The primary dentition in humans differs from permanent dentition in not having one of the following types of teeth.
A. Incisors
B. Canine
C. Premolars
D. Molars

Hint: Human beings have two sets of dentitions in their lifetime. One temporary or milk teeth and other permanent or adult teeth. This type of dentition is called diphyodont.

Complete step-by-step answer:
1. Most of the children have 20 sets of teeth. Which include pairs of: central incisor, lateral incisor, canine, first molar and second molar. The dental formula is 2102/ 2012. (There are four quadrants of the teeth in the buccal cavity, which are the upper right, upper left, lower right, and lower left)
2. Whereas in adults there are 32 sets of teeth. Which includes a pair of: central incisor, lateral incisor, canine, first premolar, second premolar, first molar, second molar and third molar (wisdom teeth). The dental formula is 2123/ 2123.
3. When the first molar teeths fall off they are replaced by first premolar and when second molar teeth fall off they are replaced by second premolar and behind them erupts adult first molar, second molar and third molar teeth.
4. In human adults there are a total eight premolar teeth.

Additional information:





So, the correct answer is “Option C premolar ”.

Note:
1. Canines and incisors have sharp ends whereas the premolars have a large flat biting surface which helps in tearing and crushing food.
2. Incisors are eight in number and in the front centre of buccal cavity.
3. Adjacent to incisors are canines they are four in number.
4. Molars are the posterior-most/ backmost teeth in the buccal cavity and they total twelve in number. Molars help in grinding and chewing of food.