Structure:

The submandibular duct, historically referred to as the submaxillary duct, is a paired salivary duct located bilaterally within the oral cavity. Each duct arises from the deep portion of the submandibular gland and measures approximately 5 cm in length.[1] After originating between the mylohyoid and hyoglossus muscles, the duct passes anteriorly, along the lateral surface of the hyoglossus and genioglossus muscles.[1] As it travels forward, the duct lies inferior to the lingual nerve before crossing it medially in the anterior floor of the mouth. The submandibular duct continues its course toward the midline and opens at the sublingual caruncle, located on either side of the lingual frenulum, where it releases saliva into the oral cavity.[2] 

Function:

The primary function of the submandibular duct is to transport saliva from the submandibular gland to the oral cavity via the sublingual caruncles.[1] This salivary secretion contributes to lubrication, digestion, and maintenance of oral health. Obstruction of the duct, most commonly due to sialolithiasis, may impair salivary flow and cause pain or swelling, sometimes requiring surgical intervention.[2] In select clinical cases, surgical modification of the duct’s outlet may be performed to redirect salivary flow, such as in the management of chronic drooling. Awareness of the duct’s anatomical course is therefore essential in both diagnosis and surgical treatment of salivary gland disorders.