The pterygoid notch is a small, triangular depression located on the lateral surface of the sphenoid bone in the skull. It is an important anatomic structure that serves as a point of attachment for several muscles and ligaments involved in the movement of the mandible (lower jaw) and the movement of the head and neck.
Structure
It is located on the lateral surface of the sphenoid bone, which is a butterfly-shaped bone located in the central part of the skull. The sphenoid bone is made up of several parts, including the body, greater wings, lesser wings, and pterygoid processes.
The pterygoid notch is located on the lateral surface of the pterygoid process, which is a bony projection that extends from the body of the sphenoid bone. The pterygoid process consists of two parts: the medial pterygoid plate and the lateral pterygoid plate. The pterygoid notch is located on the lateral pterygoid plate, which is the thinner and more posterior part of the pterygoid process.
Location
The pterygoid notch is located on the lateral surface of the sphenoid bone, which is located in the central part of the skull. It is situated in the region between the base of the skull and the mandible (lower jaw). Specifically, the pterygoid notch is located on the lateral surface of the pterygoid process, which extends from the body of the sphenoid bone.
The pterygoid notch is located posterior to the zygomatic arch (cheek bone) and the mandible, and it is located inferior to the infratemporal fossa (a shallow depression on the lateral surface of the skull). It is also located medial to the neck of the mandible (the narrowest part of the mandible) and the masseter muscle (a muscle that raises the mandible).
Function
The pterygoid notch serves as a point of attachment for several muscles and ligaments involved in the movement of the mandible and the movement of the head and neck. These muscles and ligaments include:
- Lateral pterygoid muscle: The lateral pterygoid muscle is a small muscle that originates from the infratemporal crest (a bony ridge on the lateral surface of the sphenoid bone) and the lateral pterygoid plate and inserts into the neck of the mandible. The lateral pterygoid muscle is responsible for protrusion of the mandible (pushing the mandible forward) and lateral movement of the mandible (moving the mandible to the side).
- Pterygomandibular raphe: The pterygomandibular raphe is a thin band of fibrous tissue that extends from the pterygoid notch to the median raphe (a line of fusion between the left and right halves of the mandible). The pterygomandibular raphe helps to stabilize the mandible and prevent it from moving too far to the side.
- Pterygoid venous plexus: The pterygoid venous plexus is a network of veins that drains blood from the face and neck. The pterygoid venous plexus is located within the infratemporal fossa, which is a shallow depression on the lateral surface of the skull. It is located posterior to the pterygoid notch and is formed by the infratemporal crest (a bony ridge on the lateral surface of the sphenoid bone) and the infratemporal surface of the temporal bone.
- Sphenomandibular ligament: The sphenomandibular ligament is a small, flat ligament that extends from the sphenoid bone to the lingula (a small protuberance on the mandible). The sphenomandibular ligament helps to stabilize the mandible and prevent it from moving too far forward or backward.
- Temporomandibular joint (TMJ): The TMJ is a joint located between the mandible and the temporal bone (the bone that forms the side of the skull). The TMJ allows the mandible to move up and down and side to side, allowing us to chew, speak, and swallow. The pterygoid notch is located in close proximity to the TMJ, and the muscles and ligaments attached to the pterygoid notch help to support and stabilize the TMJ.
Clinical Significance
The pterygoid notch is an important anatomic structure that is involved in various functions of the head and neck. Dysfunction or injury to the muscles and ligaments attached to the pterygoid notch can lead to problems with the movement of the mandible and the head and neck. Some of the clinical conditions that may be related to the pterygoid notch include:
- Temporomandibular joint disorder (TMJD): TMJD is a group of disorders that affect the TMJ and the muscles and ligaments surrounding it. Symptoms of TMJD include pain in the jaw, headaches, and difficulty opening and closing the mouth.
- Trismus: Trismus, also known as lockjaw, is a condition characterized by difficulty opening the mouth. It can be caused by inflammation or injury to the muscles and ligaments attached to the pterygoid notch, such as the lateral pterygoid muscle or the sphenomandibular ligament.
- Facial nerve paralysis: The facial nerve is a nerve that controls the muscles of the face. Facial nerve paralysis is a condition in which the facial nerve is damaged or not functioning properly, leading to weakness or paralysis of the muscles of the face. Facial nerve paralysis can be caused by trauma, infection, or other medical conditions.
