Stensen’s duct, also known as the parotid duct, serves as the primary drainage pathway for the parotid gland. This gland produces a significant portion of saliva. The duct transports saliva from the parotid gland into the oral cavity. This continuous flow of saliva is important for maintaining oral health and initiating the digestive process.
Anatomy and Function of Stensen’s Duct
Stensen’s duct originates within the parotid gland, located in front of the ear and extending to the angle of the jaw. From its origin, the duct travels across the masseter muscle, a large chewing muscle. After crossing the masseter muscle, the duct turns inward, piercing the buccinator muscle, which forms the cheek’s muscular wall.
The duct then runs under the mucous membrane of the inner cheek before opening into the oral cavity. Its opening, a small papilla, is typically found opposite the upper second molar tooth. The duct transports serous saliva, a thin and watery fluid, from the parotid gland into the mouth. This serous saliva is rich in enzymes like amylase, which begins starch breakdown and lubricates the mouth for speaking and swallowing.
Conditions Affecting the Duct
Several conditions can affect Stensen’s duct, leading to discomfort and problems with salivary flow. Obstruction is common, frequently caused by salivary gland stones (sialolithiasis). These stones can block the duct, preventing saliva flow, which often results in pain and swelling, especially during or after eating.
Infection and inflammation can also impact the duct and gland. Sialadenitis refers to salivary gland inflammation, while parotitis specifically denotes parotid gland inflammation, which can involve the duct. Symptoms include swelling, pain, redness over the affected area, and sometimes a foul taste if pus accumulates. Narrowing of the duct, known as stenosis, is another challenge. This condition can limit saliva flow and may occur due to inflammation, trauma, or stone complications.
Physical injury to the cheek can also damage Stensen’s duct. Trauma, such as a deep laceration, may sever or partially disrupt the duct, leading to complications like a salivary fistula (leakage of saliva onto the skin) or a sialocele (a collection of saliva under the skin). Such injuries can cause immediate pain and swelling, potentially leading to chronic drainage issues and infection if not addressed.
Diagnosis and Treatment Options
Diagnosing problems with Stensen’s duct typically begins with a physical examination by a healthcare provider. The clinician may palpate the parotid gland and duct along the cheek to detect swelling, tenderness, or stones. They may also attempt to “milk” saliva from the duct opening to assess flow and identify blockages.
Imaging techniques confirm diagnosis and pinpoint the problem’s nature. X-rays can detect larger, calcified stones. Ultrasound is a common first-line imaging tool, useful for identifying stones and assessing duct dilation. For detailed visualization, a CT scan or MRI can provide comprehensive images of stones, strictures, or other abnormalities.
Treatment varies by condition and severity, generally progressing from less invasive to more involved interventions. Conservative home care is often the initial recommendation for mild cases or acute flare-ups. This includes hydration, warm compresses, gentle gland massage, and sucking on sour candies or lemon wedges to stimulate saliva production and encourage stone passage.
For infections, antibiotics resolve bacterial sialadenitis or parotitis. When stones or strictures are present, minimally invasive procedures like sialendoscopy are common. This technique involves inserting a tiny endoscope into the duct to visualize the interior, remove small stones with micro-instruments, or dilate narrowed segments. In complex cases, such as large, impacted stones or significant ductal injury, surgery may be necessary to remove the stone, repair the duct, or in rare instances, remove the affected gland.