Pterygoideus proprius muscle

The pterygoideus proprius muscle, is an inconstant (12.82%) aberrant well-formed muscle between the temporalis and the lateral pterygoid muscles, extending between the infratemporal crest of the greater wing of sphenoid and the lateral pterygoid plate, superficial to the lateral pterygoid muscle.

The pterygoideus proprius muscle and other accessory pterygoid muscles, extending from the body of the sphenoid to the pterygoid process, may represent remnants of the muscles that act on the moveable pterygoids possessed by many lower vertebrates.