Diagnostic evaluation of the relationship between impacted mandibular third molars and the mandibular canal in panoramic radiographs shared via WhatsApp

OBJECTIVE: To compare the diagnostic accuracy of computer and smartphone screens for assessing the radiographic proximity between impacted mandibular third molars and the mandibular canal. METHODS: Four examiners evaluated 121 digital panoramic radiographs for the presence of proximity between third molars and the mandibular canal, as well as for specific radiographic signs indicative of this relationship. Assessments were performed on a computer screen and on their personal smartphone screens; for the latter, images were shared via WhatsApp. Diagnostic performance was analyzed using accuracy (Ac), sensitivity (Se), specificity (Sp), and positive and negative predictive values (PPV and NPV). Differences in the frequency of correct and incorrect responses between methods were tested using the McNemar test, as were the proportions of correct and incorrect classifications for each radiographic sign. RESULTS: Examiners correctly classified true positives and true negatives in 86.5% of cases using the computer monitor and 85.1% using the smartphone. Comparable diagnostic performance was observed for computer monitor (Se = 0.975; Sp = 0.758; Ac = 0.865) and smartphone (Se = 0.942; Sp = 0.762; Ac = 0.851) assessments. No statistically significant differences were found between methods for any radiographic sign (p > 0.05). CONCLUSION: Smartphones demonstrated diagnostic accuracy comparable to that of computer screens for evaluating the proximity between impacted mandibular third molars and the mandibular canal on panoramic radiographs.