The Developing Dentition: What To Expect

Although usually not visible at birth, there are 20 primary teeth present under an infant's gums. As the child ages, these primary teeth make way for 32 permanent teeth.

As the primary teeth get ready to erupt into the mouth, the gums get hard, red and swollen. This process, called "teething," can also cause discomfort, excessive drooling, runny noses and overall crankiness. However, each child may exhibit some differences, so there is an average range within which tooth eruption occurs.

The two lower front teeth (deciduous central incisors) are typically the first to arrive when the child is six to eight months old. There will be periodic eruption of the rest of the primary teeth, usually in pairs, on both sides of the jaws. By the time the child is two years old, all of the deciduous teeth should be visible. Eventually, the primary teeth will become loose and fall out or be removed easily. Their permanent counterparts should replace all of the primary teeth. It is important, however, to maintain a child's primary teeth. They are necessary for chewing food properly, speech, and physical appearance. If a primary tooth decays and abscesses, it could damage the developing bud of the permanent tooth underneath. Also, premature loss of a back (posterior) primary tooth could reduce the amount of space necessary for its permanent replacement. In the primary dentition, large spaces between the teeth are normal.

It is important, however, to maintain a child's primary teeth. They are
necessary for chewing food properly, speech, and physical appearance.

Usually, the first permanent teeth to erupt are the child's four first molars. They do not replace any teeth but come in directly behind the child's primary second molars. This occurs at about five to six years of age, sometimes called the "six-year molars." The progression of tooth replacement/eruption follows with the four permanent front teeth (central incisors) between six and seven years of age. The eruption of the permanent teeth is almost complete at age 13, when the second permanent molars come in. The third molars (wisdom teeth) may erupt anywhere between ages 16 to 21-plus years. It is quite common for wisdom teeth to be impacted in the bone and never erupt. Sometimes other permanent teeth are congenitally missing and will never be present. This is typically diagnosed with proper x-rays (radiographs).

One of the concerns that a dentist will verify at a check-up appointment is that the child's teeth are developing properly and taking their correct position in the mouth. If you have questions regarding your child's tooth development or eruption pattern, please call your dentist.