A close look at tooth eruption. Baby teeth do matter! They are "holding the spot in line" for their permanent tooth growing underneath them. Without the baby tooth to hold the spot, your permanent are doomed to become crowded
Sensitive teeth are primarily caused by gum recession. Gums recede for many reasons, like brushing too hard, age, and periodontal disease leaving "tubules" exposed. These tubules lead directly to the nerve of the tooth and cause pain.