plane of occlusion
lines connecting cusp tips and incisal edges
arch length
distal 3M to distal 3M of each arch; MX > MD
which arch has greatest width?
MX > MD
supporting/centric cusps
MD buccal and MX lingual
guiding/non-centric cusps
MD lingual and MX buccal
each tooth occludes with 2 opposing teeth EXCEPT?
MD CIs and MX 3Ms
Mesial step relationship between MD and MX 1Ms?
- permanent MD 1M is mesial to MX 1Ms
* MB cusp of MX 1M is in the buccal groove of MD 1M
curve on monson
spherical curve of approximately 8” resting on buccal cusps of mandibular posterior teeth
MD vs MX posterior crown tilts?
- MD= lingual
* MX= buccal
skeletal components?
condyle and articular eminence
*condylar path determined by articular eminence
1) class 1
2) class 2
3) class 3
1) MX MB cusp in MD B groove
2) retruded mandible= MX MB cusp is mesial to MD B groove
3) protruded mandible= MX MB cusp distal to MD B groove
Class 2 division 1 vs division 2?
- 1= MX incisors in normal position
* 2= MX incisors retruded and inclined lingualy
working vs non-working side of mouth
- working= side that mandible moves towards
* non-working= side which mandible moves away from
Masseter A, O, and I?
A- elevates mandible
O- zygomatic arch
I- coronoid process and anterior border of ramus
temporalis A, O, and I?
A- elevates mandible
O- pterygoid fossa
I- coronoid process and anterior border of ramus
medial pterygoid A, O, and I?
A- elevates, protrudes, and mediotrusive (unilateral) mandible movement
O- pterygoid fossa
I- medial angle of mandible
lateral pterygoid Superior Head A, O, and I?
A-
O- greater wing
I- capsule and disc and neck of condyle
lateral pterygoid Inferior Head A, O, and I?
A- protrude (bilateral) and mediotrusive (unilateral)
O- lateral pterygoid plate
I- neck of condyle
Anterior belly of Digastric
A- depress/pull mandible back and elevates hyoid when mandible is stable(swallowing)
O- digastric fossa
I- middle tendon at hyoid
Posterior belly of Digastric
A- depress/pull mandible back and elevates hyoid when mandible is stable(swallowing)
O- mastoid notch
I- middle tendon at hyoid
motor unit with few or a lot of fibers? muscles examples?
motor unit= motor neuron and # of muscle fibers it innervates
- few= precise movement (lateral pterygoid)
- more fibers= gross function (masseter)
stretch/myotactic reflex? determines what?
causes contraction when a sudden forces stretches them
***determines muscle tonus
What is the computer board of brain? does what?
CNS= thalamus= controls and directs signals from cortex
primary pain
site and source of pain are the SAME
heterotropic pain has different site and source
TMJ innervated by? BS?
innervated by auriculotemporal nerve and BS is superficial temporal, middle meningeal artery, and maxillary artery
functional vs accessory ligaments examples
- functional= collateral, capsular, temporomandibular
* accessory= sphenomandibular, stylomendibular
articular disc attaches?
posteriorly to retrodiscal tissue and anteriorly to capsular ligament
what forms sling?
medial pterygoid forms sling with masseter laterally
denture bite force compared to normal?
1/4 of natural teeth
tongue thrusting
habit where tongue pushes excessively against incisors when swallowing, causes flaring of teeth
occlusal table
- occlusal surfaces of teeth
- between B and L cusp tips of posterior teeth
- ~50-60% of BL width of tooth
buccoocclusal (BO) line vs linguooclusal (LO) line vs central fossa (CF) line?
- BO= line through all buccalcusp tips of MD posterior teeth
- LO= line through all lingual cusp tips of MX posterior teeth
- CF= line though central grooves of MX and MD teeth
centric cusps contact?
the opposing central fossa line in central fossa areas
what do lingual and buccal embrasures do? which is better?
lingual> buccal
**guide food towards tongue
nociceptor, proprioceptors, interoceptors?
- nociceptor- pain
- proprioceptors- position and movement
- interoceptors- internal organ
muscle spindles do what?
monitor length within skeletal muscle
golgi tendon organ does what?
monitors muscle tension
pacinian corpuscle does what?
movement and firm pressure?
retrodiscal ligament does NOT?
stretch
isotonic vs isometric?
- isotonic= shortening under load
* isometric= contract without shortening
controlled relaxation vs eccentric contraction?
- controlled relaxation= lengthening with decreases motor unit stimulation
- eccentric contraction= lengthening while contracting simultaneously
central pattern generator (CPG)?
It’s two phases?
higher centers in brain that control the activity of the specific muscle involved in chewing stroke
1) opening= mandible drops, then moves laterally
2) closing= crush and grind, buccal cusps of MX and MD are aligned then teeth guided to MI
central pattern control
breathe, walk, chew; brain stem
central excitatory effect
deep pain input to CNS, stimulates non-associated neurons
spinal tract recieves info from?
receives periodontal and pulpal afferent (from trigeminal nerve)
reticular formation influences?
on pain
describe the two reflex arches?
stimulus response
1) myotactic- causes contraction with stretched
2) nociceptive- protective; biting hard, causing mandible to drop quickly
reciprocal innervation controls?
antagonistic muscles
regulation of muscle activity?
gamma efferent system
secondary hyperalgesia?
increased tissues sensitivity without local cause
overjet vs overbite vs open bite?
- over-jet= horizontal
- over bite= vertical
- open bite= no contact
gliding contact
passing of cusp inclines
tall cusps and deep fossae = ____ chewing stroke?
vertical
worn and flat teeth= ____ chewing stroke?
broader