Question

Dental formula for the monophyodont teeth of human is
a. $\dfrac{{0021}}{{0021}}$
b. $\dfrac{{0003}}{{0003}}$
c. $\dfrac{{2120}}{{2120}}$
d. $\dfrac{{2102}}{{2102}}$

Answer 1

Hint: The two teeth which are monophyodont are namely, premolars and molars. 2 Premolars and 3rd molars are absent in the primary set of teeth. Hence, they grow only in permanent sets of teeth, and thus are monophyodont.

Dental formula: -
It is written as an expression of the number of each type of tooth in one side of the upper jaw over the number of teeth in one side of the lower jaw. The letters correspond to the type of teeth (I = Incisor, C = Canine, P = Premolar, M = Molar). the mouse possesses only one tooth generation (monophyodont).

Complete answer:
This suggests that the jaw has no incisor, no canine, two premolar and one molar in both the jaws which is true for monophyodont teeth. So, this option is correct

This suggests that no I no C no P and three molars in both jaws. This is a type of dentition found in deer. So, this is wrong

This suggests that two incisions, 1 canine, two premolars and zero molar are present in both the jaws. This is a dental formula for milk teeth in humans. So, this is not the correct option.

In humans, the deciduous dentition consists of 20 total teeth, with the dental formula 2102 (or 2102/2102), indicating two incisors, one canine, zero premolars, and two molars in each quadrant. So, this option is also not correct.
Our correct option is A that is $\dfrac{{0021}}{{0021}}$

Note: Monophyodont is the first set of teeth that comes in children. Monophyodont (teeth appearing just once in lifetime) and diphyodont dentition (teeth appearing twice in lifetime). Since, in humans’ teeth occur two times, it is generally referred as diphyodont dentition. We have 20 teeth in infants and 32 in adults. The 20 teeth out of 32 in adult are the same as the 20 in infant and hence these come twice in lifetime, these are diphyodont and the remaining 12 out of 32 that appears for the very first time later only occur in adult and were never the part of milk teeth in adult and hence these are monophyodont.