What is D3?

What is D3"D3" is just a simple way of saying "DDD" which in our case stands for "Developmental Dental Defect". As the long-winded name suggests, D3s originate from developmental problems – that is, things going awry when the tooth was being formed inside your child's jaw. So D3s can be viewed as a sort of congenital disorder or birth defect, as explained to 6-year-old Sam.

Several different types of D3 can occur depending on what actually went wrong (e.g. whereabouts in the jaw, when during development, and how badly the problem struck). And so it can be said of D3s that "some
are common and others rare, some affect most teeth, others here
'n' there" (with a hat tip to Ted Geisel). What is D3

Nearly all D3s affect the outward appearance of the tooth enamel – sometimes just a small patch is affected (or "wonky" as your child might say) and other times it’s wonky all over. Such discolourations may not necessarily be of concern if the enamel surface remains sufficiently hard. However, when the patches of abnormal enamel are soft and porous, there is increased risk of dental pain and tooth decay (i.e. dental caries) – so dental treatments may be recommended to nip these problems in the bud (read more).

There are four main types of D3 you may hear about, as summarised below.




Molar Hypomin (short for "Molar Hypomineralisation") is a very common D3 and one of particular concern to The D3 Group because it causes a lot of suffering and costs around the world. You can learn many things about Molar Hypomin throughout this website but a good place to start is here.





Fluorosis (or more properly "Dental Fluorosis") refers to the speckled white patches you often see on people's front teeth. Fortunately, most cases of fluorosis in our part of the world are mild and not of dental concern, particularly when the protective "anti-caries" benefits of fluoride are considered. However, there is potential for worse types of fluorosis that exhibit pitted, discoloured enamel – these arise from excessive ingestion of fluoride when the teeth are developing. So that's why there are such strong guidelines about watching how much toothpaste your infants use. Learn more about dental fluorosis here.




Surface pits or grooves (technically referred to as "Enamel Hypoplasia") are isolated depressions in the enamel surface. Although quite common they generally don't cause dental concern. But sometimes these pits can trap food and so bring increased risk for caries. The origins of these pits can be traced back to early development of the tooth, when the cells that make enamel get it wrong – instead of producing a nice thick layer of smooth enamel, they can leave gaps here and there which later get solidified as pits when the enamel hardens.  It’s worth knowing that lots of people still get the term "hypoplasia" confused with "hypomineralisation" (as in "Molar Hypomin"), but they are quite different problems as you can find out here.


4. "AI"


AI, which is short for "Amelogenesis Imperfecta", is the worst type of D3 since all teeth are affected usually – but fortunately for most of us, AI is quite rare. This is the only type of D3 that’s regarded as a genetic disorder so there will be a family history in most cases. And perhaps with AI it’s reasonable for kids to be kids and talk about  "mutant teeth", in contrast to the other types of D3 including Molar Hypomin. There are many different types of AI, depending on which gene is affected. Learn more here.