Clinical anatomy of the inferior labial gland: a narrative review

In this article we review the literature on the inferior labial gland from a clinical and anatomical perspective.Regardless of its importance in clinical practice, there are no medical literature that comprehensively reviewed the inferior labial gland.A database search using PubMed and Google Scholar was conducted. The following keywords were used in the search: "lower labial salivary gland", "lower labial gland", "inferior labial salivary gland", AND "inferior labial gland".The human labial glands are types of minor salivary gland that continuously secrete small amounts of mucous and serous substances to maintain oral health. The inferior labial glands are innervated by the inferior labial branch of the mental nerve, and the inferior labial branch of the facial artery is the main arterial supply to the lower lip. Although they only have an auxiliary role in saliva production compared to the major salivary glands, minor salivary glands provide a certain amount of lubrication in the oral cavity by the continuous outflow of saliva. The inferior labial gland not only promotes moisturization in the oral cavity but also secretes substances with antibacterial effects, which is important for the function of the oral cavity. A recent study showed that the rate of salivary secretion from the inferior labial glands does not change with age, and in some cases the inferior labial glands are used for diagnosing intractable diseases such as Sjogren's syndrome and cystic fibrosis. In addition, since the inferior labial glands themselves can be the site of cyst and/or neoplasia development, we should be careful to distinguish them from other diseases. Elucidation of the anatomy, physiology, and pathology of the inferior labial glands, is important for understanding human health and diseases.