Thursday June 7, 2001
Dear Dr. Mady: My four-year-old daughter has a tooth in the front bottom that is very large and looks like two teeth stuck together to form one. What could it be and will it affect the permanent tooth that will come in later? -JDS
Dear JDS: It sounds like you are describing what is known as the "fusion" of two teeth. When this occurs the resulting tooth appears very large and if you count, the number of teeth present will probably be less than the normal amount present for a four year old.
Fused teeth are most likely produced by some physical action, perhaps pressure forcing young tooth germs into contact during formation, giving the dentin papilla and enamel organ an opportunity to unite.
If this occurs very early, the crowns may fuse. If it happens later, only the roots may be fused and it may appear to look like two separate teeth exist. On occasion, both the crowns and roots are fused.
Fusion is much more common in deciduous (baby) teeth than in permanent teeth.
These teeth may share one common pulp or root canal or have separate ones. This trait is usually genetic or inherited.
There is another possibility that your daughter has a dental situation known as "gemination". This condition occurs when the tooth bud has made a partial attempt to divide and the result is an additional tooth.
It is actually the splitting of a single tooth germ and the development of two tooth crowns. There is a shared dental pulp (nerve inside the root canal) and root. Unlike fusion, the correct number of teeth will exist, however the gemination tooth is unusually wide. This is genetically influenced also.
Whatever the case may be, I strongly recommend that you have an x-ray taken of this particular tooth by your dentist to make an exact diagnosis and determine the cause if possible. This is especially important if the fusion or gemination will have any effect on the formation or eruption of any other teeth.
It is important to understand that this does not usually mean that the permanent teeth will be affected. Proper monitoring by routine dental examination and x-rays will help determine and prevent any possible future problems related to this anomaly or others.
This column is reprinted with the permission of the author and The Windsor Star. "Ask the Dentist" is written by Windsor dentist (and ECDS member), Dr. David Mady Jr.. The column appears the first Thursday of each month in the Windsor Star. Readers with questions can write to "Ask The Dentist", c/o The Windsor Star, 167 Ferry St., Windsor Ontario, N9A 4M5
