malocclusion epidemiology and etiology

Question 1

what are the limitations of Angle’s Classification of malocclusion?

Answer 1

1. ant/post dental relationship only (no vertical/ transverse)
2. no skeletal mal-relationships
3. no soft tissue considerations (facial appearance)
4. health related to airway not considered

Question 2

the study of the dynamics of occurrence of a condition or trait in a population or group is defined as _______________.

Answer 2

epidemiology

Question 3

what are the two major studies that serve as the basis for malocclusion study?

Answer 3

USPHS survey (1963, 1969, 1970), NHANES III (1989-2004)

Question 4

which national malocclusion survey provided meaningful conclusions for the majority of the popultion?

Answer 4

NHANES III

Question 5

when is a deviation from the normal occlusion termed malocclusion?

Answer 5

when it reaches a certain degree of severity (threshold)

Question 6

Is malocclusion a disease? if not, what is it?

Answer 6

NOT a disease, but a spectrum representing biological variability/ diversity

Question 7

is there a lot of evidence to support that malocclusion affects TMD?

Answer 7

NO

Question 8

what percentage of the population has normal occlusion?

Answer 8

1/3

Question 9

what percentage of the population has handicapped malocclusion?

Answer 9

5%

Question 10

what are the 4 components/ spatial planes of malocclusion?

Answer 10

sagittal or anterior/posterior, vertical, transverse, intra-arch (crowding/ spacing)

Question 11

what are the 5 NHANES III traits measured?

Answer 11

1. irregularity index- intra-arch crowding
2. midline diastema- intra-arch spacing
3. posterior cross-bite- transverse plane
4. overjet- anterior/posterior dimension
5. overbite/ openbite- vertical dimension

Question 12

little more than ______% of the population surveyed had little or no crowding (irregularity), but about _____% exhibited severe to extreme crowding in the _________ age group

Answer 12

50, 6-8, younger

Question 13

irregularity ______ (inc/ dec) between childhood and youth, was ________ (stable/unstable) between youth and adult age groups, but mandibular crowding increased due to ________________.

Answer 13

increased, stable, continued growth of the mandible

Question 14

_____% of population had maxillary midline diastemas in the 8-11 age group, which ______________ (inc/ dec) to _____% in later age groups.

Answer 14

26, decreased, 6

Question 15

mild class II _______ (inc/dec) while mild class III ______ (inc/dec) from childhood to adolescence due to________.

Answer 15

decreases, increases, differential jaw growth during adolescent growth spurt

Question 16

we discussed ethnic differences mainly in the_____________ dimension

Answer 16

anterior/posterior

Question 17

increased overjet is typically seen in which ethnic group?

Answer 17

european

Question 18

increased class III is typically seen in which ethnic group?

Answer 18

hispanic and AA and east asian

Question 19

anterior open bites are more often seen in which ethnic group?

Answer 19

AA

Question 20

anterior deep bites are more common in which ethnic group?

Answer 20

european

Question 21

class I malocclusions were present in _____% of the population.

Answer 21

50-55

Question 22

____% of the population had class II malocclusions.

Answer 22

15-20

Question 23

____% of the population had class III malocclusions

Answer 23

less than 1