Diagnostic accuracy of intraoral photographic orthodontic records

Objective The aims of this study were (1) to investigate how relevant intraoral photographs are to contemporary orthodontic diagnosis and (2) to assess orthodontists' ability to accurately diagnose angle classification and dental midlines using standardized intraoral photographs. Methods Study participants were orthodontists who completed a survey regarding photography protocols and their use of intraoral photographs for diagnosis. Each participant was randomized to complete 1 visual diagnostic task regarding either angle classification or midlines. Accuracy was compared across groups and camera angulations. Results In all, 80% of 192 respondents reported using photographs and clinic notes to plan orthodontic treatment; 50% also included dental casts. For the angle task, accuracy judging molar and canine classification was 79.9% and 51.3%, respectively with ideal standardized photographs. As camera angulation deviated, accuracy decreased significantly (P < 0.0001). For the midline task, accuracy judging the direction of deviation decreased with a small camera angulation change yet increased with a large change (P < 0.001). Conclusions When using ideal intraoral photographs alone to diagnose angle classification and midline relationships, accuracy is not likely to be greater than 80%. As camera angulation becomes less ideal, by 15 degrees when judging angle classification or 4 degrees when judging midlines, accuracy is likely to significantly decrease.