The document discusses the three periods of dentition that humans experience: the primary period from 6 months to 6 years where only deciduous (baby) teeth are present, the mixed period from 6 to 12 years where both deciduous and permanent teeth are emerging, and the permanent period starting at 12 years where only permanent teeth remain for the rest of one's life.

1. PERIODS OF
DENTITION

2. Dentition periods:
Humans have two dentitions namely deciduous and permanent. These dentitions overlap
in time so the periods of dentitions are:
◦ Primary
◦ Mixed
◦ Permanent

3. 1. Primary dentition period:
◦ In this period only “milk” teeth/”temporary” teeth/”baby” teeth/”deciduous teeth are present
hence it is also called deciduous dentition.
◦ It starts from approx. six months of age to six years.
◦ Its ending is marked by the eruption of first permanent tooth (usually mandibular first molar).

4. 2. Mixed dentition period:
◦ In this period both deciduous and permanent teeth are present hence it is called the mixed
dentition period.
◦ It starts from approx. six years of age and ends about at twelve years.
◦ Its ending is marked by the exfoliation of the last deciduous tooth (usually the maxillary second
molar)

5. 3. Permanent dentition period:
◦ In this period, only permanent teeth are present hence it is called permanent dentition period.
◦ It starts at approx. twelve years of age and continues through the rest of life.