TFF3 and obstructive sleep apnea syndrome: Thus, Chaiyarit et al. detected a significant reduction of TFF3 expression in oral mucosa of patients with chronic periodontitis compared to healthy mucosa [44], and Siber-Hoogeboom et al. described significantly lower TFF3 saliva protein concentrations in cases of rhonchopathy and obstructive sleep syndrome (OSA) compared to a healthy control group [45].