Objective: Surface tension in saliva might contribute to the maintenance of upper airway patency. The present study aimed to determine whether salivary surface tension is altered in patients with Down syndrome who are predisposed to upper airway collapse.
Patients and methods: We used the pull-off force technique to measure surface tension in samples (100 μL) of saliva collected from twenty-three male patients with Down syndrome and twenty-three healthy males (controls). p < 0.05 was considered to indicate significance.
Results: Salivary surface tension was significantly lower in the patients than in the controls (57.3 ± 4.9 vs. 60.3 ± 4.7 mN/m; p = 0.039). Age and surface tension positively correlated in the patients (p = 0.001).
Conclusions: The lower surface tension of saliva in patients with Down syndrome might compensate for an anatomical predisposition towards upper airway collapsibility and other risk factors. The function of surface tension in saliva might be altered due to aging in such patients.