Every baby is different, but you can expect your child’s first tooth to appear anywhere from three months up to a year and a half or so. Typically, though, most babies’ chompers start making an appearance around six months—and children should have a full set of 20 baby teeth by age three. They won’t keep them long, however; most children lose their first tooth between the ages of four and six. If your child loses a tooth before age four, see your dentist.