Muscle
Medial pterygoid
Inner partner of the jaw-closing sling
High-yield
Its motor nerve comes from the main trunk of V3, before that trunk divides. This differs from the mainly anterior-division supply of the other principal chewing muscles.
Overview
Medial pterygoid reaches the inner mandibular angle from the skull base. Together with masseter on the outer surface, it forms a muscular sling that raises the jaw. Unequal activity between sides contributes to chewing movements.
Reference facts
- Origin
- Medial surface of the lateral pterygoid plate and palatine pyramidal process; a superficial head arises from the maxillary tuberosity
- Insertion
- Inner surface of the mandibular ramus and angle
- Action
- Raises and advances the jaw; coordinated activity contributes to lateral chewing movements
- Innervation
- Nerve to medial pterygoid from the main trunk of V3
- Blood supply
- Pterygoid branches of the maxillary artery, with contributions from facial arterial branches
Clinical correlation
Trauma or bleeding involving medial pterygoid after a dental injection can contribute to trismus, meaning restricted mouth opening. The duration varies with the cause and severity.
Frequently asked questions
What does the medial pterygoid do?
Raises and advances the jaw; coordinated activity contributes to lateral chewing movements.
What nerve innervates the medial pterygoid?
The medial pterygoid is innervated by the nerve to medial pterygoid from the main trunk of V3.
Where does the medial pterygoid attach?
Origin: Medial surface of the lateral pterygoid plate and palatine pyramidal process; a superficial head arises from the maxillary tuberosity. Insertion: Inner surface of the mandibular ramus and angle.
What is the blood supply of the medial pterygoid?
The medial pterygoid is supplied by the pterygoid branches of the maxillary artery, with contributions from facial arterial branches.