3.1.3 Bones of the Viscerocranium, Facial Fractures & TMJ Flashcards
What bones make up the viscerocranium?
Zygomatic
Maxilla
Nasal
Lacrimal
Mandible
What are some common fractures of the facial bones?
Zygoma and zygomatic arch
Nasal
Mandible
What are some uncommon facial fractures?
Maxilla- Very tough, can block the airways if it gets damaged
Supraorbital ridge (frontal bone)-skin splinters
How is the mandible imaged when a fracture is suspected?
OPG view (Orthopantomography)
Normally the mandible is fractured in two places
What is the temporomandibular joint?(TMJ)
Synovial hinge-type joint
Divided into two synovial cavites by fibrocartilaginous disc
What conditions affect the TMJ?
TMJ disorder- pain referring to ear, jaw, lateral head, clicking/locking
Dislocation (secondary to trauma, yawning)
Arthritis
What is the sensory innvervation to the TMJ?
Auriculotemporal nerve, branch of CNVc
Supplies ear with sensory, therefore can get ear pain too, so if nothing wrong with ear consider TMJ
What are the articulations of the TMJ?
Mandibular Fossa and articular tubercle superiorly on the temporal bone
Mandibular Condyle of the mandible inferiorly
What are the articular surfaces of the TMJ lined with?
Separated by fibrocartilaginous disc, forms inferior and superior part of the joint
What stabilises the TMJ?
Joint capsule and 3 extracapsular ligaments
Lateral
Sphenomandibular
Stylomandibular
What are the movements of the TMJ?
Inferior joint capsule- Hinge rotational action
Superior joint capsule- Gliding movement
* Condyle slides onto articular tubercle
I Rarely See Geese
Inferior rotational
Superior gliding
Complete the table
What causes disclocation of the TMJ?
Trauma while opening jaw
Muscle of spasm of the muscles of the jaw
Yawning
What is happening when the TMJ is dislocated?
Jaw locks as joint fixes in open position
Due to anterior dislocation of condyle over articular tubercle
Contraction of muscles around joint keep joint locked in anterior displacement
How do you reduce a dislocated jaw?
Push down on molars with both hands, push jaw posteriorly and lift superiorly
