The salivary glands produce and secrete saliva, a fluid fundamental to the initial stages of digestion. Saliva contains enzymes that begin the breakdown of starches in food. It also lubricates the oral cavity, facilitating speaking and swallowing. Furthermore, saliva helps maintain oral health by keeping the mouth moist and protecting teeth from bacteria.
Identifying the Key Glands Under the Jaw
The area beneath the jaw is home to two major pairs of salivary glands: the submandibular and the sublingual glands. The submandibular glands are the second-largest pair, roughly the size of a walnut, situated beneath the jawbone. They produce a significant portion of saliva, especially when the mouth is at rest.
The sublingual glands are the smallest of the major glands, located in the floor of the mouth directly under the tongue. These glands contribute a smaller amount of the total saliva volume compared to the submandibular glands. Both gland types secrete saliva into the mouth through small ducts that open into the floor of the mouth.
Normal Palpation and Sensation
In a healthy state, the salivary glands under the jaw are soft, mobile, and difficult to feel distinctly. When palpating the area beneath the jawbone, the tissue felt is usually surrounding muscle, fat, or small lymph nodes, not the gland tissue itself.
The submandibular gland may sometimes be felt during a focused physical examination, but it should not be tender or firm. The sublingual glands, which lie in the floor of the mouth, are not discretely palpable at all. It is normal for these glands to go unnoticed in day-to-day life, though a person with a lean physique might feel the outline of the submandibular gland more easily.
When Glands Become Noticeable
A salivary gland becomes abnormally noticeable when it swells, often due to an obstruction or infection. The most frequent cause is sialolithiasis, the formation of crystallized salivary stones that block the flow of saliva through the duct. This blockage causes saliva to back up into the gland, leading to pain and swelling that may intensify during eating.
If saliva flow is blocked, the stagnant fluid can become a breeding ground for bacteria, leading to sialadenitis, or a salivary gland infection. This infection causes a painful lump, fever, and sometimes the drainage of foul-tasting pus into the mouth. Viral infections, such as mumps, can also cause the glands to swell, and dehydration increases the risk of both stone formation and infection.
When to Seek Medical Attention
You should consult a healthcare provider if you experience concerning symptoms. These include:
- Rapid or severe swelling or pain.
- Fever and chills.
- Pus drainage.
- Difficulty swallowing or opening your mouth.
- A lump that feels unusually hard or fixed to the surrounding tissue.
- Symptoms that do not resolve within a week.