The submandibular gland (submaxillary gland) is irregular in form and about the size of a walnut. A considerable part of it is situated in the submaxillary triangle, reaching forward to the anterior belly of the Digastricus and backward to the stylomandibular ligament, which intervenes between it and the parotid gland. Above, it extends under cover of the body of the mandible; below, it usually overlaps the intermediate tendon of the Digastricus and the insertion of the Stylohyoideus, while from its deep surface a tongue-like deep process extends forward above the Mylohyoideus muscle.
Its superficial surface consists of an upper and a lower part. The upper part is directed outward, and lies partly against the submandibular depression on the inner surface of the body of the mandible, and partly on the Pterygoideus internus. The lower part is directed downward and outward, and is covered by the skin, superficial fascia, Platysma, and deep cervical fascia; it is crossed by the anterior facial vein and by filaments of the facial nerve; in contact with it, near the mandible, are the submandibular lymph glands
The deep surface is in relation with the Mylohyoideus, Hyoglossus, Styloglossus, Stylohyoideus, and posterior belly of the Digastricus; in contact with it are the mylohyoid nerve and the mylohyoid and submental vessels.
The external maxillary artery is imbedded in a groove in the posterior border of the gland.
The deep process of the gland extends forward between the Mylohyoideus below and externally, and the Hyoglossus and Styloglossus internally; above it is the lingual nerve and submandibular ganglion; below it the hypoglossal nerve and its accompanying vein.
The submandibular duct (ductus submaxillaris; Wharton's duct) is about 5 cm. long, and its wall is much thinner than that of the parotid duct. It begins by numerous branches from the deep surface of the gland, and runs forward between the Mylohyoideus and the Hyoglossus and Genioglossus, then between the sublingual gland and the Genioglossus, and opens by a narrow orifice on the summit of a small papilla, at the side of the frenulum linguæ. On the Hyoglossus it lies between the lingual and hypoglossal nerves, but at the anterior border of the muscle it is crossed laterally by the lingual nerve; the terminal branches of the lingual nerve ascend on its medial side.
Vessels and Nerves.—The arteries supplying the submandibular gland are branches of the external maxillary and lingual. Its veins follow the course of the arteries. The nerves are derived from the submandibular ganglion, through which it receives filaments from the chorda tympani of the facial nerve and the lingual branch of the mandibular, sometimes from the mylohyoid branch of the inferior alveolar, and from the sympathetic.