Need for training sessions for orthodontists in the use of the American Board of Orthodontics objective grading system

Introduction: In recent years, the importance of quantitative assessment of orthodontic treatment with measures such as the objective grading system (OGS) has been emphasized for evaluating clinical outcomes in universities and clinics. Furthermore, quantitative evaluation is essential for passing orthodontic boards and examinations. However, countries outside the United States, the methods and the necessity of training sessions in the use of the OGS have not been evaluated. The OGS has great potential to be the “gold standard” to evaluate finished patients all around the world. Students and faculty members of Okayama University in Japan examined the necessity of training and the efficacy of 2 training methods. Methods: Twenty-six orthodontic faculty members and graduate students participated. Three scoring and 2 training sessions were held by using 3 sets of cast models distributed by the American Board of Orthodontics and 6 sets of cast models prepared for this study. Statistical comparisons were done before and after the training sessions by analysis of variance and independent t test. Results: Before the training session, the average difference in the total OGS scores for the 3 cases was 15.8 ± 0.2 points. Significant reductions in the difference in the OGS score (7.3 ± 2.4) were observed after 1 training session. There was no significant difference after the first and second training sessions. However, there was a significant difference in the variability of the OGS scores between the first and second sessions. There was no significant difference between the 2 training methods. Among 8 scoring criteria, the greatest difference in OGS scores was observed in buccolingual inclination throughout the training sessions. Furthermore, cases with unacceptable occlusion (high OGS score) tended to be difficult to score compared with acceptable occlusion (low OGS score). Conclusions: The OGS was suggested as an ideal scoring index to quantitatively assess orthodontic treatment outcome without specific training with well-trained orthodontists. Among the 8 categories of the OGS, extra care might be needed when scoring the buccolingual inclination. However, 1 training session greatly improved the scoring reliability of orthodontic treatment outcomes with the OGS.