Etiology of Malocclusions- FINAL - Dr. Retrouvey

Question 1

Predisposing factors to malocclusion include:

Answer 1

1. Genetics
2. Functional matrix
3. Disturbances in embryologic development
4. traumas

Question 2

Primary etiological sites include:

Answer 2

1. neuromuscular system
2. Bone
3. Teeth
4. Soft tissues

Question 3

List diseases associated with the following primary etiologic sites:

1. neuromuscular system
2. bone
3. teeth
4. soft tissues

Answer 3

1. cerebral palsy (results in severe malocclusion)
2. Osteogenesis imperfecta (Col1a1 and Col1a2)
3. Ectodermic dysplasia
4. sclerodermia

Question 4

Disturbances in embryologic development may be due to:

Answer 4

teratogens

Question 5

May interfere with cellular differentiation during pregnancy:

Answer 5

teratogens

Question 6

Some examples of teratogens include:

Answer 6

alcohol, drugs, pollution, poor nutrition

Question 7

We used to think that cleft lip and palate could be due to teratogens but the idea has shifted now to them being due to:

Answer 7

genetics

Question 8

most common craniofacial abnormality:

Answer 8

cleft lip & palate

Question 9

Crouzon syndromes is a type of:

Answer 9

craniosynostosis

Question 10

Crouzon syndrome (cranosynostosis syndrome) is caused by:

Answer 10

early fusion of sutures

(lower jaw develops normal, orbits close early)

Question 11

Crouzon is characterized by:

Answer 11

• bulging eye
• small maxilla

Question 12

What is a typical treatment for crouzon syndrome:

Answer 12

distraction osteogenesis

Question 13

Craniosynostosis (Crouzon’s syndrome) is purely a ____ disease

Answer 13

bony

Question 14

Disease characterized by underdevelopment of the mid face & eyes that seem to bulge from their sockets:

Answer 14

crouzon’s syndrome

Question 15

Disease characterized by underdeveloped cheek and jawbones, a prominent nose, broad mouth, and characteristically small chin with steep lower jaw angle:

Answer 15

treacher collins

Question 16

When the maxillary and mandibular jawbones are both under developed this is considered:

Answer 16

Bimaxillary retrusion

Question 17

In dentistry when you have syndromes, these are typically associated with:

Answer 17

hypodontia

(Exception CCD)

Question 18

Disease characterized by:

• delayed closure (ossification) of the space between the bones of the skull (fontanels)
• Premature closing of coronal suture
• Protruding jaw and protruding brow bone
• wide nasal bridge due to increase space between the eyes
• high arched palate or possible cleft palate
• short stature
• scoliosis of spine

Answer 18

cleidocranial dysplasia

Question 19

Describe the mandible of a patient with CCD:

Answer 19

Typically a class III because of hypertrophy mandible (protrusion)

Question 20

Dental abnormalities of CCD patient include:

Answer 20

failure to lose baby teeth and delayed or absent formation of teeth, slow eruption of secondary teeth

Question 21

Osteogenesis imperfecta, the ___ is affected

Answer 21

dentin

Question 22

What class of malocclusion is often seen in OI patients?

Answer 22

class III malocclusion as well as posterior open bite

Question 23

• midline deviation
• asymmetry: repercussion on the condyles
• posterior open bite
• lack of chewing capability

These are all characteristic of:

Answer 23

OI

Question 24

Type of osteogenesis imperfecta characterized by less bone but still good bone, majority of OI patients

Answer 24

Type I

Question 25

Type of osteogenesis impercta characterized by weak bone and lots of fractures, more severe, and DI

Answer 25

type III and IV

Question 26

What is one of the most significant aspects of osteogenesis imperfecta?

Answer 26

Dentinogenesis imperfecta

Question 27

If one OI member of the family have DI:

Answer 27

all the other OI members of that family will have DI as well

Question 28

Discuss the prevalence of DI in the following types of OI patients: Type 1: Type 4: Type 3:

Answer 28

1: 20% 4: 40-60% 3: 100%

Question 29

In what disease discussed is all of the teeth NOT affected in the same manner?

Answer 29

dentinogenesis imperfecta

Question 30

Down syndrome can be characterized with underdevelopment or hypoplasia of the mid face region meaning:

Answer 30

smaller and retrusive maxilla contributes to class III malocclusion

Question 31

Is the maxilla or mandible smaller due to Down syndrome?

Answer 31

maxilla (mandible is normal)

Question 32

The open bite in a patient with down syndrome is due to:

Answer 32

Thick tongue pushing on the teeth (not genetics)

Question 33

The condyles are considered:

Answer 33

growth sites

Question 34

Condition in which one condyle is absent creating significant malocclusion:

Answer 34

condylar dysplasia (the muscles still all the patient to have semi-function)

Question 35

A lot of syndromic patients have significant:

Answer 35

cranial base alterations

Question 36

Position and projection of the upper and lower jaws rely on:

Answer 36

cranial base

Question 37

30% of people have ____ occlusion

Answer 37

normal occlusion

Question 38

50-55% of people have ____ occlusion

Answer 38

class I malocclusion

Question 39

15% of people have _____ occlsuion

Answer 39

class II malocclusion

Question 40

1-4% of people have ____ occlusion

Answer 40

class III malocclusion

Question 41

Malocclusion occurs in ___ dimensions

Answer 41

3

Question 42

Angle classification of occlusion is based on:

Answer 42

AP relationships

Question 43

retrognathic jaw =

Answer 43

class II

Question 44

prognathic jaw:

Answer 44

class III

Question 45

Are most class II malocclusions a result of maxillary prognathism or mandibular retrognathism?

Answer 45

mandibular retro

Question 46

40% of our class II patient are actually:

Answer 46

bimaxillary retrognathic

Question 47

Even among the same type of malocclusions, there is:

Answer 47

phenotypic diversity

Question 48

A very common type of class III malocclusion that is characterized by overjet and overbite is:

Answer 48

edge-to-edge (wears down incisors)

Question 49

prevalence of malocclusions depends on the:

Answer 49

popluation

Question 50

What percent of southeast asians display malocclusion?

Answer 50

15%

Question 51

What percent of middle easterns display malocclusion?

Answer 51

10%

Question 52

What percent of indians display malocclusion?

Answer 52

~1%

Question 53

What percent of europeans display malocclusion?

Answer 53

1-4%

Question 54

The genetics of class III malocclusions are focused on:

Answer 54

mandibular prognathisms

Question 55

Family and twin studies of genetic of class III malocclusion suggest a ____ as a primary cause of class III malocclusions

Answer 55

polygenic model

Question 56

what aspects make up the polygenic model responsible for class III malocclusion?

Answer 56

genes + environment + condylar cartilage

Question 57

What is used to determine the chromosome loci associated with the genetics responsible for class III malocclusion?

Answer 57

linkage analysis studies

Question 58

A deep bite refers to a ____ problem

Answer 58

vertical

Question 59

A unique characteristic to open bites is that sometimes you have a _____ stage in which they will resolve themselves

Answer 59

transitory