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Pterygoid Plates

processus pterygoideus ossis sphenoidalis

The pterygoid process descends from the junction of the body and greater wing of the sphenoid as two laminae: the broader medial pterygoid plate and the narrower lateral pterygoid plate, separated by the pterygoid fossa. The lateral pterygoid plate gives attachment to both heads of the lateral pterygoid and the upper head of the medial pterygoid. The medial pterygoid plate ends inferiorly in the pterygoid hamulus around which the tensor veli palatini tendon hooks.

Region: Head & Skull

Clinical Relevance

Clinical Notes

The pterygoid plates define the posterior wall and lateral boundaries of the nasal cavity and nasopharynx and are fractured in Le Fort III craniofacial fractures at the pterygomaxillary junction. Fracture of the pterygoid plates is a consistent CT finding in Le Fort fractures, used as a landmark for classification. In orthognathic Le Fort I osteotomy, the pterygomaxillary junction is separated using curved osteotomes to allow the maxilla to be mobilised. Pterygoid plate fractures may injure the maxillary nerve in the pterygopalatine fossa.

Pathology

Common Injuries & Conditions

Pterygoid Plate Fracture in Le Fort Injury

All Le Fort fractures pass through the pterygoid plates posteriorly at the pterygomaxillary junction; on CT, bilateral pterygoid plate fractures are the sine qua non of a true Le Fort pattern, distinguishing it from isolated nasal or orbital fractures.

Pterygopalatine Fossa Haematoma

High-energy midface trauma fracturing the pterygoid plates can lacerate the internal maxillary artery or its branches in the pterygopalatine fossa, producing a deep posterior facial haematoma that may require angiographic embolisation if it expands.