Facial Muscles

• Muscular system


  Includes skeletal muscle tissue
• Muscle


  Shortens under neural control, causing soft tissue and bony structures of the body to move
• Origin


  The end of the muscle that is attached to the least movable structure
• Insertion


  The other end of the muscle, attached to the more movable structure
• When the muscle is contracted


  The insertion moves toward the origin
• Action


  The movement accomplished when the muscle fibers contract
• Muscles of facial expression

  • Paired muscles within the superficial fascia of the facial tissue
  • Used during extraoral examination to assure function of the nerves to these muscles
• Muscles of facial expression

  • All originate on bone and insert on the skin
  • All innervated by cranial nerve VII
• Facial expression


  Muscles of facial expression act in various combinations to show varying expressions and change the appearance of the face
• Innervation of muscles of facial expression

  • Temporal
  • Zygomatic
  • Buccal
  • Mandibular
  • Cervical
• Pathology of muscles of facial expression

  • Bell Palsy - cranial nerve VII paralysis
  • Facial nerve anesthesia from inferior alveolar mandibular block or oral surgery
• Epicranial muscle


  • 3 parts that cover top of the cranium
  • Origin is occipital bone
  • Insertion is forehead and eyebrows
• Frontalis muscle


  Frontal belly of epicranial muscle
• Occipitalis muscle


  Occipital belly of epicranial muscle
• Epicranial aponeurosis


  Connects the frontal and occipital bellies of the epicranial muscle
• Action of epicranial muscle

  • Raises the eyebrows and scalp, as when showing surprise
  • The two bellies can also act independently during certain facial expressions
• Orbicularis oculi muscle


  • Originates on the orbital rim, nasal process of frontal bone, and frontal process of maxilla
  • Inserts into the skin at the lateral canthus, with some inner fibers completely encircling the orbit
• Action of orbicularis oculi muscle

  • Closes the eyelid
  • Causes squinting and "crow's feet" wrinkles
• Corrugator supercilii muscle


  • Originates on the frontal bone in the supraorbital region
  • Inserts into the skin of the eyebrow
• Action of corrugator supercilii muscle

  • Frown
  • Snarl
• Nasal region muscles


  • Nasalis
  • Procerus
  • Depressor septi nasi
• Orbicularis oris muscle


  • Encircles the mouth with no bony attachment
  • Fibers insert into the skin of the lips at both labial commissures
• Action of orbicularis oris muscle

  Kissing muscle
• Loss of orbicularis oris muscle use

  Can cause excessive drooling, as after a stroke or other neurological event
• Excessive puckering of orbicularis oris muscle

  Can occur with prolonged oral habits like smoking, useful to point out in tobacco cessation discussions
• Buccinator muscle


  • Originates from the alveolar process of the maxilla and mandible, and the pterygomandibular raphe
  • Inserts at the ipsilateral labial commissure, creating an intersecting "braided" pattern
• Action of buccinator muscle

  • Pulls each labial commissure laterally and shortens the cheek both vertically and horizontally
  • Keeps food pushed back on the occlusal/masticatory surface of the posterior teeth during chewing
• Pterygomandibular raphe


  • A tendinous band located posterior to the most distal mandibular molar, spanning the area between the mandible and hard/soft palate junction
  • Landmark for administration of the inferior alveolar nerve block
• Pterygomandibular raphe


  Structure that the muscles of the pharynx are attached to
• Buccinator muscle fibers


  1. Originate from alveolar process of maxilla and superior part of pterygomandibular raphe

  2. Travel obliquely downward toward lower lip

  3. Originate from alveolar process of mandible and inferior part of pterygomandibular raphe

  4. Travel obliquely upward toward upper lip

  5. Intersect at ipsilateral labial commissure
• Buccinator muscle


  • Fibers intersect and take on "braided" effect between origin and insertion
• Buccinator muscle


  • Pulls each labial commissure laterally and shortens the cheek both vertically and horizontally
  • Forms the buccal vestibule
  • Keeps food pushed back on occlusal/masticatory surface of posterior teeth when chewing
  • Assists the muscles of mastication
• Risorius muscle


  • Originates from fascia superficial to masseter
  • Inserts into skin at ipsilateral labial commissure
  • Pulls mouth laterally, retracting labial commissure and widening the mouth
• Levator labii superioris muscle


  • Originates from infraorbital rim of maxilla
  • Inserts into skin of upper lip
  • Elevates the upper lip
• Levator labii superioris alaeque nasi muscle


  • Originates from frontal process of maxilla
  • Inserts into skin of ala of nose and upper lip
  • Elevates upper lip and ala of nose, dilating each nares
• Zygomaticus major muscle


  • Originates from zygomatic bone, lateral to zygomaticus minor
  • Inserts into skin at ipsilateral labial commissure, in and around orbicularis oris
  • Elevates labial commissure of upper lip and pulls it laterally
• Zygomaticus minor muscle


  • Originates on body of zygomatic bone
  • Inserts in skin of upper lip adjacent to insertion of levator labii superioris
  • Elevates upper lip, assisting in smiling
• Levator anguli oris muscle


  • Originates in canine fossa of maxilla, usually superior to root of maxillary canine
  • Inserts into skin at ipsilateral labial commissure
  • Elevates labial commissure
• Depressor anguli oris muscle


  • Originates on inferior border of mandible
  • Inserts into skin at ipsilateral labial commissure
  • Depresses labial commissure
• Depressor labii inferioris muscle

  • Originates from inferior border of mandible
  • Inserts into skin of lower lip
  • Depresses lower lip, exposing mandibular incisor teeth