Sialolithiasis overview

# Overview
Sialolithiasis was first discovered by Kuttner, a German physician, in 1896 during investigation of chronically swollen submandibular gland. Sialadenoscope were used for the first time in 1991. Sialolithiasis is the presence of stones within the salivary glands or the salivary gland ducts.The exact pathogenesis of sialolithiasis is not fully understood, but the relative stagnation of salivary flow and calcium concentration may be important. Almost 75 percent of sialolithiasis cases are single. 3 percent of stones are bilateral and most of them are located in parotid glands. Stone formation is 80 to 90 percent in the submandibular gland, 6 to 20 percent in the parotid glands and 1 to 2 percent in the sublingual or minor salivary glands. The exact etiology of sialolithiasis is not well understood, but the relative stagnation of salivary flow, and calcium concentration may be important. Sialolithiasis should be differentiated from other diseases that cause swelling in salivary glands, such as acute bacterial sialadenitis, chronic bacterial sialadenitis, viral sialadenitis, human immunodeficiency virus, radiation, and systemic diseases such as, sarcoidosis, and sjogren's syndrome. Common risk factors in the development of sialolithiasis include dehydration, duiretics, local trauma, sjogrens. Sialolithiasis is mainly diagnosed by history and physical examination. Diagnosis can be confirmed by computed tomography, ultrasound, magnetic resonance sialography, conventional sialography. High resolution noncontrast computed tomography (CT) scanning is the study of choice for the diagnosis of sialolithiasis. Conservative treatment is the first line of therapy in the most patients. The most commonly used treatment options are hydration, moist heat, gland massage, and pain control. Antibiotics can be used in the case of superimposed infection. Many cases of sialolithiasis may not be cured by using medical therapy alone; invasive, or open surgery methods can be used for the salivary gland stones.  Most commonly used methods are sialoendoscopy, laser lithotripsy, and stone removal with wire basket. If all of above methods fail, open surgical intervention should be used.

# Historical Perspective
Sialolithiasis was first discovered by Kuttner, a German physician, in 1896 during investigation of chronically swollen submandibular gland. Sialadenoscope were used for the first time in 1991.

# Classification
There is no established system for the classification of sialolithiasis, but it may be classified according to the location of the stone, submandibular glands, parotid glands, and sublinguals or minor salivary glands ; or radiographic charachteristics: radiopaque, or radiolucent.

# Pathophysiology
Sialolithiasis is the presence of stones within the salivary glands or the salivary gland ducts.The exact pathogenesis of sialolithiasis not fully understood but the relative stagnation of salivary flow and calcium concentration may be important. Almost 75 percent of sialolithiasis cases are single. 3 percent of stones are bilateral and most of them are located in parotid glands. Stone formation is 80 to 90 percent in the submandibular gland, 6 to 20 percent in the parotid glands and 1 to 2 percent in the sublingual or minor salivary glands. Sialoadenitis is inflammation of a salivary gland. Acute sialoadenitis may be caused by viral or bacterial infection. Chronic sialoadenitis is caused by repeated episodes of inflammation. On gross pathology, hard yellow -white spherical depositions usually less than 1 cm are seen. On microscopic pathology, dilated ducts with squamous metaplasia or calculi are usually present.

# Causes
The exact etiology of sialolithiasis is not well understood, but the relative stagnation of salivary flow and calcium concentration may be important.

# Differentiating Hereditary pancreatitis from Other Diseases
Sialolithiasis should be differentiated from other diseases that cause swelling in salivary glands, such as acute bacterial sialadenitis, chronic bacterial sialadenitis, viral sialadenitis, human immunodeficiency virus, radiation, and systemic diseases such as, sarcoidosis, and sjogren's syndrome.

# Epidemiology and Demographics
The incidence of sialolithiasis is approximately 100 per 100,000 individuals in autopsy studies worldwide. The prevalence of sialolithiasis is approximately 450 per 100,000 individuals worldwide. Sialolithiasis commonly affects individuals between the ages of 30 and 60 years. There is no racial predilection to sialolithiasis. Men are more commonly affected by sialolithiasis than women.

# Risk Factors
Common risk factors in the development of sialolithiasis include dehydration, duiretics, local trauma, sjogrens.

# Screening
There is insufficient evidence to recommend routine screening for sialolithiasis.

# Natural History, Complications, and Prognosis
If left untreated, patients with sialolithiasis may progress to develop secondary infection and chronic sialadenitis. Common complications of sialolithiasis include infection and recurrence. Prognosis is generally good.

# Diagnosis

## Diagnostic study of choice
Sialolithiasis is mainly diagnosed by history and physical examination. Diagnosis can be confirmed by computed tomography, ultrasound, magnetic resonance sialography, conventional sialography. High resolution noncontrast computed tomography (CT) scanning is the study of choice for the diagnosis of sialolithiasis.

## History and Symptoms
A positive history of intermittent pain and hard lumps is suggestive of sialolithiasis. The most common symptoms of sialolithiasis include pain and swelling. Less common symptoms of sialolithiasis include painless swelling, pain without swelling and bad breath.

## Physical Examination
Patients with sialolithiasis usually appear normal. Physical examination of patients with sialolithiasis is usually remarkable for tenderness of the involved gland, palpable hard lump and pus discharging from the duct in cases of acute bacterial sialadenitis.

## Laboratory Findings
There are no diagnostic laboratory findings associated with sialolithiasis. In the case of superimposed inflammation and infection, high ESR or leukocytosis may be seen.

## Electrocardiogram
There are no ECG findings associated with sialolithiasis.

## X-ray
An x-ray may be helpful in the diagnosis of sialolithiasis. Radiopaque stones can be seen in x-rays.

## Ultrasound
Ultrasound may be helpful in the diagnosis of sialolithiasis. Findings on ultrasound suggestive of sialolithiasis, include hyperechoic points or lines with distal acoustic shadowing and dilation of the excretory duct.

## CT scan
Head and neck CT scan is the study of choice for the diagnosis of sialolithiasis. Findings on CT scan suggestive of sialolithiasis include hyperdensity of gland with stranding and enlargement of the gland in acute obstruction. In chronic sialolithiasis, fatty atrophy and reduction in salivary gland parenchymal volume may be seen.

## MRI
Magnetic resonance sialography may be helpful in the diagnosis of sialolithiasis Findings on Magnetic resonance sialography suggestive of sialolithiasis include low signal regions outlined by saliva (high signal regions) on T2 weighted images. MRI can distinguished acute from chronic obstruction.

## Other Imaging Findings
Sialography may be helpful in the diagnosis of sialolithiasis. Findings on sialography suggestive of sialolithiasis include filling defect and the contrast agent not passing through the duct due to complete obstruction.

## Other Diagnostic Studies
There are no other diagnostic studies associated with sialolithiasis.

# Treatment

## Medical Therapy
Conservative treatment is the first line of therapy in the most patients. The most commonly used treatment options are hydration, moist heat, gland massage, and pain control. Antibiotics can be used in the case of superimposed infection. Many cases of sialolithiasis may not be cured by using medical therapy alone; invasive, or open surgery methods can be used for the salivary gland stones.

## Surgery
Many cases of sialolithiasis may not be cured by using medical therapy alone; invasive, or open surgery methods can be used for the salivary gland stones. Most commonly used methods are sialoendoscopy, laser lithotripsy, and stone removal with wire basket. If all of above methods fail, open surgical intervention should be used.

## Primary Prevention
Effective measures for the primary prevention of sialolithiasis include healthy oral care regimen and increased water intake.

## Secondary Prevention
Effective measures for the secondary prevention of sialolithiasis include healthy oral care regimen, treatment of underlying disease and avoiding anticholinergic and diuretic medications.