Learning Objective:By the end of this session, the learner will be able to describe the anatomy, relationships, vasculature, innervation, and clinical relevance of the submandibular gland and apply this understanding to clinical scenarios.
The submandibular glands are paired major salivary glands located in the face. They produce mixed serous and mucous secretions, essential for lubricating food during mastication, enabling swallowing, and initiating digestion.
Anatomical Position
The submandibular gland lies within the submandibular triangle, bordered by:
- Superiorly: Inferior border of the mandible
- Anteriorly: Anterior belly of digastric
- Posteriorly: Posterior belly of the digastric
Anatomical Structure
Each gland has a superficial and deep arm, separated by the mylohyoid muscle.
Superficial Arm
- Larger component
- Located inferior to the posterior half of the mandible
- Occupies the submandibular fossa
- Lies outside the oral cavity
Deep Arm
- Hooks around the posterior border of the mylohyoid into the oral cavity
- Lies on the lateral surface of the hyoglossus
- Lateral to the root of the tongue
Duct (Wharton’s duct)
- ~5 cm long
- Emerges from the deep arm
- Runs between mylohyoid, hyoglossus, and genioglossus
- Opens at 1–3 orifices on the sublingual papilla at the base of the lingual frenulum
Relationship with Nerves
The gland and duct are intimately associated with:
Lingual Nerve
- Starts lateral to the duct
- Loops inferiorly and runs medial to it
- Provides general sensation to the anterior 2/3 of the tongue
Hypoglossal Nerve (CN XII)
- Deep into the gland
- Runs superficial to the hyoglossus
- Motor supply to the tongue muscles
Facial Nerve – Marginal Mandibular Branch
- Exits the parotid gland
- Traverses the mandible’s lower border
- Lies superficial to the submandibular gland
- Supplies muscles of the lower lip and chin
Clinical Relevance
Submandibular Gland Excision
Performed for:
- Recurrent calculi
- Neoplasia
Due to close nerve relationships, potential injuries include:
Lingual Nerve Injury
- Loss of taste and sensation anterior 2/3 tongue
- Usually temporary
Hypoglossal Nerve Injury
- Tongue deviation to the affected side
- Dysarthria
- Rare, but disabling if severe
Marginal Mandibular Nerve Injury
- Drooping of the lower lip
- Difficulty depressing the lower lip
- Typically temporary (6–12 weeks)
