Cats are toothless at birth. Deciduous teeth are complete and functional within 2 months of birth. Permanent teeth are complete and functional by the end of the 5th or 6th month.
The formula for deciduous teeth: 2 (I3/3 C1/1 P3/2)
The formula for permanent teeth: 2 (I3/3 C1/1 P3/2 M1/1)
Incisors
Sometimes a cat's lower incisor teeth are shed in middle age.
Molars
A decrease in the number of molars leaves the cat with a shearing bite, rather than wider cusps for grinding.