A dental professional must examine and palpate the lymph nodes of the head and neck very carefully during an extraoral examination. Enlarged lymph nodes could indicate infection or cancer. Lymph nodes for the oral cavity drain intraoral structures such as the teeth, as well as the eyes, ears, nasal cavity, and deeper areas of the throat.

Lymph nodes are small round or oval structures that are located in lymph vessels. They fight disease by producing antibodies; this is part of the immune reaction. In acute infection, lymph nodes become swollen and tender as a result of the collection of lymphocytes gathered to destroy invading substances.

Lymph nodes of the head are classified as superficial (near the surface) or deep. All nodes of the head drain the right or the left tissues in the area, depending on their location.

Deep Cervical Lymph Nodes
located along the length of the internal jugular vein on each side of the neck, deep to the sternocleidomastoid muscle

Lymphadenopathy
. When a patient has an infection or cancer in a region, the lymph nodes in that region will respond by increasing in size and becoming very firm. This change in size and consistency is called lymphadenopathy
. It results from an increase in the size of individual lymphocytes (lymphocyte cells are the body’s main defense) and in overall cell count in the lymphoid tissue.
. With increased size and number of lymphocytes, the body is better able to fight the disease process.

The minor salivary glands are smaller and more numerous than the major salivary glands. The minor glands are scattered in the tissues of the buccal, labial, and lingual mucosa; the soft palate; the lateral portions of the hard palate; and the floor of the mouth. Von Ebner’s salivary gland is associated with the circumvallate lingual papillae on the tongue.

Parotid Gland
the largest salivary gland located near ear. Saliva passes form the gland into mouth through the parotid duct also know as stenoson's duct.

Submandibular Gland
located on the lower side of face. The gland releases saliva into oral cavity through submandibular duct also know as Wharton duct.

Sublingual Gland
smallest major salivary gland , the gland releases saliva into oral cavity through the sublingual duct also know as Bartholin's duct.

paranasal sinuses are air-containing spaces within the skull that communicate with the nasal cavity

making the bones of the skull lighter

sinuses are named for the bones in which they are located, as follows:
• Maxillary sinuses the largest of the paranasal sinuses.
• Frontal sinuses located within the forehead just above the left and right eyes.
• Ethmoid sinuses irregularly shaped air cells separated from the orbital cavity by a very thin layer of bone.
• Sphenoid sinuses located close to the optic nerves, where an infection may damage vision.