Interpretable two-stage deep learning for pediatric obstructive sleep apnea diagnosis using lateral cephalograms

Objective: Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a prevalent sleep-breathing disorder in pediatrics, yet early and accurate detection remains challenging due to the limited accessibility and efficiency of conventional diagnostic methods. This study aims to develop and validate an artificial intelligence framework that utilizes routine lateral cephalograms (LCs) to provide automated, accurate, and interpretable risk evaluations for pediatric OSAHS. Methods: We retrospectively enrolled 188 children from two hospitals between January 2021 and October 2025. A total of 150 LCs were used for cross- validation, and 38 LCs were reserved as an independent test dataset. Using LCs, we proposed and developed an interpretable two-stage framework for pediatric OSAHS diagnosis. The first stage segmented the upper airway, and the second stage performed classification using a modified fusion model that integrate information from both craniofacial structures and the upper airway. We compared different input strategies and used Grad-CAM for model interpretation. Clinical utility was evaluated in a reader study comparing dentists' performance across different experience levels. Results: The upper airway segmentation achieved a mean DSC of 0.931 and an IoU of 0.872. For OSAHS classification, the fusion model achieved an AUC of 0.945 (95% CI: 0.863-0.994) and an F1 score of 0.933 (95% CI: 0.818-0.995), outperforming the LCs model (AUC 0.797, 95% CI: 0.585-0.968) and the mask-based ROI model (AUC 0.882, 95% CI: 0.748-0.983). Grad-CAM consistently highlighted anatomically plausible regions related to craniofacial structure and the upper airway. In the reader study, AI assistance increased diagnostic accuracy by 0.165 for junior dentists and 0.237 for senior dentists. Conclusion: Our model represents a promising tool for automated pediatric OSAHS diagnosis based on routinely acquired LCs in dental settings. By enhancing diagnostic accuracy and interpretability, it has the potential to support early detection and individualized management.