THE MUSCULATURE OF THE HEAD By: Dr. Pamela Josefina T. Fabie
MUSCLES OF FACIAL EXPRESSION Related mainly to the orbital margins and eyelids, the external nose and nostrils, the cheeks and mouth, the pinna, scalp and cervical skin.COMMON CHARACTERISTICS:1) All are inserted into the skin of the face2) All are supplied by the muscular branches of the facial nerve3) All produce facial expression
The craniofacial ,muscles receive their innervations from thebranches of the FACIAL NERVE. They are grouped as: 1. Epicranial 2. Circumorbitaland Palpebral 3. Nasal 4. Buccolabial
1. OCCIPITOFRONATALIS – covers the dome of the skull
1. Frontalis musclesThe muscle that covers the forehead. It has no bony attachment. ORIGIN: anterior part of the galea aponeurotica INSERTION: skin on the lower part of the forehead ACTION: produce transverse wrinkles on the forehead as in surprise. It raises the eyebrows.
2. Occipitalis musclesA short and narrow muscle that arises from the occipital bone ORIGIN: lateral 2/3 of the superior nuchal line INSERTION: posterior part of the galea aponeurotica ACTION: draw the galea aponeurotica backwards to fix and tense it.
2. TEMPOROPARIETALIS– variablydeveloped sheet of muscle that lies between the frontal partsof the occipitofrontalis and anterior and superior auricular muscles Temporoparietalis
A. PALPEBRAL PORTIONORIGIN: medial palpebralligament and adjacent part ofthe maxillaINSERTION: outer surface ofthe lateral palpebral marginACTION: close the eyelids asin sleeping and winkling
B. ORBITAL PORTIONORIGIN: medial palpebral ligament,frontal bone and maxillaINSERTION: medial palpebral ligament (no lateral attachment)ACTION: helps close the eyelids and draw lateral part of lidsmedially. They are responsible for the “crow’s feet” usuallyseen at the lateral angles of the eye
C. LACRIMAL PORTION - aka HOMER’S MUSCLE or tensor tarsiORIGIN: posterior lacrimalcrestINSERTION: tarsal plate TENSOR TARSIACTION: compress lacrimalsac, forcing the tears intothe nasal cavity through thenaso-lacrimal duct
2. CORRUGATOR SUPERCILLI – - deep muscle blending with the upper portion of the orbicularis muscle ORIGIN: fronto-nasal suture and frontal bone, and medial part of the supercilliary arch INSERTION: skin on the medial half of the eyebrow ACTION: throw the skin of forehead into folds as in frowning
3. LEVATOR PALPEBRAESUPERIORISORIGIN: lesser wing of thesphenoid bone just above theoptic foramenINSERTION: skin of the uppereyelid as well as the superiortarsal plateACTION: elevates the uppereyelid thereby opening the eyes
A. PROCERUS – small muscle overlying the basal bone (frowning) ORIGIN: nasal bone and lateral nasal cartilage INSERTION: skin at the root of the nose ACTION: compress the nostril and depress the cartilage of nose
B. NASALIS – aka COMPRESSOR NARES or PARS TRANSVERSUSORIGIN: side of the bonyaperture of the nose and theupper end of the canineeminence of maxillaINSERTION: the aponeurosis ofthe cartilaginous part of thenoseACTION: compress the nostrilsand depress the cartilage of thenose
C. DILATOR NARESORIGIN: nasal notch of themaxilla and the nasolabialgrooveINSERTION: inferior border ofthe ala of the noseACTION: dilate the nostrils
D. DEPRESSOR SEPTI NASI ORIGIN: medial fiber of the dilator naris muscle INSERTION: mobile part of the nasal septum ACTION: draw the septum downwards and to narrow the nostril
1. ELEVATORS, RETRACTORS and EVERTORS OF THE UPPER LIP Levator labii superioris alaque nasi Levator labii superioris Zygomaticus major and minor Levator anguli oris Risorius
A. LEVATOR LABIISUPRIORIS ALAQUE NASIORIGIN: frontal nasal processINSERTION: one slip goes toala of the nose while the othergoes to the orbicularis orisACTION: elevate the ala of thenose and the upper lip
B. LEVATOR LABII SUPRIORISORIGIN: infraorbital head,zygomatic head and angularheadINSERTION: upper lipACTION: elevate lateral par ofupper lip. Contraction ofinfraorbital head givesexpression of sadness.Contraction of infraorbital headgives expression of disdain ordoubt
C. ZYGOMATICUS MAJOR - Smiling muscle or muscle of happinessORIGIN: zygomatic bone andarchINSERTION: angle of themouthACTION: elevate or draw angleof the mouth up and back as inlaughing or smiling
D. ZYGOMATICUS MINOR - gives the expression of pain or sorrow ORIGIN: zygomatic bone, medial to zygomatic major INSERTION: skin on the nasolabial groove ACTION: deepen the nasolabial groove as in sorrow
E. LEVATOR ANGULI ORIS OR CANINUSORIGIN: maxilla below theinfraorbital foramen and thecanine fossa of maxillaINSERTION: fibers are directeddownward, to be inserted to theangle of the mouthACTION: elevate angle of themouth (also a muscle ofhappiness)
F. RISORIUS -lies horizontally across thecheek. Gives the expression of irony orplasticity ORIGIN: superficial fascia over the parotid INSERTION: skin and mucosa of the angle of the mouth ACTION: draw the angle of the mouth laterally, giving an expression of strain and stress
A. DEPRESSOR LABIIINFERIORS - a quadrilateral muscle; givesthe expression of frowning ORIGIN: base of the mandible, between mental protuberance and mental foramen INSERTION: skin and mucosa of the lower lip ACTION: draw the lower lip downward, as in ‘irony”
B. DEPRESSOR ANGULIORIS or TRIANGULARIS - gives the expression of sadness ORIGIN: oblique line of mandible INSERTION: angle of the mouth ACTION: depress the angle of the mouth
C. MENTALIS MUSCLEORIGIN: mandible below thelower incisor teeth and beneathoral mucosaINSERTION: skin of chinACTION: elevate chin. It alsocauses trembling of the chin. Itwrinkles the skin of the chin asin disdain or doubt.
3. A COMPOUND SPHINCTER Orbicularis oris Accessory muscles to the orbicularis oris incisivus superior and incisivus inferior
ORBICULARIS MUSCLE - muscle that forms thesphincter around the mouthORIGIN: buccinator muscleINSERTION: upper lip- angle ofthe mouth; lower lip - mandibleACTION: close the mouth invarious ways such as closing,pressing against teeth, twistingand protruding
ORIGIN: outer surface ofalveolar process of maxilla andmandible in the region of themolar teeth andpterygomandibular ligamentINSERTION: angle of the mouthblending with the orbicularisorisACTION: press the cheekagainst the teeth while chewing.Useful in mastication, whistling,sucking and blowing
ORIGIN: skin and superficialfascia of the pectoral anddeltoid regionsINSERTION: directed upwardand forward to be inserted intothe lower border of themandibleACTION: retract and depressthe angle of the mouth;Depress the mandible.