The sublingual glands are the smallest of the three major pairs of salivary glands, since the salivary glands are divided into major and minor categories. The major glands are entire masses of secretory tissue with a single duct that connects the exocrine glands with the oral cavity, while the minor glands are individual exocrine glands that secrete directly into the oral cavity via their own individual ducts that are part of their makeup. This is where the sublingual glands, although classes as major glands, fall into both categories. They are collectives exocrine tissue masses, but they have many ducts that open in the area in which they are situated.
The sublingual glands lie bilaterally in the floor of the mouth and within the sublingual folds. They are bordered by the mandible anteroinferiorly and the genioglossus muscle posteroinferiorly. It is covered superiorly by the tongue. Numerous ducts can be seen secreting saliva along the margin of the sublingual folds.
In opposition to the parotid glands, the sublingual glands secrete entirely mucinous saliva, which accounts for approximately 3-4% of all saliva production.
Blood Supply and Innervation
The nervous supply of the sublingual gland reflects that of the submandibular gland. It occurs via the chorda tympani, which carries fibers that originate from the facial nerve (CN VII) and are classed as secretomotor fibers. There are two separate arterial supplies that contribute to the vascularisation of the sublingual gland, which are venously drained via their corresponding veins. The first is that of the lingual artery which branches into the sublingual artery. The second is that of the facial artery which gives rise to the submental artery. The submandibular lymph nodes are responsible for draining the sublingual glands lymphatic region.
There are several pathological disorders that can occur in both the minor and the major salivary glands. Since the sublingual glands have traits from both categories, they are most likely to be affected by a bacterial or viral infection. This can cause pain and a hard swelling in the gland that is infected. Staphylococcus bacteria is the most common bacterial form of infection, while the viruses that can inhabit the salivary glands include the Cytomegalovirus (CMV), the Epstein-Barr virus (EBV), the Coxsackie virus and HIV. Treatment includes antibiotics or antivirals.