Dental formula in human beings is

Options

A. `(2123)/(2123)`
B. `(2021)/(2021)`
C. `(2321)/(2321)`
D. `(2133)/(2133)`

Answer

### Step-by-Step Text Solution:

1. **Understanding Dental Formula**: The dental formula represents the arrangement of teeth in the upper and lower jaws of an organism. It provides a systematic way to denote the number and types of teeth present.

2. **Total Number of Teeth**: The dental formula is typically expressed for one half of the mouth (either upper or lower jaw). To find the total number of teeth, the formula is multiplied by 2.

3. **Dental Formula for Adults**: In adult humans, the dental formula for permanent teeth is:
- Upper Jaw: 2 incisors, 1 canine, 2 premolars, and 3 molars.
- Lower Jaw: 2 incisors, 1 canine, 2 premolars, and 3 molars.
- Therefore, the dental formula can be written as:
- \( \frac{2 \, 1 \, 2 \, 3}{2 \, 1 \, 2 \, 3} \)

4. **Complete Dental Formula**: This means that the complete dental formula for an adult human is:
- \( 2 \, 1 \, 2 \, 3 \) for the upper jaw and \( 2 \, 1 \, 2 \, 3 \) for the lower jaw.
- Hence, the total number of teeth in an adult human is \( 2 \times (2 + 1 + 2 + 3) = 32 \).

5. **Dental Formula for Milk Teeth**: In the case of milk teeth (deciduous teeth), the dental formula is different:
- Upper Jaw: 2 incisors, 1 canine, 0 premolars (as they are absent), and 2 molars.
- Lower Jaw: 2 incisors, 1 canine, 0 premolars, and 2 molars.
- Therefore, the dental formula for milk teeth is:
- \( \frac{2 \, 1 \, 0 \, 2}{2 \, 1 \, 0 \, 2} \)

6. **Conclusion**: The dental formula for adult humans is \( 2 \, 1 \, 2 \, 3 \) for each half of the jaw, while for milk teeth it is \( 2 \, 1 \, 0 \, 2 \).

### Final Answer:
The dental formula in human beings is \( 2 \, 1 \, 2 \, 3 \).

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