Sometimes a child’s newly erupted permanent teeth are discoloured and extremely sensitive to heat and cold, a condition known as molar incisor hypo mineralization (MIH).
“This is a particular defect in enamel formation,” said Ruth Santamaria, a dentist at Greifswald University Hospital, Germany. It is so named because it primarily affects the molars, which are the wide teeth at the back of the mouth, and to a lesser extent the incisors, the chisel–shaped teeth in front.
Compared with healthy teeth, those with MIH are deficient in minerals – specifically calcium and phosphorus – explained Dietmar Oesterreich, vice president of the German Dental Association.
“Porosity develops,” making the teeth much more susceptible to cavities, he said.
MIH in primary school children is quickly diagnosed nowadays. This was not the case just a few years ago, and the term MIH was coined in 2001.
The oral health of children and adolescents has also improved over the years and is now very good, Oesterreich said. Dentists used to have trouble determining whether a tooth had already been porous before developing cavities.
About one child in 10 has MIH, according to Santamaria, and half that number have the severe form involving significant hypersensitivity or tooth surface loss.
Due to greater focus on MIH in recent years, it is hard to tell whether the incidence of this dental disorder is increasing or simply more cases are being diagnosed. In Oesterreich’s view, it seems to be increasing.
What is certain, he said, is that regular dental check–ups today make it easier to distinguish between a porous, tooth lacking in minerals and an originally healthy tooth affected by tooth decay.
What is the cause?
“Little is known about the cause” of MIH, however, Oesterreich noted.
Among the possible culprits, he said, are problems during pregnancy that disrupt tooth development in the foetus, dioxins in the mother’s milk, feverish infections in infancy, respiratory illnesses and exposure to antibiotics.
Santamaria pointed to oxygen shortages during or after birth as another possible trigger of MIH, which is likely a consequence of a combination of factors. As long as its cause or causes remain unknown, it will be difficult to prevent, she added.
MIH is treated in various ways. When it is detected early, dentists normally seal the teeth, Santamaria said. Fillings and crowns are used in serious cases.
In very serious cases, Oesterreich said, dentists have to decide whether “the tooth, over the long term, is worth saving.” If it is extracted, the resulting gap can often be closed, at least for the molars. A gap in the front teeth presents more of a problem.DPA