Exam 1

Question 1

Initiation: Bud Stage

Answer 1

Tooth # determined in this stage.

Disturbance → missing or supernumerary teeth

Question 2

Proliferation: Cap Stage

Answer 2

Tooth # determined in this stage

Disturbance → missing or supernumerary teeth

Question 3

Histodifferentiation: Bell Stage

Answer 3

Structure of dentin & enamel.

Ameloblasts and odontoblasts form.

Disturbance → Amelogenisis Imperfecta

Question 4

Morphodifferentiation: Advanced Bell Stage

Answer 4

Tooth size and shape formed at this stage

Question 5

Apposition

Answer 5

Structure of enamel & dentin.

Enamel & dentin matrix form. This accounts for the layered appearance of enamel & dentin.

Enamel hypoplasia - most common

Question 6

Calcification

Answer 6

Structure of enamel & dentin.

Sensitive and lenghty process. 4+ years needed for calcification process.

Distrubances → enamel hypocalcification, molar incisor hyperplasia (MIH)

Question 7

Primary Tooth Eruption

Answer 7

Central → Lateral → 1st Molar → Canine → 2nd Molar

Timing: starts at 7 mo (4+ rule)

Question 8

Perment Tooth Eruption

Answer 8

MN 1st Ms → MX 1st Ms → MN CIs → MX CIs → MN LIs → MX LIs → MN Cs → MX 1st PMs → MN 1st PMs → MX 2nd PMs → MN 2nd PMs → MX Cs → MN 2nd Ms → MX 2nd Ms → MN 3rd Ms → MX 3rd Ms

MN: canine erupts before premollars

MX: canine erupts after the premolars

Question 9

What is the first primary tooth to erupt?

Answer 9

MN Central Incisor

7 months

Question 10

When do primary first molars erupt?

Answer 10

After the lateral incisors and prior to canines

Question 11

How can delayed tooth eruption (DTE) be determined?

Answer 11

• Biologically: eruption has not occurred despite formation of 2/3 or more of the root
• Chronologically: 2 standard deviations from average expected eruption time based on population studies

Question 12

What is the most common deviation in eruption?

Answer 12

Delayed Tooth Eruption (DTE)

Question 13

What causes delayed eruption?

Answer 13

• Genetic disorders (amelogenisis imperfecta, Down Syndrome, etc.)
• Environment (trauma, radiation damage, etc.)
• Systemic conditions (nutrition, rickets, HIV infection, celiac disease, anemia, drugs - phenytoin, low birth weight, etc.)

Question 14

Primate Space

Answer 14

• MX diastema: b/t primary lateral & canine
• MN diastema: b/t primary canine & 1st molar