There are 20 teeth in the first (or milk) set which will appear by the time your child is 2 1/2 years old—ten in the upper jaw, ten in the lower, comprising 8 incisors, 4 canines (or cuspids) and eight molars. They usually come through in a particular order and the lower teeth tend to break through before the corresponding uppper teeth.
The first tooth to appear is usually a lower central incisor at between 5 to 7 months, although in some babies it erupts at 3 months and in others not until a year. Next come the upper central incisors (6-9 months), the lower central incisors (7-10 months), the four first molars (12 to 14 months), the canines (16 to 18 months) and the second molars (20-30 months). At the end of her first year, your baby could have 6 to 8 teeth.
Let us Hope
There are 32 teeth in the second or permanent set which, during the first six years, lie in the jaws beneath the gums waiting to erupt. Remember? The first to come through are the “six-year-old molars” or first molars which appear between 6 to 7 years and are sometimes mistaken for milk teeth. They sprout next to the second molars of the first set, so no teeth are disturbed. These are very important teeth and are called by “Keystones of the Dental Arch” which means that the shape of your child’s mouth depends to a large extent on them.
Decay in the baby tooth can affect the permanent tooth which has been waiting to emerge. It can also cause infection of the jaw and sometimes so much pain that it has to be pulled out, leaving a gap that may allow nearby teeth to grow out of position so that the permanent tooth will be crowded out when it is ready to come through. Remember baby teeth are around till your child is about 12, hence they need care.
The six-year-old molars are followed closely by new central incisors. Your child loses first teeth in the same order that they will be replaced by the permanent set. The permanent teeth push up from underneath, destroy the roots of the baby teeth which get loose and fall out or can be pulled out easily.
Sometimes the permanent teeth come behind the baby teeth and later move forward; often, they have jagged edges which smoothen out in time.