Dr. Norman J. Nagel recalls his first encounter with rampant molar hypomineralization (MH) was among indigenous people in Alaska, while doing humanitarian work with the U.S. Army National Guard and Indian Health Service more than 25 years ago. Colloquially called “chalky teeth,” MH is a developmental dental defect (DDD, or “D3“) involving areas of discoloration on affected teeth, crumbling enamel that rapidly progresses to decay and often, dental pain.

Orthodontists first coming out of residency programs may not have seen many examples of compromised molars, but Dr. Nagel, who was the AAO’s 2022-23 president, says that will likely change after a few more years’ experience.

“When I speak with colleagues who have been in practice for a while, they often report having seen chalky molars in their practices, noting that not much seems to be known about chalky enamel,” says Dr. Nagel, who became re-energized about MH while attending an orthodontics mini-symposium last year, led by Dr. Mike Hubbard from the University of Melbourne, Australia.

A dentally-trained career scientist, Dr. Hubbard is the founder and director of “D3G” – or formally, The D3 Group for Developmental Dental Defects (D3s). D3G is an international research and education network comprising all key stakeholder groups – including orthodontics – that currently spans 56 countries.

One in Five Children Worldwide Affected
Dr. Hubbard authored an influential guest editorial about MHin the Journal of the American Dental Association thatpoints tothe high prevalence and long-term burdens of this disorder. Notably, an average of one in five children worldwide have 2-year and/or 6-year molars impacted by hypomineralization, as detailed here.
Dr. Hubbard says MH is typically a long-term issue that “can be seen in 2-year, 6-year and 12-year molars as well as wisdom teeth. It is common for kids who have chalky 2-year molars to go on to have chalky 6-year molars, and sometimes chalky 12-year molars appear later in kids with chalky 6-molars. The latter situation can prove troublesome to the unwary orthodontist, who may have extracted the chalky 6-year molars presuming that healthy 12-year molars will later fill the gap – but that may not be an option, if the 12-year molars turn out to be severely hypomineralized and require extraction.”

AAO member and D3G’s lead orthodontist Dr. Paul Schneider headed the orthodontic program at the University of Melbourne until recently. Having encountered a great deal of MH over decades in private practice, he helped recruit Dr. Hubbard to investigate the scientific, clinical and population health perspectives of chalky teeth.

“In examining molars where there is severe decay, it may appear that dental caries is the only issue because it often obscures the underlying cause – the chalky enamel,” says Dr. Schneider. “In some cases, decay may advance so quickly and be so severe that extraction is necessary almost as soon as a tooth erupts.”

Dr. Barbara Shearer, D3G’s newly-installed global director, points to a key aspect of chalky teeth that surprises many – the differences between enamel hypomineralization (chalky enamel) and classical dental caries.

“Lifestyle factors that are normally considered preventive for dental caries, such as excellent oral hygiene and minimizing sugary food and beverages in the diet, may not be effective for stopping tooth decay stemming from enamel hypomineralization,” says Dr. Shearer, former Worldwide Director of Professional Strategy and Innovation for Colgate-Palmolive.

“Decay of chalky enamel will often continue regardless, due to mechanical breakdown from chewing and erosion from dietary acids,” says Dr. Shearer. “In some societies, there may be little awareness of how to prevent tooth decay, but many parents of children diagnosed with MH may feel guilty that their child has decayed teeth, and may be shocked to learn that good lifestyle and hygiene habits won’t necessarily prevent further problems.” *

Early Intervention is Key, with Widespread Awareness Needed
“Dental professionals of all types, including orthodontists, have a key role to play in screening for chalky teeth,” says Dr. Hubbard. “If children visit orthodontists at age 7 as recommended by the AAO, their 6-year-molars will likely have erupted. This is a good time to screen for chalky enamel. It’s even better if started earlier – say at age 3 or 4 – to detect chalky 2-year molars, which are a major risk factor for early childhood decay and also carry orthodontic connotations. Better still, in New Zealand, D3G has helped implement chalky teeth screening at about 18 months, when chalky baby canines appear. Consequently, families become ‘chalky teeth aware’ from the outset and can then be on the lookout as their infant grows up.”

“As alarming as MH can be, it is a myth that all chalky molars have to be extracted right away,” says Dr. Schneider. “In some less severe cases of decay, a provisional metal crown is an option, but in others, use of an easy-to-apply cement to coat the surface of the tooth may stabilize it for several years – such as from ages 6 to 11. Eventually a permanent restoration will be needed, of course.”

If a tooth’s condition is not so severe that immediate extraction is required, decision-making on extraction timing may be complicated, as universally accepted for compromised molars more generally.

“If a child is going to have one or more molars extracted, ideally we would want to have the orthodontist involved in treatment planning,” says Dr. Hubbard. “That is one reason we are working to increase awareness among orthodontists as well as other dental specialists likely to be on teams providing care to patients with MH.”

In a special article published in the March 2024 issue of the AJO-DO, “Why Orthodontists Need to Know about Molar Incisor Hypomineralization,” Dr. Patrıcia Bittencourt Santos further addresses management of orthodontic patients impacted by MH. Dr. Hubbard explains that “Molar Incisor Hypomineralization is a popular, but 20-year-old clinical term relating to 6-year molars and incisors – that is, an important yet incomplete part of the broader problem we call MH today.”

The Evolving Understanding of MH, D3s and Chalky Teeth
In addition to a prime focus on MH, D3G educates about three other types of Developmental Dental Defects (D3s) affecting enamel. While MH is the most common such disorder, Wikipedia notes that the rare genetic condition, amelogenesis imperfecta, “may cause all teeth to be chalky.”

D3G’s website explains in simple terms that chalky teeth did not harden properly during their development. Contributing factors may include childhood illness, nutrition and genetics. Exciting discoveries have led D3G to focus their etiological research efforts on enamel malformation at the extracellular level, as outlined under “Pathogenesis of Molar Hypomineralisation.”

D3G also works to educate dentists and other healthcare providers about chalky teeth as a public health issue. The group’s article in Frontiers in Physiology summarizes the 100-year history of chalky enamel research and the pressing need for further research efforts, from basic science to clinical and population health levels.

Engagement with orthodontic groups throughout the world to inform and inspire members is a priority for D3G. To learn more about MH and chalky teeth, contact Dr. Hubbard at [email protected].

Additional Helpful Resources
● Family-friendly introduction, “The Chalky Teeth Campaign”
● “What Are D3s?”
● “What Is Molar Hypomin?”

* Colgate-Palmolive’s guide to chalky teeth is also a family -friendly resource.