greatly improved’ but only 3 treatments (0.9%) as ‘worse or no different’; 81.5% of all cases finished with a high-quality treatment outcome (≤5 PAR points at T1). Logistic regression analyses detected staff experience as a significant predictive factor for high-quality results (odds ratio 1.27, p = 0.001, 95% confidence interval 1.11–1.46). CONCLUSION: The improvement rate among this selected German cohort indicated an overall very good standard of orthodontic treatment. Staff experience proved to be a predictive factor for high-quality results.