Lateral pterygoid

• Lateral pterygoid

  Origin -

  Upper small head from infratemporal surface and crest of greater wing of sphenoid

  Lower larger head from lateral surface of lateral pterygoid plate of sphenoid
• Insertion of lateral pterygoid:

  Fibres of two head forms thick tendon inserted into

  1. Pterygoid fovea on front of neck of mandible
  2. Articular disc and capsule of TM joint
• Nerve supply of lateral pterygoid:

  Branch of anterior division of mandibular
• Lateral pterygoids of two sides depress the mandible (opens the mouth)


  1. Pulling forward the condylar processes of the mandible

  2. Pulling forward the articular discs of the temporomandibular joints
• Lateral and medial pterygoid muscles of two sides acting together

  Protrude the mandible
• Lateral and medial pterygoid muscles of the two sides

  1. Contract alternately

  2. Produce side-to-side movements of the lower jaw as in chewing
• Lateral pterygoid is the only masticatory muscle which opens mouth
• Lateral pterygoid is the key muscle of infratemporal region
• Relations of lateral pterygoid:

  Superficial -

  1. Ramus of mandible
  2. Masseter
  3. Tendon of temporalis
  4. Superficial head of medial pterygoid
  5. Maxillary artery and it's temporal and masseteric branch
• Deep relations of lateral pterygoid:

  1. Mandibular nerve
  2. Middle meningeal artery
  3. Sphenomandibular ligament
  4. Deep head of medial pterygoid
• Structures at upper border of lateral pterygoid:

  1. Deep temporal nerves (2)
  2. Masseteric nerve
• Structure emerging at lower border of lateral pterygoid:

  1. Inferior alveolar nerve and artery
  2. Lingual nerve
  3. Middle meningeal artery (passes deep to lower border)
• Structure passing through gap between 2 heads of lateral pterygoid:

  1. Maxillary artery (enters to reach pterygopalatine fossa through pterygomaxillary fissure)
  2. Buccal nerve (branch of mandibular, comes out to provide sensory innervation to skin and mucous membrane of neck)