1. The document discusses the development and eruption of both primary (deciduous) and permanent teeth at different ages. 2. For primary teeth, calcification begins between 4-6 months in utero, eruption occurs between 6-11 years, and roots begin to resorb 3 years before shedding. 3. For permanent teeth, calcification begins at birth for the first molar and between 1-2 years for premolars, with eruption sequences of lower first then upper and molars erupting at ages 6, 12, and 18 years.