Small Bumps on the Teeth Edges
Thursday march 6, 2003

Dear Dr. Mady: My child has had about half of her adult teeth come in but I have some concerns. First, they are not as white as the baby teeth, but more importantly, the front teeth have small bumps on the edges and this looks funny. Is this normal and what should we do? – Nancy in Long Beach

Dear Nancy: You are correct in noticing that the colour of the primary (baby) teeth is whiter than the permanent teeth. As the anterior (front) baby teeth are replaced by permanent teeth, the colouration difference becomes less noticeable. Also these new anterior adult teeth almost always have bumps on their incisal (biting) edge, known as mamelons. These are normal also and will become smaller or even disappear from normal wear.

As far as tooth colour goes, primary teeth normally have thinner, lighter enamel and this causes them to appear whiter. In addition to being lighter and thinner, the enamel of these deciduous (another term for primary) teeth has a more consistent depth throughout. This is why the colour is more uniform in shade unlike adult teeth where the shade changes from one part of the tooth to another. This is evident in the way that permanent teeth are usually more yellow by the gum line, especially with age. Also the enamel matrix structure of deciduous teeth is weaker and this is evident through it’s appearance. The enamel is much less pigmented. These qualities often enable primary teeth to decay faster once bacterial invasion begins.

Mamelons usually develop in groups of three. They resemble rounded protuberances and they are found on the incisal edges of newly erupted incisor teeth, both upper and lower. When each of the anterior (front) teeth develop, they originate from four lobes. Each one of these lobes terminates it’s formation incisally in these rounded eminences. They are usually the most profound right after eruption, but with time they usually wear down until they are undetectable. Occasionally they won’t wear down, especially in situations where there is malalignment of teeth where the front upper and lower teeth do not occlude or touch when biting.

Most individuals do not like the appearance of mamelons and will even present to their dentist requesting to have them polished off. I don’t usually recommend this. Some even want to go as far as placing cosmetic porcelain veneers or facings on their teeth to improve the look and get rid of the mamelons at the same time.

Part of the reason that the mamelonsare so noticeable is because these extensions are made of pure enamelwith no dentin layer underneath. This and their thinness contributes to their translucent appearance as opposed to the rest of the clinical crown which is almost always more opaque than the mamelons. With this translucent quality, they often appear to be a different shade than the rest of the tooth and therefore are sometimes much more distinct. In most cases, they wear down flush soon after eruption and if a person grinds their teeth even mildly, the resulting attrition speeds up the process.

All of this is normal and at this point, nothing should be done. If you have any more specific questions or concerns, consult with your dentist.




