Accuracy of extraoral bitewing compared with histopathology in proximal caries detection of primary molar teeth

Abstract

Proximal caries detection in pediatric patients is critical for a suitable treatment plan and prevents premature loss of deciduous teeth. Using direct visual examination alone may not be able to yield an accurate diagnosis for proximal caries. Intraoral bitewing radiography is an additional method that helps determine proximal caries. However, some limitations of the intraoral radiograph technique cannot be compatible with some patients and might lead them to become uncooperative. Extraoral bitewing radiography overcomes the issue of patients who refused to undergo intraoral radiographs. Our research study aimed to compare the accuracy of extraoral bitewing radiography and histopathological examination for proximal caries detection in the primary molars. Fifty-six extracted primary molars with and without proximal caries were divided into seven groups. Each group was arranged in the mimetic alveolar sockets of a 3D-printed skull and mandible. Intraoral bitewing was taken with photostimulable phosphor (PSP) plates size 0 using the paralleling technique. Extraoral bitewing was obtained using a digital panoramic X-ray unit. Two observers were evaluated extraoral bitewing radiographs separately, twice at one-week intervals, to minimize the possibility of recalling their previous assessments. The weighted kappa coefficients showed excellent intra- and inter-observer agreements between each observer. The Mann-Whitney U test showed no difference between the radiographic grading scores and the gold standard histological examination. The Wilcoxon signed-rank test showed the differences between intra- and extra-oral radiographic modalities were insignificant. The sensitivity, positive predictive value (PPV), negative predictive value (NPV), and the area under the receiver operating characteristic (ROC) curve of both observers for cavitated carious lesions were higher than non-cavitated carious lesions. The Az value for cavitated caries revealed that the diagnostic accuracy of extra- and intra-oral bitewings was excellent. In conclusion, the accuracy of dental caries information from the extraoral bitewing in primary molars was similar to the histopathological examination. The precision of itself was less than the gold standard in proximal caries detection. Therefore, extraoral bitewing could be an alternative to intraoral technique for pediatric patients who are uncooperative or intolerant to intraoral radiography.

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