Salivary duct stricture (also termed salivary duct stenosis) is narrowing of the duct of a major salivary gland.
The salivary glands in mammals are exocrine glands that produce saliva through a system of ducts. Humans have three paired major salivary glands as well as hundreds of minor salivary glands. Salivary glands can be classified as serous, mucous or seromucous (mixed).
Strictures are the second most common cause of chronic obstructive sialadenitis, after salivary stones. [1] In line with this, strictures may give rise to the "meal time syndrome", [1] where there is pain and swelling of the involved salivary gland upon salivary stimulation with the sight, smell and taste of food. In other cases, there is irregular and intermittent pain and swelling of the gland which is not related to meal times. [1] Typically the swelling is present upon waking or occurs before the first meal of the day. After several hours, the swelling goes down suddenly with a rush of foul tasting saliva. [1] Strictures are more common in the parotid duct system compared to the submandibular duct system. [2]
Sialadenitis (sialoadenitis) is inflammation of salivary glands, usually the major ones, the most common being the parotid gland, followed by submandibular and sublingual glands. It should not be confused with sialadenosis (sialosis) which is a non-inflammatory enlargement of the major salivary glands.
Chronic inflammation of the duct system (sialodochitis) may cause some segments of the duct to narrow due to fibrosis, and others to dilate. [2]
Sialodochitis, is inflammation of the duct system of a salivary gland. This is compared to sialadenitis, which is inflammation of the gland parenchyma.
Fibrosis is the formation of excess fibrous connective tissue in an organ or tissue in a reparative or reactive process. This can be a reactive, benign, or pathological state. In response to injury, this is called scarring, and if fibrosis arises from a single cell line, this is called a fibroma. Physiologically, fibrosis acts to deposit connective tissue, which can interfere with or totally inhibit the normal architecture and function of the underlying organ or tissue. Fibrosis can be used to describe the pathological state of excess deposition of fibrous tissue, as well as the process of connective tissue deposition in healing. Defined by the pathological accumulation of extracellular matrix (ECM) proteins, fibrosis results in scarring and thickening of the affected tissue, it is in essence an exaggerated wound healing response which interferes with normal organ function.
Saliva stagnates and forms a mucus plug behind the stricture during sleep when the salivary output of the parotid is reduced. Then, when salivary secretion is stimulated, the mucus plug becomes stuck in the stricture. [1] The backlog of saliva behind the blockage causes the swelling, and the increased pressure inside the gland causes the pain. When the mucus plug is dislodged, the built up saliva is released and the swelling subsides.
Strictures tend to be diagnosed based on difficulty with insertion and manipulation during sialendoscopy, [2] or by sialography or ultrasound. [1]
Sialography is the radiographic examination of the salivary glands. It usually involves the injection of a small amount of contrast medium into the salivary duct of a single gland, followed by routine X-ray projections.
Ultrasound is sound waves with frequencies higher than the upper audible limit of human hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hear it. This limit varies from person to person and is approximately 20 kilohertz in healthy young adults. Ultrasound devices operate with frequencies from 20 kHz up to several gigahertz.
Treatment is by endoscopic dilation, or failing this, surgery. [1]
In one report, about 20% of individuals with mealtime syndrome had strictures upon sialography. [1] For unknown reasons, strictures seem to be more common in females. [1]
Sjögren syndrome is a long-term autoimmune disease that affects the body's moisture-producing glands. Primary symptoms are a dry mouth and dry eyes. Other symptoms can include dry skin, vaginal dryness, a chronic cough, numbness in the arms and legs, feeling tired, muscle and joint pains, and thyroid problems. Those affected are at an increased risk (5%) of lymphoma.
The parotid gland is a major salivary gland in many animals. In humans, the two parotid glands are present on either side of the mouth and in front of both ears. They are the largest of the salivary glands. Each parotid is wrapped around the mandibular ramus, and secretes serous saliva through the parotid duct into the mouth, to facilitate mastication and swallowing and to begin the digestion of starches. There are also two other types of salivary glands; they are submandibular and sublingual glands.
The paired submandibular glands are major salivary glands located beneath the floor of the mouth. They each weigh about 15 grams and contribute some 60–67% of unstimulated saliva secretion; on stimulation their contribution decreases in proportion as the parotid secretion rises to 50%.
Xerostomia, also known as dry mouth, is dryness in the mouth, which may be associated with a change in the composition of saliva, or reduced salivary flow, or have no identifiable cause.
Parotitis is an inflammation of one or both parotid glands, the major salivary glands located on either side of the face, in humans. The parotid gland is the salivary gland most commonly affected by inflammation.
The parotid duct or Stensen duct is a duct and the route that saliva takes from the major salivary gland, the parotid gland into the mouth.
Oral mucocele is a clinical term for two related phenomena: mucus extravasation phenomenon and mucus retention cyst. Other names include mucous extravasation cyst, mucous cyst of the oral mucosa, and mucous retention and extravasation phenomena.
Sialolithiasis, is a condition where a calcified mass or sialolith forms within a salivary gland, usually in the duct of the submandibular gland. Less commonly the parotid gland or rarely the sublingual gland or a minor salivary gland may develop salivary stones.
Sialoendoscopy is a minimally invasive technique that allows for salivary gland surgery for the safe and effective treatment of obstructive salivary gland disorders and other conditions of the salivary glands. During sialoendoscopy a small endoscope is placed into the salivary glands through the salivary ducts that empty into the mouth. Sialoendoscopy is an efficient yet simple mode of treatment for major salivary gland obstructions, strictures and sialoliths. Depending on the obstruction, sialoendoscopy can be conducted under local anesthesia in an outpatient office or in the operating room under general anesthesia.
Salivary gland diseases (SGD) are multiple and varied in cause.
A sialocele is a localized, subcutaneous cavity containing saliva. It is caused by trauma or infection. They most commonly develop about 8–14 days after injury.
A parotidectomy is the surgical excision (removal) of the parotid gland, the major and largest of the salivary glands. The procedure is most typically performed due to neoplasms (tumors), which are growths of rapidly and abnormally dividing cells. Neoplasms can be benign (non-cancerous) or malignant (cancerous). The majority of parotid gland tumors are benign, however 20% of parotid tumors are found to be malignant. A parotidectomy is performed mostly by the oral and maxillofacial surgeons and otolaryngologist.
The human digestive system consists of the gastrointestinal tract plus the accessory organs of digestion. Digestion involves the breakdown of food into smaller and smaller components, until they can be absorbed and assimilated into the body. The process of digestion has many stages. The first stage is the cephalic phase of digestion which begins with gastric secretions in response to the sight and smell of food. The next stage starts in the mouth.
Pneumoparotitis, is a rare cause of parotid gland swelling which occurs when air is forced through the parotid (Stenson) duct resulting in inflation of the duct.
A salivary gland fistula is a fistula involving a salivary gland or duct.