Teething Parents think of teething as the few days of swelling, discomfort, and irritability before a baby's tooth erupts, but tooth development actually begins before birth . Primary or "baby" teeth form below the gum line around the sixth week of pregnancy , and they're covered by hard enamel during the third to fourth month. Permanent or "adult" teeth also begin developing at this time. During pregnancy, you can get your child's teeth off to a healthy start by following your doctor's advice and eating a well-balanced diet, including calcium-rich foods such as yogurt and dark leafy greens. And once your baby sprouts these little teet...