Salivary gland stones, or sialoliths, are small, calcified deposits that form within the salivary glands or their ducts, hindering the normal flow of saliva. They cause temporary discomfort, pain, and swelling, which often intensifies when eating as saliva production is triggered. The submandibular glands, located beneath the jaw, are the most common site for these formations, accounting for up to 80% of all cases.
The Mechanism of Salivary Stone Formation
Salivary stones are primarily composed of mineral salts, such as calcium phosphate and hydroxyapatite, which precipitate around an initial microscopic core of organic debris. Formation is often triggered by decreased saliva flow, known as stasis, or changes in the saliva’s composition.
Dehydration is a contributing factor because it causes saliva to become thicker and more concentrated with minerals, increasing the likelihood of precipitation. The submandibular gland is susceptible because its duct (Wharton’s duct) is longer and requires saliva to flow slightly against gravity, slowing the rate. Once formed, the stone accelerates the deposition of more material, creating a calcified mass. Management focuses on physically removing or passing the stone, as chemical dissolution is not effective.
Conservative Home Management Techniques
For smaller stones, the initial approach uses non-invasive methods to encourage natural passage through the duct. These conservative techniques aim to increase salivary output and physically manipulate the stone toward the duct opening.
Stimulating saliva flow is a primary strategy, as the resulting increase in pressure and volume can help flush out the stone. This is achieved using sialogogues, substances that prompt the glands to produce more saliva. Sucking on sour items, such as sugar-free lemon drops or citrus fruit, is effective for this purpose.
Maintaining high hydration levels is also important to ensure the saliva is thin and less concentrated, allowing it to flow easily. Drinking plenty of water helps counteract the thickening of saliva that contributes to stone formation.
Manual manipulation of the affected area is another helpful technique. Gently massaging the salivary gland, typically under the jawline for a submandibular stone, can help physically milk the duct and push the stone forward. Combining this massage with moist heat, such as a warm compress, can reduce localized swelling and irritation, making passage less uncomfortable.
Clinical Interventions for Stone Removal
When conservative methods fail, or if the stone is large or deeply impacted, medical intervention is necessary. The standard of care favors minimally invasive, gland-preserving techniques over traditional surgery.
Sialendoscopy
Sialendoscopy is often the first-line treatment for salivary stones. This technique involves inserting a tiny, flexible scope into the salivary duct to visualize the stone directly. Small instruments, such as micro-forceps or a basket, are passed through the scope to grasp and retrieve the stone. Stones up to 4 millimeters can often be removed entirely using this outpatient procedure, frequently performed under local anesthesia.
Fragmentation Techniques
For larger or more complex stones, fragmentation techniques are employed. Intraductal shock wave lithotripsy (ISWL) involves inserting a probe through the sialendoscope to deliver targeted shock waves directly to the stone, breaking it into smaller pieces. These fragments are then flushed out by saliva flow or retrieved using the endoscope. Extracorporeal Shock Wave Lithotripsy (ESWL), which uses shock waves delivered from outside the body, is now less common than sialendoscopy-related methods.
Surgical Removal
If a stone is too large, too far back in the gland, or if the gland has suffered repeated infections, traditional surgical removal may be required. If the stone is near the duct opening, a small incision in the mouth may suffice to remove it while preserving the gland. Removal of the entire salivary gland is now reserved for complex cases due to the success of minimally invasive options.
Preventing Future Stone Formation
Reducing the risk of recurrence relies on maintaining a consistent environment that promotes healthy saliva flow. The most effective measure is consistent hydration, which ensures saliva remains thin and reduces the concentration of mineral salts prone to crystallization. A common recommendation is aiming for a daily fluid intake of approximately two to two and a half liters.
Routine oral hygiene also minimizes potential organic cores, such as cellular debris, around which stones can begin to form. Additionally, be mindful of medications that cause dry mouth, such as certain antihistamines or antidepressants, as reduced saliva flow increases risk. Consulting a healthcare provider about medication alternatives or management strategies for dry mouth can help mitigate this risk.