Statistical analysis and plots were performed using the statistical software R [12]. To evaluate the differences in the proportions of correct diagnostic answers between OS and ORTH and between different imaging modalities, Fisher’s exact tests were used and odds ratios (OR) including confidence intervals (CI) were computed for every question separately. Likewise, Fisher’s exact tests were applied to estimate whether there was a difference between the answers given by OS and ORTH on the question if the image provided sufficient information to treat the case (treatability).The same test procedure was also used to investigate if a CBCT after OPG was requested with regard to treatment planning and if specialisation, gender and years of experience as a dentist (dichotomized in 0–4 years of experience versus more) were associated with it. Statistical significance was set to α = 0.05 for all analysis.