How Deep Is Their Understanding? The Illusion of Explanatory Depth in Pediatric Dentistry Training

Purpose: This study examined the Illusion of Explanatory Depth (IOED) among final-year dental students in pediatric dentistry by comparing perceived explanatory understanding with objectively evaluated explanatory performance and diagnostic accuracy. The goal was to determine whether IOED represents a metacognitive vulnerability that may contribute to diagnostic errors in pediatric dental decision-making. Methods: A cross-sectional explanatory design was used with 142 final-year Bachelor of Dental Surgery students across two academic years. Students rated their perceived explanatory understanding (PEUS) for three pediatric topics (caries risk assessment, pulp diagnosis, behaviour guidance). They then completed structured written explanations scored using a validated rubric to generate Observed Explanatory Performance Scores (OEPS). The Explanatory Calibration Index (ECI = PEUS - OEPS×2) quantified the degree of over- or underestimation. Diagnostic accuracy was assessed through six pediatric key-feature vignettes (DAS). Associations among PEUS, OEPS, ECI, and DAS were examined using paired comparisons and Pearson correlations. Results: Students consistently overestimated their explanatory understanding across all topics, with the largest IOED effect observed in behaviour guidance. Mean global ECI indicated substantial overestimation. OEPS showed a moderate positive correlation with diagnostic accuracy (r = 0.47, p < .001), whereas PEUS did not (r = 0.12, p = .14). Higher ECI values were negatively associated with diagnostic accuracy (r = –0.31, p < .001), suggesting that greater overestimation was linked to poorer clinical reasoning performance. Conclusions: Dental students systematically overestimate the depth of their understanding in pediatric dentistry, and IOED appears to function as a meaningful metacognitive risk factor. Explanatory performance - not perceived understanding, was the reliable predictor of diagnostic accuracy. Incorporating structured explanation tasks, metacognitive calibration activities, and targeted feedback into pediatric dental education may help align students’ perceived and actual understanding, improving diagnostic performance and supporting safer clinical practice.