Wharton’s Duct
Wharton’s Duct is the tube that carries saliva from your submandibular gland to your mouth. It’s examined in radiology when patients have pain or swelling under the jaw, especially during eating. This article explains what Wharton’s duct is, how it appears on imaging, and common conditions that affect it.
What Is Wharton’s Duct?
Wharton’s Duct (also known as the submandibular duct) is a thin tube that carries saliva from the submandibular gland into the mouth. It measures approximately 5 cm in length, with walls that are thinner than those of the parotid duct. This duct begins deep in the submandibular gland and follows a path forward through the floor of the mouth.
The duct courses through the sublingual space between the mylohyoid muscle and sublingual gland laterally, and the hyoglossus and genioglossus muscles medially. It continues anteriorly and superiorly before ultimately draining into the sublingual caruncle, which is located at the side of the frenulum (the small fold of tissue under your tongue) in the floor of the mouth.
How Wharton’s Duct Appears on Imaging Studies
Different imaging techniques can visualize Wharton’s Duct in various ways:
X-ray Sialography
X-ray sialography involves injecting contrast medium into the duct opening in the mouth. During a normal sialography examination, the contrast medium fills the peripheral parts of salivary ducts.
Ultrasound (US)
Ultrasound provides a non-invasive way to examine the duct, particularly for stones.
Computed Tomography (CT)
CT scans can display the duct and any abnormalities, especially calcifications or stones. According to some experts, unenhanced CT is considered the best method for detecting sialolithiasis (stone formation), particularly when dealing with painful salivary glands or suspicion of calculi.
Magnetic Resonance Imaging (MRI)
MR sialography using T2-weighted sequences can provide detailed images of the ductal system without invasive contrast injections. Studies have shown that T2-weighted images have a sensitivity of 93% and specificity of 100% for detecting calculi in the duct.
Common Conditions Affecting Wharton’s Duct
Sialolithiasis (Stone Formation)
Submandibular gland/duct stones are the most common form of sialolithiasis. This condition typically presents with recurrent swelling and pain in the submandibular gland, especially during meals.
Sialolithiasis, or calculus disease, is the most common benign process affecting the salivary glands. The pathogenesis is debated but thought to be due to stagnation of saliva that is high in calcium. Risk factors include dehydration, smoking, and various medications (most commonly anticholinergics and diuretics).
Sialadenitis (Inflammation)
Stone formation can predispose to infection (sialadenitis) due to obstruction. When the flow of saliva is blocked, bacteria can proliferate, leading to inflammation and infection of the gland.
Ductal Strictures
Narrowing of the duct can occur due to chronic inflammation, previous trauma, or after stone removal. These strictures can impede saliva flow and cause symptoms similar to stones.
Diagnostic Approaches
Modern imaging offers several options for evaluating Wharton’s duct problems:
- Initial Assessment: Often begins with physical examination and ultrasound, which is non-invasive and readily available.
- Detailed Evaluation: For stone detection, CT scans may be preferred, especially for small or multiple stones that might be difficult to differentiate on ultrasound.
- Functional Assessment: MR sialography allows visualization of the ductal system using the patient’s own saliva as a natural contrast agent, making it a quick procedure without complications.
- Direct Visualization: Sialoendoscopy permits direct internal examination of the duct and can be both diagnostic and therapeutic.
Treatment Approaches
Treatment options for Wharton’s duct conditions include:
- Conservative Management: Includes hydration, warm compresses, massage, and sialogogues (substances that increase saliva production).
- Minimally Invasive Techniques: Sialoendoscopy can both diagnose and treat by removing stones, dilating strictures, or placing stents.
- Surgical Intervention: May be necessary for large stones, recurrent issues, or when minimally invasive approaches fail.
Relationship to Other Structures
Understanding the anatomical context of Wharton’s duct helps in interpreting imaging findings:
The submandibular gland is the second largest salivary gland, located in the floor of the mouth adjacent to the posterior body of the mandible along the free edge of the mylohyoid muscle. The lingual nerve and submandibular ganglion are superficial to the gland, while the hypoglossal nerve lies deep to it.
Besides the sublingual gland, the sublingual space (where Wharton’s duct runs) also contains the deep portion of the submandibular gland, the lingual artery/vein, and the lingual branch of the mandibular division of the trigeminal nerve.
Conclusion
Wharton’s duct plays an important role in salivary function, and problems affecting it can significantly impact quality of life. Modern imaging techniques offer excellent visualization of this small but important structure, allowing for accurate diagnosis and appropriate treatment planning. When you see this terminology on a radiology report, it typically indicates that the radiologist has specifically examined Wharton’s duct, either as part of a routine assessment or because there were symptoms suggesting possible pathology in this region.
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