The Face & Muscles of facial expressions

1. The Face & Muscles of facial expressions Head & Neck Unit – Lecture 5 د. حيدر جليل الأعسم

2. The Face Is the part of the head between the superciliary arches superiorly, the lower edge of the mandible inferiorly, and between the ears on either side

3. The Skin of the Face 1- Epidermis of the Skin 2- Loose connective tissue, in which muscles of the face are embedded. 3- No deep fascia in the Face.

4. The Innervation of the Face • Mainly by the trigeminal nerve, EXCEPT for small area over the angle of the mandible and the parotid gland by the great auricular nerve (cervical nerves C2-C3). • The ophthalmic and maxillary divisionsare ONLY SENSORY. • The mandibular division is SENSORY to the face, scalp and dura and MOTOR to the muscles of mastication.

5. The Innervation of the Face Important Face areas of innervation: • Upper Eyelid & Tip of the nose - Ophthalmic Nerve • Lower Eyelid, Upper Lip & Cheek prominence – Maxillary nerve • Lower Lip & rest of the Cheek - Mandibular nerve • Angle of the Mandible & small parotid area – Great Auricular nerve (C2,C3)

6. The Innervation of the Face Important Face areas of nerve testing: • Forehead - Ophthalmic Nerve • Cheek – Maxillary nerve • Lower Lip - Mandibular nerve

7. Arterial Supply – Facial Artery • ECA Branch • Arches upward over the submandibular salivary gland in the neck. • Arches around inferior margin of mandiblular body @ the anterior border of masseter muscle. • Runs upward in a tortuous course toward the angle of the mouth (First) then Runs along the side of the nose to the medial angle of the eye and here it is called the ANGULAR ARTERY. • Angular artery anastomoses with the terminal branches of the ophthalmic artery.

8. Arterial Supply – Pre-auricular Artery • ECA Terminal Branch (1st) - Also called The superficial temporal • Ascends in front of the auricle to supply lateral side of the scalp. • Pass through the parotid gland. • Gives transverse facial artery within the parotid gland, that runs forward across the cheek just above the parotid duct.

9. Arterial Supply – Other Branches • Maxillary Artery Branches – ECA Terminal Branch. • Infra-orbital Artery 2. Buccal Artery 3. Mental Artery • Ophthalmic Artery Branches – ICA Branch • Zygomatico-facial Artery 2. Dorsal Nasal Artery

10. Face Venous Drainage - • Starts at medial angle of the eye by the union of the supraorbital and supratrochlear veins. • Connected to cavernous sinus by superior ophthalmic vein & to Pterygoid Venous Plexus by deep facial vein • Danger Area of the face ??? Infection spread ? Valveless system? • Descends behind the facial artery to the lower margin of the body of the mandible • Crosses the submandibular gland and ends by draining into the internal jugular vein.

11. Face Venous Drainage - Is the part of the head between the superciliary arches superiorly, the lower edge of the mandible inferiorly, and between the ears on either side

12. Lymphatic Drainage of the Face • Anterior part of the face and forehead → submandibular lymph nodes. • Lateral part of the face → parotid lymph nodes. • Central part of the lower lip and the skin of the chin → submentallymph nodes.

13. Muscles of The Face(Muscle of Facial Expressions)

14. Muscles of The Face(Muscle of Facial Expressions) Features: • All muscles are developed from the 2nd pharyngeal arch. • All muscles are supplied by the facial nerve. • All muscles are embedded in the superficial fascia • Most of muscles arise from the bones of the skull and are inserted into the skin (to move the skin)(NOT ALL) Functions: • Sphincters of facial orifices (orbital, nasal, and oral) • Dilators of facial orifices (orbital, nasal, auricular & oral) • Modifiers of facial expressions

15. Muscles of The Face- Orbital Group(Muscles of the Eyelids) • Sphinctermuscle of the eyelids: Orbicularis Oculi, • Dilator muscles of the eyelids: Levator Palpebrae Superioris & Occipitofrontalis. • Modifierof facial expression: Corrugator Supercilli. Orbicularis oculi: completely surrounds each orbital orifice & extends into each eyelid. It has two parts: 1. Orbital part: outer broad ring that encircles the orbital orifice and extends beyond the orbital rim; it closes the eye gently. 2. Palpebral part: inner and in the substance of eyelids, originates in the medial corner of the eye & arch across each lid to attach laterally in the lateral corner of the eye. It closes the eye more forcefully. Corrugator supercilii: is deep to orbicularis oculi muscle & arises from the medial end of superciliary arch to insert into the skin of the medial half of the eyebrow. It causes vertical wrinkles above the nose (Frowning).

16. Muscles of The Face- Nasal Group(Muscles of the Nostrils) • Sphincter muscle: Compressor naris. • Dilator muscle: Dilator naris & Depressor septi nasi. • Modifierof facial expression: Procerus. Nasalis: is largest muscle of oral group causing flaring of the nares. It has two parts: A- Transverse part (the compressor naris): originates from the maxilla and its fibers pass upwards and medially to insert into an aponeurosis across the dorsum of the nose; It Compresses the nares. B- Alar part (the dilator naris): originates from the maxilla, below and medial to the transverse part, and inserts into the alar cartilage. It draws the alar cartilages downward and laterally, so opening the nares Procerus: produces horizontal wrinkles of the nose.

17. Muscles of The Face- Oral Group(Muscles of the Lips and Cheeks) • Sphincter muscles: Orbicularis Oris& Buccinator • Dilator & Modifier muscles: several muscles that radiate out from the lips. Orbicularis oris: encircles the mouth within the substance of the lips. • Some of its fibers originate near the midline from the maxilla superiorly and the mandible inferiorly, while other fibers are derived from both buccinator, in the cheek, and the other muscles of oral group. • It inserts into the skin of the lips & into itself. • It narrows the mouth and closes the lips.

18. Muscles of The Face- Oral Group(Muscles of the Lips and Cheeks) Buccinator: (muscle of the cheek) • arises from outer surface of maxilla & mandible & from Pterygomandibular ligament . • Its fibers pass forward and form the muscular layer of the cheek and insert into the lips. • It is pierced by the parotid duct. • Muscle Central Fibres Decussate @ the angle of the mouth, So those from upper part enter lower lip & those from lower part enter the upper lip; • while the Highest & Lowest Fibers continue into upper & lower lips without decussation. • It is deep to the other facial muscles. It compresses the cheeks and lips against the teeth.

19. Muscles of The Face- Oral Group(Muscles of the Lips and Cheeks) Dilator & Modifier muscles are several & radiate out from the lips & are divided into Upper & Lower groups: Features of dilator and modifier muscles of the oral group: • They ALL separate the lips • They arise from bones and fascia around the oral orifice & converge to be inserted into substance of lips. • They are innervated by buccal & mandibular branchesof facial nerve. Terminology of muscles: Levator →elevate, Depressor →Depress, labii →related to lips, anguli→angle, angulioris→angle of mouth

20. Muscles of The Face- Other Groups(Muscles of forehead, Ear & Neck) Features:They are NOT in the face, but derived from 2nd pharyngeal arch & innervated by facial nerve. Platysma: is a large, thin sheet of muscle in the superficial fascia of the neck. • It arises below the clavicle in upper part of the thorax and ascends through the neck to the mandible. • The medial fibers insert on the mandible, while the lateral fibers join the muscles around the mouth. Auricular muscles:They are not usually under voluntary control: 1- Anterior auricular muscle 2- Superior auricular muscle 3- Posterior auricular muscle Occipitofrontalisis associated with the scalp.

21. End of the Lecture GOOD LUCK