Teeth grinding, medically known as bruxism, is an involuntary habit involving the clenching or gnashing of teeth, often occurring during sleep. The submandibular glands are a pair of major salivary glands positioned beneath the floor of the mouth that produce saliva. People often wonder if the strain from grinding can cause the nearby submandibular gland to swell. There is no direct biological mechanism by which the mechanical force of teeth grinding causes pathology within the salivary gland itself. However, the conditions share a similar anatomical location, leading to frequent confusion between muscle enlargement caused by bruxism and true glandular swelling.
The Common Effects of Bruxism
Chronic teeth grinding subjects the entire masticatory system to intense, repetitive forces, leading to a range of physical consequences. One immediate effect is damage to the dental structures, manifesting as worn tooth enamel, chipped dental work, or fractured teeth. This constant friction can also lead to increased tooth sensitivity due to the exposure of the underlying dentin layer.
The extreme muscle activity also places strain on the temporomandibular joints (TMJ), which connect the jawbone to the skull. Dysfunction can cause persistent pain in the jaw and face, sometimes accompanied by a clicking or popping sound when the mouth is opened or closed. Muscle tension commonly radiates to other areas, causing pain in the temples, ears, and along the jawline.
A significant effect of long-term bruxism is the hypertrophy, or enlargement, of the masticatory muscles, particularly the masseter muscles located at the angle of the jaw. Chronic overuse from clenching causes these muscles to grow stronger and increase in bulk, similar to how weight training enlarges other skeletal muscles. This muscular enlargement can change the contour of the lower face, sometimes creating a more pronounced or square-shaped jawline. This bulkiness is often misinterpreted as a swollen gland due to its prominent location.
What Causes Salivary Gland Swelling
True swelling of the submandibular gland, distinct from muscle enlargement, results from issues that affect the gland’s ability to produce or drain saliva. The most common cause is sialolithiasis, which is the formation of salivary stones within the duct system. These stones, composed of calcium salts and other minerals, obstruct the flow of saliva into the mouth.
When the duct is blocked, saliva backs up within the gland, causing swelling and pain that frequently worsens immediately after eating. This occurs because eating stimulates the gland to produce more saliva, which then has nowhere to drain. Sialolithiasis affects the submandibular gland more often than other salivary glands.
Another primary cause of glandular swelling is sialadenitis, an infection that can be bacterial or viral. Bacterial sialadenitis often arises when a blocked duct creates a stagnant environment, allowing bacteria from the mouth to thrive and cause inflammation. Symptoms of an acute infection include sudden, tender swelling, redness over the affected area, and sometimes fever or pus discharge.
Less common causes of persistent submandibular swelling include systemic conditions or the presence of a tumor. Autoimmune disorders, such as Sjögren syndrome, can affect the salivary glands, leading to chronic inflammation and enlargement. Tumors, whether benign or malignant, may also present as a lump in the area, though they usually feel firmer and do not fluctuate in size with meals.
Distinguishing Muscle Swelling from Gland Swelling
The masseter muscle runs along the side of the jawbone, while the submandibular gland is positioned slightly below and deeper, tucked under the chin. This proximity is the main reason for confusion between the two types of swelling. When chronic bruxism leads to masseter muscle hypertrophy, the resulting bulge can easily be mistaken for a glandular issue.
A key method for distinguishing the two is the clinical examination of the area during jaw movement. Masseter muscle hypertrophy is characterized by a firm swelling that becomes more pronounced and palpable when the teeth are clenched tightly. The enlargement is a result of muscle growth, which has a distinct texture compared to a fluid-filled or inflamed gland.
True glandular swelling, particularly from a stone, has a direct relationship with salivary flow. The swelling and pain from sialolithiasis intensify when a person starts eating or even thinking about sour foods that stimulate saliva production. This response to eating is not seen with simple masseter muscle hypertrophy. Muscle tension from bruxism can also cause referred pain, where discomfort from the overworked jaw muscles and TMJ is felt in the neck and submandibular region, incorrectly suggesting a problem with the gland itself.
When to Consult a Healthcare Professional
It is important to seek professional evaluation whenever a lump or persistent pain develops in the neck or jaw region. A dentist is the professional to assess symptoms directly related to teeth grinding, such as tooth damage, jaw pain, or facial muscle soreness. They can determine if the symptoms are caused by masseter muscle hypertrophy or temporomandibular joint dysfunction.
If the swelling exhibits characteristics specific to glandular issues, consultation with a primary care physician or an otolaryngologist (Ear, Nose, and Throat specialist) is advised. Symptoms like rapid, tender swelling accompanied by a fever or chills suggest an acute infection requiring medical attention. Any swelling that noticeably increases in size when you eat, followed by a slow reduction, strongly suggests a salivary gland stone and duct blockage. A lump that feels fixed, very hard, or continues to enlarge over time should be examined quickly to rule out more serious pathology.