Abstract:Objective Regarding the association between severe adenoid hypertrophy (AH) and craniofacial development abnormalities in children during the mixed dentition period, to investigate the correlation between non-invasive facial measurements, clinical symptoms and AH, and construct a predictive model for the early diagnosis of severe AH.Methods A cross-sectional study was adopted, including 201 children aged from 6 to 8 years in the mixed dentition stage who visited Shanghai Ninth People’s Hospital from August 2023 to December 2024. The craniofacial morphological parameters including facial measurement angles and ratios from lateral photos, data of clinical symptom indicators including breathing patterns, degree of tonsillar hypertrophy, history of recurrent tonsillitis, history of rhinitis/asthma, OSA-18 questionnaire scores, history of otitis media, etc were collected. All the study subjects were randomly divided into a modeling group (n=149) and a validation group (n=52) at a ratio of 3∶1. The modeling group was further divided into a mild-to-moderate AH group (n=77) and a severe AH group (n=72) based on nasal endoscopy. LASSO regression was used to screen positive variables, and a Logistic regression prediction model was constructed. The model performance was verified via receiver operating characteristic (ROC) curves, calibration plots, and decision curve analyses (DCA).Results Compared to the mild-to-moderate AH group, children with severe AH presented with decreased facial convexity [(173.24±2.71)° vs (171.01±4.08)°,P<0.001], enhanced lip prominence (0.90±0.09 vs 1.02±0.11, P<0.001),and increased maxillary convexity [(30.37±6.52)° vs (35.98±7.25)°,P<0.001], as well as other characteristic facial changes. Multivariate analysis revealed that the breathing patterns (OR<1, P<0.05), chronic tonsillitis (OR=6.035, P=0.007), chronic rhinitis (OR=5.183, P=0.013), asthma (OR=14.927, P=0.002), and severe snoring (OR=5.803, P=0.011) were also associated with severe AH. The composite prediction model based on these factors had an AUC of 0.949 in the modeling group and 0.961 in the validation group, indicating good discrimination and clinical applicability.Conclusions The facial convexity, lip prominence, and maxillary convexity in children during the mixed dentition stage are early sensitive indicators of severe AH. The facial-symptom prediction model constructed based on these factors provides a non-invasive and efficient screening method that can effectively assist in the preclinical diagnosis and wide screening of severe AH.