Etiology of Malocclusions (Part II)

Question 1

What contributes to a deep bite? (3)

Answer 1

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

Question 2

What type of transverse deficiency is seen in a deep bite? What is this caused by?

Answer 2

maxillary transverse deficiency
-overdeveloped mandible
-unfavorable dental angulations

Question 3

List some disturbances of dental development: (5)

Answer 3

1. congenitally missing teeth
2. malformed & 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. Moyer’s explanations for congenitally missing teeth: (5)

Answer 6

1. heredity
2. ectodermal dysplasia
3. localized inflammations/infections
4. systemic conditions (Ricketts)
5. evolutionary Changs in the dentition (specifically third molars)

Question 7

1. heredity
2. ectodermal dysplasia
3. localized inflammations/infections
4. systemic conditions (Ricketts)
5. evolutionary Changs in the dentition (specifically third molars)

These are _____ explanations for _____

Answer 7

Dr. Moyer’s; congenitally missing teeth

Question 8

Describe some characteristics of the teeth in ectodermal dysplasia:

Answer 8

1. oligodontia
2. poorly shaped teeth

Question 9

What are the MOST frequently missing teeth:

Answer 9

1. upper lateral incisors
2. lower second premolars
3. 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 describes the proportionality of tooth sizes within a dentition (MD):

Answer 12

Bolton ratio

Question 13

In order to develop a proper overbite & 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 upper dentition to develop a proper:

Answer 14

overbite & overjet

Question 15

The size of the lower dentition must be proportional to the upper dentition to develop a proper overbite & overjet, this proportion is called:

Answer 15

Bolton ratio

Question 16

Bolten ratio = overall ratio = sum of ____ (___mm) / sum of _____ (__mm)

Answer 16

mandibular 6-6 mm / maxillary 6-6 mm

Question 17

Bolten 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