Head and Neck Exam 2: Muscles and TMJ

frontal belly of the epicranial insertion

skin of eyebrow and root of nose

corrugator supercilii origin

frontal bone in supraorbital region

orbicularis oris insertion

labial commissures, maxillary ridges of philtrum

buccinator insertion

tissue at commissure(under orbicularis oris)

risorius insertion

skin at labial commissure

pterygomandibular raphe

tendious band of tissue extending from hamulus to posterior end of mylohyoid line

pterygomandibular fold

fold of tissue in oral cavity superficial to pterygomandibular raphe

zygomaticus major

upper lip muscle, innervated CN 7

zygomaticus major insertion

labial commissure

zygomaticus major action

pulls corner of mouth laterally, makes mechanical smile, contracts with orbicularis oculi to make true smile

levator anguli oris

upper lip, underneath zygo major and minor, innervated by CN 7

levator anguli oris origin

canine fossa of maxilla

levator anguli oris insertion

labial commissure

levator anguli oris action

elevate the labial commissure as when a person smiles

depressor anguli oris insertion

labial commissure

depressor anguli oris action

depress labial commissure, frowning muscle

depressor labii inferioris

lower lip, deep to depressor anguli oris, innervated by CN 7

depressor labii inferioris origin

inferior border of mandible

depressor labii inferioris insertion

skin of lower lip

mentalis action

raises chin, wrinkling skin, protruding lower lip, narrows vestibule near md incisors, when active fibers may dislodge complete denture with patient with loss of alveolar height

platysma origin

skin superficial to clavicle and shoulder

platysma insertion

inferior border of ms and into the other muscles surrounding the mouth

platysma action

raises skin of neck, pulls labial commissures down(grimace), often contracts with risorius

masseter superficial head insertion

lateral surface of angle of mandible

masseter deep head origin

posterior 1/3 of inferior surface and entire medial surface of zygomatic arch

temproalis insertion

coronoid process: apex anterior and posterior border and entire medial surface

temporalis action

when full muscle contracts: elevate mandible

if only posterior part of muscle: moves lower jaw back(retracts)

mantains the mandible in its physiological(rest) position

medial pterygoid muscle

parallel with masseter, deepest muscle of mastication, 2 heads, innervated by CN 5

superficial head of medial pterygoid muscle origin

lateral surface(pyramidal process), of the palatine bone and maxillary tuberosity

superficial head of medial pterygoid muscle insertion

medial surface of mandibular ramus and angle of mandible as far superior as mandibular foramen

deep head of medial pterygoid muscle origin

pterygoid fossa on medial surface of the lateral pterygoid plate

deep head of medial pterygoid muscle insertion

medial surface of mandibular ramus and angle of mandible as far superior as mandibular foramen

superior head of lateral pterygoid muscle origin

infratemporal surface and infratemporal crest of greater wing of sphenoid

superior head of lateral pterygoid muscle insertion

anterior surface of pterygoid fovea on md, anterior margin of TMJ disc and capsule

inferior head of lateral pterygoid muscle origin

lateral surface of lateral pterygoid plate

inferior head of lateral pterygoid muscle insertion

anterior surface of pterygoid fovea on md

anterior belly of digastric muscle origin

intermediate tendon of the digastric muscle, anterior surpahyoid muscle, innervated by CN 5

anterior belly of digastric muscle insertion

digastric fossa on the medial surface of md

posterior belly of digastric muscle origin

mastoid notch, medial to mastoid process of temporal bone, posterior of suprahyoid muscles, innervated by CN 7

intermediate tendon of digastric muscle

between anterior and posterior bellies

Mylohoid muscle origin

mylohyoid line on the medial surface of the mandible

Mylohoid muscle action

elevate hyoid bone, depressing the mandible, forms the floor of the mouth and helps elevate the tongue

geniohyoid muscle insertion

body of hyoid bone

geniohyoid muscle action

elevates the hyoid bone, depress mandible

Stylohyoid action

elevates hyoid bone

superior head of omohyoid origin

intermediate tendon attached to inferior belly

superior head of omohyoid insertion

lateral border of the body of hyoid bone

inferior belly of omohyoid insertion

intermediate tendon attached to superior belly

omohyoid action

depress hyoid bone

sternohyoid origin

posterior and superior surfaces of the sternum joins clavicle

Sternohyoid insertion

body of hyoid bone

Sternohyoid action.

depress hyoid bone

sternothyroid origin

posterior surface of the sternum, deep and medial to sternohyoid

sternothyroid insertion

thyroid cartialge

thyrohyoid origin

thyroid cartilage

thyrohyoid insertion

body and greater cornu of hyoid bine

thyrohyoid action

depressing the hyoid, raises the thyroid cartilage and larynx

inferior longitudinal muscle of the tongue

close to ventral surface, runs in longitudinal direction, from base to apex

styloglossus action

retracts the tongue moving it superiorly and posteriorly, elevates the tongue

Genioglossus insertion

most fibers insert into tongue from base almost to apex, some inferior fibers insert into hyoid bone

hyoglossus origin

greater cornu and part of body of hyoid bone

hyoglossus action

depress tongue

palatoglossus origin

posterior part of median palatine raphe

palatoglossus insertion

lateral surface of tongue

palatoglossus action

elevates and arches tongue toward soft palate, depress soft palate towards tongue, closes nasopharynx during swallowing, innervated by CN X(vagus)

palatopharyngeal origin

soft palate

palatopharyngeal insertion

walls of laryngopharynx and on thyroid cartilage

palatoglossus clinincally

median palatine raphe

demarcating the deeper median palatine suture

TMJ capsule

fibrous and completely surrounds the joint and articulating areas of condyle, very few to no bv, few cartilage cells, superiorly wraps around articular eminence and articular fossa, inferiorly wraps around condyle

temporomandibular ligaments function

strengthens and reinforces joint capsule, limits laterally displacement and slipping, resist excessive retraction

muscle shortens

under neural control, causing soft tissue and bony structures to move

sternocleidomastoid(SCM)

paired, large and strap like, divides each side of neck into anterior and posterior cervical triangle, innervated by 11th CN(cranial nerve)

trapezius origin

superior nuchal line of the occipital bine and the posterior midline of the cervical and thoracic regions

trapezius insertion

lateral third of clavicle and parts of scapula

trapezius action

lift the clavicle and scapula, as when the shrugging the shoulders

epicranial(occipitofrontalis)

composed of 2 bellies:frontal and occipital that are connected by epicranial aponerurosis, innervated by 7th CN

occipital belly of the epicranial origin insertion

epicranial aponeurosis

epicranial action

raise eyebrows and scalp, wrinkle of forehead, surprised look

lateral canthus

outer corner of eye

corrugator supercilii action

wrinkles forehead, frowning

oral region of facial muscles

orbicularis oris, buccinator, risorius, levator labii superioris, levator labii superioris alaque nasi, zygomaticus major, zygomaticus minor, levator anguli oris, depressor anguli oris, depressor labii inferioris, mentalis, and platysma

orbicularis oris

encircles the mouth, acts to shape and control mouth opening, creates the lip positioning and movements during speecg, innervated by 7th cranial nerve

orbicularis oris action

pressing lips together, pursing lips, rolling inward between teeth, thrusting lips outward(pouting/kissing), can show more wrinkles with smoking

buccinator origin

maxillary alveolar process, mandible alveolar process, pterygomandibular raphe

buccinator action

pulls mouth laterally, keeps food on occlusal surface when chewing, compress cheek inward

risorius origin

fascia superficial to masseter

risorius action

stretches lips laterally widening mouth, produces a grimace- contracts with platysma muscle

levator labii superioris

broad flat muscle of the upper lip, innervated by CN 7

levator labii superioris origin

infraorbital rim of maxilla

levator labii superioris action

elevates upper lip

levator labii superioris alaeque nasi insertion

skin of the ala of the nose and upper lip

zygomaticus minor

upper lip, small variable muscle of facial expression, medial to zygo major, innervated by CN 7

depressor anguli oris

triangular muscle of lower lip, lateral and superior to depressor labii inferioris, innervated by CN 7

depressor anguli oris origin

inferior border of mandible

mentalis origin

mandible near midline

mentalis insertion

skin of chin

masseter

anterior to partoid salivary gland, largest and most superficial mastication muscle, innervated by CN 5, 2 heads

masseter superficial head origin

zygomatic process of maxilla, anterior 2/3 of the inferior border of zygomatic arch

masseter deep head insertion

mandibular ramus superior to angle of mandible