CH 5: joint?
site of a junction between 2 or more bones
joint on each side of head; allows for movement of mand, speech, mastication
What 2 articulations does the TMJ have?
2 temporal bones and 2 condyles of mand ( both covered by fibrocartilage)
cranial bone; articulates with the mandible at TMJ.
Where is the articulating area of temporal bone?
inferior aspect (Inc: articular eminence/fossa)
What is the articular eminence, where is it positioned?
smooth rounded ridge; anterior to articular fossa
Articular fossa? Where?
aka; mandibular fossa. Post to articular eminence; depression on temp bone.
What is located posterior to articular fossa?
a sharper ridge; postglenoid process
facial bone; articulates w/temp bone at condyle w/its articulating surface of condyle
Where is the condyle in relation to coronoid process?
Where is the depression of the mand notch located?
between condyle and coronoid process
What completely encloses the TMJ?
fibrous joint capsule
Superiorly, what does the capsule wrap around?
margin of articular eminence and articular fossa of temp bone
Inferiorly, what does the capsule wrap around?
circumference of mand condyle (inc; condyle neck)
In the TMJ, where does the condyle sit?
Where is the Fibrous disc of the joint (meniscus) located?
between temp bone and condyle of mand on each side
What 2 compartments do the discs divide the TMJ into?
synovial cavities (upper and lower)
What does the membrane lining inside the joint capsule secrete?
Purpose of synovial fluid?
makes joint move smoothly; lubricates/fills synovial cavities
What does synovial fluid look like?
clear, viscous, like an egg white
How does the disc attach to temp bone anteriorly?
not attached, exept indirectly through capsule, but is attached through lateral/medial poles of mand condyle
Posteriorly, what areas is the disc divided into?
upper division of post disc attached to postglenoid process. Lower division attaches to neck of condyle. At these points the disc blends w/capsule
What happens to the disc when a person ages or undergoes trauma?
becomes thinner or even perforated. Calcifications may be caused w/i disc
How may disc become dislocated forward?
by injury to the posterior attachment
What 3 ligaments associated w/TMJ keep jaw from dislocating?
TMJ ligament, sphenomandibular ligament, stylomandibular ligament
band of fibrous tissue; connects bones
on lateral side of each joint; forms reinforcement of capsule; prevents exessive retraction of the mandible
not portion of TMJ; on medial side of mand.; from spine of shpenoid to lingula of mand foramen; in embryonic lower jaw(meckel's cartilage); becomes accentuated and taut when mand protruded
formed from thickened cervical fascia; from styloid process of temp bone to angle of mand; becomes taut when mand protruded
When does the TMJ allow for movement of the mandible?
during speech and mastication
What two types of movement are performed by TMJ and assoc. muscles?
Gliding and rotational movements
back/front; occurs between discs and articular eminence in upper synovial cavity
protrusion of mandible involves what?
bilateral contraction of lateral pterygoid muscles
retraction of mandible involves what?
posterior portions of both temporalis muscles
opening/closing; occurs between disc and condyle of mand in lower synovial cavity
what is the axis of rotation between disc and mandible?
transverse; movement is depression/elevation
How can finer movements of the jaw be accomplished?
gliding, rotating, and w/ right and left TMJ working together
What type of movement does opening of the jaws during speech/mastication inv.?
depression and protrusion
What muscles of mastication are involved in elevating (closing) the mand?
masseter, temporalis, medial pterygoid
What muscles of mastication are involved in depressing(opening) the mand?
anterior suprahyoid; when they bilateraly contract as hyoid stabilized by other hyoid muscles; also inferior heads of lateral pterygoid
lateral excursion of mandible/shifting of lower jaw(during mastication)
What type of movement does lateral deviation involve?
gliding and rotational
explain lateral deviation
one disc plus condyle glide forward and medially on articular eminence in upper synovial cavity, while other condyle and disc remain stable in position in articular fossa. Produces rotation around more stable condyle.
How is the lateral pterygoid muscle involved during lateral deviation?
when mand laterally deviated to left, rght lateral ptrygoid muscle contracts, right condyle moves forward, while left condyle stays in place, thus causing mand to move to left
What does the "power stroke" refer to?
during mastication, when teeth crunch the food.
What does the power stroke involve?
movement form laterally deviated position back to midline
During mastication, if food is on the right, what will happen to the mandible if we want to crunch on the food.
mand will be deviated to right by left lateral petrygoid muscle, mand centered by power stroke, so movement is to left and involves retraction (temporalis muscle) of left side, simultaneously all muscles of right contract to crush food
What is the resting position of TMJ?
space of 2-4mm
What happens when teeth are lost concerning TMJ?
jaw may overclose (uncomfortable); likewise dentures that "JACK" the jaw open are intolerable for patient
Effective way to palpate?
have pt go through all movements of the jaw; anterior to EAM; bilateral; open close several times; left/right/forward
disease process associated with one or both of TMJ's; tenderness, swelling, painful muscle spasms; limited/deviated mandibular opening
How do you recognize TMD?
palpation of joint and related muscles of mastication as patient performs all movements
Symptoms and signs of TMD?
amount of mandibular opening and fcial pain, any parafunctional habits that can cause TMD (Bruxism) and related systemic diseases must be recorded
What can be helpful in diagnosis of TMD
traditional skull xray or MRI
noninvasive nuclear procedure for imaging soft tissue with high fat and water content (can distinguish normal from diseased tissue)
Do all TMD patients have abnormalities in the joint disc or joint?
No, most symptoms come from muscles
Why do joint sound occur?
disc derangement. post portion of disc gets caught between condyle and articular eminence.
Why are joint sounds not a good indicator of TMD?
they can change over time in a pt. Clicking, grinding, popping of joint also found in 40-60% w/o TMD
What can be caused by opening too wide?
acute episode of TMD; causing max depression/ protrussion of mand as while yawning or prolonged dent care. This causes subluxation (dislocation of both joints) When pt tries to close mand, condylar heads cannot move post b/c muscles have become spastic
When does subluxation occur?
When head of each condyle moves too far anteriorly on articular eminence.
What is the articular eminence supposed to prevent?
condyle from going to far forward
P.136 table 5-1
relaxing these muscles and carefully moving them back and down. Avoid extreme depression of mand.
What is the condition when pt can't close after opening jaw?
CH 6; What does the vasular system of the head and neck consist of?
arterial blood supply, capillary network, and venous drainage.
Blood vessels may spread cancerous cells from tumor to distant sites at faster rate than lymphatic vessels. T/F
What are more numerous, bood vessels or lymphatic vessels?
large network of blood vessels
how blood vessels communicate with each other; a vessel connecting channel
component of vascular system; arises from heart; carries blood away from heart; starts large then small vessels
when artery goes from large to small vessels, what are they called?
smaller than arteriole; supply blood to large tissues b/c there are so many of them
vascular syst component;travels to heart and carries blood;
where are valves absent?
in veins in head and neck area; two way flow
what is the concern of having a 2way valveless flow in veins?
facial/dental infections can lead to serious complications
smaller than veins; drains capillaries of tissue area; coalesce to become larger veins
what is larger and more numerous, veins or arteries?
what accompanies larger arteries in a protected location w/i the tissue?
blood-filled spaces between the 2 layers of tissue; connected by anastomoses
unlike innervation, which is 1-to-1(nerve to muscle), blood supply is_________.
regional; arteries supply all structures in their vicinity and veins receive blood from all nearby structures
heart makes irregular noise b/c of stenosis or insuficiency
when valve doesn't want to close completely
what comes off the left ventricle of the heart through the aortic valve?
the aorta, right turns into brachiocephalic artery, then divides into right subclavian and right common carotid, middle branch is left common carotid and left branch is left subclavian artery
right/left subclavian arteries branches?
congestive heart failure?
blood congesting in heart, doesn't flow
path of vertebrals?
through foramen magnum, hook up w/ internal carotids which lie inside cranial cavity
carotid pulse in the neck; just before the common carotid bifurcates; exhibits a swelling
what are the major arteries that supply the head and neck?
common carotid and subclavian
what arteries on the left side arise directly from the aorta?
left common carotid and left subclavian
what branches off from the right side of the aorta?
brachiocephalic (direct branch of aorta), then divides into right common carotid and right subclavian
branchless; up neck, lateral to trachea and larynx, to upper border of thyroid cartilage
what artery travels in a sheath deep to the SCM muscle? What else does this sheath hold?
common carotid artery. internal jugular vein
how does the common carotid artery end?
by dividing into internal/external carotid arteries at level of larynx.
where can the most reliable pulse in the body be monitored?
by pressing the carotid artery against the larynx
if anterior boder of sternocleidomastoid muscle is rolled posteriorly at the level of the thyroid cartilage of the larynx what can be felt?
carotid pulse can be felt in groove of tissue produced.
why is the carotid pulse the most reliable?
the carotid is a major artery supplying the brain: in an emergency situation (cpr) remains palpable by HCW when peirpheral arteries such as the radial artery are not
which pulse is easily accessible during dent. tx?
arises lateral to common carotid artery; gives off branches to supply intercranial and extracranial structures; major destination=upper extremities
internal carotid artery?
travels upward in lateral (to external common carotid) position after leaving common carotid artery; no branches; enters cranium thru skull base
what artery is hidden by SCM?
internal carotid artery
what does the internal carotid artery supply?
intracranial structures; source of opthalmic artery, which supplies the eye, orbit, and lacrimal gland.
circle of willis
supplies brain; made up of vertebrals (go thru foramen magnum) and internal carotids ( go thru carotid canals) then anastimose so that circle of willis is formed
external carotid artery
begins at sup. border of thyroid cartilage at termination of common carotid artery and carotid sheath; travels up in more medial (when compared to internal carotid artery) position after arising from common carotid artery.
what does the external carotid artery supply?
head/neck, and oral cavity
how many branches does the external carotid artery have?
4 sets; anterior, medial, posterior, terminal
anterior branches of external carotid branches?
superior thyroid artery, lingual artery, facial artery
which anterior branches of the external carotid artery continue to divide to serve areas of the head/neck that are of interest to dental professionals?
facial and lingual arteries
superior thyroid artery
anterior branch of external carotid artery; indirect branches= infrahyoid, scm
what do the superior thyroid artery branches supply?
tisues inferior to hydoid including infrahyoid muscles, scm, muscles of larynx, thyroid gland
anterior branch of external carotid artery; above suprerior thyroid artery at level of hyoid bone; travels to apex of tongue on inferior surface.
what does the lingual artery supply?
tissues superior to hyoid bone including suprahyoid muscles and floor of mouth by dorsal, deep lingual (tip of tongue),sublingual, and suprahyoid branches.
what indirect branches of lingual artery supply the tongue?
dorsal lingual supplies base and body. deep lingual artery,which is the terminal portion of lingual artery, supplies apex
what are the indirect branches of lingual artery?
dorsal lingual, deep lingual, sublingual, suprahyoid
indirect branch of lingual artery (anterior branch of external carotid artery); supplies mylohyoid muscle, sublingual salivary gland, mucous membranes of floor of mouth
small indrect branch of lingual artery; supplies suprahyoid muscles
facial artery indirect branches
ascending palatine, lateral nasal, submetal, glandular, inferior labial, superior labial, angular
final anterior branch from external carotid artery; arises superior to lingual artery as it branches off anteriorly
sometimes facial and lingual arteries share a common trunk T/F?
what runs over mandibular salivary gland and around mandible's inferior border to its lateral side?
where does the facial artery terminate?
medial canthus of the eye
what does the facial artery supply?
the face in the oral, buccal, zygomatic. nasal, infraorbital, and orbital regions.
what separates the facial artery from facial vein?
posterior belly of digastric muscle, stylohyoid muscle, and submandibular salivary gland
ascending palatine artery
1st facial artery indirect branch; supplies soft palate, palatine smuscles, palatine tonsils.
if injured during a tonsilectomy, what can be the source of serious blood loss or hemorrhage?
ascending palatine artery
what branches from facial artery supply the submandibular lymph nodes, submandibular salivary gland, mylohyoid and digastric muscles?
submental artery and gladular branches
a facial artery branch that supplies the lower lip tissues, incl. muscles of facial expression(depressor anguli oris)?
inferior labial artery
superior labial artery
supplies upper lip tissues
termination of facial artery; supplies tissues along side of nose
What medial branch comes from the medial branch of external carotid artery?
ascending pharyngeal artery; cannot be seen in most lateral views of head and neck; arises close to origin of external carotid artery
indirect branches of ascending pharyngeal artery?
pharyngeal branches; supplies pharynx and soft palate
posterior branches of external carotid artery?
occipital and posterior auricular artery
indirect branches of occipital artery?
(epicranius), muscular, scm
indirect branches of posterior auricular artery?
from external carotid artery as it passes upward behind ascending ramus of mandible; travels posterior portion of scalp
what supplies the suprahyoid, scm, scalp, and meningeal muscles and how?
the occipital artery; through muscular, scm, and epcranial branches (to occipital bone)
posterior auricular artery
posterior branch of external carotid artery; arises sup. to occipital artery and stylohyoid muscle at tip of styloid process.
what supplies the internal ear, muscles around ear, and mastoid air cells?
posterior auricular artery by its auricular branch
what are the terminal branches of the external carotid artery?
superficial temporal and maxillary artery
indirect branches of superficial temporal artery?
4; transverse facial, middle temporal, frontal, parietal
superficial temporal artery
smaller terminal branch of external carotid artery; arises w/i parotid salivary gland; can sometimes be visible under the skin of temporal region
transverse facial artery supplies?
parotid salivary gland duct near facial structures
middle temporal artery supplies?
frontal/parietal branch supplies?
scalp in fronal/parietal regions
larger terminal branch of external carotid artery; begins at neck of mand. condyle w/i parotid salivary gland; runs between mand and sphenomandibular ligament ant/sup through infratemporal fossa; either superficial or deep to lateral pterygoid muscle
what 3 arteries of the maxilla supply the molars, premolars, and anteriors?
Molars (Posterior superior alveolar artery), premolars ( Middle superior alveolar artery), anteriors (anterior superior alveolar artery)
after traversing the infratemporal fossa, the maxillary artery enters the____?
What do the maxillary branches w/i the infratemporal fossa include?
middle meningeal and inferior alveolar arteries
what does the middle meningeal artery supply?
meninges of brain by way of foramen spinosum
inferior alveolar artery enters what?
mandibular foramen then mandibular canal; while in canal branches into teeth; before reaching mental foramen it spits; mental artery (comes out), incisive artery (stays in canal)
what branches off inferior alveolar artery before it enters mandibular canal?
The_______travels in the mylohyoid groove on inner surface of mandible and supplies____________.
mylohyoid artery. floor of the mouth and mylohyoid muscle
what gives off dental and alveolar branches w/i the mandibular canal? What do the dental branches supply?
inferior alveolar artery. pulp tissue of mandibular posterior teeth by way of each tooth's apical foramen.
what do the alveolar branches of the inferior alveolar artery supply?
periodontium of mand. post. teeth, including gingiva
from inferior alveolar artery; exits canal by mental foramen; supplies tissues of the chin, anastomoses w/ inferior labial artery
from inferior alveolar artery; remains in canal; divides into dental/alveolar branches.
what do dental branches of incisive artery supply?
pulp of mand ant teeth b way of @ tooth's apical foramen
what do the alveolar branches of incisive artery supply/
periodontium of mand ant teeth, inc gingiva; anastomose w/ alveolar branches of incisive artery on other side.
Deep temporal artery (branch of maxillary artery) supply?
ant/post portion of temporalis muscle
pterygoid artery (branch of maxillary artery) supply?
lateral/medial pterygoid muscles
masseteric artery (branch of maxillary artery) supply?
buccal artery (branch of maxillary artery) supply?
buccinator muscle and other soft cheek tissues
when does the maxillary artery give off the post sup alveolar artery?
when it leaves the infratemporal fossa and enters the pterygopalatine fossa.
posterior superior alveolar artery?
enters the possterior superior alveolar foramina on max tuberosity; gives off dental/alveolar branches. ANASTEMOSES w/ ant.sup. alveolar artery
what do the dental branches of the PSA artery supply?
pulp of post max teeth by way of apical foramen
what do the alveolar branches of PSA artery supply?
periodontium of post.max teeth, including the gingiva. some also supply max. sinus.
from max artery in pterygopalatine fossa; may share trunk w/ PSA artery; enters orbit thru infraorbital fissure; to orbital canal
how is the ASA artery given off?
by the infraorbital artery, which provides orbital branches w/i the canal
anterior superior alveolar artery?
from infraorbial artery; gives off dental/alveolar branches; anastomoses w/ PSA artery.
what do the dental branches of the ASA artery supply?
pulp of ant max teeth by way of apical foramen.
what do the alveolar branches of the ASA artery supply?
periodontium of ant max teeth, inc. gingiva
where does the infraorbital artery emerge after giving off branches in the infraorbital canal? What do the terminal branches supply?
onto the face from the infraorbital foramen. supply; portions of infraorbital region of face and anastomose w/facial artery
decsending palatine artery
from max artery in pterygopalatine fossa; travels to palate thru pterygopalatine canal; terminates in greater/lesser palatine artery by way of greater/lesser palatine foramen
what do the descending (greater/lesser) palatine arteries supply?
posterior hard palate
which are the max artery ends? what do they supply? what does it give rise to?
nasal cavity/ant. hard palate.
goes through incisive foramen
what vein drains the brain as well as other tissues of head and neck?
internal jugular vein thru jugular foramen
vein that drains to the heart?
superior/inferior vena cava
what runs parallel to carotid artery
drains into common facial vein then into internal jugular vein;begins at medial corner of eye w/ junction of 2 veins from frontal region
which vein drains the tissues of the orbit?
cavernous venous sinus?
may become fatally infected through spread of dental infection; significant b/c facial veins (like other veins of head)have no valves to control direction
the facial vein anastomoses w/ which deep veins? Where?
pterygoid plexus in infratemporal fossa and w/ large retromand vein before joining internal jugular vein at level of hyoid bone
superior labial vein (of facial vein)?
drains upper lip
inferior labial vein (of facial vein)?
drains lower lip
sbmental vein (of facial vein)?
drains chin tissues and submandibular region
inc. dorsal lingual veins=drain dorsal surface of tongue. Deep lingual veins=drain ventral surface of tongue. Sublingual veins=drain floor of the mouth.
what may the dorsal lingual, deep lingual, and sublingual veins form?
a single vessel or may empty into larger vessels separately. May drain indirectly into facial vein or directly into internal jugular vein.
forms external jugular vein from portion of its route; formed by merger of superficial temporal vein and max vein.
where does does the retromand vein emerge from?
parotid salivary gland
inferior to parotid gland the retromand. vein divides into what?
into anterior retromand. vein (joins the facial vein) and posterior retromand. vein (continues on SCM)
posterior auricular vein ? 154-55
joins post.retromand.vein; drains lateral scalp behind ear; posterior division of retromand. vein becomes external jugular vein.
superficial temporal vein
drains lateral salp; superficial; goes on to drain and form retromand. vein along w/ deep max vein
deeper than superficial temporal vein; begins in nfratemporal fossa by collecting blood from pterygoid plexus, near max artery.
How does max vein receive middle meningeal, PSA, inferior alveolar, and other veins such as those from the nose and palate?
through pterygoid plexus
after the pterygoid plexus, the max vein joins the superficial temporal vein to make what?
the retromandibular vein (behind the mandible)
collection of small anastomosing vessels around pterygoid muscles; surrounding max artery on each side in infratemporal fossa
what protects the maxillary artery from being compressed during mastication?
How can the pterygoid plexus accomodate changes in volume of infratemporal fossa that occur when mand moves?
by emptying or filling
what does the pterygoid plexus drain?
deep veins from face and then into max vein
what happens if you pierce one of the veins in the pterygoid plexus in a PSA injection?
hematoma; tissue tenderness, swelling, discoloration
middle meningeal vein?
drains from meninges into pterygoid plexus; connects pterygoid plexus to cavernous sinus (infections can travel to sinus=Meningitis)
drained by pterygoid plexus; formed by merging of its dental/alveolar branches
Dental branches of PSA vein drain?
pulp of max by way of apical foramen
alveolar branches of PSA vein drain?
periodontium of max teeth, inc. gingiva
inferior alveolar vein?
from merging of its dental, alveolar, mental branches in mand; where they drain into pterygoid plexus
mental branches of inferior alveolar vein?
enter mental foramen after draining chin area on outer surface of mandible where they anastomose w/ facial vein
in meninges of brain; w/i dura matter (dense connective tissue-lines inside of cranium)
dural sinuses (venous sinuses)?
channels by which blood is conveyed from cerebral veins into veins of neck (INTERNAL JUGULAR VEIN)
cavernous venous sinus
most important to dentistry; on side of body of sphenoid;communicates w/ each other, pterygoid plexus, and ophthalmic vein, which anastomoses w/facial vein
what may be involved w/ the spread of infection from the teeth, eye, or periodontium and can be fatal?
cavernous venous sinus
internal jugular vein
drains most of tissues of head and neck; no 1-way valves; can become involved w/ spread of infection
where does internal jugular vein originate?
cranial cavity; leaves skull thru jugular foramen; receives lingual, sublingual, and pharyngeal area veins as well as facial vein
external jugular vein
formed by posterior retromand.vein; descends along neck terminating in subclavian vein; has VALVES near subclavian vein; visible as it crosses SCM
anterior jugular vein
drains into external jugular vein before joining subclavian vein; begins inferior to chin; descends near midline; only one vein may be present
pathway to heart from head/neck
right external jugular vein to subclavian from arm form brachiocephalic veins which unite to form superior vena cava which travel to heart.
why are brachiocephalic veins asymmetrical?
b/c superior vena cava is on right side only.
Right brachiocephalic short and vertical and
Left brachiocephalic long and horizontal.