Unit III - Mandible Flashcards
What are the two subdivisions of the mandible?
body and mandibular ramus
What are the four areas of the body of the mandible?
external surface, base, alveolar part, internal surface
What muscles attach to the external surface of the body of the mandible (and what are their specific attachment sites, functions, innervation, and blood supply)?
(1) depressor labii inferioris
attachments: lower oblique line of mandible –> skin & mucosa of lower lip
functions: draws lower lip downward
innervation: facial n. (marginal mandibular branch)
blood supply: inferior labial & mental a.
(2) depressor anguli oris
attachments: mandible –> buccal angle
function: depresses buccal angle laterally
innervation: facial n. (marginal mandibular branch)
blood supply: inferior labial & mental a.
(3) platysma
attachments: lower border of mandible –> superficial fascia of the skin of the neck overlying the clavicle
function: wrinkles anterior nuccal skin
innervation: facial n. (cervical branch)
blood supply: facial, submental & suprascapular a.
(4) mentalis
attachments: incisive fossa of mandible –> skin of chin
function: raises lower lip
innervation: facial n. (marginal mandibular branch)
blood supply: inferior labial & mental a.
(5) buccinator
attachments: alveolar processes of maxilla & mandible, pterygoid hamulus & pterygomandibular raphe to the buccal angle
function: compresses cheek
innervation: facial n. (buccal branch)
blood supply: facial & buccal a.
What are the two landmarks of the external surface of the body of the mandible?
mental foramen (transmits mental nerve, artery, vein)
incisive fossa (mentalis muscle attaches here)
What is the landmark of the base of the body of the mandible?
digastric fossa (anterior digastric muscle attaches here)
What are the six landmarks of the internal surface of the body of the mandible?
mylohyoid line (mylohyoid muscle attaches here)
submandibular fossa (houses submandibular gland)
sublingual fossa (houses sublingual gland)
superior genial tubercle (genioglossus muscle attaches here)
inferior genial tubercle (geniohyoid muscle attaches here)
mylohyoid groove (houses mylohyoid nerve)
What muscles attach to the internal surface of the body of the mandible (and what are their specific attachment sites, functions, innervation, and blood supply)?
(1) genioglossus muscle
attachments: superior genial tubercle –> hyoid (body), middle constrictor & length of ventral aspect of the tongue
function: protrusion of the tongue
innervation: hypoglossal n.
blood supply: deep lingual & sublingual a.
(2) geniohyoid muscle
attachments: inferior genial tubercle –> anterior aspect of body of the hyoid
function: elevation & anterior displacement of hyoid, or depression of mandible with a fixed hyoid
innervation: ventral ramus of C1 (via the hypoglossal n.)
blood supply: sublingual a.
(3) anterior digastric muscle
attachments: digastric fossa –> intermediate tendon (greater cornu) of hyoid
function: depression of mandible or elevation of hyoid
innervation: mylohyoid branch of inferior alveolar n.
blood supply: submental branch of facial a.
(4) mylohyoid muscle
attachments: mylohyoid line –> midline raphe & anterior aspect of body of hyoid
function: elevation of floor of oral cavity
innervation: mylohyoid branch of inferior alveolar n.
blood supply: submental branch of facial & lingual a.
What are the six areas of the mandibular ramus?
angle (masseter & medial pterygoid muscles attach)
medial surface (sphenomandibular ligament & temporalis muscle attach)
anterior border (temporalis & depressor labii inferioris muscles attach)
coronoid process (temporalis muscle attaches)
mandibular notch (transmits nerve & artery to the masseter muscle)
condylar process (lateral pterygoid muscle attaches)
What muscles attach to the medial surface of the mandibular ramus (and what are their specific attachment sites, functions, innervation, and blood supply)?
(1) mylohyoid muscle
attachments: mylohyoid line –> midline raphe & anterior aspect of body of hyoid
function: elevation of floor of oral cavity
innervation: mylohyoid branch of inferior alveolar n.
blood supply: submental branch of facial & lingual a.
(2) medial pterygoid muscle
attachments: medial surface of lateral pterygoid plate & fossa –> medial aspect of angle of mandible
function: elevation of mandible & acts with ipsilateral lateral pterygoid to rotate the mandible to produce the site-to-side movements during trituration of food
innervation: mandibular n.
blood supply: pterygoid a.
(3) temporalis muscle
attachments: temporal fossa –> coronoid process & temporal crest
function: elevation & retraction of mandible
innervation: mandibular n.
blood supply: deep temporal a.
(4) lateral pterygoid muscle
attachments: infratemporal surface of sphenoid & lateral surface of lateral pterygoid plate –> pterygoid fovea & TMJ disc
function: protraction of mandible & acts with ipsilateral medial pterygoid to rotate mandible to produce side-to-side movements during trituration of food
innervation: mandibular n.
blood supply: pterygoid & ascending palatine a.
What are the five bony landmarks of the medial surface of the mandibular ramus?
mandibular foramen (transmits inferior alveolar n., a., v.)
mandibular canal (houses inferior alveolar n., a. & v. within ramus & body of mandible)
lingula (sphenomandibular ligament attaches)
temporal crest (temporalis muscle attaches)
mylohyoid groove (houses mylohyoid n.)
What muscle attaches to the temporal crest (and what are its specific attachment sites, functions, innervation, and blood supply)?
temporalis muscle
attachments: temporal fossa –> coronoid process & temporal crest
function: elevation & retraction of mandible
innervation: mandibular n.
blood supply: deep temporal a.
What is the one bony landmark of the anterior border of the mandibular ramus?
Oblique line (depressor labii inferioris attaches)
What muscle attaches to the oblique line (and what are its specific attachment sites, functions, innervation, and blood supply)?
depressor labii inferioris
attachments: lower oblique line of mandible –> skin & mucosa of lower lip
functions: draws lower lip downward
innervation: facial n. (marginal mandibular branch)
blood supply: inferior labial & mental a.
What are the three bony landmarks of the condylar process of the mandibular ramus?
head of mandible (medial pole, lateral pole)
neck of mandible
pterygoid fovea (lateral pterygoid muscle attaches)
What muscle attaches to the pterygoid fovea (and what are its specific attachment sites, functions, innervation, and blood supply)?
lateral pterygoid muscle
attachments: infratemporal surface of sphenoid & lateral surface of lateral pterygoid plate –> pterygoid fovea & TMJ disc
function: protraction of mandible & acts with ipsilateral medial pterygoid to rotate mandible to produce side-to-side movements during trituration of food
innervation: mandibular n.
blood supply: pterygoid & ascending palatine a.
