Etiology of Malocclusion Part 2

Question 1

What contributes to a deep bite?

Answer 1

1. skeletal
2. over eruption of incisors
3. under eruption of molars

Question 2

What type of transverse deficiency is seen with a deep bite and what is this caused by?

Answer 2

maxillary transverse deficiency

• overdeveloped mandibule
• unfavorable dental angulations

Question 3

List some disturbances of dental development: (5)

Answer 3

1. congenitally missing teeth
2. malformed and supernumerary teeth
3. interference with eruption
4. ectopic eruption
5. early loss of primary teeth

Question 4

When all teeth are congenitally missing:

Answer 4

anodontia (rare)

Question 5

When several teeth are congenitally missing

Answer 5

oligodontia

Question 6

Dr. Moyers explanations for congenitally missing teeth: (5)

Answer 6

1. heredity
2. ectodermal dysplasia
3. localized inflammations/infections
4. systemic conditions (rickets)
5. evolutionary changes in the dentition (specifically 3rd molars)

Question 7

1. heredity
2. ectodermal dysplasia
3. localized inflammations/infections
4. systemic conditions (rickets)
5. evolutionary changes in the dentition (specifically 3rd molars)

These are ____ explanations for ___

Answer 7

Dr. Moyer’s; congenitally missing teeth

Question 8

Describe some characteristics of the teeth of ectodermal dysplasia:

Answer 8

1. oligodontia
2. poorly shaped teeth

Question 9

What are the most frequently missing teeth?

Answer 9

• upper lateral incisors
• lower second premolars
• lower central incisors

Question 10

List some examples of malformed teeth: (3)

Answer 10

1. peg maxillary lateral incisors
2. misshaped crown
3. shortened root

Question 11

What does the bolton ratio describe?

Answer 11

mesio-distal size of the dentition/ proportionality of tooth sizes within a dentition

Question 12

What describe site proportionality of tooth sizes within a dentition (MD)

Answer 12

Bolton ratio

Question 13

In order to develop a proper overbite and overjet:

Answer 13

the size of the lower dentition must be proportional to the size of the upper dentition

Question 14

The size of the lower dentition must be proportional to the size of the upper dentition to develop a proper:

Answer 14

overbite and overjet

Question 15

The size of the lower dentition must be proportional to the size of the upper dentition to develop a proper overbite and overjet. This proportion is called:

Answer 15

Bolton ratio

Question 16

Bolton ratio= overall ratio = sum of ____ (__mm) / sum of ______ (_ mm)

Answer 16

mandibular 6-6 (mm)/ maxillary 6-6 (mm)

Question 17

Bolton ratio= anterior ratio = sum of ____ (__mm) / sum of ______ (_ mm)

Answer 17

mandibular 3-3 (mm)/ maxillary 3-3 (mm)

Question 18

Supernumerary tooth in the maxillary central incisor region:

Answer 18

mesiodens