Oral dryness in Sjögren's syndrome patients. Not just a question of water

► SS-patients complain of xerostomia, affecting their oral health and quality of life. ► Glands of SS-patients show altered signalings that result in reduced water output. ► In SS-patients, mouth dryness correlates poorly with the unstimulated salivary flow. ► Lubricating properties of saliva depend on both salivary flow and the mucins' quality. ► Altered maturation of salivary mucins contributes to the mouth dryness in SS-patients.