Chapter 5.2: Teeth - Numerical Problems

Question 1: An adult human has a dental formula of 2(I 2/2, C 1/1, PM 2/2, M 3/3). a) How many incisors does an adult human have in total? b) How many canines does an adult human have in total? c) How many premolars does an adult human have in total? d) How many molars does an adult human have in total?

Answer 1: a) Incisors (I): 2 in upper half + 2 in lower half = 4 per side. Total = 4 * 2 = 8 incisors. b) Canines (C): 1 in upper half + 1 in lower half = 2 per side. Total = 2 * 2 = 4 canines. c) Premolars (PM): 2 in upper half + 2 in lower half = 4 per side. Total = 4 * 2 = 8 premolars. d) Molars (M): 3 in upper half + 3 in lower half = 6 per side. Total = 6 * 2 = 12 molars.

Question 2: Using the adult dental formula 2(I 2/2, C 1/1, PM 2/2, M 3/3), calculate the total number of teeth in an adult human. Show your calculation.

Answer 2: Teeth in one upper half-jaw = 2 (Incisors) + 1 (Canine) + 2 (Premolars) + 3 (Molars) = 8 teeth. Teeth in one lower half-jaw = 2 (Incisors) + 1 (Canine) + 2 (Premolars) + 3 (Molars) = 8 teeth. Total teeth in one half of the mouth = 8 (upper) + 8 (lower) = 16 teeth. Total teeth in the entire mouth = 16 teeth * 2 (for both sides) = 32 teeth.

Question 3: If a person has lost all their molars, how many teeth would they have remaining, assuming they had a full set of 32 permanent teeth initially?

Answer 3: Total initial teeth = 32. Total molars = 12 (as calculated in Question 1d). Remaining teeth = Total initial teeth - Total molars = 32 - 12 = 20 teeth.