Class 2 Flashcards
Malocclusion is not
A disease but a spectrum respresenting biological variability
Normal %
35%
% handicapped
5%
Overjet
Antero posterior
Overbite
Vertical
Irregularity increased between _____ and _____ and was stable between _____ and _____
Childhood youth
Youth adulthood
When does mandibular crowding increase
Youth and adulthood
When would a mild class II decrease
From childhood to a dole scene probably a results of differential jaw growth during growth spurt
Transverse components
Refers to Cross bite
Vertical problems of anterior open bite versus anterior deep bite exhibits
Racial differences
Open bites seen more in
African Americans
Severe anterior deep bites more common in
European Americans
Malocclusion is in most instances a
Developmental condition
Hereditary factors
Disproportion between size of upper and lower jaws
Disproportion between size of teeth and jaw
Heterogenous gene pool
With increasing age heritability estimates _____ for skeletal and _____ for dental variables
Increase
Decrease
Inheritance is particularly strong for ______ ______ followed by ________ of facial development
Mandibular prognathism
Long face pattern
Childhood fractures heal mostly
Uneventful
Interferences with post natal development
Fractures
Muscle dysfunction
Acromegaly
Condyerl huperplasia
Hypodontia
Missing 5 or fewer teeth
Oligodonitia
Missing 6 or more teeth
Endodontia
Missing all teeth
Form Function interaction
If function could affect the growth of the jaws and or the position of teeth, then altered function would be a major cause of malocclusion
Forces on teeth
Are in equilibrium
Functional influences
Digit sucking
Tongue thrusting
Respiratory pattern
Diet
Threshold time
6 hours
Tongue thrusting
Compensatory for open bite-not causation
Tongue interposed at rest will have an effect
Adenoid Facies
Long face syndrome-increased lower face length
Total obstruction of nasal breathing will haven an effect
Higher % of mouth breathers in long face individuals but the majority of long face individuals are nose breathers
Malocclusion is estimated by
Incisor irregularity Overbite/open Overjet Posterior crossbite Diastema >2
Straight Profile indicates
Optimal relations of maxilla and mandible and cranial base
Usually skeletal and Dental class I
Convex profile
Protrusive maxilla
Retrieve mandible
Usually skeletal and dental Class II
Concave Profile
Retrusive Maxilla
Protrusive Mandible
Usually skeletal and dental Class III
Angles classification only applied to
Permanent teeth
AP plane of space
Most common malocclusion is
Skeletal/Dental Class I crowded
Within Class I problems exist in the ______ and _______ and you can have Dental malocclusion problems
Transverse
Vertical planes
Posterior crossbites can be
Dental or skeletal constriction
Short face often with
Deep bite
Short face mandible angled
Very straight
Maxillary position
SNA
Mandibular Position
SNB
Maxilla to Mandible
ANB
Growth direction
Y-axis
Upper incisor position
Upper insider to FH
Lower incisor position
Lower incisor to Mand Plane
To predict the size of the premolar and canine of the mandible
1/2 the width of the lower incisors +10.5 mm
to predict size of the premolars and canine on side of the maxilla
Take 1/2 width of the lower incisors +11 mm
Space discrepancy for each arch=
Space available- size of incisors + predicted size fo the canine and premolars
