Long-term oral and dental effects in childhood acute lymphoblastic leukemia survivors: a cross-sectional study comparing early and late post-treatment periods

Childhood cancer survivors face significant long-term oral health challenges following antineoplastic treatment. The primary aim of this study was to examine the effect of time elapsed since completion of antineoplastic treatment on oral health parameters — caries experience, salivary function, and dental developmental anomalies — in childhood ALL survivors. Secondary objectives included comparing oral health parameters between survivors and healthy sibling controls and identifying independent predictors of caries outcomes. This cross-sectional study included 38 ALL survivors (aged 5–18 years) and 20 healthy sibling controls. Dental caries was assessed using the International Caries Detection and Assessment System (ICDAS II) and DMFT/dft indices. Salivary flow rate (SFR) and pH were measured using standardized protocols. Dental developmental anomalies were assessed by combined clinical and panoramic radiographic examination. Comparisons were performed using the Mann-Whitney U test, the Kruskal-Wallis test, and the chi-square test, with multivariable linear regression used to identify independent predictors of caries outcomes. Early survivors demonstrated significantly higher mean ICDAS scores (median 1.38 vs. 0.60; p = 0.007) and elevated DMFT/dft indices (median 12.0 vs. 7.0; p = 0.002), together with significantly lower SFR (median 0.28 vs. 0.40 mL/min; p = 0.017), compared with late survivors. Dental developmental anomalies were significantly more prevalent in survivors (84.2%) than controls (10%; p < 0.001); microdontia was most common (37.7%), followed by root malformation (24.5%) and taurodontism (15.1%). Multivariable regression identified age and time since treatment completion as independent predictors of ICDAS scores (adjusted R² = 0.285, p = 0.014), while time since treatment completion independently predicted DMFT/dft scores (B = − 4.522, p = 0.003). Dental developmental anomalies were highly prevalent among childhood ALL survivors and, being a direct consequence of treatment, were independent of the time elapsed since its completion. In contrast, salivary flow rate and caries experience were poorer among survivors examined within 24–36 months of treatment completion than among those examined later, indicating gradual recovery of salivary function over time. Closer preventive dental monitoring during the first years after treatment, supported by sustained oncology–dental collaboration, is therefore recommended.