Primary teeth develop between 5-6 weeks in utero and erupt between 6 months and 3 years of age. They are replaced by permanent teeth starting around age 6. Tooth development occurs through stages of initiation, proliferation, morphodifferentiation, and maturation to form the enamel, dentin, and cementum layers. Eruption involves both active movement into the mouth and passive exposure through gingival recession over time. Proper nutrition during development and preventive care after eruption are important for dental health.