Saliva Basics – Source and Composition

Saliva’s composition and fluid dynamics are complex. Healthy saliva is primarily water and accounts for 99% of overall salivary volume. The remaining 1% is a complex mix of proteins, enzymes, mucins and buffering compounds, making saliva one of Mother Nature’s most sophisticated fluids.2,11

Ninety percent of whole saliva comes from three major glands. The parotid gland contributes 30% to the total volume, the submandibular glands account for 60%, and sublingual glands make up the remaining 5%. All three of these glands are located outside the mouth. Saliva is introduced into the oral cavity via a duct system specific to each gland. Minor salivary glands, responsible for the final 5% of salivary composition, are found throughout the mouth. Most of the minor salivary glands are located on the inside surface of the lower lip.2,11,31,32

Saliva has both serous and mucous components. Each gland supplies a different mix that contributes to overall oral wetness and comfort. The parotid gland is classified as serous, secreting mostly water and enzymes. The submandibular gland is considered seromucous. 90% of the flow is serous and 10% is mucous. The sublingual and minor salivary glands are mucous glands and deliver 80% of the daily mucins in the oral cavity.2,11,31,32

Salivary mucins add three critical properties: viscosity, elasticity and stickiness properties necessary to keep the saliva in continuous contact with oral structures. Mucins prevent the feeling of mouth dryness by lubricating and wetting all oral tissues.2,11,31,32