New IPCL Classification Using NBI for Early Detection of OPMDs Malignant Transformation.

OBJECTIVES: Introduce a new intrapapillary capillary loop (IPCL) classification using narrow-band imaging (NBI) to diagnose early malignant transformation in oral potentially malignant disorders (OPMDs). METHODS: In the exploratory phase, NBI images from 241 patients with OPMDs and oral squamous cell carcinoma (OSCC) were assessed for three basic IPCL features-dilation, unevenness, and tortuosity-to identify patterns associated with OPMDs malignant transformation. Chi-square analysis and logistic regression differentiated these patterns between low-risk (no/mild dysplasia) and high-risk (moderate/severe dysplasia, invasive carcinoma) lesions, establishing a new classification system. In the validation phase, the system was applied to 90 patients with histopathological results confirming diagnostic accuracy. RESULTS: Four distinct IPCL types were identified: normal, dilated, irregular, and chaotic, with increasing odds ratios for high-risk lesions. The ROC curve had an AUC of 0.913, with irregular and chaotic types providing the best diagnostic performance, achieving sensitivities and specificities of 84.2% and 88.4%, respectively. In the validation phase, the new classification achieved an overall diagnostic accuracy of 84.4% and substantial inter-observer consistency (kappa = 0.694). CONCLUSION: The new IPCL classification effectively identifies high-risk oral lesions, enhancing the diagnostic utility of NBI for early detection of OPMDs malignant transformations.