Eruption Patterns Part 1 (CONCEPTS/TERMS)

Question 1

When do tooth buds/tooth germs grow?

Answer 1

during the sixth week in utero (fetal life)

Question 2

Does cementum form before or after dentin and enamel?

Answer 2

After

Question 3

Secondary dentin continues to form…

Answer 3

throughout lifetime

Question 4

Calcification

Answer 4

the hardening of tooth tissues through the deposition of mineral salts within these tissues
-the root apex is the last part the calcify

Question 5

When do primary vs permanent calcify

Answer 5

Primary: calcified by 4th-5th month of fetal life
Permanent: begins soon after birth

Question 6

Explain developmental lobes

Answer 6

Growth centers where each tooth begins to develop. These center grow from the tooth germ, and continue to grow until they fuse (coalescence) and leave a developmental groove behind. The number of lobes necessary depends on the type of tooth.

Question 7

All anterior teeth develop from how many lobes?

Answer 7

4 (3 labial and 1 lingual)

Question 8

For primary teeth, calcification continues until what age

Answer 8

3-4 years old (starting with the crown)

Question 9

For primary teeth, roots are done developing by what age

Answer 9

3-4 years old

Question 10

For permanent teeth, calcification continues until what age

Answer 10

25

Question 11

What is active eruption?

Answer 11

when the tooth pushes through mucous membrane covering the alveolar bone, this begins before total calcification

Question 12

What is attrition?

Answer 12

a type of tooth wear caused by tooth to tooth contact. active erupting contributes to attrition

Question 13

Explain supra-eruption

Answer 13

When the same tooth in the opposite arch is missing, and the tooth continues to keep erupting

Question 14

True or False: teeth generally erupt/appear in pairs. one on the left and one on the right

Answer 14

True

Question 15

True or False: Mandibular teeth usually precede maxillary teeth of the same type in eruption

Answer 15

True

Question 16

True or False: permanent teeth may erupt slightly earlier in boys than in girls

Answer 16

FALSE; they may erupt earlier in GIRLS than in BOYS

Question 17

Describe the occlusal plane

Answer 17

Often called the Curve of Spree (unless it is flat), the occlusal plane is a normal curved alignment of that forms when teeth in opposite arches erupt and meet. This curvature is necessary for efficient mastication (chewing).

Question 18

What is exfoliation

Answer 18

when the deciduous roots resorb and dissolve, resulting in loosening of the tooth and eventually it falling out

Question 19

What is resorption?

Answer 19

when the root is destroyed by osteoclasts (bone destroying cells). the body is triggered to active osteoclasts by pressure from permanent teeth preparing to erupt

Question 20

What does mesial drift mean?

Answer 20

the tendency of permanent molars to have an erupting force towards the midline.

Question 21

What are the two effects of mesial drift?

Answer 21

-spaces between teeth close as the molars push deciduous teeth together
-if a deciduous teeth was lost prematurely, or if premolars and canines have not yet erupted, this can cause problems in the alignment of teeth

Question 22

At what age does eruption of primary teeth complete?

Answer 22

2-3 years old

Question 23

What are primate spaces?

Answer 23

Spaces that may occur between primary teeth due to the jaw continue to grow after the teeth have finished erupting.

Question 24

Why is it important to keep deciduous teeth (until they are supposed to exfoliate) ?

Answer 24

-Primary teeth are needed for jaw growth and development
-Aids in speech
-Esthetics
-Guides permanent tooth eruption (proper position of all permanent teeth depends on 1st molar)

Question 25

What are the “6 year molars”?

Answer 25

The 1st molars. They are larger than deciduous molars, and look the same as primary 2nd molars. They need jaw growth to erupt (hence why the jaw continues to grow after primary teeth have erupted)

Question 26

When does root formation of permanent teeth finish?

Answer 26

10-16 years old (excluding 3rd molars)