Pterygoid plates are bony structures within the human skull, part of a larger bone at the skull’s base. Understanding them provides insight into jaw mechanics and surrounding areas.
Where Are Pterygoid Plates Located?
The pterygoid plates are two thin, bony projections that extend downwards from the sphenoid bone. Each pterygoid process is found behind the third molar tooth, where the sphenoid bone’s body meets its greater wing. These projections are known as the medial and lateral pterygoid plates.
Towards the front, these two plates join, forming a continuous anterior surface. At the back, they diverge, creating a V-shaped space known as the pterygoid fossa. This positioning places them near the nasal cavity and the back of the throat, behind the upper jaw. The lateral pterygoid plate also forms the medial wall of the infratemporal fossa.
What Do Pterygoid Plates Do?
The pterygoid plates serve as attachment points for muscles involved in chewing and jaw movement. They provide origins for the medial and lateral pterygoid muscles, both considered muscles of mastication. The outer surface of the lateral pterygoid plate gives rise to the inferior head of the lateral pterygoid muscle, while its inner surface provides the origin for the deep head of the medial pterygoid muscle.
Contraction of these muscles facilitates various jaw movements. The medial pterygoid muscle, when contracting bilaterally, elevates the mandible, closing the mouth. Unilateral contraction of the medial pterygoid muscle, along with the lateral pterygoid muscle, enables the jaw to swing to the opposite side. The lateral pterygoid muscle, through bilateral contraction, protrudes and depresses the mandible, moving it forward and opening the mouth. When contracting unilaterally, the lateral pterygoid muscle moves the mandible medially, contributing to side-to-side jaw movements for grinding food.
Pterygoid Plates and Your Jaw Health
The pterygoid plates play an indirect but significant role in jaw health due to the muscles attached to them. Issues affecting the medial and lateral pterygoid muscles can contribute to conditions like temporomandibular joint (TMJ) disorders. For example, muscle spasm or inflammation in the lateral pterygoid muscle can lead to pain and limited mobility in the TMJ.
Dysfunction of these muscles can manifest as jaw pain, difficulty chewing, or clicking and popping sounds in the TMJ. Medical and dental professionals often consider the pterygoid plates as anatomical landmarks during diagnosis of jaw-related issues. They are also important for planning surgical procedures or administering local anesthesia in the region.