W4 Skull And TMJ Flashcards
What is the skull divided into?
Neurocranium and viscerocranium (facial skeleton)
What is unique about the TMJ?
Only moveable joint of the head, only joint of human body that operates bilaterally, a modified synovial joint
Why is the TMJ a modified synovial joint?
Because articulate surfaces of bones of the joint are covered in fibrocartilage instead of hyaline cartilage.
What are the movements of the mandible?
Protrusion, retraction, depression and elevation.
What are the bones of the viscerocranium?
(Zombies like punching my very manly nose in)
Zygomatic, lacrimal, palatine, mandible, vomer, maxilla, nasal, inferior nasal concha
How are the bones of the TMJ never in contact?
The TMJ has 2 synovial cavities with an articulation disc in the middle so the bones (head and tubercle) are never in contact.
Label a mandible
Image
What is the anatomical significance of the alveolar process of the mandible?
It holds the roots of the teeth in place.
What are the suprahyoid muscles?
Mylohyoid, geniohyoid, stylohyoid, digastrics (all lie above the hyoid bone)
Where does the genioglossus attach to the mandible?
Underside of the tongue and body of the hyoid
Where does the medial pterygoid attach to the mandible?
Medial surface of ramus, angle of mandible, inferior to the mandibular foramen
Where does the mylohyoid attach to the mandible?
Body of hyoid bone, median ridge, arises from mylohyoid line
Where does the geniohyoid attach to the mandible?
Hyoid bone
Where does the lateral pterygoid attach to the mandible?
Neck of condylar process of the mandible
Which nerve passes through the mandibular foramen and what does it supply?
Inferior alveolar nerve supplies sensation to the lower teeth.
How does the inferior alveolar nerve leave the mandible?
Emerges from the mental foramen as the mental nerve which supplies the chin and lower lip.
What articular surfaces are involved in the formation of the TMJ? (Inferior aspect of cranium)
Mandibular fossa, articular disc, articular eminence
What are the 3 ligaments stabilising the TMJ?
Temporomandibular, sphenomandibular, stylomandibular
What are the functions of the articular disc?
Fills the space between the condyle and the temporal bone. Acts as a stress absorber and distributor during jaw activity.
Label the TMJ
Image
Where does the head of the condylar process insert into?
Mandibular fossa, articular disc and articular eminence
What are the muscles of mastication innervated by?
CNV3, which supplies sensation
What are the infrahyoid bones?
TOSS - thryohyoid, omohyoid, sternohyoid, sternothyroid
They start at the hyoid bone and attach to structures below it.
Attachments of the digastric
Posterior runs from the mastoid process on the temporal bone to the attachment. Anterior will attach around geniotubercle.
What does the mylohyoid run from?
Runs from mylohyoid line and attach on hyoid bone.
What does geniohyoid run from?
Runs from geniotubercle (on mandible) to the hyoid bone
Where does the stylohyoid run from?
From styloid process on back of skull to the hyoid bone.
What innervates the posterior belly of digastric and stylohyoid muscles?
Facial nerve CNVII
What innervates the anterior belly of digastric and the mylohyoid muscle?
Mandibular division of the trigeminal nerve CNV3
What innervates the geniohyoid?
CNXII hypoglossal nerve
What does the stylohyoid initiate?
Swallowing
What does shortening the suprahyoid muscles do?
Elevates the hyoid bone and depresses the mandible.
What bones form the zygomatic arch?
Zygomatic bone and zygomatic process of temporal bone.
Bony points on temporal bone
Mandibular fossa, articular eminence, squamous part, zygomatic process, mastoid process, styloid process, external acoustic meatus, petrous part
What is the strongest ligament and what movement does it restrict?
Stylomandibular ligament limits excessive protrusion of the jaw
