Temple, infratemporal fossa, TMJ and submandibular gland Flashcards
what are the main divisions of the mandible?
- the body
- the ramus
what is the point at which the ramus and body** join** on the mandible?
the** angle** of the mandible
what are the 2 subparts of the body of the mandible?
- the base - forms the lower portion of the mandible
- the alveolar part holds the lower teeth
Whar is the TMJ?
function, location etc
- the** temporomandibular joint** connects the skull to the mandible
- located between the mandibular fossa and articular tubercle of the temporal bone &** condylar process of the mandible **
what are the digastric fossae of the mandible?
the** attachment sites **for the left and right anterior bellies of digastric muscles
what kind of joint is the TMJ?
atypical synovial type of joint
what are the mental foramina of the mandible?
- foramina located halfway between the base and alveolar part of mandible
- they form the opening of the mandibular canal which transports the inferior alveolar nerve & vessels
what are the mandibular condyles?
part of mandible that allows it to articulate with temporal bone via TMJ
what is the function of the articular disc in the TMJ?
- divides the joint into 2 anatomically and functionally seperate compartments - superior and inferior compartment and each compartment is lined by its own synovial membrane
Describe the** superior compartment** of the TMJ?
- this compartment is bordered superiorly by the manidbular fossa of temporal bone and inferiorly by the articular disc
- responsible for translational movement (ie retraction and protrusion) of the joint
Describe the inferior compartment of the TMJ - describe boundaries and what movement it allows
- bounded superiorly by the articular disc and inferiorly by the condyle of the mandible
- allows rotational movement of the joint
what are the 2 extrinsic ligaments of the TMJ?
- stylomandibular (runs from styloid process to mandible)
- sphenomandibular (runs from sphenoid to mandible)
what are the 4 muscles of mastication?
- the temporalis muscle
- the masseter muscle
- the medial pterygoid muscle
- the lateral pterygoid muscle
Describe the masseter muscle
- rectangular in shape
- seperated into 2 layers - known as the superficial and deep layers
Describe the superficial layer of the masseter muscle
ie where it originates from and where it attaches
- originates from the maxillary process of the zygomatic bone and the anterior 2/3 of the zygomatic arch
- muscle inserts itself onto the lateral surface of the ramus of the mandible
Describe the **deep layer **of the masseter muscle
ie where it originates from and where it attaches
- this part originates from the deep or interior surface of the posterior of the third zygomatic arch
- much larger muscle layer than the superficial (not seen in pic)
- inserts along the lateral surface of the ramus
what branch of the mandibular nerve (V3) innervates the masseter muscle?
the masseteric nerve
what is the function of the masseter muscle?
- elevates/ draws up the mandible
- ie helps to close mandible so you can chew food
Describe the temporalis muscle
- muscle located on the lateral side of the skull
- covers a large part of the temporal bone
Where does the temporalis muscle originate from and where does it run too?
- originates from the** temporal fossa**
- temporalis descends through gap between zygomatic arch and the skull forming a thick tendon which **inserts into the coronoid process of the mandible **
what branches of the mandibular nerve (V3) is the temporalis innervated by?
the anterior and posterior deep temporal branches of the mandibular nerve (V3)
what is the temporal fossa?
a shallow depression on the lateral part of the skull
what is the function of the temporalis muscle?
elevates and retracts (pulls it backwards)
* ONLY MUSCLE THAT PERFORMS RETRACTION OF MANDIBLE
what are the boundaries of the temporal fossa?
-superior temporal line
-zygoma
-zygomatic arch
what are the two heads of the lateral pterygoid muscle?
- upper head
- lower head
what are the contents of the temporal fossa (muscles, nerves & arteries)?
-temporalis muscle
-deep temporal nerve (Vc)
-deep temporal arteries
where does the upper head of the lateral pterygoid muscle originate from?
**greater wing **of sphenoid bone
where does the **lower head **of the lateral pterygoid muscle originate from?
lateral surface of lateral pterygoid plate of the sphenoid bone
where do the heads of the lateral pterygoid muscle** insert onto**?
the heads fuse onto the pterygoid fossa of the mandibular condyle
what branches of the mandibular nerve innervate the lateral pterygoid muscle?
lateral pterygoid nerves
what functions does the lateral pterygoid muscle have?
- protruding mandible - ie sticking it out
- depression of mandible - moving it downwards
- upper head inserted into the TMJ capsule - therefore it** pulls the articular disc anteriorly **
- can also cause **side to side movements **of mandible
like the masseter muscle, what are the 2 layers of the medial pterygoud muscle?
the superficial and deep layer
where does the deep head of the medial pterygoid muscle arise/originate from?
the medial surface of the lateral plate of the** pterygoid process of the sphenoid bone**
where does the** superficial head **of the medial pterygoid muscle originate from?
the maxillary tuberosity (located just beneath wisdom teeth)
where do the** superficial and deep heads** of the medial pterygoid muscle join?
- medial aspect of the angle of the **mandible **
what is the function of the medial pterygoid muscle?
elevation of the mandible so you can close teeth and chew
what branch of the mandibular nerve innervates the medial pterygoid muscle?
medial pterygoid nerve
what** type of nerve** is the trigeminal nerve?
mixed nerve - ie has both motor and sensory functions
what **motor functions **does the trigeminal nerve have?
what different muscles ?
- innervates the** muscles of mastication**
- innervates the** mylohyoid muscle** (1of the 4 suprahyoid muscle )
- innervates the** anterior belly of the digastric muscle **
- innervates the** tensor tympani muscles** (muscle within middle ear)
what sensory functions does the trigeminal nerve have?
provides sensory functions to the
* scalp
* face
* orbit
* paranasal sinuses
* anterior 2/3 of tongue
what are the 3 divisions of the trigeminal nerve?
IE MOM
- ophthalamic nerve (V1)
- maxillary nerve (v2)
- mandibular nerve (v3)
where is the ganglion of the trigeminal nerve located?
- located in Meckel’s cave (near petrous part of temporal bone) within the middle cranial fossa
what are the branches of the ophthalamic nerve ?
- frontal nerve
- lacrimal nerve
- nasocillary nerve
what does the frontal nerve (branch of ophthalamic nerve) branch into?
the **supraorbital **nerve and supratrochlear nerve
where does the supraorbital nerve pass through ?
the supraorbital foramen
through which fissure, does the opthalamic nerve exit the cranial cavity?
the superior orbital fissure
through which foramen does the maxillary nerve exit the cranial cavity?
foramen rotundum (opening in the greater wing of sphenoid bone)
through which** foramen** does the **mandibular nerve **exit the cranial cavity?
formane ovale (middle bigger hole located on greater wing of sphenoid bone)
what branche of the maxillary nerve (V2) supplies the buccal (cheek) region of face and jaw?
the infraorbital nerve - runs through the cranium to supply the gums,pulp, mucosa and PDL of teeth
what 2 branches come off the infraorbital nerve (branch of V2)
- anterior superior alveolar nerve
- middle superior alveolar nerve
after the infraorbital gives off the 2 branches (ASAN and MAAN), where does it exit?
it exits through the infraorbital foramen
what 3 branches of the maxillary nerve supply the lingal region of the face and jaw?
- **lesser palatine nerve **- soft palate
- greater palatine nerve - gums, teeth (3-8)and mucosa of hard palate .. not PULP
- nasopalatine nerve - gums, teeth (1-3) of hard palate .. not pulp
what 2 branches of the mandibular nerve (V3) supply the** lingual region** of the face and jaw?
* lingual nerve - runs on lingual surface of mandible
* inferior alveolar nerve - goes through mandibular foramen and canal
**
Describe the 2 branches of the mandibular nerve (V3) supply the** buccal region **of the face and jaw?
- inferior alveolar nerve - enters mandibular foramen and** travels through mandibular canal** - exits mental foramen where it branches into the **mental nerve **
- buccal nerve - runs across retromolar space (space beside 3rd molar) to supply cheek, gums, oral mucosa, PDL etc
What is the chorda tympani nerve?
side note - to do with tongue
a branch of the facial nerve that provides TASTE SENSATION to the tongue
what is the infra temporal fossa?
a depression or hollow of the skull located inferior & lateral to the temporal fossa
what are the boundaries of the infra temporal fossa?
-laterally - ramus of mandible
-medially - lateral pterygoid plate
-anterior - maxilla
-posterior - carotid sheath
-roof - greater wing of sphenoid bone
what are the contents of the infra temporal fossa?
-lateral pterygoid muscle
-medial pterygoid muscle
-mandibular nevre
-maxillary artery
-pterygoid venous plexus
what is the pterygopalatine fossa?
a depression in the skull located deep to the infra temporal fossa and posterior to the maxilla
