Occlusion Flashcards
what Angle class does the Triangular ridge of MB cusp of Max 1st molar articulates in B groove of Man 1st molar?
Class 1
**max canine between man canine and 1st premolar
*70% of pop
what percentage of pop has class 2?
25%
where does the MB cusp of Max 1st molar fall in angle class 2?
between 1st molar and 2nd premolar
in angle class 2 what direction do the max incisors tip?
bucally
what does “sunday bite” mean?
patient typically functions in a class 2 bite, but can go into class 1
*this can trick a dentist
Class 2 division 1
class II molar relationship with protruded Max incisors
class 2 division 2
max lat incisors tipped labially and mesial, centrals retruded
Describe class angle class 3 bite
Molars and canines
- MB cusp of Max 1st molar falls between Man 1st and 2nd molars
- Max canine distal to Man canine
- 5% of pop
what is a skeletal class 1?
max and mand are similar in poportion
what is skeletal class 2?
mand is smaller than max
what is a skeletal class 3
mand is larger than max
what is the terminal plane and what is it used for?
Distal aspect of 2nd primary molars, used to determine amount of shift
What is leeway space?
size differential between primary posterior teeth and permanent canine and premolars
- 2.5/side uppers
1. 5/side lowers
*example perm premolar (smaller) erupts where there the primary molar (larger) was
what is a flush terminal plane relationship?
Molars are directly on top of each other.
normal relationship for primary teeth. Will shift to class 2, then eventually class 1 when primary molars are lost
What is a mesial step relationship?
Distal surface of Man molar mesial to Max
*usually shifts to class 1, but can shift to class 3
what is a distal step relationship?
Distal surface of Man molar Distal to Max
**Can shift to Class II or End to end
what is primate spacing?
- gap between Max lateral incisors and canines
- Gap between Man canines and 1st molars
6 keys to normal occlusion?
1-molar relationship 2-Crown angulation (gingiva is distal) 3-crown inclination (inclination) 4-elimination of rotation 5-tight contacts 6-flat occlusal plane
what is a facial/buccal crossbite?
posterior maxillary facial cusps contact mandibular fossa
*max non-functional cusps are in the fossa rather than functional ones
what is Lingual crossbite/scissor bite?
lingual inclines of maxillary lingual cusps contact buccal inclines of mandibular teeth
what muscle controls translation?
Lateral pterygoid muscle contracts and moves condyle-articular disk assembly forward
in rotation, how many mm before incisor separation?
12mm
what are the Overbite and overjets for anterior open bite?
negative overbite with positive or negative overjet
what do the max incisors cause in an anterior deep bite?
can cause retrusive force on mandible
in increased overjet the posterior cusps are ________ and in overbite the posterior cusps are ______
shorter, longer
what are the glenoid fossa and condylar disk covered with?
avascular fibrous tissue
what is the articular disk?
Dense connective tissue
what is the posterior aspect of the articular disk attached to?
retrodiscal tissue which is connected to the posterior wall of articular capsule
what are the medial and lateral walls of the articular disk connected to?
poles of condylar process
what is the anterior wall of the articular disk connected to?
superior lateral pterygoid muscle and capsule
what does the articular eminence do?
causes early separation of posterior teeth (taller posterior cusps) and creates the downward movement.
more lateral movement in glenoid fossa results in what?
shorter cusp height
immediate slide in the medial walls in glenoid fossa results in what?
shorter cusp tips
Is condylar guidance fixed or changeable?
fixed and unalterable
steeper condylar guidance results in what kind of cusp tips?
taller
*greater vertical component
what determines anterior guidance?
Overbite, overjet, and incisor angle
**can be altered by ortho
T/F Cuspal inclines mirror guidance angles
True
if the occlusal plane is more parallel to condylar guidance, what happens to the cusp tips?
shorter
if the curve os spee is acute, what happens to the cusp tips in anterior and posterior?
Anterior: Tall
Posterior: Short
T/F CR has translation?
False. No translation and is independent of tooth contant
*very hard to locate/define
Highest forces and longest duration of contact occur at the intercuspal position of functional or non functional cusps?
Functional
**Aka supporting cusps, aka holding cusps
Do functional or non functional cusps have sharper tips?
non-functional
**aka non-supporting, aka non-centric, aka non-holding
Laterotrusion results in movement on the working or non-working side?
working side.
what 3 things effect medio and laterotrusion?
1-condylar distance
2- tooth distance from condyle
3-tooth distance from midsagittal plane
greater intercondylar distance results in?
smaller angle between Medio and laterotrusion angle
Greater distance between tooth and condyle results in?
Wider Medio and laterotrusion angle
greater tooth distance from midsagittal plane reuslts in?
wider angle between Medio and laterotrusion angle
what is Tooth-to-tooth, cusp to marginal ridge relationship?
maxillary lingual cusp contact distal marginal ridge of single tooth
which type of functional cusp contact is most stable?
- tooth-to-two tooth
- cusp to two marginal ridges contact
Tripod contact is what kind of functional cusp contact?
Tooth-to-tooth cusp-fossa contact
when equilibrating occlusion do you adjust mediotrusive or laterotrusive contacts first?
Mediotrusive, then medio and latero together
what ligament limits mandibular rotation on opening?
Temporomandibular ligament
what ligament limits separation between condylar process and articular disk?
Sphenomandibular ligament
what ligament limits separation between condylar process and articular disk, limits forward movement of mandible?
Stylomandibular ligament
what are the 4 muscles of mastication?
1-masseter
2-temoral
3-Medial pterygoid
4- lateral pterygoid
what are the 3 suprahyoid muscles and what do they do?
1-geniohyoid
2-mylohyoid
3-digastic (posterior and anterior belly)
*they elevate hyoid bone or depress and retract the mandible
