Sialolithiasis is a term used to describe stones which form in the salivary glands. The overwhelming majority of stones are found in the submandibular salivary gland, which lies near the angle of the jaw. Stones are much more likely to form in the submandibular gland because there is a greater concentration of calcium in the saliva produced here than the other glands. Its duct is also much longer than those of the other glands, which also predisposes to stone formation. They can also less commonly affect the parotid salivary gland, which lies on the face in front of the ear. It is rare for stones to affect the sublingual and other minor salivary glands. Signs and SymptomsSialolithiasis is a painful condition. The pain is often made worse by eating, and the patient may notice some swelling in the gland. Some patients may also notice, or have noticed in the past, sand-like particles in their mouth. It is possible for the salivary gland to become infected, especially if the duct is blocked by the stone. In this case, there may be pus coming from the salivary gland and the mouth may also be red, tender and swollen. The patient may also feel a hard lump near their tongue if the stone is located in the end of the duct. It may also be difficult for the patient to eat if the duct is completely blocked by the stone, as saliva cannot easily enter the mouth from the affected gland. DiagnosisIt is possible to view some salivary stones on an x-ray. This is because stones in the submandibular gland are rich in calcium phosphate. Calcium deposits are visible on an x-ray as a white mass. However, stones in the parotid glands have a different composition and are less likely to show up on x-ray. Sialography is a superior method to x-ray in detecting sialolithiasis. This is a technique which is similar to plain x-ray, however, a contrast dye is injected into the salivary gland in question which helps to better visualise the anatomy of the gland and associated structures. Ultrasounds are of little value in the diagnosis of salivary stones. CausesOne of the main causes of salivary stones is dehydration. Dehydration reduces the water content of the saliva and causes the other components of the saliva to crystallise. A number of medications have been identified that increase the risk of developing sialolithiasis, such as certain diuretics and antidepressants. There is also a link between Sjogren’s syndrome (an autoimmune disease) and the development of sialolithiasis. Patients with Sjogren’s syndrome have antibodies against tissue in the eyes and the salivary glands, which gradually destroy the tissue and cause symptoms of dry eyes and dry mouth. The loss of fluid content in the saliva predisposes the patient with Sjogren’s syndrome to suffer with sialolithiasis. Interestingly, gout may also cause sialolithiaisis in rare instances. However, in patients with gout-induced sialolithiasis, the crystals are made up of uric acid; the substance forming the crystals which affect the joints of the sufferer. People who suffer from chronic inflammation of the salivary glands are also more likely to develop salivary stones. ComplicationsUntreated sialolithiasis can cause recurrent, painful infections, which can lead to scarring and abscess formation in the salivary gland. There are also risks involved with the treatment options for sialolithiasis. Surgical approaches to the salivary glands may result in damage to nearby nerves and blood vessels. The parotid gland is particularly at risk because the facial nerve passes through it. Intra-oral extraction techniques may also result in scarring to the duct and affect the drainage of saliva into the mouth. There is also a risk of infection following removal of the stones, due to the high volumes of bacteria in the mouth and surrounds. TreatmentThere are a number of treatment options available for sialolithiasis, largely dependent on the size and location of the stone. If the stones are small and near the end of the duct of the salivary gland, it may be possible to extract the stone via the mouth under local anaesthesia. Some larger stones may also be able to be extracted by placing a cannula in the duct and making a small cut in the duct, which allows for removal of the stone. In cases of very large, complicated stones, the entire salivary gland may be removed. Recent advances have seen the development of endoscopic techniques which can help to remove salivary stones in a much less invasive manner than other surgical methods. If you have questions about sialolithiasis and salivary gland problems contact your local doctor, who will arrange for you to see an Ear Nose Throat Specialist. We‘ll provide you with a straightforward, efficient and very effective treatment plan targeted to your condition. Sialolithiasis (also termed salivary calculi,[1] or salivary stones)[1] is a crystallopathy where a calcified mass or sialolith forms within a salivary gland, usually in the duct of the submandibular gland (also termed "Wharton's duct"). Less commonly the parotid gland or rarely the sublingual gland or a minor salivary gland may develop salivary stones.
The usual symptoms are pain and swelling of the affected salivary gland, both of which get worse when salivary flow is stimulated, e.g. with the sight, thought, smell or taste of food, or with hunger or chewing. This is often termed "mealtime syndrome".[2] Inflammation or infection of the gland may develop as a result. Sialolithiasis may also develop because of the presence of existing chronic infection of the glands, dehydration (e.g. use of phenothiazines), Sjögren's syndrome and/or increased local levels of calcium, but in many instances the cause is idiopathic (unknown). The condition is usually managed by removing the stone, and several different techniques are available. Rarely, removal of the submandibular gland may become necessary in cases of recurrent stone formation. Sialolithiasis is common, accounting for about 50% of all disease occurring in the major salivary glands and causing symptoms in about 0.45% of the general population. Persons aged 30–60 and males are more likely to develop sialolithiasis.[2] The term is derived from the Greek words sialon (saliva) and lithos (stone), and the Greek -iasis meaning "process" or "morbid condition". A calculus (plural calculi) is a hard, stone-like concretion that forms within an organ or duct inside the body. They are usually made from mineral salts, and other types of calculi include tonsiloliths (tonsil stones) and renal calculi (kidney stones). Sialolithiasis refers to the formation of calculi within a salivary gland. If a calculus forms in the duct that drains the saliva from a salivary gland into the mouth, then saliva will be trapped in the gland. This may cause painful swelling and inflammation of the gland. Inflammation of a salivary gland is termed sialadenitis. Inflammation associated with blockage of the duct is sometimes termed "obstructive sialadenitis". Because saliva is stimulated to flow more with the thought, sight or smell of food, or with chewing, pain and swelling will often get suddenly worse just before and during a meal ("peri-prandial"), and then slowly decrease after eating, this is termed meal time syndrome. However, calculi are not the only reasons that a salivary gland may become blocked and give rise to the meal time syndrome. Obstructive salivary gland disease, or obstructive sialadenitis, may also occur due to fibromucinous plugs, duct stenosis, foreign bodies, anatomic variations, or malformations of the duct system leading to a mechanical obstruction associated with stasis of saliva in the duct.[2] Salivary stones may be divided according to which gland they form in. About 85% of stones occur in the submandibular gland,[3] and 5–10% occur in the parotid gland.[2] In about 0–5% of cases, the sublingual gland or a minor salivary gland is affected.[2] When minor glands are rarely involved, caliculi are more likely in the minor glands of the buccal mucosa and the maxillary labial mucosa.[4] Submandibular stones are further classified as anterior or posterior in relation to an imaginary transverse line drawn between the mandibular first molar teeth. Stones may be radiopaque, i.e. they will show up on conventional radiographs, or radiolucent, where they not be visible on radiographs (although some of their effects on the gland may still be visible). They may also symptomatic or asymptomatic, according to whether they cause any problems or not. Swelling of the submandibular gland as seen from the outside The stone seen in the submandibular duct on the person's right side Signs and symptoms are variable and depend largely upon whether the obstruction of the duct is complete or partial, and how much resultant pressure is created within the gland.[1] The development of infection in the gland also influences the signs and symptoms.
Rarely, when stones form in the minor salivary glands, there is usually only slight local swelling in the form of a small nodule and tenderness.[1] The major salivary glands (paired on each side). 1. Parotid gland, 2. Submandibular gland, 3. Sublingual gland. There are thought to be a series of stages that lead to the formation of a calculus (lithogenesis). Initially, factors such as abnormalities in calcium metabolism,[3] dehydration,[2] reduced salivary flow rate,[2] altered acidity (pH) of saliva caused by oropharyngeal infections,[2] and altered solubility of crystalloids,[2] leading to precipitation of mineral salts, are involved. Other sources state that no systemic abnormality of calcium or phosphate metabolism is responsible.[1] The next stage involves the formation of a nidus which is successively layered with organic and inorganic material, eventually forming a calcified mass.[2][3] In about 15-20% of cases the sialolith will not be sufficiently calcified to appear radiopaque on a radiograph,[3] and will therefore be difficult to detect. Other sources suggest a retrograde theory of lithogenesis, where food debris, bacteria or foreign bodies from the mouth enter the ducts of a salivary gland and are trapped by abnormalities in the sphincter mechanism of the duct opening (the papilla), which are reported in 90% of cases. Fragments of bacteria from salivary calculi were reported to be Streptococci species which are part of the normal oral microbiota and are present in dental plaque.[2] Stone formation occurs most commonly in the submandibular gland for several reasons. The concentration of calcium in saliva produced by the submandibular gland is twice that of the saliva produced by the parotid gland.[3] The submandibular gland saliva is also relatively alkaline and mucous. The submandibular duct (Wharton's duct) is long, meaning that saliva secretions must travel further before being discharged into the mouth.[3] The duct possesses two bends, the first at the posterior border of the mylohyoid muscle and the second near the duct orifice.[3] The flow of saliva from the submandibular gland is often against gravity due to variations in the location of the duct orifice.[3] The orifice itself is smaller than that of the parotid.[3] These factors all promote slowing and stasis of saliva in the submandibular duct, making the formation of an obstruction with subsequent calcification more likely. Salivary calculi sometimes are associated with other salivary diseases, e.g. sialoliths occur in two thirds of cases of chronic sialadenitis,[4] although obstructive sialadenitis is often a consequence of sialolithiasis. Gout may also cause salivary stones,[4] although in this case they are composed of uric acid crystals rather than the normal composition of salivary stones.
Stone resulting in inflammation and dilation of the duct[5] Diagnosis is usually made by characteristic history and physical examination. Diagnosis can be confirmed by x-ray (80% of salivary gland calculi are visible on x-ray), by sialogram, or by ultrasound. Salivary gland stone and the hole left behind from the operation Some current treatment options are:
The prevalence of salivary stones in the general population is about 1.2% according to post mortem studies, but the prevalence of salivary stones which cause symptoms is about 0.45% in the general population.[2] Sialolithiasis accounts for about 50% of all disease occurring in major salivary glands, and for about 66% of all obstructive salivary gland diseases. Salivary gland stones are twice as common in males as in females. The most common age range in which they occur is between 30 and 60, and they are uncommon in children.[2]
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