süljevoolu

Süljevoolu, Estonian for salivary flow, refers to the secretion and movement of saliva from the salivary glands into the mouth. Saliva is produced mainly by the major glands—the parotid, submandibular, and sublingual glands—and by numerous minor glands distributed throughout the oral mucosa. The flow serves to lubricate the oral cavity, aid digestion, protect teeth and mucosa, remineralize enamel, and buffer acidic challenges.

Regulation and composition: Salivary flow is controlled by the autonomic nervous system. Parasympathetic activity increases the volume of watery saliva, while sympathetic activity tends to increase protein content and viscosity. Flow rates vary with activity: resting (unstimulated) salivary flow averages about 0.3–0.5 mL/min, whereas stimulated flow can typically reach about 1–2 mL/min. The composition of saliva changes with flow rate, with higher water content during stimulation and more enzymes and mucins at different states of secretion.

Clinical relevance: Measurement of salivary flow, or sialometry, helps assess conditions such as xerostomia (subjective dryness) and hyposalivation (reduced flow). Reduced süljevoolu is associated with Sjögren's syndrome, diabetes, head and neck radiation, and certain medications (for example, anticholinergics). Adequate flow supports oral health by reducing caries risk and mucosal irritation; when flow is diminished, therapies may include saliva substitutes, sialogogues to stimulate secretion, hydration, and management of underlying causes.

Research and variation: Ongoing studies investigate how aging, hydration, medications, and diseases affect süljevoolu, as well as how saliva composition influences the oral microbiome and overall dental health.