Midterm Flashcards
What innervates the TMJ?
Trigeminal>Mandibular>auriculotemporal, deep temporal, and masseteric
What vasculates the TMJ?
Post - Superficial temporal a.
Ant - middle meningeal a.
Inf - Internal maxillary a.
What is the capsule filled with?
Synovial fluid
What are the 2 types of synovial lubrication mechanisms?
Boundary - bathes surfaces
Weeping - absorbed into surfaces
Name the 5 zones of the condylar head from superficial to deep.
Articular Proliferative Fibrocartilaginous Calcified cartilage Bone
The proteoglycan network in the ECM is made of what?
Hyaluronic acid
Monomers (Attached and detached)
Interstitial fluid
Collagen
The articular cartilage, what type is it?
Dense fibrous CT. NOT HYALINE
Nourished by weeping lubrication
The temporomandibular ligament has two parts. What are they?
Outer oblique - Limits rotation
Inner horizontal - Posterior movement
What are the other two small ligaments associated with the TMJ?
Sphenomandibular - inferior
Stylomandibular - protrusive
What are the 3 controlling mechanisms of occlusion?
Neuromuscular system
R and L TMJs
Contacts of teeth
What are the three phases of mastication?
Opening
Crushing
Grinding
Why is the TMJ considered a compound joint?
Usually means 3 bones, but we include the disc as non-ossified bone, making the TMJ a compound joint.
What is the diff b/t centric occlusion and centric relation?
Occlusion - Max intercuspation of teeth, tooth-determined position
Relation - condyles in their uppermost position in mand fossa. Jaw to jaw relation determined by the condyles in the fossa. INDEPENDENT OF TOOTH CONTACT.
Max opening?
Max lateral?
Max protrusive?
Max retrusion?
50-60 mm
10-12 mm
8-11 mm
1 mm
What is the Bennett movement?
Lat movement, the condyle appears to rotate with a slight lateral shift in direction of the movement.
What are the primary elevators of the mandible?
Masseter
Temporalis
Medial Pterygoid
What are the mandibular protruded mm.?
Inf. lat pterygoid
Med pterygoid
Masseter
What is working movement?
What is non-working movement?
Laterotrusive movement
Mediotrusive movement
What is the difference b/t functioning and non-functioning cusps?
Functioning - Support vertical dimension - Also called working cusps
Nonfunctioning - Guiding cusps. Maintain bonus of food on occlusal table. Minimize tissue impingement.
What is eccentric relation?
Any position of the condyles and teeth when not in centric relation
On the mandible, the buccal cusps are what type of cusps?
On the maxilla, the buccal cusps are what type of cusps?
Mandible - Functioning/working cusps
Maxilla - Non-Functioning
Class I Occlusion is called?
Neutro-occlusion
What characterizes the class I occlusion?
The mesiobuccal cusp of the mandibular first molar occluded in the embrasure area b/t the max second premolar and first molar.
Mesiobuccal cusp of max first molar is directly over the buccal groove of mandibular first molar.
MESIOLINGUAL CUSP OF MAX FIRST MOLAR IS IN CENTRAL FOSSA AREA OF THE MAND FIRST MOLAR.
What characterizes a class II occlusion?
Disto-occlusion
Mesiobuccal cusp of mand first molar occluded in the C-F area of max first molar.
Distolingual cusp of max first molar occluded in the C-F area of the mand first molar.
What characterizes class III occlusion?
Mesio-occlusion
Distobuccal cusp of mand first molar is situated in the embrasure b/t the max second premolar and first molar
Mesiolingual cusp of the max first molar is situated in the mesial pit of mand second molar.
What is the BSS of Occlusion?
Bilateral
Simultaneous
Stable
These are “stops” that we want to see when teeth come together.
What is overjet?
What is overbite?
Overjet - distance b/t labial incisal edge of max incisor and labial surface of the mand incisor in intercuspal position
Overbite - distance b/t the incisal edges of the opposing anterior teeth in intercuspal position
What is the most powerful muscle in the body?
The lateral pterygoid
What are exteroceptors?
Provided info from ext tissues of body to inform the CNS of environmental conditions
What are nociceptors?
Provide info regarding discomfort and pain
What are proprioceptros?
Provide information regarding position and movement of the mandible and associated oral structures.
What are interoceptors?
Inform CNS of internal organs and processes.
T/F - Ligaments actively participate in normal function of the TMJ.
FALSE. They act like guidewires. Ligaments do not stretch. They can become elongated, increasing in length, and this usually compromises normal joint function.
What is hyperalgesia?
Increased sensitivity to painful stimuli.
What is allodynia?
Pain produced by innocuous stimulation of normal skin or tissues.
The sup head of the lat pterygoid m is most active when?
During clenching
The inf head of the lat pterygoid is responsible for what?
T-lation of the mandibular condyle during opening
What are three major functions of the masticatory system?
Speech, mastication, and swallowing
Chewing strokes vary in intensity and directional movements according to which factors?
Gender
Food type
Stability of TMJ complex
Functional state of the masticatory muscles
T/F - Neutral position of the teeth, where lingual and labial forces are in equilibrium, exists for both ant and post teeth.
TRUE
