The structure indicated is the submandibular gland
There are three main large sets of salivary glands in the face:
- Parotid glands
- Submandibular glands
- Sublingual glands
The submandibular glands are hook shaped
and consist of a deep
part and a superficial
part, separated by the mylohyoid muscle.
The deep part of the submandibular gland is formed from the shorter arm of the hook, which loops posteriorly around the mylohyoid muscle
to enter the floor of the oral cavity.
The superficial part of the submandibular gland is formed from the longer arm of the hook and lies outside the oral cavity.
The duct of the submandibular gland (Wharton duct) opens adjacent to the inferior point of attachment of the frenulum.
The submandibular glands receive parasympathetic
innervation via the chorda tympani
branch of the facial nerve
(cranial nerve VII).