Introduction: The Anatomy and Physiology of Salivary Glands

Abstract

Saliva is the mixed glandular secretion which constantly bathes the teeth and the oral mucosa. It is constituted by the secretions of the three paired major salivary glands; the parotid, submandibular and sublingual. It also contains the secretions of the minor salivary glands, of which there are hundreds contained within the submucosa of the oral mucosa and some gingival crevicular fluid. The presence of saliva is vital to the maintenance of healthy hard (teeth) and soft (mucosa) oral tissues. Severe reduction of salivary output not only results in a rapid deterioration in oral health but also has a detrimental impact on the quality of life for the sufferer. Patients suffering from dry mouth can experience difficulty with eating, swallowing, speech, the wearing of dentures, trauma to and ulceration of the oral mucosa, taste alteration, poor oral hygiene, a burning sensation of the mucosa, oral infections including Candida and rapidly progressing dental caries. The sensation of dry mouth or xerostomia is becoming increasingly common in developed countries where adults are living longer. Polypharmacy is very common among the older adult population and many commonly prescribed drugs cause a reduction in salivary flow. Xerostomia also occurs in Sjögren's syndrome, which is not an uncommon condition. In addition to specific diseases of the salivary glands, salivary flow is usually severely impaired following radiotherapy in the head and neck area for cancer treatment in both children and adults of all ages. Clearly oral dryness is a problem which faces an increasingly large proportion of the population. An understanding of saliva and its role in oral health will help to promote awareness among health care workers of the problems arising when the quantity or quality of saliva is decreased; this awareness and understanding is important to the prevention, early diagnosis and treatment of the condition. There is an extensive body of research on saliva as a diagnostic fluid. It has been used to indicate an individual's caries susceptibility; it has also been used to reflect systemic physiological and pathological changes which are mirrored in saliva. One of the major Introduction: the anatomy and physiology of salivary glands