Objective To explore the diagnostic value of the radiomic model based on panoramic radiographs in differentiating single or multiple root canals in mandibular first premolars.Methods A retrospective analysis was conducted on 68 patients with CBCT and panoramic radiographs from the affiliated Stomatological Hospital of Nanjing Medical University between July 2022 and November 2023.One hundred and thirty one mandibular first premolars(105 single-root and 26 multiple-root canals)were included in this study.Using stratified random sampling,the mandibular first premolars were divided into a training cohort(104 teeth)and a test cohort(27 teeth)at a ratio of 8∶2.CBCT was used to confirm the root canal configuration,and radiomic features were extracted from panoramic radio-graphs.After feature screening,radiomic models were constructed using extratrees,LightGBM,logistic regression(LR),multi-layer perceptron(MLP),random forest,support vector machine(SVM),and XGBoost.The optimal radiomic model was selected based on receiver operating characteristic(ROC)curve,accuracy,sensitivity,specificity,positive predictive value(PPV),negative predictive value(NPV),and decision curve analysis(DCA).Results A total of 107 radiomicfeatures were extracted from panoramic radiographs.After feature filtering,4 radiomic features were ultimately selected using the Lasso model.The XGBoost model showed higher predictive efficiency and stability,with an AUC of 0.962 in the training cohort and 0.770 in the test cohort.DCA curves also in-dicated that the XGBoost model was optimal.Conclusion The radiomic model based on panoramic radiographs demonstrates good per-formance in differentiating single or multiple root canals in mandibular first premolars.

Objective To explore the diagnostic value of the radiomic model based on panoramic radiographs in differentiating single or multiple root canals in mandibular first premolars.Methods A retrospective analysis was conducted on 68 patients with CBCT and panoramic radiographs from the affiliated Stomatological Hospital of Nanjing Medical University between July 2022 and November 2023.One hundred and thirty one mandibular first premolars(105 single-root and 26 multiple-root canals)were included in this study.Using stratified random sampling,the mandibular first premolars were divided into a training cohort(104 teeth)and a test cohort(27 teeth)at a ratio of 8∶2.CBCT was used to confirm the root canal configuration,and radiomic features were extracted from panoramic radio-graphs.After feature screening,radiomic models were constructed using extratrees,LightGBM,logistic regression(LR),multi-layer perceptron(MLP),random forest,support vector machine(SVM),and XGBoost.The optimal radiomic model was selected based on receiver operating characteristic(ROC)curve,accuracy,sensitivity,specificity,positive predictive value(PPV),negative predictive value(NPV),and decision curve analysis(DCA).Results A total of 107 radiomicfeatures were extracted from panoramic radiographs.After feature filtering,4 radiomic features were ultimately selected using the Lasso model.The XGBoost model showed higher predictive efficiency and stability,with an AUC of 0.962 in the training cohort and 0.770 in the test cohort.DCA curves also in-dicated that the XGBoost model was optimal.Conclusion The radiomic model based on panoramic radiographs demonstrates good per-formance in differentiating single or multiple root canals in mandibular first premolars.

Objective To explore better methods of ceramic crown design and reduce foreign body sensation of prostheses by digitally replicating the lingual morphology of the original teeth in the patient's aesthetic zone.Methods Patients with anterior tooth defects were collected from July 2022 to December 2023 at Department of Second Clinical Division of the Affiliated Stomatological Hospital,Nanjing Medical University.Patients with crown prostheses designed using automatically matched tooth morphology from the tooth shape database served as the control group.Patients with crown prostheses designed using digital technology to replicate the lingual morpholo-gy of the original teeth were used as the experimental group.Differences in occlusal evaluation and foreign body sensation evaluation of the prostheses in the two groups were compared.Results Results showed that the minimal interocclusal distance of the experimental group was greater than that of the control group,and the difference was statistically significant.The occlusal evaluation of the prostheses in the experimental group was better than that of the control group,and the difference was statistically significant.The foreign body sen-sation of the prostheses in the experimental group was also less than that of the control group.Conclusion Prostheses designed using digital technology to replicate the original lingual morphology of the teeth have a better lingual occlusal relationship with less foreign body sensation and better comfort.