Examiner differences in the assessment of different malocclusions

In the current discussion about ensuring treatment quality and reducing costs in the health sector, indication systems with which to determine the need for a treatment and the success of therapy are increasingly being used in orthodontics. These indication systems require the objective evaluation of malocclusions. Our objective was to determine the examiner reliability in the assessment of various malocclusions.

In 180 adults (64 male, 116 female, aged 20-49) from the population-based Study of Health in Pomerania (SHIP), malocclusions were recorded clinically and on models by calibrated examiners. An experienced orthodontist conducted the clinical examination. Another orthodontically-experienced examiner analyzed the models. To compare the model examiners, two examiners with varying degrees of orthodontic experience evaluated 60 of the 180 models as well (29 male, 31 female). One of the model examiners repeated the assessment of 60 models at a later time (intra-individual comparison).

Reliability amongst the examiners depended on which malocclusions were judged: crowding and contact point displacement showed little agreement, while cross bite, edge-to-edge bite, deep bite and enlarged overjet revealed greater agreement. Comparison between the clinical examination and model analysis (kappa median 0.57) revealed the greatest differences between the examiners. Comparison of the three model examiners also showed differences. The contrast to the orthodontically least experienced examiner was greater (kappa median 0.61 and 0.62) than the divergence between the two orthodontically more experienced examiners (kappa median 0.70). The intra-individual examiner comparison revealed the smallest differences (kappa median 0.82).