Osteology |
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| Bone | Structure | Description |
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| temporal | temporal lines (TG7-04) | two low ridges that run parallel to each other, arching across the lateral surface of the calvaria; they define the upper limit of the temporalis m. origin |
| articular tubercle (TG7-06) | inferior projection anterior to mandibular fossa; important in dislocations of the mandible |
|
mandibular fossa (N4, TG7-32) |
articulates with condylar process of mandible |
| sphenoid |
body (N8, TG7-07, TG7-08) |
central part, containing sinuses (Greek, sphenoid = wedge-shaped) |
|
infratemporal fossa (N4, TG7-32) |
bounded superiorly by the infratemporal surface of greater wing of the sphenoid and inferiorly by the alveolar border of the maxilla; bounded laterally by the ramus of the mandible and medially by the lateral pterygoid plate of the sphenoid bone |
|
foramen ovale (N4, N8, N11, TG7-06, TG7-07, TG7-32) |
through greater wing between foramen rotundum & foramen spinosum; transmits mandibular division of trigeminal nerve |
|
foramen spinosum (N8,N11, TG7-06, TG7-07) |
through greater wing; transmits middle meningeal artery |
|
lateral pterygoid plate (N6, N8, TG7-06, TG7-08) |
projects posterolaterally from pterygoid process; attachment of lateral & medial pterygoid muscles (Greek, pterygoid = wing-shaped) |
|
medial pterygoid plate (N6, N8, TG7-06, TG7-08) |
projects posteriorly from pterygoid process; attachment of superior pharyngeal constrictor & pharyngobasilar fascia (Greek, pterygoid = wing-shaped) |
| mandible |
body (N15, TG7-32B, TG7-32C) |
U-shaped, halves fused at symphysis menti |
|
coronoid process (N15, TG7-32B) |
anterosuperior projection from ramus; attachment of temporalis muscle |
|
condyle (N15, TG7-32B) |
posterosuperior projection from ramus; articulates with mandibular fossa of temporal bone; constricted below articular surface at neck of mandible (Greek, kondylos = knuckle) |
|
mandibular notch (N15, TG7-32B) |
notch between the coronoid and condylar processes; transmits masseteric neurovascular bundle |
|
lingula (N15, TG7-32C) |
projection of bone medial to mandibular foramen; attachment of sphenomandibular ligament (Latin, lingula = tongue) |
|
mandibular foramen (N15, TG7-32C) |
on medial surface of ramus, opening to mandibular canal; transmits inferior alveolar neurovascular bundle |
|
pterygoid fovea (N15, TG7-32C) |
depression on anterior side of neck of mandible; insertion of lateral pterygoid m. (Greek, pterygoid = wing-shaped) |
Muscles |
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| Muscle | Origin | Insertion | Action | Innervation | Notes | Image |
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| masseter (N54, TG7-31) |
zygomatic arch and zygomatic bone | lateral surface of ramus and angle of mandible | elevates mandible | nerve to masseter, from mandibular division of trigeminal nerve (V) | a powerful chewing muscle (Greek, masseter = the chewer) |  |
| temporalis (N54, TG7-31, TG7-34) |
temporal fossa and temporal fascia | coronoid process and anterior surface of the ramus of the mandible | elevates mandible; retracts mandible (posterior fibers) | anterior and posterior deep temporal nerves from mandibular division of trigeminal nerve (V) | a powerful chewing muscle |  |
| pterygoid, lateral (N55, TG7-34) |
superior head: greater wing of sphenoid; inferior head: lateral surface of lateral pterygoid plate | superior head: capsule & articular disk of temporomandibular joint; inferior head: neck of mandible | protracts mandible; opens mouth | lateral pterygoid branch of mandibular division of trigeminal nerve (V) | the only one of the muscles of mastication that opens the mouth; the superior head of lateral pterygoid is sometimes called sphenomeniscus due to its insertion into the disc of the temporomandibular joint (Greek, pterygoid = wing-shaped) |  |
| pterygoid, medial (N55, TG7-34) |
medial surface of the lateral pterygoid plate, pyramidal process of palatine bone, tuberosity of maxilla | medial surface of ramus and angle of mandible | elevates and protracts mandible | medial pterygoid branch of mandibular division of trigeminal nerve (V) | this muscle mirrors the masseter m. in position and action with the ramus of the mandible between (Greek, pterygoid = wing-shaped) |  |
| digastric (N27, N28 TG7-12, TG7-17) |
anterior belly: digastric fossa of the mandible; posterior belly: mastoid
notch of the temporal bone |
body of the hyoid via a fibrous loop over an intermediate tendon |
elevates the hyoid bone; depresses the mandible |
anterior belly: mylohyoid nerve, from the mandibular division of the trigeminal
nerve (V); posterior belly: facial nerve (VII) |
the digastric m. forms two sides of the submandibular triangle; it is formed
from mesenchyme derived from the first two pharyngeal arches, hence its dual
innervation |
 |
| geniohyoid (N53, N59,N63, TG7-38, TG7-40) |
mental spines of mandible | body of hyoid bone | elevates hyoid; depresses mandible | C1 ventral primary ramus via fibers carried by hypoglossal nerve | thyrohyoid and geniohyoid receive ansa cervicalis fibers that travel with the hypoglossal nerve distal to the superior limb of the ansa cervicalis |  |
| genioglossus (N63, N59, TG7-38, TG7-40) |
mental spine on inner aspect of mental symphysis | fans out to insert into the tongue from tip to base | protrudes tongue (inferior fibers); depresses tongue (middle fibers) | hypoglossal nerve (XII) | an extrinsic muscle of the tongue; XII innervates all tongue muscles except palatoglossus (innervated by vagus (X), as are most of the palate and pharynx muscles) |  |
| hyoglossus (N53, N59, TG7-40) |
upper border of greater horn of the hyoid and body of the hyoid bone | mingles with intrinsic muscles of the tongue | depresses sides of tongue; retracts tongue | hypoglossal nerve (XII) | an extrinsic muscle of the tongue |  |
| mylohyoid (N27,N28, N53, N59, TG7-12, TG7-37, TG7-40) |
mylohyoid line of mandible |
midline raphe and body of the hyoid bone |
elevates the hyoid bone and the tongue; depresses the mandible |
mylohyoid nerve from the inferior alveolar nerve, a branch of the mandibular
division of the trigeminal nerve (V) |
the nerve to mylohyoid also innervates the anterior belly of digastric m.;
both muscles are derivatives of the second pharyngeal arch |
 |
| styloglossus (N59, N68, TG7-20, TG7-40) |
styloid process | side of the tongue | retracts and elevates tongue | hypoglossal nerve (XII) | an extrinsic muscle of the tongue |  |
| stylohyoid (N59, TG7-17, TG7-40) |
posterior side of the styloid process |
splits around the intermediate tendon of the digastric m. to insert on the
body of the hyoid bone |
elevates and retracts the hyoid bone |
facial nerve (VII) |
facial nerve innervates both the stylohyoid m. and the posterior belly of
the digastric m. shortly after exiting from the stylomastoid foramen |
 |
Nerves |
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| Nerve | Source | Branches | Motor | Sensory | Notes |
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| mandibular (N46, N55, TG7-37, TG7-84A, TG7-84B, TG7-84C, TG7-85A, TG7-85B) |
trigeminal ganglion; motor root of trigeminal from pons | meningeal br., medial & lateral pterygoid, masseteric, anterior & posterior deep temporal, buccal, auriculotemporal, lingual, inferior alveolar | mylohyoid, anterior belly of digastric; tensor tympani, tensor veli palatini; muscles of mastication (temporalis, masseter, medial & lateral pterygoid) | GSA: skin of lower lip & jaw extending superiorly above level of ear; GVA: tongue, & floor of mouth, lower teeth & gingiva | also known as: V3, mandibular division of trigeminal; passes through foramen ovale; otic ganglion hangs off medial side of V3 below foramen ovale; auriculotemporal n. carries postganglionic parasympathetic to parotid gland; submandibular ganglion hangs off lingual n. near submandibular gland; postganglionic parasympathetics reach this gland & sublingual gland |
| auriculotemporal (N46, N61,N122, TG7-30, TG7-84) |
mandibular division of trigeminal n. (V3) | parotid brs., articular brs., anterior auricular brs. | secretomotor to parotid gland: postganglionic parasympathetic from communicating br. of otic ganglion; preganglionic parasympathetic from lesser petrosal br. of glossopharyngeal n. (IX) | skin of anterior ear & anterosuperior to ear; part of external auditory meatus; temporomandibular joint | two roots of auriculotemporal encircle the middle meningeal a. |
| inferior alveolar (N42,N122, TG7-36, TG7-84) |
mandibular division of trigeminal (V3) | n. to mylohyoid; inferior dental plexus; terminates as mental nerve | mylohyoid muscle via n. to mylohyoid |
teeth of mandible; skin of chin |
| mylohyoid, n. to (N42,N122, TG7-36, TG7-84) | inferior alveolar | | mylohyoid, anterior belly of digastric | | arises near lingula of mandible |
| lingual (N55, N57, N65, TG7-37, TG7-84A, TG7-84C) |
mandibular division of trigeminal (V3) | | | general sense from anterior 2/3rds of tongue, floor of mouth | joined by chorda tympani (taste & pregang. parasymp.) from facial n. in infratemporal fossa; submandibular gang. hangs from lingual nerve in paralingual space |
| buccal (N50, N128, TG7-37, TG7-84) |
mandibular division of trigeminal n. (V3) | | | skin of cheek, oral mucosa | not a motor nerve |
| chorda tympani (N46, N94,N123, TG7-37, TG7-84, TG7-88B) |
facial (VII) | | secretomotor to submandibular & sublingual glands (preganglionic parasympathetic to submandibular ganglion) | taste to anterior 2/3rds of tongue | joins lingual nerve in infratemporal fossa and continues with it to the tongue (Latin, corda = cord; Greek, tympanum = a kettle drum) |
| masseteric (TG7-85A) | mandibular division of trigeminal | | masseter | | passes over mandibular notch |
| temporal, anterior deep (N42, N122, TG7-36, TG7-85) |
mandibular division of trigeminal (V3) | |
temporalis | | |
| temporal, posterior deep (N42, N122, TG7-36, TG7-85) |
mandibular division of trigeminal (V3) | |
temporalis | | |
| trigeminal (TG7-81AB, TG7-81C, TG7-81D) | pons: trigeminal motor nucleus (SVE) to motor root; spinal trigeminal nucleus from trigeminal ganglion (GSA) via sensory root | ophthalmic, maxillary & mandibular divisions | SVE: temporalis, masseter, lateral & medial pterygoid, anterior belly of digastric, mylohyoid, tensor veli palatini, tensor tympani | skin of face, nasal & oral cavities, ant. 2/3rds of tongue (GSA only) | also known as: CN V, 5th cranial nerve; some brs. carry pre- or postganglionic parasympathetic fibers; divides into three divisions at trigeminal ganglion; SVE supplies muscles of branchial arch origin |
| hypoglossal (N32, N71, N128, TG7-17, TG7-18, TG7-94AB, TG7-94C) |
medulla: hypoglossal nucleus | branches of C1 carried by this nerve are not considered to be branches of the hypoglossal nerve | intrinsic and extrinsic muscles of the tongue (except palatoglossus m.) | | also known as: CN XII, 12th cranial nerve; passes through the hypoglossal canal; superior root of ansa cervicalis travels with the hypoglossal n. |
| ganglion, submandibular (N46, N59, N61, N122, TG7-37, TG7-40, TG7-84) |
preganglionic parasympathetic from chorda tympani accompanying lingual n. | postganganglionic parasympathetic to submandibular & sublingual glands | secretomotor to submandibular & sublingual glands | | hangs off lingual n. above deep part of submandibular gland |
Arteries |
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| Artery | Source | Branches | Supply | Notes |
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| carotid, external (N69, TG7-19, TG7-34, TG7-35) |
common carotid | superior thyroid, ascending pharyngeal, lingual, facial, occipital, post. auricular, maxillary & superficial temporal (terminal brs.) | upper neck, face & scalp | primary blood supply to face & superficial head |
| maxillary (N69, TG7-19, TG7-34, TG7-35) |
external carotid | deep auricular, anterior tympanic, middle meningeal, inferior alveolar, masseteric, post. & ant. deep temporal, buccal, post. superior alveolar, infraorbital, art. of pterygoid canal, descending palatine, sphenopalatine | deep face, infratemporal fossa, tympanic cavity, muscles of mastication | may course medial or lateral to the lateral pterygoid m. in equal frequency |
| alveolar, inferior (N69, TG7-34, TG7-35) |
maxillary artery | lingual branch, mylohyoid, dental, nutrient, mental | lower teeth & gingiva, mandible, closely associated muscles | runs with the inferior alveolar nerve within the mandibular canal |
| middle meningeal (N69, TG7-35) |
maxillary | frontal br., parietal br., petrous br., superior tympanic | most of the dura mater (approx. 80%), cranial vault bones | passes through foramen spinosum; may be torn by fracture at pterion |
| temporal, anterior deep (N69, TG7-35) |
maxillary | | temporalis anteriorly | branches in the infratemporal fossa and runs deep to temporalis m. |
| temporal, posterior deep (N69, TG7-35) |
maxillary | | temporalis posteriorly | branches in the infratemporal fossa and runs deep to temporalis m. |
| buccal (N69, TG7-34, TG7-35) |
maxillary | | cheek and associated muscles | runs with the buccal branch of CN V |
| masseteric (N69, TG7-34, TG7-35) |
maxillary | | masseter m. | |
| alveolar, posterior superior (N69, TG7-35) |
maxillary artery | dental, mucosal | upper molar teeth, part of maxillary sinus | enters the maxilla in the infratemporal fossa |
| lingual (N69, N59, N51, TG7-19, TG7-40) |
external carotid | suprahyoid br., dorsal lingual brs., deep lingual, sublingual | tongue, suprahyoid muscles, palatine tonsil | |
Viscera/Fascia |
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| Organ | Location/Description |
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| intrinsic muscles of the tongue (N126, TG7-38) |
includes the superior and inferior longitudinals, transverse, and vertical muscles |
| submandibular triangle (N60, N61, N69, N73, TG7-02, TG7-12, TG7-37) |
comprised of the submandibular gland and lymph nodes, hypoglossal nerve, mylohyoid nerve, and parts of the facial artery and vein |
| submandibular gland (N60, N61, N69, N73, TG7-12, TG7-37A, TG7-37B) |
salivary gland; located beneath mylohyoid in submandibular triangle; innervated by postgang. parasymp. fibers from submandibular gang. |
| sublingual gland (TG7-37A, TG7-37B) |
salivary gland; located beneath oral mucosa in floor of mouth; drains via multiple small ducts |
| submandibular duct (N60, N61, N69, N73, TG7-12, TG7-37A, TG7-37B) |
drains submandibular gland to sublingual caruncle in floor of mouth |
| foramen cecum (of tongue) (N58, TG7-39) |
located on midline of tongue in sulcus terminalis; remnant of thyroid diverticulum (Latin, foramen cecum = blind apeture) |
| vallate papillae (N58, TG7-39) |
located in line anteriorly along sulcus terminalis of tongue; possess taste buds in circular sulcus; a.k.a. circumvallate papillae |
| frenulum of tongue (N51, TG7-38) |
fold of mucous membrane under tongue (Latin, frenulum = a bridle, a narrow reflection or fold of mucous membrane, passing from a more fixed to a movable part) |
| sublingual caruncle (N51, TG7-38) |
papilla on lateral side of frenulum of tongue; opening of the duct of the submandibular gland |
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