Etiology of Malocclusions- Dr. Retrouvey (FINAL)

Question 1

Predisposing factors to malocclusion include:

Answer 1

1. Genetics (primary factor)
2. Functional matrix
3. Disturbances in embryologic development
4. Traumas

Question 2

Primary etiologic 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 Imperfeta (COL1A1 & COL1A2)
3. Ectodermic dysplasia
4. Scleroderma

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

1. Alcohol
2. Drugs
3. Pollution
4. Poor nutrition

Question 7

We used to think cleft lip & palate could be due to teratogens but the idea have shifted now to them being due to:

Answer 7

Genetics

Question 8

Most common craniofacial abnormality:

Answer 8

Cleft lip & palate

Question 9

Crouzon syndrome is a type of:

Answer 9

Craniostynostosis

Question 10

Crouzon syndrome (craniostynostosis syndrome) is caused by:

Answer 10

Early fusion of sutures

-the lower jaw develops normally
-the orbits close early

Question 11

Crouzon syndrome is characterized by:

Answer 11

1.Bulging eyes
2. Small maxilla

Question 12

What is a typical treatment for Crouzon syndrome?

Answer 12

Distraction osteogenesis

Question 13

Crouzon syndrome (Craniosynostosis) is purely a ____ disease

Answer 13

Bony

Question 14

Disease characterized by underdevelopment of the midface & eyes that seem to bulge from their sockets

Answer 14

Crouzon syndrome

Question 15

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

Answer 15

Treacher-Collins

Question 16

When the maxilla & mandible are both underdeveloped this is considered:

Answer 16

Bimaxillary retrusion

Question 17

In dentistry when you have syndromes, you typically have:

Answer 17

Hypodontia (exception Cleidocranial dysplasia)

Question 18

Disease characterized by:

-delayed closure (ossification) of the space between the bone of the skull (fontanels)
-premature closing of coronal suture
-protruding jaw
-protruding brow bone
-wide nasal bridge due to increased space between the eyes
-high arched palate or possible cleft palate
-short stature
-scoliosis of spine

Answer 18

Cleidocranial dysplasia (CCD)

Question 19

Describe the mandible of a patient who has CCD:

Answer 19

Typically a class III (because of hypertrophic mandible)

Question 20

Dental abnormalities of CCD patient include:

Answer 20

Failure to loose baby teeth & delayed or absent percent teeth, slow eruption of secondary teeth

Question 21

In 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

Osteogenesis imperfecta

Question 24

Type of osteogenesis imperfect that characterized by less bone but still good bone; majority of OI patients

Answer 24

Type I

Question 25

Types of osteogenesis imperfecta characterized by weak bone with lots of fractures; more severe

Answer 25

Type III & 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 has DI:

Answer 27

All the other OI members of that family have DI as well

Question 28

Discuss the prevalence of DI in the following types of OI patients: Type I: Type IV: Type III:

Answer 28

Type I= 20% Type IV= 40-60% Type III= 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 midface region, meaning:

Answer 30

Smaller & 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 seen in a patient with down syndrome is due to:

Answer 32

The large/thick tongue pushing on the teeth, not genetics

Question 33

Condylar are:

Answer 33

Growth sites

Question 34

Condition in which one condyle is absent, creating significant malocclusion:

Answer 34

Condylar dysplasia -we see the muscle compensations in this situation to keep patient semi-functional

Question 35

A lot of syndromic patient have significant:

Answer 35

Cranial base alterations

Question 36

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

Answer 36

Cranial base

Question 37

Types of malocclusion: 30% of people have ____ occlusion

Answer 37

Normal occlusion

Question 38

Types of malocclusion: 50-55% of people have ____ occlusion

Answer 38

Class I malocclusion

Question 39

Types of malocclusion: 15% of people have ____ occlusion

Answer 39

Class II malocclusion

Question 40

Types of malocclusion: 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 (overbite)=

Answer 43

Class II

Question 44

Prognathic (underbite)=

Answer 44

Class III

Question 45

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

Answer 45

Mandibular retrognathism

Question 46

40% of our class two patients are actually:

Answer 46

Bimaxillary retrusive

Question 47

Even among the same class of malocclusions, there is:

Answer 47

Phenotypic diversity

Question 48

A very common type of class III malocclusion is called characterized by overjet & overbite:

Answer 48

Edge-to-edge -wears down incisors

Question 49

The prevalence of malocclusions depends on the:

Answer 49

Population

Question 50

What percent of southeast Asians display a malocclusion?

Answer 50

15%

Question 51

What percent of middle easterns display a malocclusion?

Answer 51

10%

Question 52

What percent of Indians display malocclusions?

Answer 52

~1%

Question 53

What percent of europeans display a malocclusion?

Answer 53

1-4%

Question 54

The genetics of class III malocclusions are focused on:

Answer 54

Mandibular prognathism

Question 55

Family & twin sides of genetics of class III malocclusions suggest a ____ as a primary cause of class III malocclusions

Answer 55

Polygenic model

Question 56

What aspects contribute to 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

If you catch a class III malocclusion at 8-9 years of age and intervene in the mixed dentition bringing them back to a class I profile, what will result?

Answer 58

Some correct nicely, some do not (unpredictable)

Question 59

Deep bite is a _____ problem:

Answer 59

Vertical

Question 60

A unique characteristic to open birds is that sometimes you have a ___ stage in which they can resolve themselves

Answer 60

transitory

Question 61

Deep & open bites have _____ etiologies

Answer 61

Multifactorial