Sialolithotomy: Intraoral Technique for Salivary Stone Removal

Salivary stones, or sialoliths, can obstruct salivary gland ducts, leading to pain and swelling, especially during meals. While small stones may pass on their own, larger ones often require medical intervention to prevent infection or persistent blockage.

One effective method for removing accessible stones is intraoral sialolithotomy, a minimally invasive procedure that avoids external incisions. This technique is preferred when preserving gland function is a priority.

Salivary Stone Basics

Sialolithiasis, the formation of calcified deposits within salivary ducts, is the most common cause of non-neoplastic salivary gland obstruction. These stones primarily develop in the submandibular gland due to its long, upward-sloping duct and alkaline secretions, which promote mineral precipitation. Less frequently, sialoliths occur in the parotid or sublingual glands. The exact cause remains unclear, but dehydration, reduced salivary flow, and altered salivary composition—particularly increased calcium and phosphate concentrations—are contributing factors.

Most salivary stones consist of calcium phosphate or calcium carbonate mixed with organic material such as glycoproteins and cellular debris. Their size ranges from a few millimeters to over a centimeter, with larger stones more likely to cause complete ductal obstruction. Symptoms include episodic pain and swelling, particularly during meals when salivary flow increases. Chronic blockage can lead to bacterial infections, abscess formation, or glandular atrophy if left untreated.

Risk factors include conditions that reduce salivary flow, such as Sjögren’s syndrome, chronic dehydration, and medications like antihistamines and diuretics. Dietary habits, including low fluid intake and high calcium consumption, may also contribute. Some stones remain asymptomatic and are discovered incidentally, while others require intervention due to significant discomfort.

Common Diagnostic Approaches

Diagnosing sialolithiasis involves clinical evaluation and imaging to confirm the stone’s presence, location, and size. Patients often report intermittent swelling and pain in the affected gland, especially during eating. Palpation may reveal a firm, mobile mass if the stone is near the ductal orifice, but deeper stones require imaging.

Conventional radiography, particularly occlusal and panoramic views, can identify radiopaque stones composed of calcium phosphate or carbonate. However, up to 20% of stones are radiolucent and not visible on standard X-rays. Ultrasound, using high-frequency transducers (7–12 MHz), provides detailed visualization of both radiopaque and radiolucent stones, with sensitivity rates exceeding 90%.

For inconclusive cases or when detailed anatomical assessment is needed, non-contrast computed tomography (CT) offers superior sensitivity and spatial resolution, detecting stones of varying compositions and identifying complications like glandular inflammation or abscess formation. Cone-beam CT, a lower-radiation alternative, is increasingly used for smaller stones. Magnetic resonance sialography (MR sialography) is another advanced option, particularly useful for detecting radiolucent stones and assessing ductal abnormalities without ionizing radiation, though it is less widely available.

Sialography, an older technique, involves injecting a contrast agent into the duct before obtaining fluoroscopic images. While it provides detailed visualization of ductal architecture and can identify strictures, its invasive nature and risk of infection have led to reduced use in favor of non-invasive methods. Diagnostic sialendoscopy, which involves inserting a miniature endoscope into the duct, can both confirm a stone’s presence and facilitate its removal in the same procedure.

Surgical Approaches

When stones fail to pass spontaneously or cause persistent symptoms, surgical intervention is necessary. The choice of technique depends on stone size, location, and the goal of preserving gland function. Minimally invasive procedures have largely replaced gland excision, allowing for targeted removal while maintaining salivary flow.

Intraoral Sialolithotomy

For stones in the distal submandibular or parotid duct, intraoral sialolithotomy provides a direct, minimally invasive approach. Performed under local anesthesia, the procedure involves making a small incision in the oral mucosa over the stone. Blunt dissection exposes the duct, allowing for stone extraction with forceps or a probe. If the stone is embedded in the ductal wall, controlled dilation or marsupialization may be necessary.

Postoperative care focuses on maintaining ductal patency and preventing stenosis. Patients are encouraged to perform regular gland massage and use sialogogues, such as citrus lozenges, to stimulate salivary flow. Antibiotics may be prescribed if there is concern for infection. Compared to external approaches, intraoral sialolithotomy avoids visible scarring and reduces the risk of nerve injury, making it the preferred option for accessible stones.

Gland-Sparing Techniques

Preserving salivary gland function is a priority in modern sialolithiasis management. When stones are deeper within the ductal system or too large for simple extraction, minimally invasive methods can be used.

Extracorporeal shock wave lithotripsy (ESWL) employs focused acoustic waves to fragment stones into smaller pieces that can pass naturally. While effective in some cases, ESWL may require multiple sessions and is less successful for dense, non-fragmentable stones.

Ductal dilation and stenting are alternative approaches, particularly for recurring sialolithiasis or ductal strictures. By inserting a small catheter or balloon into the duct, surgeons can widen the passage to facilitate stone expulsion. This technique is often combined with sialendoscopy, which allows for direct visualization and retrieval of stone fragments. These approaches reduce the need for gland excision, lowering the risk of xerostomia and preserving salivary function.

Endoscopic Removal

Sialendoscopy has revolutionized salivary stone management by providing a minimally invasive, gland-preserving alternative to traditional surgery. A miniature endoscope, typically 1.1 to 1.6 mm in diameter, is inserted into the duct to visualize the stone. Specialized micro-instruments, such as wire baskets or graspers, enable extraction without external incisions.

For larger or impacted stones, laser lithotripsy can be used alongside sialendoscopy. This method employs holmium:YAG or thulium fiber lasers to fragment the stone into smaller pieces for removal or natural passage. Sialendoscopic techniques have high success rates with minimal complications and a low recurrence rate. As technology advances, endoscopic removal continues to gain preference for its ability to preserve gland function while effectively managing obstructions.

Post-Procedural Considerations

Recovery after intraoral sialolithotomy or other minimally invasive removal methods is generally well-tolerated. Pain and swelling are common in the immediate postoperative period but typically subside within a few days. NSAIDs such as ibuprofen help manage discomfort, while cold compresses can reduce localized swelling. Patients are advised to start with a soft diet to minimize irritation, gradually reintroducing firmer foods as healing progresses.

Salivary flow stimulation is essential to prevent postoperative complications like ductal stenosis. Frequent hydration, gland massage, and sialogogues such as sugar-free lemon drops or xylitol gum encourage saliva production and reduce the risk of recurrent obstruction. If ductal trauma occurs during extraction, temporary stenting may be used to maintain patency, particularly for patients with recurrent sialolithiasis or ductal narrowing. Stents are typically removed after one to two weeks.

Prevention

Reducing the risk of salivary stone formation involves addressing factors that contribute to ductal obstruction and mineral precipitation. While some individuals may have a genetic predisposition or anatomical variations that increase susceptibility, lifestyle modifications can help lower recurrence rates.

Hydration is key to maintaining healthy salivary flow, as reduced fluid intake leads to thicker secretions that encourage stone formation. Drinking sufficient water, particularly in warm climates or during illness, helps maintain saliva consistency and prevents stagnation.

Dietary choices also play a role. While no specific diet guarantees prevention, reducing excessive calcium intake from supplements or high-dairy diets may be beneficial for individuals with recurrent stones. Acidic foods like citrus fruits and vinegar-based dressings stimulate saliva production, which helps flush out particulate matter before it aggregates. Conversely, excessive caffeine and alcohol consumption can contribute to dehydration and increase risk. Chewing sugar-free gum or using xylitol-containing lozenges can further promote salivary flow.

Good oral hygiene helps prevent secondary complications such as infections that exacerbate salivary gland dysfunction. Regular dental checkups allow for early detection of abnormalities, while daily brushing and flossing minimize bacterial buildup. For individuals with recurrent sialolithiasis, periodic ultrasound monitoring may help detect developing stones before they become symptomatic. In cases of persistent salivary stasis, physicians may recommend sialogogue therapy or gland massage techniques to enhance secretion and reduce future obstruction risk.