The muscles of the facial region are described as follows-
Superficial muscle / cutaneous muscle
- This is well developed and extensive.
- It covers whole of the frontal region-frontalis muscle.
- The part of the muscle extending over the lower jaw and the masseter and buccinator and blending with the orbicularis oris and in the angle of the mouth it is called as the retractor anguli oris .
Muscles of the lips and cheeks
- Orbicularis oris
- Levator nasolabialis
- Levator labii superioris proprius
- Levator labii superioris proprius accessorius
- Dilator naris lateralis (Caninus)
- Depressor labii superioris
- Zygomaticus
- Incisivus superior
- Incisivus inferior (levator labii inferioris)
- Mentalis
- Buccinator
- Levator buccalis
- Depressor labii inferioris
The muscles of the lips and cheeks are-
- Orbicularis oris
- It is the sphincter around the anterior opening of the mouth but is incomplete in the muzzle.
- The muscle is included between the skin and mucous membrane of the lips to which it is intimately adherent. It blends with all the muscles of the face, which converge to the angle of the mouth.
- Action: To close the lips and help in suction and mastication.
- Blood supply: Superior and inferior labial arteries.
- Nerve supply: Facial nerve
- Levator nasolabialis
- The muscle is thin and extensive and extends in oblique direction from the inferior border of the frontalis muscle to the nostril and the upper lip. It is elongated from above downwards and covers the external face of the nasal region.
- Origin: Frontal and nasal bones.
- The muscle divides below into two layers – superficial and deep. The superficial part passes over the lateral face of the levator labi superioris proprius and dilator naris lateralis. The deep division is thin, aponeurotic and passes beneath the above said muscles.
- Insertion: Upper lip and lateral part of the nostril.
- Action: To elevate the upper lip and dilate the nostril.
- Blood supply: Facial, dorsal, labial and malar arteries.
- Nerve supply: Facial nerve.
- Levator labii superioris proprius
- This is a flat, narrow muscle located in the antero-lateral aspect of the face and extending from the facial tuberosity to the upper lip. It is covered partly by the superficial division of the levator naso labialis and the malaris.
- Origin: Facial tuberosity.
- Insertion: By several tendons to the upper lip.
- Action: To elevate the upper lip or to draw it to a side.
- Blood supply: Superior labial artery.
- Nerve supply: Facial nerve.
- Levator labii superioris proprius accessorius
- This is a narrow muscle, extends infront of the facial tuberosity to the upper lip and which is regarded as accessory to the preceding and lies between the levator labii superioris proprius and the dilator naris lateralis.
- Origin: Facial tuberosity.
- Insertion: By several tendons to the upper lip.
- Action: To assist the preceding muscle.
- Blood supply: Superior labial artery.
- Nerve supply: Facial nerve.
- Dilator naris lateralis (Caninus)
- This a narrow band placed between the levator labii superioris proprius and depressor labii superioris muscles.
- Origin: Facial tuberosity.
- Insertion: Lateral wing of the nostril.
- Action: To dilate the nostril.
- Blood supply: Superior labial artery.
- Nerve supply: Facial nerve.
- Depressor labii superioris
- This is a small fusiform muscle situated below the preceding.
- Origin: Facial tuberosity.
- Insertion: Muzzle and upper lip by several tendons.
- Action: To compress the upper lip.
- Blood supply: Superior labial artery.
- Nerve supply: Facial nerve.
- Zygomaticus
- It is a long strap like muscle located on the side of the face in a downward and forward direction from the zygomatic arch to the upper lip.
- Origin: Zygomatic process of malar bone.
- Insertion: To the buccinator and orbicularis at the angle of the mouth.
- Action: To retract and raise the angle of the mouth.
- Blood supply: Facial artery.
- Nerve supply: Facial nerve.
- Incisivus superior
- It consists of an indefinite group of fibres extending from the antero-lateral angle of the premaxilla to the deep surface of the upper lip. The action is to pull the lip towards the premaxilla.
- It is supplied by the superior labial artery and facial nerve.
- Incisivus inferior (levator labii inferioris)
- It is a small, round muscle lies between the orbicularis of the lower lip and inferior and lateral faces of the body of the mandible to about the level of the fossa containing the mental foramen.
- Origin: Body of the mandible, at the level of the second incisor tooth.
- Insertion: Lower lip.
- Action: To elevate the chin .
- Blood supply: Inferior labial artery.
- Nerve supply: Facial nerve.
- Mentalis
- This muscle lies in the chin, ventral to the body of the mandible.
- Origin: Body of mandible on either side of the symphysis.
- Insertion: Skin of the chin.
- Action: Wrinkle the skin and pull it forward.
- Blood supply: Mental artery.
- Nerve supply: Mental nerve.
- Buccinator
- This muscle forms the main mass of the muscular tissue of the cheek and is situated in the side of the face.
- Origin: Alveolar border of the mandible, the lower part of the external surface of the alveolar border of the maxilla.
- Insertion: Angle of the mouth blending with the orbicularis.
- Action: Chiefly mastication. To flatten the cheek, presses the food between the teeth and also to retract the angle of the mouth.
- Blood supply: Facial and buccinator arteries.
- Nerve supply: Facial nerve.
- Levator buccalis
- Origin: Facial part of lacrimal bone
- Insertion: Buccal mucosae, ventral to the facial tuberosity.
- Action: To raise the posterior part of the cheek.
- Blood supply: Malar artery.
- Nerve supply: Superior buccal and sub zygomatic nerve.
- Depressor labii inferioris
- This muscle lies along the inferior border of the preceding muscle. It is separable from it only at its anterior part.
- Origin: Alveolar border of the mandible, behind the last cheek tooth.
- Insertion: Lower lip.
- Action: To depress the lower lip.
- Blood supply: Ventral labial artery.
- Nerve supply: Facial nerve.
Muscles of the nostrils
- Levator naso labialis
- Dilator naris lateralis
- Dilator naris apicalis
- Dilator naris superioris (dorsal part )
- Dilator naris inferioris (ventral part)
Levator naso labialis
- The muscle is thin and extensive and extends in oblique direction from the inferior border of the frontalis muscle to the nostril and the upper lip. It is elongated from above downwards and covers the external face of the nasal region.
- Origin: Frontal and nasal bones.
- The muscle divides below into two layers-superficial and deep. The superficial part passes over the lateral face of the levator labi superioris proprius and dilator naris lateralis. The deep division is thin, aponeurotic and passes beneath the above said muscles.
- Insertion: Upper lip and lateral part of the nostril.
- Action: To elevate the upper lip and dilate the nostril.
- Blood supply: Facial, dorsal, labial and malar arteries.
- Nerve supply: Facial nerve.
Dilator naris lateralis (Caninus)
- This a narrow band placed between the levator labii superioris proprius and depressor labii superioris muscles.
- Origin: Facial tuberosity.
- Insertion: Lateral wing of the nostril.
- Action: To dilate the nostril.
- Blood supply: Superior labial artery.
- Nerve supply: Facial nerve.
Dilator naris apicalis
- It is situated in the muzzle.
- Origin: Body of the premaxilla.
- Insertion: Medial wing of the nostril.
- Action: To dilate the nostril.
- Blood supply: Naso labial arteries.
- Nerve supply: Facial nerve
Dilator naris superioris (dorsal part)
- It is very small, short thin muscle.
- Origin: Alar cartilage of the nostril.
- Insertion: Medial wings of nostril.
- Action: To dilate the nostril.
- Blood supply: Facial and infra orbital arteries.
- Nerve supply: Facial and infraorbital nerves.
Dilator naris inferioris (ventral part)
- This muscle is arranged in two layers
- Origin: Nasal process of premaxilla.
- Insertion: Lateral wing of the nostril.
- Action: To dilate the nostril.
- Blood supply: Facial and infra orbital arteries.
- Nerve supply: Facial and infraorbital nerves.
