A novel intelligent gingival inflammation grading model based on dual-domain analysis and adaptive attention

This study proposes the gingival inflammation grading model Hybrid-Frequency Self-Attention Detection Transformer (HFSA-DETR), which is based on a dual-domain spatial-frequency analysis and adaptive sparse attention mechanism. The model aims to improve the grading accuracy of subtle inflammatory features and the sensitivity of identifying early gingival inflammation under non-uniform lighting conditions.

This study included 2300 gingival inflammation images for model training and evaluated the model's generalisation using an open-source dataset containing 1096 images of gingival inflammation. A spatial-frequency hybrid transformation module was introduced into the Real-Time Detection Transformer (RT-DETR) backbone network. Through dual-domain collaborative analysis, it simultaneously captured the colour, morphological, and texture periodic characteristics of gingival inflammation, addressed non-uniform lighting, and enhanced the model's ability to perceive subtle changes in gingival inflammation. Introducing an adaptive sparse self-attention mechanism in the neck network enabled the model to adaptively focus on key areas of gingival inflammation, reducing computational complexity while maintaining grading accuracy.

On the self-built internal gingivitis grading dataset, the HFSA-DETR model demonstrated improvements of 3.9%, 3.8%, and 3.3% in precision, recall, and mean average precision (mAP)50, respectively, compared to the baseline model; it exhibited significantly reduced parameter counts and computational requirements. On external validation datasets, the model achieved 92.8% precision, 91.5% recall, and 93.2% mAP50, demonstrating exceptional generalisation across diverse clinical imaging conditions.

The HFSA-DETR model achieved accurate grading of gingival inflammation by fusing spatial-frequency dual-domain analysis with an adaptive sparse attention mechanism. This model significantly reduces computational costs while maintaining high grading accuracy, providing an effective technical solution for objective quantitative assessment of gingival inflammation.

The HFSA-DETR model proposed in this study can help dentists detect and intervene early in gingival inflammation, providing a quantitative basis for clinical decision-making, especially for dental clinics with limited resources.