Teeth develop in three stages:
The first stage, growth, begins as early as the seventh week of fetal development when tooth buds start forming. These tooth buds are masses of cells containing the tissue that eventually forms the teeth.
During calcification, the second stage of tooth development, calcium and mineral deposits harden the tooth in layers, forming the enamel. This is an effective process since tooth enamel is the hardest material in the human body, but this toughness comes at a price. Because there is no living tissue in enamel, it cannot repair itself the way other parts of the body can.
Babies are actually born with all 20 primary teeth, but they are embedded in the gums. The fun really begins during the third and final stage, eruption, when these teeth begin working their way to the surface. This is sometimes painful because the tooth is twisting and maneuvering its way through the gums to take its place in the mouth. For as long as it takes for the tooth to emerge, the discomfort can persist. And because communicating this sensation is still years beyond a baby's ability, his frustration and anxiety can compound the situation.
Heredity also plays a role in tooth development. A parent and child may have similar teething patterns, so understanding your own teething history may help when your own children are going through it. Additional factors that influence how disruptive teething may be for a particular child include gum density and pain tolerance.
Hygiene is critical during teething because irritated or swollen gums are susceptible to infection. For this reason, it's a good idea to keep the area around the mouth as clean and dry as reasonably possible and periodically wash the gums with a soft, wet cloth. And because teething babies often are not very discriminating about what they put in their mouths, you should be sure to sanitize all teething rings and other chew toys.
Even though primary teeth are eventually lost, taking care of them is important for long-term dental health. It's not uncommon for babies to get cavities and other oral problems. Also, prematurely losing primary teeth can force the remaining teeth to crowd together in an effort to close gaps, causing permanent teeth to come in crooked or out of place.
In the next section we'll discuss some of the symptoms commonly associated with teething, and some that are less common but more severe.