Sub-mental lymph nodes are located below the chin. They are glands that are a key element of our immune system. These nodes consist of lymphatic tissues which are enclosed by a fibrous capsule. They contain scavenging white blood cells that fight infection and its spread.
The sub-mental lymph nodes are seen as filters which have the role to strain out potentially harmful pathogens and microorganisms from lymph fluid that drains from teeth and inside of the mouth. When the sub-mental lymph nodes get swollen they are a sign of disease or infection.
These nodes contain sinuses, germinal centers, trabeculae, scavenger cells, and reticular fibers. There are several conditions that can afflict the sub-mental lymph nodes. They include oral cancer, tooth abscess, infected wisdom tooth, lymphadenopathy, swollen lymph nodes, metastasis of cancer, leukemia, and lymphoma.
Anatomy of Cervical or Neck Lymph Nodes
There are six different groups of lymph nodes. They are situated in the neck and depending on their location they can be classified as follows:
- Anterior cervical lymph nodes – lie in the front of the neck. They are of two types: superficial and deep. They drain the internal structures of the throat as well as the tonsils and thyroid gland.
- Posterior cervical lymph nodes – located in a line at the back of the neck. They extend from the mastoid part of the temporal bone to the clavicle. In case of an upper respiratory tract infection, they normally become enlarged.
- Tonsillar lymph nodes – beneath the mandible. They drain the tonsils and posterior part (back) of pharynx.
- Sub-mandibular lymph nodes – along the bottom of the mandible and drain the floor of the mouth tongue, lips, and conjunctiva. In case of infection of the head, neck, sinuses, ears, eyes and pharynx, they get enlarged.
- Sub-mental lymph nodes – below the chin. They help to drain the teeth, lower lip, floor of the mouth, tongue and cheek. They commonly enlarge due to mononucleosis, toxoplasmosis, and dental infections such as periodontitis.
- Supraclavicular lymph nodes – in the hollow above the clavicle.
Causes of Neck Lymph Node Swelling
The common causes of lymph node swelling of the neck include :
As we mentioned above, the most common causes for swollen neck lymph nodes are the infections. Whether we are talking about a viral, bacterial or parasitic infection, this is still an infection. Some of the most common infections that trigger the swelling of sub-mental lymph nodes, are the following:
- Strep throat.
- Peritonsillar abscess.
- Rubella (German measles).
- Dental infections.
- Ear infections.
- Skin infections and infected wounds of the head and neck particularly.
- Infectious mononucleosis.
- Cat scratch disease.
- Sexually transmitted disease (STD) such as syphilis can also produce lymph node swelling of the neck.
Malignant tumors, particularly in the head or neck, may cause lymphadenopathy of the cervical lymph nodes. Unfortunately, there are cases when this indicates metastasis (cancer spread) from other parts of the body or the areas drained by the affected lymph nodes. It is important to take note of the Virchow’s node which may be an early warning sign of stomach cancer. There are different types of cancer that can represent the cause of the swollen sub-mental lymph nodes:
- Lymphoma is cancer of the lymph node and there are two forms of lymphomas – Hodgkin’s disease and non-Hodgkin’s disease.
- Leukemia is cancer of the blood forming tissues. It includes bone marrow and lymphatic system and may cause lymph node enlargement.
- Melanoma – a type of skin cancer.
- Cancer of the mouth, larynx, or oropharynx. They can cause an enlargement of the draining lymph nodes in the neck.
Systemic causes of swollen neck lymph nodes usually involve different types of autoimmune diseases and other diseases that cause an immune deficiency. This includes :
- Rheumatoid arthritis.
- Systemic lupus erythematosus (SLE).
Usually, the lymph node swelling is not isolated to the cervical lymph nodes and may be generalized.
Drugs and Vaccines
- There are certain drugs that can cause the swelling of the sub-mental lymph nodes. These can be phenytoin and carbamazepine. However, the list does not end here and there are other drugs that may also be responsible.
- Vaccinations like the MMR vaccine for protection against measles, mumps, and rubella as well as the typhoid vaccine may occasionally cause lymph node swelling although this is usually temporary.
The characteristics of the swollen lymph node often help to determine the cause of the swelling. When the lymph node swelling appears as a result of an infection, the nodes are soft, painful, and mobile, with signs of inflammation on the overlying skin. On the other hand, cancerous lymph nodes are hard, fixed (not mobile) and usually not painful. Doctors have named the lymph nodes that seem connected to each other as “matted” lymph nodes. In this case, they may be associated with tuberculosis, sarcoidosis or malignancy.
Lymph nodes are sometimes described as “shotty”. In this case, they are small, non-tender and have a rubbery consistency. This type of lymph node may be seen following an infection which has already resolved and does not have the typical characteristics of either an infected or a malignant lymph node.
There are other constitutional symptoms that can indicate a swelling of the sub-mental lymph nodes. These symptoms are fever, night sweats, weight loss and fatigue. There are cases when the doctor can ask for a biopsy for further investigation in order to make a conclusive diagnosis. This is why it is very important that, as soon as you notice some of the above symptoms, to contact your doctor immediately.