Infratemporal Fossa and Temperomandibular Joint Flashcards
What does the temporal region contain?
- Temporal fossa, located above the zygomatic arch
- Infratemopral fossa, located above the zygomatic arch
Locate the pterygopalatine fossa
on the bone
Locate
- articular tubercle
- Zygomatic bone (zygomatic process is not on SL)
locate the
lateral pterygoid plate
pterygoid hamulus
sphenoidal spine
sphenopalatine foramen
Mandibular fossa
what are the boundaries of the infratempral fossa?
- Lateral: ramus of mandible
- Anterior: Maxilla
- Medial: lateral pterygoid plate
- Roof: greater wing of the spenoid bone
- Posterior: tympanic plate, mastoid process and styloid process
- Inferior: angle of the mandible
What. are the contents of the infratemporal fossa?
1. Inferior portion of the temporalis m.
2. Lateral and medial pterygoid muscle
3. Maxillary A
4. Pterygoid venous plexus
5. Nerves:
- inferior alveolar (V3),
- Lingual n (V3),
- Long buccal N. (V3),
- chorda tympanic (CN VII),
- otic ganglion
- Auriculotemporal N.
In the infratemporal fossa, will we be able to see the chorda tympani N?
it will be covered by the lateral pterygoid m.
in the infratemporal region, what is important to find?
maxillary. A
what does the long buccal N do?
Part of V3
Provide sensation to the inner cheek and gum. does NOT innervate. buccinator. m.
where does chorda tympani N arise from in the infratemporal fossa?
actions?
- Petrotympanic fissue > lingual N -> carries taste to the anterior 2/3 of the tongue and GVE to sublingual and submandibular N.
Where does the inferior alveolar A and N go to in the infratemporal fossa
Mandibular foramen
It will have a the mylohyoid N coming off of it.
What tells us that. we bit. our tongue?
lingual N. (V3)
Go over maxillary A
What veins do we need to identify on the face?
- Supraorbital V
- Superficial temporal V.
- Retromandibular V.
- Superior opthalamic V
What branches of the mandibular N (V3) should we see in the infratemporal region?
- Buccal N.
- Lingual N.
- Mental N.
THOSE THREE ARE SOMATIC SENSORY
- Inferior alveolar N, branching into N to the mylohyoid M.
If a muscle has the name TENSOR in it, what. innervates it?
Trigeminal N (V)
Describe how the anesthesia of a dentician is done through nerve blocks
The posterior superior alveolar N is an independent branch off of V2 (maxillary N). The middle and anterior superior alveolar nerves come off of the infraorbital nerve - just like the arteries.
If the dentist wants to pull out the back deeth, anestasize the poterior superior alveolar n.
If he wnts to pull out the side teeth, he will inject in the middle superior alveolar n.
If he wants to pull ut the front tooth, anestasize in the middle of gums, [goes or infraorbital N -> anterior superior alveolar N]/
Where does maxillary. N go through?
foramen rotundum
Where does the posterior superior alveolar N go to?
maxilla -> maxillary sinus
What nerves will we see in the infratemporal region?
Branches of V2 (maxillary N)
What goes through. stylomastoid foramen
facial N
What happens if you get a fracture on the neck of the mandible?
what. about the ramus and corpus of the mandible?
Neck: damage the. maxillary A.
Ramus: damage the infraalveolar structures
If you hit. the corpus of. the mandible, it is not as bad.
What. are the branches of V3. (mandibular N)?
- Buccal N
- Lingual N
- Mental N
- Inferior alveolar N.
- Auriculotemporal N
how does the maxillary A run in relation to the lateral pterygoid m.
it. can run lateral to it or medial (behind) it.
how can maxillary A run in relation to the nerves in the infratemporal fossa
medial to buccal abut lateral lingual and inferior alveolar
lateral to inferior alveolar but medial to everything else
medial in front. of mandibular N (V3)
The muscles of mastication. are innervated by what?
how do they work?
Trigeminal N (V3), which move the mandible. at the TMJ joint
what are. the 4 PAIRED muscles of mastication?
- Temporalis
- Masseter
- Lateral pterygoid M.
- Medial pterygoid M
What innervates orbicularis oris m
Facial N
Bucciator m and the oribicularis oris muscle are ACCESORY MUSCLES OF MASTICATION
how do the lateral pterygoid m and medial pterygoid m act in relation to one another?
Lateral pterygoid miscle has a superior and inferior head.
Medial pterygoid will hug (wrap around) lateral
What does the masseter m look like?
1. Has a superficial head
2. Has a deep head
overal axn of pterygoid muscles
- Lateral opens mouth, protrudes and helps to move side to side.
- Medial will close mouth, protrude mandible and helps move side to side
What opens our mandible?
- Stabilize the hyoid inferiorly. If not, it will raise the larynx when we swallow.
- Digastric m, geniohyiod m, mylohyoid m, stylohyoid m
- Sternohyoid m, sternothyroid m, thyrohyoid m, omohyoid m will anchor the jaw in place that we. can pull down on the hyoid bone -> open jaw -> move trachea inferiorly
Whtat. ms help to elevate. (close) our mandible
- Temporalis
- Masseter.
- Medial pterygoids
What helps to depress (open) our mandible?
- Lateral pterygoids
- Suprahyoid muscles
- Infrahyoid muscles.
What helps to protrude our mandible?
- LAteral pterygoids
- Masseter. m
- Medial pterygoids
What helps to retract our mandible?
- Temporalis m.
- Masseter M
What helps. to laterally. move our mandible?
- Ipsilateral temporalis and masetter m
- Contralateral. pterygoids.
what L stabilize TMJ joint
1. Lateral (temporo-mandibular) L
2. Stylomandibular L
what kind of joint is the TMJ joint
synovial
What L limit the movement anterior dislocation of TMJ
1. Sphenomandibular L
2. Stylomandibular L
What allows free movement of the TMJ?
articular disk, which has superior head and inferior head of lateral pterygoid attached to it
What keeps the gleniod in the middle of the disk as it slides posteriorly. and anterioly?
Posterior and anterior bands of articular disc
Describe TMJ during GAPE
- the first 15 degrees, the condylar process rotates in the joint.
- Once we exceed 15 degrees, we dislocate the joint anteriorly (articular disk pops out) onto the ridge of the mandibular fossa. Articular disc moves onto the articular eminence because thr lateral pterygoid pulls it forward. If it keeps moving it forward, the disk stays there. and the condyle goes back. ->. TMJ!!!
What innervates the TMJ?
Branches of the mandibular N (V3)
1. Auriculotemporal N
2. Posterior deep temporal N
3. Masseteric N
what is the most common type of TMJ dislocation
anterior dislocation.
HEad of the mandible can go into the temporal fossa from the mandibular fossa
how to reposition TMJ?
stick fingers in mouth and slide the jaw rearward
Anesthetic agents are commonly administered by injection to block pain during dental procedures. CN ____ is important..
5
because it is the sensory nerve of the head, serving the teeth and mucosa of the oral cavity. Because the superior alveolar nerves (branches of CN V2) are not accessible, the maxillary teeth are locally anesthetized by injecting the agent into the tissues surrounding the roots of the teeth and allowing the solution to infiltrate the tissue to reach the terminal (dental) nerve branches that enter the root. By contrast, the inferior alveolar nerve (CNV3) is readily accessible and is probably anesthetized more frequentlythan any other nerve
An inferior alveolar nerve block anesthetizes the inferior alveolar nerve, a branch of CN
V3
how to do a inferior alveolar n block
In mouth
go anterior to the pterygomandibular raphe (between the buccinator and superior pharyngeal constructor m) -> where you will hit the inferior alveolar N.
vein. When this nerve block is successful, all mandibular teeth (lower teeth) are anesthetized to the median plane
in inferior alvolar N block what is also taken out (anesthasized?
. The skin and
mucous membrane of the lower lip, the labial alveolar
mucosa and gingivae, and the skin of the chin are also anesthetized
because they are supplied by the mental nerve, a
branch of the inferior alveolar nerve
Sometimes during yawning or taking a large bite (above 15 degrees),
excessive contraction of the __________ may
cause the heads of the mandible to dislocate ______
lateral pterygoids
anterioly
mandible remains depressed and person cannot close their. mouth
Because of the close relationship of the ____ and _______to the TMJ, care must be taken during surgical to prevent damage to them
facial and auriculotemporal
where do we inject. to take out posterior superior alveolar N
next to second molar
How do we take out the front teeth?
The anterior teeth can only be anesthetized via a block of the infraorbital nerve as it comes out of the infraorbital foramen. This is a deep injection.
Whill also take up upper lip and front teeth