Nomogram For Predicting Weak Response To Non-Surgical Periodontal Therapy

This study aimed to identify risk factors for weak response to non-surgical periodontal therapy in patients with stage III/IV periodontitis and develop a predictive model to guide personalized treatment strategies. A total of 146 stage III/IV periodontitis patients who underwent non-surgical periodontal treatment were retrospectively examined and divided into training (n=104) and validation (n=42) datasets. Clinical and blood test data were collected. Training dataset was categorized into strong (n=63) and weak (n=41) response groups based on the percentage of sites with initial probing depths (PD) ≥5 mm showing a reduction of ≥2 mm. Logistic regression analyses identified independent risk factors, and a nomogram prediction model was constructed. Model discrimination was assessed using the area under the ROC curve (AUC), while calibration was evaluated through the Hosmer-Lemeshow test and calibration curves. Clinical decision curve analysis was used to assess net benefit. Thick gingival phenotype, Grade C periodontitis, elevated platelet to lymphocyte ratio (PLR), and mean corpuscular hemoglobin (MCH) were significant risk factors for weak response. The model demonstrated strong discrimination (AUC: 0.813 training, 0.719 validation) and good calibration. Clinical decision analysis confirmed the utility of the model within specific probability thresholds. Gingival phenotype, periodontitis grade, PLR, and MCH significantly affect non-surgical therapy outcomes in stage III/IV periodontitis patients. The nomogram provides reliable clinical predictive capabilities.