Tooth Development

There is a lot of variation in the normal eruption time for children's teeth.
Baby Teething
My question concerns my 16-month-old son, Patrick. His tooth development seems to me to be somewhat delayed. He has had his front teeth for some time and molars have just come in. But, in casual discussion with my dental technician, she seemed surprised that his "laterals" (I understand that to be the teeth between the molars and the front teeth) have yet to come in. Should I be worried?
There is a lot of variation in the normal eruption time for children's teeth. The front two teeth (central incisors) are first--lower ones at six to ten months of age, followed by upper ones. The lateral incisors, on either side of those front two teeth, come in next, between 9 and 16 months of age. This completes the front set of teeth, resulting in four on the top and four on the bottom.

The first molar comes in next, at about 14 to 18 months. However, this tooth is not right next to the front teeth. The canine tooth is the tooth that appears between the front four and the first molar, but it comes in after the first molar, usually about three months later. Thus it is perfectly normal to see a toddler with four front teeth, then a space on both sides, and then a "back tooth" on each side.

I am not sure from your description if this is what your child has. Athough it would be unusual for your child not to have the lateral incisors if he already has his first molars, it does not mean there is a problem if he does. As long as the appearance of the teeth is normal, and the gums are healthy, a slight change in order of appearance should not cause you to worry. Once your child has the full set of eight top teeth and eight bottom teeth, there is usually a long wait until the second molars (the two year molars) appear between 24 and 32 months of age.

Shari Nethersole is a physician at Children's Hospital, Boston, and an instructor in Pediatrics at Harvard Medical School. She graduated from Yale University and Harvard Medical School, and did her internship and residency at Children's Hospital, Boston. As a pediatrician, she tries to work with parents to identify and address their concerns.

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