Malocclusion

Question 1

This was a national survey of health care populations and needs which the majority of malocclusion data comes from

Answer 1

NAHNES (National Health And Nutirtion Estimates Survey III)

Question 2

True of False

Malocclusion is a disease

Answer 2

False, it is not a disease, but a spectrum representing biological variability/diversity

Question 3

When deviation from the normal reaches a certain degrees of severity, known as what, it is them termed malocclusion

Answer 3

threshold

Question 4

What percentage of people have some sort of malocclusion, ranging from mild to handicapped

Answer 4

60%

Question 5

What are the four components of malocclusion

Answer 5

sagittal or A-P
vertical
transverses
intra-arch

Question 6

What were the five components of the NHANES traits

Answer 6

irregularity index
midline diastema
posterior cross bite - all three of these are inter arch
overjet
overbite/openbite

Question 7

Irregularity increased where

Answer 7

between childhood and youth

Question 8

Irregularity was largely stable where

Answer 8

between youth and adult except for mandibular crowding which increased

Question 9

What typical causes mandibular crowding

Answer 9

later mandibular growth; 3rd molars do not cause crowding, its a confounder though

Question 10

A little more than 50% surveyed had what

Answer 10

little or no crowding, with 6-8% exhibiting severe crowding

Question 11

26% had what, in the 8-11 age group, which decreased 6% in the later age groups

Answer 11

maxillary midline diastemas

Question 12

What is the ideal overjet

Answer 12

less than 3mm

Question 13

Mild class II decreases from childhood to adolescence, why is that?

Answer 13

probably the result of differential jaw growth during the adolescent growth spurt; this also increases class IIIs

Question 14

What is the ideal overbite

Answer 14

25% or less

1-2mm

Question 15

Vertical problems of anterior open bite versus anterior deep bite exhibits what kind of differences

Answer 15

racial; anterior open bites = African Americans

anterior deep bites = European-Americans

Question 16

Deep bite decreases from childhood to adult due to what

Answer 16

continuous growth; vertical dimension is the last to stop

Question 17

Posterior bite increases due to what

Answer 17

the transverse plane is the first to stop growing

Question 18

What percentage of people had normal class I occlusion

Answer 18

30-35%

Question 19

What percentage of people had class I malocclusion (crowding)

Answer 19

50-55%

Question 20

What percentage of people had class II malocclusion

Answer 20

15-20%

Question 21

What percentage of people had class III malocclusions

Answer 21

less than 1%

Question 22

In what populations was class II more prevalent

Answer 22

european descent

Question 23

In which populations was class III more prevanelt

Answer 23

african americans
hispanic
east asia

Question 24

Maloccluson in most instances was what kind of condition

Answer 24

developmental

rarely pathological

Question 25

malocclusion results from what

Answer 25

a complex interaction along multiple factors; occasionally a single specific cause is apparent

Question 26

What percentage of malocclusion is there a known cause of

Answer 26

5% known cause

60% unknown cause

Question 27

What are four etiologic factors of malocclusion

Answer 27

heredity
interference with normal development
trauma
disturbances in normal function

Question 28

what are three heredity factors of malocclusion

Answer 28

inherited disproportion between size of upper and lower jaws
inherited disproportion between size of teeth and jaws
heterogeneous gene pool

Question 29

What percentage of the dental and facial variations that lead to malocclusion can be attributed to heredity factors

Answer 29

40%

Question 30

With increasing what heritability variables increase for skeletal and decrease for dental variables

Answer 30

age

Question 31

Inheritance was particularly strong for what malocclusion

Answer 31

mandibular prognathism followed by a long face pattern of facial development

Question 32

What are three factors that can affect pre-natal development

Answer 32

agents such as teratogens, radiation, etc.
fetal molding and birth injuries; cleft lip/palate
migration of neural crest cells

Question 33

What are four factors that can affect post-natal development

Answer 33

childhood fractures
muscle dysfunction
acromegaly
condylar hyperplasia/hemi-mandibular hypertrophy

Question 34

These factors can interfere with normal dental development

Answer 34

fusion
supernumerary teeth
partial anodontia
ectopic eruption

Question 35

If this could affect the growth of the jaws and/or the position of teeth, then it being altered would be a major cause of malocclusion

Answer 35

function

Question 36

When talking about the equilibrium theory, its not necessarily the amount of force, but what

Answer 36

the duration

Question 37

What could be three functional influences of malocclusion

Answer 37

digit sucking habits
tongue thrusting habit
respiratory pattern