The following flow chart Figure 4 shows the events associated with stimulus secretion coupling which involves the basic process of receptor stimulation which results in increase in the concentration of a secondary messenger, which will further trigger additional events leading to a cellular response [ 3 , 4 , 5 , 6 ].
Flowchart depicting sequence of events following neural stimulation. Copious watery saliva is secreted in response to parasympathetic stimulation and thicker saliva in response to sympathetic stimulation. Other factors affecting saliva composition are flow rate, circadian rhythm, duration of stimulus, nature of stimulus and diet.
During sleep very little saliva is secreted by major salivary glands and majority of the saliva secreted is by the minor salivary glands. Concentration of saliva depends on rate of flow and not on nature of stimulus [ 2 , 3 , 4 , 5 , 6 ]. Historically, it was suggested that parotid salivary gland secretes a hormone called parotin which was considered to have a protein-anabolic function and deficiency resulted in diseases such as chondrodystrophia fetalis, Kaschin-Beck disease, etc.
An increase in the flow of saliva is referred to as sialorrhea ptyalism , while a decrease in the salivary flow is referred to as xerostomia dry mouth. Xerostomia is observed in menopause, patients treated by radiation therapy, old age, prolonged use of tranquilizers, amphetamines, antihypertensive and anticonvulsant drugs. A number of systemic conditions affect the functioning of the secretion of salivary glands. Hyperthyroidism, pernicious anemia, vitamin D deficiency, multiple sclerosis and poorly controlled diabetes mellitus affect the salivary glands.
Inflammatory, infective and neoplastic diseases also disrupt the activity of salivary gland secretion. Salivary secretion is influenced by hormones. For example antidiuretic hormone facilitates water reabsorption by striated duct, aldosterone causes increased sodium reabsorption by striated duct, testosterone and thyroxine increase salivary secretion [ 2 , 8 , 9 ]. Protection: the saliva contains mucin and glycoproteins which provides it with lubricating properties and moistening the oral cavity, thus preventing friction between the oral structures during physiological functions like mastication.
The constant flow of saliva provides clearance of accumulated food debris and microorganisms. Mucins also provide thermal and chemical insulation. Proteins, glycoproteins and mucins form a coating called pellicle formation. Saliva acts as a source of calcium, phosphate, fluoride, statherin and proline rich protein which maintain the integrity of enamel and repair.
Digestion: water and mucin content of saliva aids in bolus formation during the process of mastication. Antimicrobial activity: mucins aid in providing a physical barrier to infections by preventing attachment of microorganisms to tooth and tissue surface.
Presence of secretory immunoglobulin A provides immune defense. Peroxidase, lysozyme, lactoferrin, histatin, mucins, agglutinin, defensins and cathelicidin also help in providing antimicrobial activity. Buffering: bicarbonate, phosphate, basic proteins, urea and ammonia help maintain the pH and neutralization of acids.
Tissue repair: salivary glands release growth factors, trefoil proteins into saliva which aid is tissue repair and regeneration. Taste: saliva acts as a solvent in which molecules from food items can dissolve and reach the taste buds, epidermal growth factor and carbonic anhydrase VI maintains taste buds. Role of saliva in periodontal pathology: saliva exerts a major influence on plaque initiation, maturation and metabolism. The first step in plaque formation is formation of pellicle followed by plaque formation and maturation [ 1 , 2 , 3 , 4 , 5 , 6 , 8 , 9 ].
Salivary proteins may play a role in plaque mineralization. It is indicated that esterase, pyrophosphatase, acid phosphatase and lysozyme may be involved. Persons with heavy calculus, have higher levels of salivary glycoproteins than non-calculus formers [ 1 , 2 , 3 , 4 , 5 , 6 , 8 , 9 ]. Polymorphonuclear neutrophils PMNs reach the oral cavity by migrating through the lining of gingival sulcus.
Skougaard and Bay, believe that orogranulocytic migratory rate correlates with severity of gingival inflammation and is therefore reliable index for assessing gingivitis [ 8 , 9 , 10 , 11 ].
The saliva acts as an important diagnostic oral fluid owing to its ease and non-invasive mode of collection. A number of components secreted in saliva can be assessed and used to assess diseased states. A few of the components used as specific biomarkers for detection of periodontal disease include immunoglobulins Ig such as IgA, IgM, IgG which interfere in adherence and bacterial metabolism and are present in increased concentration in saliva of chronic and aggressive periodontal patients.
Nonspecific markers for aggressive periodontitis include mucins which interfere with the colonization of Aggregatibacter actinomycetemcomitans A. Markers for chronic periodontitis include lysozyme which regulates biofilm accumulation and peroxidase which interferes with biofilm accumulation.
Nonspecific markers for both chronic and aggressive periodontitis include histatin which neutralizes lipopolysaccharide and enzymes known to affect periodontium and C-reactive proteins which are present in increased concentrations in saliva and serum of patients with periodontitis [ 8 ]. Other areas where saliva can be used for diagnosis of diseases and conditions include cystic fibrosis, which is a genetically transmitted disease of children and young adults characterized by generalized exocrinopathy.
In this condition, saliva contains increased calcium levels, elevated levels of sodium and a decrease in flow rate [ 8 , 9 ].
A low resting flow rate and abnormally low stimulated flow rate of whole saliva. An antibody p53 can also be detected in the saliva of patients diagnosed with oral squamous cell carcinoma SCC.
Saliva can be used for monitoring of anti-epileptic drugs as a positive correlation between salivary and serum carbamazepine levels has been observed. In another study, salivary levels of phenobarbital and phenytoin demonstrated excellent correlations with serum levels of these medications. Other drugs that can be identified in saliva are amphetamines, barbiturates, benzodiazepines, cocaine, phencyclidine PCP , and opioids [ 8 , 9 , 10 ].
Steroid hormones can be detected in saliva. Recent focus on the potential role of periodontal disease as a risk factor for cardiovascular and cerebrovascular diseases [ 13 , 14 ] and the occurrence of pre-term low-birth-weight babies [ 15 ] bring new importance to this aspect of salivary analysis [ 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ]. Salivary markers as potential diagnostic tests for periodontal disease include proteins of host origin i.
National Institute of Dental and Craniofacial Research, has highlighted the use of saliva for translational and clinical application by use of salivary proteome and the salivary transcriptome for early detection, disease progression and therapeutic monitoring [ 8 , 9 ]. Gene therapy has been developed to deliver growth hormone in deficiency states by salivary gland expression of growth hormone [ 16 ]. The secretions of salivary gland form an integral part of maintaining the physiology of the oral cavity.
Saliva is the most important and essential secretion of the salivary glands. Saliva itself has varied functions in the oral cavity and provides additional insight and details of the systemic status of the individual as well. With the advancement in the field of proteomics, transcriptomics and genomics, better and easier methods of detecting diseases by analyzing saliva are being discovered.
In many cases, yes. In fact, it is often safer to do the surgeries concurrently because the parotid surgical procedure carefully traces the facial nerve and positions it safely.
Doing a facelift at the same time lowers the chance of accidentally damaging this nerve at a later time because of its shifted position. Depending on the size of the tumor removed, there may be excess skin on one side of the face that will need to be tightened. To maintain facial symmetry, the other side of the face may also need tightening. So a facelift at this time may be an ideal choice.
Larian and his team will advice you if a facelift is an option for you. The most common approach to dealing with parotid tumors, even benign ones, is to surgically remove them. These tumors can grow to abnormal sizes that can disfigure the face. More importantly, even a benign parotid tumor can become cancerous if left alone to grow.
There are a number of non-surgical procedures that often help the stones go away without surgery. You can plan on one to two weeks for initial incision healing and about six weeks for complete incision healing.
Scar creams are advised for use to hasten healing and should be used for the first six weeks. Incisions may continue to change in form for up to two years after surgery, but most scars are hidden behind the jawline and ear and not readily noticeable.
Frequently Asked Questions about Parotid Surgery: At the Center for Advanced Parotid Surgery, our team of medical professionals specializes in performing minimally invasive parotidectomy with a focus on facial nerve preservation and facial reconstruction. How Should I Prepare for Surgery?
Ensure all your questions are answered. Write them down when you think of them. You should have a clear idea of exactly what surgery is planned, what will be done, the risks, all your options and what the expected benefits are. You should tell your surgeon what medications and supplements including herbal and OTC medications like ibuprofen you are currently taking. Ensure that you have stopped taking any medication or supplement that our surgeon asks within the proper timeframe.
If you are not already leading a healthy life, it is best to start doing so several weeks before the surgery, not just before. Bicarbonate secretion is of tremendous importance to ruminants because it, along with phosphate, provides a critical buffer that neutralizes the massive quantities of acid produced in the forestomachs.
Small collecting ducts within salivary glands lead into larger ducts, eventually forming a single large duct that empties into the oral cavity. Most animals have three major pairs of salivary glands that differ in the type of secretion they produce:.
The basis for different glands secreting saliva of differing composition can be seen by examining salivary glands histologically. Two basic types of acinar epithelial cells exist:. Acini in the parotid glands are almost exclusively of the serous type, while those in the sublingual glands are predominantly mucus cells. In the submaxillary glands, it is common to observe acini composed of both serous and mucus epithelial cells. In the histologic sections of canine salivary gland shown above, the cells stained pink are serous cells, while the white, foamy cells are mucus-secreting cells.