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A baby boy aged two years is admitted to...

A baby boy aged two years is admitted to play school and passes through a dental check-up. The dentist observed that the boy had twenty teeth. Which teeth were absent?

A

Canines

B

Pre-molars

C

Molars

D

Incisors

Text Solution

AI Generated Solution

The correct Answer is:
To determine which teeth are absent in a two-year-old baby boy who has 20 teeth, we can follow these steps: ### Step 1: Understand the Dental Formula - The dental formula for adults is 2-1-2-3 (upper jaw) and 2-1-2-3 (lower jaw), which totals to 32 teeth. - The dental formula for children (deciduous teeth) is 2-1-0-2 (upper jaw) and 2-1-0-2 (lower jaw), which totals to 20 teeth. ### Step 2: Identify Types of Teeth - In the dental formula for children: - Incisors: 8 (2 in upper jaw + 2 in lower jaw) - Canines: 4 (1 in upper jaw + 1 in lower jaw) - Premolars: 0 (none present in children) - Molars: 8 (2 in upper jaw + 2 in lower jaw) ### Step 3: Analyze the Given Information - The boy has 20 teeth, which aligns with the expected number of teeth for a child. - According to the dental formula for children, premolars are absent in this age group. ### Step 4: Conclusion - Since the boy has 20 teeth, and the only type of teeth that are not present in children are the premolars, we conclude that the absent teeth in the baby boy are the premolars. ### Final Answer The absent teeth in the baby boy are the **premolars**. ---
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