Muscles of Facial Expression and Motor Branches of Facial Nerve PDF

MUSCLES OF FACIAL EXPRESSION Shireen Hafez, DVM, PhD, PGCertVetEd, FHEA, PgDipVetEd Objectives ◦ Identify main facial features. ◦ Identify muscles of facial expression and their action and innervation. ◦ Discuss motor branches of the facial nerve after it exits the stylomastoid foramen. ◦ D...

MUSCLES OF FACIAL EXPRESSION Shireen Hafez, DVM, PhD, PGCertVetEd, FHEA, PgDipVetEd Objectives ◦ Identify main facial features. ◦ Identify muscles of facial expression and their action and innervation. ◦ Discuss motor branches of the facial nerve after it exits the stylomastoid foramen. ◦ Discuss some clinical correlations: Shingles  Superficial features ◦ Palpebral fissure looking someone eyes opening pfYYPPgha ◦ Medial canthus orner ◦ Lateral canthus i Therapynetting've ◦ Superciliary arch ◦ Naris ◦ Ala of nose ◦ Nasal columella themiddle of nostrils p ◦ Philtrum grooveintuff in ◦ Nasolabial sulcus i fromnose tolips ◦ Oral fissure ◦ Oral commissures ◦ ◦ Modiolus node or Mentolabial sulcus h fistfthy cornersofmouth theft makes ◦ Mental protuberance elevation at chin buttchin Tubercle of upper lip ◦ U shaped on upper lip ◦ Skin ◦ SMAS (Superficial Muscular Aponeurotic System) connectall muscles muscles L determine attachment of Netter’s Anatomy of the Head and Neck for Dentistry  Superficial features ◦ Palpebral fissure ◦ Medial canthus ◦ Lateral canthus ◦ Naris ◦ ◦ ◦ ◦ Ala of nose Nasal columella Philtrum Nasolabial sulcus I ◦ Oral fissure ◦ Oral commissures ◦ Modiolus ◦ Mentolabial sulcus ◦ Mental protuberance ◦ Tubercle of upper lip ◦ Skin ◦ SMAS (Superficial Muscular Aponeurotic System), organized fibrous network, facial fasciae, facial muscles. Fig. 21.3 Gray’s Clinical Photographic Dissector of the Human body 2nd ed. L everything below the eye Muscles of facial expression groups ◦ Oral group ◦ Nasal groupinostrol's ◦ Orbital group palpi ◦ Epicranial group (scalp)  Muscles of facial expression ◦ Oral group IT Orbicularis oris duck mouth w Depressor anguli oris depress Depressor anyman if angiesmoughsher labii inferioris Mentalis Zygomaticus major laughing muscles Zygomaticus minor Frafetepper Levator labii superioris Upper lip Levator labii superioris alaeque nasi Levator anguli oris Those www.T.ae Risorius Lha Buccinator nmn iiaes iky Facial Expressions intervated by Facial N Netter’s Anatomy of the Head and Neck for Dentistry Muscles of facial expression ◦ Oral group Orbicularis oris Depressor anguli oris Depressor labii inferioris Mentalis Zygomaticus major Zygomaticus minor Levator labii superioris Levator labii superioris alaeque nasi pi Levator anguli oris iE iy Buy Perry.fi Risorius nerc Buiin'soYns Buccinator eniEtion Netter’s Anatomy of the Head and Neck for Dentistry Muscles of facial expression ◦ Oral group Orbicularis oris – buccal and marginal mandibular brs. Depressor anguli oris – buccal and marginal mandibular brs. Depressor labii inferioris – marginal mandibular br. Mentalis – marginal mandibular br. Zygomaticus major - zygomatic and buccal brs. Zygomaticus minor - zygomatic and buccal brs. Levator labii superioris zygomatic and buccal brs. Levator labii superioris alaeque nasi - same Levator anguli oris – zygomatic and buccal brs. Risorius - buccal brs. Buccinator - buccal brs. Netter’s Anatomy of the Head and Neck for Dentistry Muscles of facial expression ◦ Nasal group Nasalis Compressor naris (transverse part) Dilator naris (alar part) dopant Procerus 8 not on test f d Netter’s Anatomy of the Head and Neck for Dentistry Muscles of facial expression 00 ◦ Orbital group Orbicularis oculi Orbital part voluntary control wink Lacrimal part littlefibersinsidetheeye 596 Palpebral part involuntary blink Corrugator supercilii 0 Muscles of facial expression ◦ Orbital group Orbicularis oculi – temporal and zygomatic brs. Orbital part Lacrimal part Palpebral part Corrugator supercilia – temporal br. Muscles of facial expression ◦ Scalp group Occipitofrontalis m. Frontalis – temporal br. Occipitalis – posterior auricular br. Separated by the epicranial aponeurosis Frittendon Netter’s Anatomy of the Head and Neck for Dentistry KNOW name location innervation MOTOR BRANCHES OF FACIAL NERVE Shireen Hafez, DVM, PhD, PGCertVetEd, FHEA, PgDipVetEd  Facial nerve most complicated branches motor ◦ The facial nerve exits the facial canal and the skull at the stylomastoid foramen. nerveto digastriust styloni ◦ It gives off the posterior auricular branch, enters the parotid gland, and forms the parotid plexus, which gives rise to branches of muscles of facial expression (derivatives retiines of the second pharyngeal arch). murder above are 2ⁿᵈ Branchial motor supply of the facial nerve (derivatives of the 2nd pharyngeal arch): ◦ Muscles of facial expression ◦ Auricular muscles L ◦ Platysma cervical m ◦ Scalp muscles occultigutionalis ◦ Posterior belly of the digastric ◦ Stylohyoid m. ◦ Stapedius m. tiny mulke in ear Lbk it mastoidforamen exits stylo Fig. 8.23 Moore’s Clinically Oriented Anatomy 9th ed.  Branchial motor supply of the facial nerve (derivatives of the 2nd pharyngeal arch): ◦ Posterior auricular nerve supplies the auricularis posterior and occipital belly of the occipitofrontalis muscle nerveto stylohyoid ◦ Branches of the parotid plexus are, nerveto digestris ◦ Temporal Supplies auricular muscles, frontal belly of occipitofrontalis, and orbicularis oculi ◦ Zygomatic Supplies orbicularis oculi and muscles inferior to orbit o ◦ Buccal Supplies buccinator, upper lip muscles including levator labii superioris, orbicularis oris 1◦ Marginal mandibular Supplies risorius, muscles of the lower lip if◦ Cervical (passes inferiorly from the inferior border of parotid gland) Supplies platysma Netter’s Anatomy of the Head and Neck for Dentistry  Branches of facial nerve (CN VII).A. Overview. The terminal branches of CN VII arise from the I parotid plexus within the parotid gland. They emerge from the gland under cover of its lateral surface and radiate in a generally anterior direction across the face. Although intimately related to the parotid gland (and often contacting the submandibular gland via one or more of its lower branches), CN VII does not send nerve fibers to the salivary glands. Two muscles representing the extremes of the distribution of CN VII, the occipitofrontalis and platysma, are also shown. B. Parotid plexus of facial nerve embedded in parotid gland. The gland is sectioned in a coronal plane. C. Method for demonstrating and general course of terminal branches of CN VII. D. Dissection. The great auricular nerve (C2 and C3), which supplies the parotid sheath and skin over the angle of the mandible, and terminal branches of platyha untargin the facial nerve, which supply the muscles of facial expression are demonstrated. B, buccal; C, Fig. 8.23 Moore’s cervical; Clinically M, marginalOriented Anatomy mandibular; T, 9th ed. temporal; Z, zygomatic.  as Summary pairindi is iii I  Ramsay Hunt Syndrome ◦ Shingles (Herpes Zoster) outbreak affects the facial nerve ◦ Same virus as the chickenpox ◦ Symptoms: ◦ A painful red rash with fluid-filled blisters on, in and around one ear ◦ Facial weakness or paralysis on the same side as the affected ear