Developmental defects of enamel in children with nephrotic syndrome: a cross-sectional study of proportion and independently associated factors.

BACKGROUND: To investigate the proportion, tooth distribution, and severity of developmental defects of enamel (DDE) in children with nephrotic syndrome (NS), and to identify factors associated with DDE. METHODS: A cross-sectional study was conducted involving 237 children aged 3-18 years with primary NS. Oral examinations were performed by calibrated pediatric dentists. To account for the clustering of multiple teeth within each patient, generalized estimating equations (GEE) with an exchangeable correlation structure were used to identify factors associated with tooth-level DDE. Patient-level stratification was also performed to explore the combined effects of clinical characteristics. RESULTS: The overall proportion of children with DDE (≥ 1 affected tooth) was 33.8% (80/237), with the highest proportion in the permanent dentition (53.5%, 53/99), followed by mixed (24.0%, 18/75) and primary dentition (14.3%, 9/63). Most lesions were mild (88.8%). Permanent dentition was an independent correlate of DDE (primary vs. permanent: OR = 0.207, P = 0.014; mixed vs. permanent: OR = 0.390, P = 0.008). Steroid-dependent NS was not significantly associated with DDE in the multivariable model (OR = 2.50, 95% CI: 0.73-8.62, P = 0.147). At the patient level, the highest DDE proportion was observed in children with both permanent dentition and steroid-dependent NS (63.8%). CONCLUSION: Among children with NS, the proportion of DDE was highest in the permanent dentition. Permanent dentition was independently associated with DDE. Steroid-dependent NS was not significant; however, the point estimate and subgroup findings suggest a signal requiring prospective validation. Interdisciplinary collaboration between pediatric nephrology and stomatology is recommended.