QUIZ 2 STUDY GUIDE- EHDA

the function of the temperomandibular ligament

prevents excessive retraction or backward moving of the mandible

How to primary molar roots differ from permanent molars?

They are shorter, smaller, narrower, and flare out.

If a tooth has not erupted within three months of its contralateral sister tooth...

Efforts to diagnose should be made

What forms the TMJ?

An articulation between the temporal bone and the condyle of the mandible

articular eminence of temporal bone

Raised portion of the temporal bone just anterior to the glenoid fossa.

articular fossa of temporal bone

also called glenoid fossa: is posterior to the articular eminence

fibrous joint capsule

completely encloses the TMJ

what do the fibers of the inferior portion of the capsule do

they connect the condyle of the mandible to the articular disc

what does the upper portion of the fibrous capsule of the tmj do

it is looser and attaches the articular disc to the temporal bone

where does the articular disc get its nourishment

the synovial fluid that the surrounding cells exctrete

What is synovial fluid?

Lubricates and nourishes the cartilage covering the bones at movable joints

what are the 3 ligaments associated with the TMJ

Temporomandibular, stylomandibular, and sphenomandibular

Compared to the permanent teeth, how thick is the enamel on primary teeth?

0.5 mm

How thick is the enamel on a permanent tooth?

1.00 mm or more

True or false: primary teeth tend to erupt in pairs

True- a tooths contralateral sister should erupt along with or soon after

Is a baby whose molar erupts before the incisor normal?

No. This is a highly abnormal situation

Preservation of the primary teeth is important because

primary teeth act as space maintainers

True or false: preservation of primary teeth isn't important because the teeth with be lost anyway

FALSE

What is the TMJ innervated by?

mandibular division of trigeminal nerve (V)

Where does the TMJ get its blood supply?

branches of external carotid artery

Function of stylomandibular ligament

limits excessive protrusion of mandible

the function of the sphenomandibular ligament

Suspends the mandible and limits excessive anterior motion

what is important about the sphenomandibular ligament

it is used as a landmark for the administration of the inferioir alveolar block

what are the two movements that the tmj performs

gliding and roation

Rotational movement of TMJ

occurs mainly between the disc and the mandibular condyle in the lower synovial cavity

gliding movement of TMJ

allows jaw to move forward and backward
occurs between disk and articular eminence in the upper synovial cavity

what are the muscles of mastication involved in elevating the mandible during closing of the jaws

the bilateral contraction of the masseter, temporalis, and pterygoid muscles

what does the contraction of one of the lateral pterygoids cause

the mandible to deviate to the contralateral side

what is lateral excursion

side to side movement of the mandible

masseter

closes jaw by elevating mandible AND protrudes the mandible

what is the function of the anterior and mid fibers of the temporalis

closes jaw and elevates mandible to help chew

medial ptyergoid muscle

closes jaw, lifts the mandible, helps protrude the mandible, and helps with side to side movement

what is special about the lateral ptergoid

it is the only muscle of mastication that can elevate and depress the mandible

anterior digastric muscle

opens the jaw

mylohyloid muscle

opens the jaw

lateral pterygoid muscle

protrudes the mandible, pulls the articular disk forward, and contributes to lateral (side to side) movement of mandible

what is the function of the posterior fibers of the temporalis

retract the mandible

when the jaw is at rest where is the condyle positioned

centered on its fossa (the teeth are not in occlusion)

What is freeway space?

The space between your maxillary teeth and mandibular teeth when you are fully relaxed

what is a nightguard designed for

to reestablish natural freeway space, which protects from grinding

what is subluxation of the tmj

partial dislocation of a joint

is dislocation of the tmj a medical emergency

yes

What is trismus?

LOCKJAW
inability to open the mouth due to a contraction/spasmsof the chewing muscles