Muscles of Mastication
Description
Name
- Muscles of Mastication
- Muscles of the chewing apparatus
General
- Four muscles that work together to control movement of the temperomandibular joint
- This includes chewing, opening and closing mouth, other related jaw movements
Temporalis
- Origin:
- Temporal fossa and temporal fascia
- Insertion:
- Coronoid process and anterior border of the ramus of the mandible
- Action:
- Elevates the mandible (closes the jaw)
- Posterior fibers retract the mandible
Masseter
- Origin:
- Superficial head: zygomatic arch (anterior two-thirds)
- Deep head: zygomatic arch (posterior one-third)
- Insertion:
- Lateral surface of the ramus and angle of the mandible
- Action:
- Elevates the mandible (closes the jaw)
- Superficial fibers help with protraction of the mandible
Medial Pterygoid
- Origin:
- Deep head: medial surface of the lateral pterygoid plate and pyramidal process of the palatine bone
- Superficial head: maxillary tuberosity
- Insertion:
- Medial surface of the ramus and angle of the mandible (mirror image of the masseter)
- Action:
- Elevates the mandible
- Assists in protrusion
- Unilateral contraction causes small grinding movements
Lateral Pterygoid
- Origin:
- Superior head: infratemporal surface and crest of the greater wing of the sphenoid
- Inferior head: lateral surface of the lateral pterygoid plate
- Insertion:
- Neck of the mandible, articular disc, and capsule of the temporomandibular joint (TMJ)
- Action:
- Protracts the mandible
- Depresses the mandible (opens the mouth)
- Unilateral contraction produces side-to-side movements
Actions
- Protrusion (protraction): moves the mandible forwards
- Retraction: pulls the mandible backwards
- Elevation: elevates the mandible and closes the mouth
- Depression: depresses the mandible and opens the mouth
- Rotation: produces side-to-side movements of the mandible
Innervation
- All muscles are innervated by the mandibular branch of the trigeminal nerve
Vascular Supply
- Main vascular supply is from the maxillary artery
Clinical Significance
- Needs to be updated
See Also
References
- ↑ Image courtesy of https://www.thousandoaksfamilydentistry.com/
- ↑ Image courtesy of https://anatomyqa.com/
- ↑ Image courtesy of drdentnotes.com
- ↑ Image courtesy of teachmeanatomy.info