PREVALENCE OF D3s

Some D3s are surprisingly common and others rare (but still of potential importance to those suffering them), hence prevalence information is significant for researchers and healthcare providers as well as the at-risk public. Comparison of studies done in different places might yield clues about causation, and how individuals or population groups vary in their vulnerability (e.g. geographic and racial risk factors). Prevalences of the 4 major D3s, and resulting impacts on affected individuals and society, are compared here.

Prevalence of Molar HYPOMINERALISATION

Popularly termed 'chalky molars', Molar Hypomineralisation is both a worldwide problem and the commonest type of D3. The 6-year molars are affected most often, followed by the 2-year and 12-year molars. A combined average prevalence of 19% (i.e. about 1-in-5 kids) has been determined for chalky 2-year and 6-year molars in otherwise healthy children – this finding comes from over 141 studies in 47 countries (see map and tables below). While most studies originate in Europe, other countries around the globe are increasingly investigating this problem – including the USA which in 2019 reported its first study (at long last).

Most data are for 7–12 year old children who will carry the liabilities of Molar Hypomineralisation for the rest of their lives. Given this high prevalence and life-long burden, Molar Hypomineralisation clearly merits increased attention as a global concern for public health. See also the projected global incidence of Molar Hypomineralisation, which strongly reinforces our concerns.

Map showing countries with 'chalky 6-year molar' studies

Main Map New Zealand Australia Kenya india HongKong Singapore Malaysia Thailand Japan United Arab Emirates Iran Iraq Lebanon Jordan Egypt Libya Spain Albania Nigeria Saudi Arabia Nepal China Brazil Chile Argentina Uruguay Colombia Ecuador Mexico United States Canada Turkey Greece Bulgaria Italy Slovenia Austria Poland Lithuania Finland Sweden Norway Denmark Germany Netherlands United Kingdom Bosnia
TOUCH PINS TO SEE COUNTRY NAMES


For further reference, the prevalence studies for chalky 6-year molars and equivalent data for chalky 2-year molars are graphed and tabulated below. In the graphs you can readily see the range and distribution of prevalence values for both types of molar. Notably, hypomineralised 6-year molars are roughly twice as common as hypomineralised 2-year molars – hence these "chalky molars" together affect about 1-in-5 schoolchildren when allowing for overlap (i.e. those who have both types of molar affected). In the tables, you can also see the variations, both between studies in different countries and between those within the same country. It is noteworthy that the reports for chalky 6-year molars extend back to 1987, at which time the prevalence reported for Sweden was similar to today's global average (10% & 15%, respectively). Caution should be applied when making detailed comparisons because not all studies were conducted equivalently – e.g. some involve much larger datasets than others, and variations exist for the diagnostic criteria used and the population types studied. Given such imprecision, we have rounded the reported prevalence values to whole numbers.

These online data are updated periodically. The latest information is available to D3G members on request. To join D3G and support our social-good venture, go here.

Prevalence of Molar Hypomineralisation graph in 6 year olds and 2 year olds

PREVALENCE STUDIES FOR CHALKY 2-YEAR MOLARS

Region/Location Prevalence Report
Oceania    
Australia
Melbourne
14% Owen et al, 2018 Hypomineralized second primary molars: prevalence, defect characteristics and relationship with dental caries in Melbourne preschool children.
Melbourne 8% Gambetta-Tessini et al, 2018 Carious lesion severity and demarcated hypomineralized lesions of tooth enamel in schoolchildren from Melbourne, Australia.
Melbourne 20% Silva et al, 2019 Etiology of Hypomineralized Second Primary Molars: A Prospective Twin Study.
Europe    
Netherlands
Alphen aan de Rijnland, Gouda, Breda and Den Bosch
5% Elfrink et al, 2008 Hypomineralized second primary molars: prevalence data in Dutch 5-year-olds.
Rotterdam 9% Elfrink et al, 2012 Deciduous Molar Hypomineralization and Molar Incisor Hypomineralization.
Germany
Munich
4% Kuhnisch et al, 2014 Proportion and extent of manifestation of molar-incisor-hypomineralizations according to different phenotypes.
Spain
Valencia
15% Negre-Barber et al, 2016 Hypomineralized second primary molars as predictor of Molar Incisor Hypomineralization.
Asia    
Iraq
Mosul City
7% Ghanim et al, 2013 Prevalence of demarcated hypomineralisation defects in second primary molars in Iraqi children.
India
Guatam Budh Nagar
6% Mittal & Sharma 2015 Hypomineralised second primary molars: prevalence, defect characteristics and possible association with molar incisor hypomineralisation in Indian children.
Nagpur 5% Mittal et al, 2016 Assessment of association between molar incisor hypomineralization and hypomineralized second primary molar.
Chandigarh 8% Goyal et al, 2019 Prevalence, defect characteristics and distribution of other phenotypes in 3- to 6-year-old children affected with Hypomineralised Second Primary Molars.
Singapore
All 4 quarters
3% Ng et al, 2015 Prevalence of molar incisor hypomineralization (MIH) in Singaporean children.
Africa    
Nigeria
Ile-Ife
5% Temilola et al, 2015 The prevalence and pattern of deciduous molar hypomineralization and molar-incisor hypomineralization in children from a suburban population in Nigeria.
Ile-Ife 6% Oyedele et al, 2016 Hypomineralised second primary molars: prevalence, pattern and associated co-morbidities in 8- to 10-year-old children in Ile-Ife, Nigeria.
Americas    
Brazil
Botelhos
20% Costa-Silva et al, 2013 Influence of deciduous molar hypomineralization on the development of molar-incisor hypomineralization.
Paranoa 7% Se et al, 2017 Are hypomineralized primary molars and canines associated with molar-incisor hypomineralization?
Curitaba 9% Lopes-Fatturi et al, 2019 Systemic Exposures Associated with Hypomineralized Primary Second Molars.
Teresina 15% Lima et al, 2019 Pre-term birth and asthma is associated with hypomineralized second primary molars in pre-schoolers: A population-based study.
Chile
Talca
5% Gambetta-Tessini et al, 2019 The impact of MIH/HSPM on the carious lesion severity of schoolchildren from Talca, Chile. 
Canada
Toronto
4% Sidhu et al, 2019 Prevalence and presentation patterns of enamel hypomineralisation (MIH and HSPM) among paediatric hospital dental patients in Toronto, Canada: a cross-sectional study.
Average prevalence 9% (for 20 studies from 11 countries)

PREVALENCE STUDIES FOR CHALKY 6-YEAR MOLARS

Region/Location Prevalence Report
Oceania    
Australia
Perth
22% Arrow, 2008 Prevalence of developmental enamel defects of the first permanent molars among school children in Western Australia.
Sydney 44% Balmer et al, 2005 Prevalence of enamel defects and MIH in non-fluoridated and fluoridated communities.
Melbourne 15% Gambetta-Tessini et al, 2018 Carious lesion severity and demarcated hypomineralized lesions of tooth enamel in schoolchildren from Melbourne, Australia.
New Zealand
Wellington
15% Mahoney & Morrison, 2009 The prevalence of Molar-Incisor Hypomineralisation (MIH) in Wainuiomata children.
Wellington 19% Mahoney & Morrison, 2011 Further examination of the prevalence of MIH in the Wellington region.
Europe    
Sweden
Jönköping
10% Koch et al, 1987 Epidemiologic study of idiopathic enamel hypomineralization in permanent teeth of Swedish children.
Kållered & Mölndal 18% Jalevik et al 2001 The prevalence of demarcated opacities in permanent first molars in a group of Swedish children.
Malmo 16% Brogardh-Roth et al, 2011 Molar-incisor hypomineralization and oral hygiene in 10- to-12-yr-old Swedish children born preterm.
Vastra Gotaland 12% Jälevik et al, 2018 The prevalence of developmental defects of enamel, a prospective cohort study of adolescents in Western Sweden: a Barn I TAnadvarden (BITA, children in dental care) study.
Finland
Helsinki & Kuopio
17% Alaluusua et al, 1996 Polychlorinated dibenzo-p-dioxins and dibenzofurans via mother’s milk may cause developmental defects in the child’s teeth.
Vantaa 25% Alaluusua et al, 1996 Developmental dental defects associated with long breast feeding.
Helsinki 19% Leppaniemi et al, 2001 Nonfluoride hypomineralizations in the permanent first molars and their impact on the treatment need.
Lammi, Jalasjarvi, Helsinki, Oulu, Lappeenranta 17% Wuollet et al, 2014 Background factors of molar-incisor hypomineralization in a group of Finnish children.
Lammi, Jalasjarvi 12% Wuollet et al, 2016 Molar-incisor hypomineralization and the association with childhood illnesses and antibiotics in a group of Finnish children.
Lammi, Jalasjärvi, Lappeenranta 18% Wuollet et al, 2018 The Association between Molar-Incisor Hypomineralization and Dental Caries with Socioeconomic Status as an Explanatory Variable in a Group of Finnish Children.
Netherlands
Alphen aan de Rijnland, Gouda, Breda and Den Bosch
10% Weerheijm et al, 2001 Prevalence of cheese molars in eleven-year-old Dutch children.
Alphen aan de Rijnland, Gouda, Breda, Den Bosch 14% Jasulaityte et al, 2008 Prevalence of molar-incisor-hypomineralisation among children participating in the Dutch National Epidemiological Survey (2003).
Rotterdam 9% Elfrink et al, 2012 Deciduous Molar Hypomineralization and Molar Incisor Hypomineralization.
United Kingdom
Leeds
15% Zagdwon et al, 2002 The prevalence of developmental enamel defects in permanent molars in a group of English school children.
Leeds 40% Balmer et al, 2005 Prevalence of enamel defects and MIH in non-fluoridated and fluoridated communities.
Northern England 16% Balmer et al 2012 The prevalence of molar incisor hypomineralisation in Northern England and its relationship to socioeconomic status and water fluoridation.
Germany
Dresden
6% Dietrich et al, 2003 Molar incisor hypomineralisation in a group of children and adolescents living in Dresden (Germany).
Giessen 6% Preusser et al, 2007 Prevalence and severity of molar incisor hypomineralization in a region of Germany – a brief communication.
Munich 14% Kohlboeck et al, 2013 Is there a relationship between hyperactivity/inattention symptoms and poor oral health? Results from the GINIplus and LISAplus study. 
Greifswald, Heidelberg, Dusseldorf, Hamburg 10% Petrou et al, 2014 Prevalence of Molar-Incisor-Hypomineralisation among school children in four German cities. 
Munich 17% Kunisch et al, 2018 Relationship between caries experience and demarcated hypomineralised lesions (including MIH) in the permanent dentition of 15-year-olds.
Italy
Lissone
14% Calderara et al, 2005 The prevalence of Molar Incisor Hypomineralisation (MIH) in a group of Italian school children.
Rome 7% Condo R et al, 2012  MIH: epidemiologic clinic study in paediatric patient.
Spain
Catalonia
18% Gomez et al, 2011 Prevalence of molar-incisor hypomineralisation observed using transillumination in a group of children from Barcelona (Spain).
Barcelona  18% Martinez Gomez et al, 2012 Prevalence of molar-incisor hypomineralisation observed using transillumination in a group of children from Barcelona (Spain). 
Valencia 22% Garcia-Margarit et al, 2013  Epidemiologic study of molar-incisor hypomineralization in 8-year-old Spanish children.
Valencia 24% Negre-Barber et al, 2016  Hypomineralized second primary molars as predictor of Molar Incisor Hypomineralization.
Barcelona province 8% Hernández M et al, 2018 First Permanent Molars and Permanent Incisors Teeth by Tooth Prevalence of Molar-Incisor-Hypomineralisation in a Group of Spanish Schoolchildren.
Lithuania
Kaunas
10% Jasulaityte et al 2007 Molar incisor hypomineralization: review and prevalence data from the study of primary school children in Kaunas/Lithuania.
Bosnia & Herzegovina
9 communities
12% Muratbegovitz et al, 2007 Molar-incisor-hypomineralisation impact on developmental defects of enamel prevalence in a low fluoridated area.
Foca 13% Jankovic et al, 2014 Distribution and characteristics of molar-incisor hypomineralization.
Kljuc 12% Mulic et al, 2017 How serious is molar incisor hypomineralisation (MIH) among 8- and 9-year-old children in Bosnia-Herzegovina? A clinical study.
Bulgaria
Plovdiv
5% Kukleva et al, 2008 Molar incisor hypomineralisation in 7-to-14-year old children in Plovdiv, Bulgaria—an epidemiologic study.
Greece
Athens
10% Lygidakis et al, 2008 Molar-incisor-hypomineralisatoin (MIH). Retrospective clinical study in Greek children. I. Prevalence and defect characteristics.
Thessaloniki, Ptolemaida, Ioannina 21% Kevrekidou et al, 2015 Molar incisor hypomineralization of eight- and 14-year-old children: prevalence, severity, and defect characteristics.
Denmark
North Jutland County
38% Wogelius et al, 2008 Prevalence and distribution of demarcated opacities in permanent 1st molars and incisors in 6 to 8-year-old Danish children.
Turkey
Istanbul
15% Kusku et al, 2008 The prevalence and aetiology of molar-incisor hypomineralisation in a group of children in Istanbul.
Kocaeli & Canakkale 9% Kusku et al, 2009 The prevalence of molar incisor hypomineralization (MIH) in a group of children in a highly polluted urban region and a windfarm-green energy island.
Ankara 8% Sonmez et al, 2013 Putative factors associated with molar incisor hypomineralisation: an epidemiological study.
Istanbul 14% Koruyucu et al, 2018 Prevalence and etiology of molar-incisor hypomineralization (MIH) in the city of Istanbul.
Izmir 12% Kılınc et al, 2019 Prevalence, aetiology, and treatment of molar incisor hypomineralization in children living in Izmir City (Turkey).
3 regions 21% Groselj & Jan, 2013 Molar incisor hypomineralisation and dental caries among children in Slovenia.
Wielkopolska 8% * Opydo-Szymaczek & Gerreth, 2015 Developmental Enamel Defects of the Permanent First Molars and Incisors and Their Association with Dental Caries in the Region of Wielkopolska, Western Poland.
Pomerania
6% Glodkowska N, Emerich K, 2019 Molar Incisor Hypomineralization: prevalence and severity among children from Nothern Poland.
Tromso, Balsfjord 14% Schmalfuss et al, 2016 Canines are affected in 16-year-olds with molar-incisor-hypomineralisation (MIH): an epidemiological study based on the Tromso study "Fit Futures".
Tirana 14% Hysi et al 2016 Prevalence and aetiology of Molar-Incisor Hypomineralisation among children aged 8-10 years in Tirana, Albania.
Graz 7% Buchgraber et al, 2017 Molar incisor hypomineralization: proportion and severity in primary public school children in Graz, Austria.
Asia    
Hong Kong 3% Cho et al, 2008 Molar incisor hypomineralization in Hong Kong Chinese children.
Iraq
Mosul City
19% Ghanim et al, 2011 Molar-incisor hypomineralisation: prevalence and defect characteristics in Iraqi children.
Jordan
Amman, Irbid, Al-Karak
18% Zawaideh et al, 2011 Molar incisor hypomineralisation: prevalence in Jordanian children and clinical characteristics.
India
Gandhinagar
9% Parikh et al, 2012 Prevalence and characteristics of Molar Incisor Hypomineralisation (MIH) in the child population residing in Gandhinagar, Gujarat, India.
Chandigarh 6% Mittal et al, 2014 Molar incisor hypomineralisation: prevalence and clinical presentation in school children of the northern region of India.
Udaipur 10% Bhaskar et al, 2014 Molar-incisor hypomineralization: prevalence, severity and clinical characteristics in 8- to 13-year-old children of Udaipur, India.
Guatam Budh Nagar 7% Mittal & Sharma 2015 Hypomineralised second primary molars: prevalence, defect characteristics and possible association with molar incisor hypomineralisation in Indian children.
Salem 8% Krishnan et al, 2015 Prevalence and characteristics of MIH in school children residing in an endemic fluorosis area of India: an epidemiological study.
Davangere, Karnataka 9% Kirthiga et al 2015 Prevalence and severity of molar incisor hypomineralization in children aged 11-16 years of a city in Karnataka, Davangere.
Udupi, Karnataka 27% Tadikonda et al 2015 Prevalence of Molar Incisor Hypomineralization and its relation with dental caries in school children of Udupi district, South India.
Bengaluru 2% Subramaniam et al, 2016 Prevalence of molar incisor hypomineralization in 7–9-year-old children of Bengaluru city, India.
Uttar Pradesh 14% Mishra & Pandey 2016 Molar incisor hypomineralization: an epidemiological study with prevalence and etiological factors in Indian paediatric population.
Nagpur 7% Mittal et al, 2016 Assessment of association between molar incisor hypomineralization and hypomineralized second primary molar.
Chennai 10% Yannam et al, 2016 Prevalence of molar incisor hypomineralization in school children aged 8-12 years in Chennai.
Tiruchengode, Tamil Nadu 5% Samuel et al, 2017 Caries status and salivary characteristics of south indian school children with Molar Incisor Hypomineralization: a cross-sectional study.
Muradnagar, Ghaziabad 21% Rai et al, 2018 Molar Incisor Hypomineralization: Prevalence and Risk Factors Among 7-9 Years Old School Children in Muradnagar, Ghaziabad.
Chennai 13% Padavala & Sukumaran, 2018 Molar Incisor Hypomineralization and Its Prevalence.
Virajpet, Karnataka 13% Rai et al 2019 Prevalence of Molar Incisor Hypomineralization among school children aged 9 to 12 years in Virajpet, Karnataka, India.
Malabar, Kerala 13% Peedikayil et al 2019 Molar incisor hypomineralization in North Malabar: An epidemiological study.
Muvattupuzha, Kerala 4% Emmatty et al 2020 The prevalence of molar incisor hypomineralization of school children in and around Muvattupuzha, Kerala.
Iran
Zahedan
13% Ahmadi et al, 2012 Molar incisor hypomineralization: a study of prevalence and etiology in a group of Iranian children. 
Shiraz 20% Ghanim et al, 2014 Molar-incisor hypomineralisation: a prevalence study amongst primary schoolchildren of Shiraz, Iran.
Guilan 18% Salem et al, 2016 Prevalence and predictors of molar incisor hypomineralization (MIH) among rural children in northern Iran.
China
Wenzhou
 26% Li & Li 2012  Investigation of molar-incisor hypomineralization among children from 6 to 11 years in Lucheng District, Wenzhou City. 
Suzhou  4% Hong et al, 2017 Prevalence study of Molar-Incisor Hypo Mineralisation in primary school children in South China.
Foshan  8% Pang et al, 2019 Interactions with the aquaporin 5 gene increase the susceptibility to molar-incisor hypomineralization.
Saudi Arabia
Jeddah
9% Allazzam et al, 2014 Molar incisor hypomineralization, prevalence, and etiology.
Riyadh 41% Al-Hammad et al, 2018 Prevalence and Clinical Characteristics of Molar-Incisor-Hypomineralization in School Children in Riyadh, Saudi Arabia.
All 4 quarters 10% Ng et al, 2015 Prevalence of molar incisor hypomineralization (MIH) in Singaporean children.
Thailand
Muang district
28% Pitiphat et al, 2014 Factors associated with molar incisor hypomineralization in Thai children.
Kranuan district 21% Pitiphat et al, 2014 Molar incisor hypomineralization and dental caries in six- to seven-year-old Thai children.
Kavre 14% Shresthra et al, 2014 Prevalence of molar incisor hypomineralisation among school children in Kavre.
Shah Alam 17% Hussain et al, 2015 Distribution of molar incisor hypomineralization in Malaysian children attending university dental clinic.
Dubai 27% Hussain et al 2018 The Prevalence and Severity of Molar Incisor Hypomineralization and Molar Hypomineralization in Dubai, UAE.
Dubai
8% Ahmad et al 2019 Prevalence of Molar-Incisor Hypomineralisation in an Emerging Community, and a Possible Correlation with Caries, Fluorosis and Socioeconomic Status.
8 regions 20% Saitoh et al, 2018 Prevalence of molar incisor hypomineralization and regional differences throughout Japan.
5 regions 27% Elzein et al, 2020 Molar incisor hypomineralisation in Lebanon: prevalence and clinical characteristics.
Africa    
Libya
Benghazi
3% Fteita et al, 2006 Molar-incisor hypomineralization (MIH) in a group of school-aged children in Benghazi, Libya.
Kenya
Matungulu & Kangundo
14% Kemoli, 2008 Prevalence of molar incisor hypomineralisation in six to eight year-olds in two rural divisions in Kenya.
Nigeria
Ile-Ife
 18% Oyedele et al, 2015 Prevalence, pattern and severity of molar incisor hypomineralisation in 8- to 10-year-old school children in Ile-Ife, Nigeria.
Ile-Ife  10% Temilola et al, 2015 The prevalence and pattern of deciduous molar hypomineralization and molar-incisor hypomineralization in children from a suburban population in Nigeria.
Ile-Ife  13% Oyedele et al, 2015 Co-morbidities associated with molar-incisor hypomineralisation in 8 to 16 year old pupils in Ile-Ife, Nigeria.
Ile-Ife & Ibadan  3% Folayan et al, 2018 Developmental defects of the enamel and its impact on the oral health quality of life of children resident in Southwest Nigeria.
Cairo 2% Saber et al, 2018 Prevalence of molar incisor hypomineralisation in a group of Egyptian children using the short form: a cross-sectional study.
Americas    
Brazil
Rio de Janeiro
40% Soviero et al, 2009 Prevalence and distribution of demarcated opacities and their sequelae in permanent 1st molars and incisors in 7 to 13-year-old Brazilian children.
Botelhos 20% Da Costa-Silva et al, 2010 Molar incisor hypomineralization: prevalence, severity and clinical consequences in Brazilian children. 
Araraquara 12% Jeremias et al, 2013 Dental caries experience and Molar-Incisor Hypomineralization
Botelhos 17% Costa-Silva et al, 2013 Influence of deciduous molar hypomineralization on the development of molar-incisor hypomineralization.
Teresina 18% de Lima et al, 2015 Epidemiologic study of molar-incisor hypomineralization in schoolchildren in north-eastern Brazil.
Lavras 20% Tourino et al, 2016 Association between molar incisor hypomineralization in schoolchildren and both prenatal and postnatal factors: a population-based study.
Paranoa 15% Se et al, 2017 Are hypomineralized primary molars and canines associated with molar-incisor hypomineralization?
Botelhos 16% da Costa Silva et al, 2017 The Impact of Molar-Incisor Hypomineralisation on Dental Caries in Permanent First Molars: A Prospective Cohort Study.
Teresina 29% Teixeira et al, 2018 Exploring the association between genetic and environmental factors and molar incisor hypomineralization: evidence from a twin study.
Paranoa 16% Raposo et al, 2019 Prevalence of hypersensitivity in teeth affected by Molar-Incisor Hypomineralization (MIH).
Curitiba 12% Portella et al, 2019 Impact of molar incisor hypomineralization on quality of life in children with early mixed dentition: A hierarchical approach.
Florianopolis 10% * Santos et al, 2019 Prevalence of self-reported dental pain and associated factors among eight- to ten-year-old Brazilian schoolchildren.
Argentina
Buenos Aires
16% Biondi et al, 2011 Prevalence of molar incisor hypomineralization in the city of Buenos Aires
Buenos Aires 6% Biondi et al, 2012 Prevalence of molar-incisor hypomineralization (MIH) in children seeking dental care at the Schools of Dentistry of the University of Buenos Aires (Argentina) and University of la Republica (Uruguay).
Montevideo 7% Biondi et al, 2012 Prevalence of molar-incisor hypomineralization (MIH) in children seeking dental care at the Schools of Dentistry of the University of Buenos Aires (Argentina) and University of la Republica (Uruguay).
Mexico City 16% Gurrusquieta et al, 2017 Prevalence of molar incisor hypomineralization in Mexican children.
Mexico City
35% Villanueva-Gutiérrez et al, 2019 Prevalence and Severity of Molar-Incisor Hypomineralization, Maternal Education, and Dental Caries: A Cross-Sectional Study of Mexican Schoolchildren with Low Socioeconomic Status.
Mexico City
20%, 32% Irigoyen-Camacho ME et al, 2019 Evaluating the changes in molar incisor hypomineralization prevalence: A comparison of two cross-sectional studies in two elementary schools in Mexico City between 2008 and 2017.
Talca 16% Gambetta-Tessini et al, 2019 The impact of MIH/HSPM on the carious lesion severity of schoolchildren from Talca, Chile.
Medellin 11% Mejía et al, 2019 Molar Incisor Hypomineralization in Colombia: Prevalence, Severity And Associated Risk Factors.
Milwaukee 10% Davenport et al, 2019 Prevalence of molar-incisor hypomineralization in Milwaukee, Wisconsin, USA: a pilot study.
Pittsburgh
8% * Hartsock et al, 2020 A Snapshot of the Prevalence of Molar Incisor Hypomineralization and Fluorosis in Pittsburgh, Pennsylvania, USA.
Toronto 17% * Sidhu et al, 2019 Prevalence and presentation patterns of enamel hypomineralisation (MIH and HSPM) among paediatric hospital dental patients in Toronto, Canada: a cross-sectional study.
Guayaquil 9% Ordonez-Romero et al, 2019 Distribution of Molar Incisor Hypomineralization in Ecuadorian children. Dent Hypoth. 2019; 10, 65-69.
Average prevalence 15% (for 121 studies from 47 countries)

* for technical reasons (e.g. to better match the widely accepted definition of MH/MIH), indicated prevalence values have been sourced from data within the article, not the abstract – validation has been achieved through personal communication with the authors in some instances (contact us for details)

NB: Authors – please advise us of new studies suitable for inclusion here.