Eruption Patterns Part 1 (CONCEPTS/TERMS) Flashcards
When do tooth buds/tooth germs grow?
during the sixth week in utero (fetal life)
Does cementum form before or after dentin and enamel?
After
Secondary dentin continues to form…
throughout lifetime
Calcification
the hardening of tooth tissues through the deposition of mineral salts within these tissues
-the root apex is the last part the calcify
When do primary vs permanent calcify
Primary: calcified by 4th-5th month of fetal life
Permanent: begins soon after birth
Explain developmental lobes
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.
All anterior teeth develop from how many lobes?
4 (3 labial and 1 lingual)
For primary teeth, calcification continues until what age
3-4 years old (starting with the crown)
For primary teeth, roots are done developing by what age
3-4 years old
For permanent teeth, calcification continues until what age
25
What is active eruption?
when the tooth pushes through mucous membrane covering the alveolar bone, this begins before total calcification
What is attrition?
a type of tooth wear caused by tooth to tooth contact. active erupting contributes to attrition
Explain supra-eruption
When the same tooth in the opposite arch is missing, and the tooth continues to keep erupting
True or False: teeth generally erupt/appear in pairs. one on the left and one on the right
True
True or False: Mandibular teeth usually precede maxillary teeth of the same type in eruption
True
True or False: permanent teeth may erupt slightly earlier in boys than in girls
FALSE; they may erupt earlier in GIRLS than in BOYS
Describe the occlusal plane
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).
What is exfoliation
when the deciduous roots resorb and dissolve, resulting in loosening of the tooth and eventually it falling out
What is resorption?
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
What does mesial drift mean?
the tendency of permanent molars to have an erupting force towards the midline.
What are the two effects of mesial drift?
-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
At what age does eruption of primary teeth complete?
2-3 years old
What are primate spaces?
Spaces that may occur between primary teeth due to the jaw continue to grow after the teeth have finished erupting.
Why is it important to keep deciduous teeth (until they are supposed to exfoliate) ?
-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)
What are the “6 year molars”?
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)
When does root formation of permanent teeth finish?
10-16 years old (excluding 3rd molars)
