Oral health conditions in children with idiopathic nephrotic syndrome: a cross-sectional study

BACKGROUND: Nephrotic syndrome is one of the chronic illnesses in the pediatric age group. The aim of this study was to assess the oral health of patients with steroid-sensitive idiopathic nephrotic syndrome (iNS). METHODS: A case-control study was performed on iNS patients and healthy from May 2018 to April 2019. Dental caries was assessed by the World Health Organization criteria, developmental defects of enamel by the mDDE index, oral hygiene by the OHI-S and API, and gingival condition by the GI. Oral health behavior was recorded using a standardized questionnaire including tooth brushing, fluoride prevention, dietary habits and utilization of dental care. Additionally, Streptococcus mutans (SM) and Lactobacillus spp. (LB) bacteria in saliva were assessed using the CRT bacteria test. Statistical analysis comparing oral health parameters was carried by Pearson’s chi-squared, Fisher’s exact, Shapiro-Wilk verified by Student’s t or Mann-Whitney U tests. RESULTS: The study included 94 participants of both sexes at the age of 4 to 17 years (47 cases and 47 controls) who were treated in Clinic of Pediatric Nephrology or outpatients’ dental clinic in Wroclaw, Poland. The iNS patients compared to the controls revealed some lower caries experience (83.0% vs 95.7%) and number of caries affected primary and/or permanent teeth (4.6 ± 3.5 vs 6.0 ± 4.1), a significantly lower number of filled primary and/or permanent teeth (1.1 ± 1.6 vs 3.5 ± 3.0, P < 0.001) and higher incidence of enamel hypoplasia (31.9% vs 4.3%, P < 0.001). The numbers of the iNS patients with high level of SM and LB were similar to the controls. The iNS patients had a higher OHI-S score (1.89 ± 1.59 vs 1.05 ± 1.02, P < 0.010) and a higher GI score (0.7 ± 1.0 vs 0.3 ± 0.6, P = 0.050). Moreover, they less frequently brushed their teeth twice a day (78.8% vs 93.6%, P = 0.026) and more frequently consumed three or more snacks daily (53.2% vs 23.4%, P = 0.002). CONCLUSIONS: The iNS patients despite the poor oral hygiene revealed lower caries experience but smaller number of restored caries-affected teeth, more severe gingivitis and more frequently teeth affected by enamel hypoplasia.