Recognition of Digital Dental X-ray Images Using a Convolutional Neural Network

Digital dental X-ray images are an important basis for diagnosing dental diseases, especially endodontic and periodontal diseases. Conventional diagnostic methods depend on the experience of doctors, so they are highly subjective and consume more energy than other approaches. The current computer-aided interpretation technology has low accuracy and poor lesion classification. This study proposes an efficient and accurate method for identifying common lesions in digital dental X-ray images by a convolutional neural network (CNN). In total, 188 digital dental X-ray images that were previously diagnosed as periapical periodontitis, dental caries, periapical cysts, and other common dental diseases by dentists in Qilu Hospital of Shandong University were collected and augmented. The images and labels were inputted into four CNN models for training, including visual geometry group (VGG)-16, InceptionV3, residual network (ResNet)-50, and densely connected convolutional networks (DenseNet)-121. The average classification accuracy of the four trained network models on the test set was 95.9%, while the classification accuracy of the trained DenseNet-121 network model reached 99.5%. It is demonstrated that the use of CNNs to interpret digital dental X-ray images is an efficient and accurate way to conduct auxiliary diagnoses of dental diseases.