Salivary flow rate and oral findings in Prader-Willi syndrome: a case-control study

BACKGROUND. Prader-Willi syndrome (PWS) is a rare complex multisystemic genetic disorder. AIM. The objective of this study was to provide a systematic assessment of whole saliva secretion and oral manifestations associated with PWS. DESIGN. Fifty individuals (5-40 years) with PWS and an age- and sex-matched control group were included. Whole saliva was collected. All participants underwent an anamnestic interview. Radiological and dental clinical examinations were carried out to identify hypodontia, dental caries, enamel defects and gingival inflammation. RESULTS. Mean whole salivary flow rate was 0.12 ± 0.11 mL/min in the study group compared with 0.32 ± 0.20 mL/min in the control group (P < 0.001). Hypodontia was significantly more common in PWS (P < 0.001), and dental caries in the age group >19 years was significantly lower in PWS (P = 0.04) compared with the controls. There was no significant difference in the prevalence of dental caries in the primary dentition or in the frequency of enamel defects in the permanent dentition between the two groups. Median Gingival Index was significantly higher in the Prader-Willi group compared with the controls (P = 0.02). CONCLUSIONS. Low salivary flow is a consistent finding in PWS. Nevertheless, despite dry mouth and dietary challenges, dental caries is not increased in Norwegian individuals with PWS.