Accuracy and reliability of orthodontists using cone-beam computerized tomography for assessment of adenoid...

Our objectives were to evaluate the reliability of agreement between orthodontists, with various degrees of cone-beam computed tomography (CBCT) imaging manipulation comfort, in classifying adenoid hypertrophy through CBCT generated images and also to determine how accurate orthodontists are compared with the gold standard diagnosis, nasopharyngoscopy.

This was a cross-sectional study in which a randomized list of board-certified orthodontists evaluated different degrees of adenoid hypertrophy of a stratified sampling of 10 scans. The available pool of CBCT images was from a multidisciplinary airway clinic in which children and adolescents had a CBCT scan and a nasopharyngoscopy (reference standard) by an otolaryngologist (head and neck surgeon) on the same day. The participating orthodontists used the same viewer software and computer, and had access to a previously published visual guideline for evaluating adenoid size.

Fourteen orthodontists evaluated 10 CBCT reconstructions. Interoperator reliability was excellent (intraclass correlation coefficient [ICC], 0.941; 95% confidence interval, 0.882-0.984). However, the orthodontists' evaluations against the reference standard demonstrated poor accuracy, (ICC mean, 0.39; ICC range, 0.0-0.74). Dichotomous data representing healthy and unhealthy patients were analyzed individually, and the orthodontists' evaluations and the nasopharyngoscopy results (accuracy) showed, on average, poor kappa values (mean, 0.44; range, 0.20-0.80).

Different levels of CBCT expertise impacted the assessment accuracy. The participating orthodontists showed excellent consistency among themselves; however, poor agreement between their CBCT assessments compared with nasopharyngoscopy demonstrated that this sample of clinical orthodontists had poor diagnostic accuracy. Together, these findings suggest that orthodontists may make consistent and systematic errors in this type of evaluations.