COA Dental Anatomy & Oral Development 2 — Questions and Answers
Question 1: At approximately what age do primary (deciduous) teeth typically begin to erupt in infants?
- 2–3 months
- 6–10 months (Correct answer)
- 12–18 months
- 18–24 months
Correct answer: 6–10 months
Primary teeth typically begin erupting between 6 and 10 months of age, with the mandibular central incisors usually appearing first.
Question 2: How many teeth are present in a complete primary (deciduous) dentition?
- 16
- 20 (Correct answer)
- 24
- 28
Correct answer: 20
A complete primary dentition consists of 20 teeth: 8 incisors, 4 canines, and 8 molars (no premolars in primary dentition).
Question 3: Which permanent teeth typically erupt FIRST into the oral cavity around age 6?
- Maxillary central incisors
- Mandibular central incisors only
- First permanent molars only
- Mandibular central incisors and first permanent molars (Correct answer)
Correct answer: Mandibular central incisors and first permanent molars
Both the mandibular central incisors and the first permanent molars (upper and lower) typically erupt around age 6, marking the transition from primary to mixed dentition.
Question 4: What is the clinical term for the natural shedding of primary teeth as their roots are resorbed to allow permanent tooth eruption?
- Exfoliation (Correct answer)
- Resorption
- Eruption
- Avulsion
Correct answer: Exfoliation
Exfoliation refers to the natural, physiologic shedding of primary teeth; it is the result of root resorption triggered by the erupting permanent tooth beneath.
Question 5: The mandibular central incisors typically erupt at approximately what age?
- 4–5 years
- 6–7 years (Correct answer)
- 8–9 years
- 10–11 years
Correct answer: 6–7 years
Mandibular central incisors are among the first permanent teeth to erupt, typically appearing between ages 6 and 7 years.
Question 6: Which term describes a permanent tooth that fails to erupt into the oral cavity and remains embedded within the bone?
- Ectopic tooth
- Impacted tooth (Correct answer)
- Ankylosed tooth
- Transposed tooth
Correct answer: Impacted tooth
An impacted tooth is one that is prevented from erupting fully into its normal position, often due to obstruction by adjacent teeth, bone, or soft tissue.
Question 7: During tooth development, which stage involves the deposition of enamel, dentin, and cementum to form the hard tooth structures?
- Initiation stage
- Bud stage
- Bell stage
- Apposition stage (Correct answer)
Correct answer: Apposition stage
The apposition stage is when ameloblasts, odontoblasts, and cementoblasts deposit enamel, dentin, and cementum respectively, forming the mineralized tooth structure.
COA Dental Anatomy & Oral Development 2
At approximately what age do primary (deciduous) teeth typically begin to erupt in infants?