Submandibular sialolithiasis is a common condition characterized by the formation of calcified stones, or sialoliths, within the salivary glands or their ducts. These stones can obstruct saliva flow, leading to discomfort and other symptoms. While salivary stones can occur in any major salivary gland, they are most frequently found in the submandibular glands. This condition affects approximately 0.45% of the general population and is more commonly observed in adults between 30 and 60 years of age.
What It Is and How It Forms
A sialolith is a calcified mass that develops most often in the submandibular gland. This gland, located beneath the floor of the mouth in the submandibular triangle, produces saliva that drains into the mouth through Wharton’s duct. This duct opens into the floor of the mouth, near the frenulum of the tongue.
The submandibular duct is relatively long and has two bends, which can slow saliva flow. Saliva from the submandibular gland is also more viscous and contains higher concentrations of calcium and phosphate, contributing to stone formation. Additionally, submandibular saliva is more alkaline compared to other salivary glands, which can encourage the precipitation of inorganic salts.
Sialoliths are primarily composed of inorganic materials like calcium phosphate, hydroxyapatite, and whitlockite, with a central organic core. The exact mechanism of stone formation is not fully understood, but it is thought to involve the calcification of mucus plugs within the duct or issues with cellular component movement. Dehydration, certain medications (such as diuretics, anticholinergics, or antidepressants), and smoking can increase the risk of stone formation by altering saliva composition or flow.
Recognizing the Signs
Individuals with submandibular sialolithiasis experience pain and swelling in the affected salivary gland. These symptoms often worsen during or after eating, a phenomenon called “mealtime syndrome,” because eating stimulates saliva production and flow. The swelling can appear suddenly and may be diffuse, though it usually subsides within a few hours.
Besides pain and swelling, a person might notice tenderness or redness around the affected gland. Difficulty swallowing can occur if swelling is significant. Symptoms can fluctuate, with periods of discomfort followed by relief, depending on whether the stone partially or completely blocks the duct. Persistent obstruction can lead to gland inflammation, known as sialadenitis, and potentially bacterial infection, presenting with increased pain, warmth, and fever.
Diagnosis and Treatment Approaches
Identifying submandibular sialolithiasis begins with a physical examination, where a doctor might feel the stone within the duct, especially in the submandibular region. To confirm the diagnosis and determine the stone’s size and location, imaging techniques are employed. X-rays can detect calcified stones, though smaller or less calcified stones might be missed. Ultrasound is a common initial imaging choice as it is non-invasive and can visualize stones and any associated swelling.
For more detailed imaging, a CT scan provides a comprehensive view of the gland and ductal system, accurately pinpointing the stone’s position and size. Sialography, which involves injecting a contrast dye into the salivary duct before X-rays, is a highly accurate method for visualizing the ductal system and any blockages. These diagnostic tools help guide the appropriate treatment strategy.
Treatment approaches for submandibular sialolithiasis range from conservative measures to medical and surgical procedures. Conservative management is often the first step, aiming to encourage the stone’s natural passage. This includes maintaining hydration to keep saliva flowing, gently massaging the affected gland, and applying moist heat to reduce swelling and discomfort. Sucking on sour candies or chewing sugar-free gum can stimulate saliva production, which might help flush out smaller stones.
If conservative methods are insufficient, medical interventions may be considered. Sialagogues, medications or substances that increase saliva flow, can promote stone expulsion. If an infection develops, antibiotics will be prescribed to clear the bacterial infection and reduce inflammation. For stones that do not pass on their own, more invasive procedures may be necessary.
Sialoendoscopy is a minimally invasive procedure where a tiny endoscope is inserted into the salivary duct to visualize and remove the stone. This technique is effective for smaller stones located closer to the duct opening. If the stone is large, deeply embedded, or sialoendoscopy is not feasible, surgical removal of the stone (sialolithotomy) may be performed. In some cases, particularly with recurrent stone formation or significant gland damage, surgical removal of the entire submandibular gland might be necessary, though this is a last resort. The choice of treatment depends on the stone’s size, location, symptoms, and the patient’s overall health.
Prevention and Management
Preventing the recurrence of submandibular sialolithiasis focuses on maintaining optimal salivary flow and composition. Staying well-hydrated by drinking plenty of water throughout the day is a key strategy. This helps maintain a healthy volume and consistency of saliva, making it less likely for mineral deposits to form.
Stimulating saliva flow regularly can help prevent stone formation. Chewing sugar-free gum or sucking on sour candies, especially after meals, encourages the glands to produce more saliva, which can help flush out any accumulating debris or small calcifications before they develop into larger stones. Practicing good oral hygiene, including regular brushing and flossing, contributes to overall oral health, which can indirectly support salivary gland function. If symptoms persist or recur despite these measures, consulting a doctor is important for further evaluation and management.