Understanding Human Teeth: Primary and Permanent Dentition

Humans develop two successive dentitions:

Primary (Deciduous) Teeth

• 20 teeth total
• Erupt ~6 months to 3 years
• Function: chewing, speech development, space maintenance

Permanent Teeth

• 32 teeth (including wisdom teeth)
• Begin erupting ~age 6 (first molars, incisors)
• Complete by ~21 (third molars variable)
• Composition: 8 incisors, 4 canines, 8 premolars, 12 molars

Transition period (mixed dentition) lasts ~6–12 years. Good oral hygiene from infancy protects both sets.