Human Anatomy: Facial Muscles Overview

Obicularis Oris

• Origin: No bony attachment; directly inserts into the lips.
• Action: Controls mouth and lip movement, including closing, opening, pursuing lips, and kissing.

Buccinator Muscle

• Origin: Alveolar processes of the maxilla and mandible, and the pterygomandibular raphe.
• Insertion: Skin of the labial commissure.
• Action: Pulls labial commissures laterally and shortens the cheek vertically and horizontally.

Corrugator Supercilli

• Origin: Frontal bone in the supraorbital region.
• Insertion: Skin of the eyebrow.
• Action: Frowning (crows feet); draws eyebrow skin medially and inferiorly towards the nose, creating wrinkles.

Levator Anguli Oris Muscle

• Origin: Canine fossa.
• Insertion: Skin at the ipsilateral labial commissure.
• Action: Raises the corner of the mouth.

Temporalis Muscle

• Origin: Fossa on the temporal bone.
• Insertion: Coronoid process and ramus of the mandible.
• Action: Elevates the mandible, raising the lower jaw.

Medial Pterygoid Muscle

• Origin: Pterygoid plate of the sphenoid bone, palatine bone process, and maxillary tuberosity.
• Insertion: Medial surface of the ramus and angle of the mandible.
• Action: Elevates the mandible and parallels the masseter muscle, though it is weaker.

Lateral Pterygoid Muscle

• Origin: Superior head from the greater wing of the sphenoid bone; inferior head from the lateral pterygoid plate of sphenoid bone.
• Insertion: Pterygoid fovea of the mandible, TMJ disc, and capsule.
• Action: Depresses the mandible, facilitating jaw opening and moving the mandible forward.

Masseter Muscle

• Origin: Zygomatic arch from various areas.
• Insertion: External surface of the mandible.
• Action: Elevates the mandible during jaw closing; one of the strongest muscles involved in mastication.

Mentalis Muscle

• Action: Raises the chin and protrudes the lower lip.

Platysma

• Action: Assists in raising neck skin and grimacing.

Trapezius Muscle

• Origin: External surface of the occipital bone and posterior midline of the cervical and thoracic regions.
• Insertion: Lateral third of the clavicle and parts of the scapula.
• Action: Lifts the clavicle and scapula.

Risorius Muscle

• Insertion: Labial commissure; aids in smiling and grimacing.