**4.1 Diagnose of MIH**

Traditionally, a wide variety of terms and definitions have been used to describe various developmental defects of enamel (DDE). However, this original index turned out to be too complicated to use in practice and a modified DDE index (mDDE) was presented by FDI (1992). The modified development dental enamel (DDE) index was considered to be too time consuming and not adequate for MIH prevalence studies because the post-eruptive breakdown is a pathognomonic feature in MIH but the mDDE index does not clearly distingue PEB from enamel hypoplasia.

According to European Academy of Pediatric Dentistry seminar (EAPD) placed in Athens in 2003. (Weerheijmet al., 2003) The diagnose of MIH must be based on scores range from 0 to 10 (Table 2). (Ghanim et al., 2011) The screening of MIH must be done in children eight years of age; examination for MIH should be performed on wet teeth after removing debris with cotton roll; first permanent molars and incisors should be examined, each tooth as seen in Table 2.


Table 2. Criteria for scoring molar incisor hypomineralisation (MIH) according to European Academy of Paediatric Dentistry recommendations cited by GHANIM et al., 2011 (Ghanim et al., 2011).

Clinically, the enamel defects can vary from white, cream, yellow to brownish, but they always show a sharp demarcation between the affected and sound enamel. The tooth surface enamel initially develops to a normal thickness, but can chip off under masticatory forces called post eruption breakdown (PEB) (Figure 2B) PEB is characterized by poor aesthetic appearance and sensitivity to thermal and mechanical stimuli. After such PEB, the clinical pictures can resemble enamel hypoplasia. However, the margins of the disintegrated areas are irregular, whereas those in hypoplasia are smooth and rounded. The demarcated lesions in MIH should also be distinguished from the diffuse opacities typical of fluorosis. Dentitions with generalized opacities present on all teeth such as in Amelogenesis *Imperfecta*, rather than limited to the first permanent molars and incisors, are not considered to have MIH. Nowadays, to simplify the use of MIH scores, the severity of MIH can be

Traditionally, a wide variety of terms and definitions have been used to describe various developmental defects of enamel (DDE). However, this original index turned out to be too complicated to use in practice and a modified DDE index (mDDE) was presented by FDI (1992). The modified development dental enamel (DDE) index was considered to be too time consuming and not adequate for MIH prevalence studies because the post-eruptive breakdown is a pathognomonic feature in MIH but the mDDE index does not clearly

According to European Academy of Pediatric Dentistry seminar (EAPD) placed in Athens in 2003. (Weerheijmet al., 2003) The diagnose of MIH must be based on scores range from 0 to 10 (Table 2). (Ghanim et al., 2011) The screening of MIH must be done in children eight years of age; examination for MIH should be performed on wet teeth after removing debris with cotton roll; first permanent molars and incisors should be examined, each tooth as seen

5 Partially erupted (i.e., less than one-third of the crown high) with evidence of MIH

Table 2. Criteria for scoring molar incisor hypomineralisation (MIH) according to European Academy of Paediatric Dentistry recommendations cited by GHANIM et al., 2011 (Ghanim

Clinically, the enamel defects can vary from white, cream, yellow to brownish, but they always show a sharp demarcation between the affected and sound enamel. The tooth surface enamel initially develops to a normal thickness, but can chip off under masticatory forces called post eruption breakdown (PEB) (Figure 2B) PEB is characterized by poor aesthetic appearance and sensitivity to thermal and mechanical stimuli. After such PEB, the clinical pictures can resemble enamel hypoplasia. However, the margins of the disintegrated areas are irregular, whereas those in hypoplasia are smooth and rounded. The demarcated lesions in MIH should also be distinguished from the diffuse opacities typical of fluorosis. Dentitions with generalized opacities present on all teeth such as in Amelogenesis *Imperfecta*, rather than limited to the first permanent molars and incisors, are not considered to have MIH. Nowadays, to simplify the use of MIH scores, the severity of MIH can be

**4. Epidemiological considerations about MIH** 

1 White creamy demarcated opacities, no PEB 1a White creamy demarcated opacities, with PEB 2 Yellow brown demarcated opacities, no PEB 2a Yellow brown demarcated opacities, with PEB

6 Unerupted partially erupted with no evidence of MIH

9 Combined lesion (diffuse opacities hypoplasia with MIH)

distingue PEB from enamel hypoplasia.

**4.1 Diagnose of MIH** 

in Table 2.

et al., 2011).

Code Criteria

0 Enamel defect free

3 Atypical restoration 4 Missing because of MIH

7 Diffuse opacities (not MIH) 8 Hypoplasia (not MIH)

10 Demarcated opacities in incisors only

determined by dividing the affected teeth in only two groups: mild defect (demarcated opacities) (Figures 4A, B) and moderate/severe defect (enamel breakdown and atypical restorations) (Lygidakis et al., 2008) (Figures 4B, C ).

Molar Incisor Hypomineralization:

recording and different age groups. (Jalevik, 2010)

China and Bulgaria epidemiological surveys.

Boznia and

**Country Prevalence Subjects**

Morphological, Aetiological, Epidemiological and Clinical Considerations 435

After that, epidemiological data comes from studies conducted in European countries and reported the prevalence of MIH had varied from 3.6 to 25%.(Weerheijm & Mejare, 2003) Lately, a systematic review showed a wide variation in the prevalence of MIH (2.4 - 40.2 %) and stated that the cross comparison of the results of the various studies were difficult because of use of different indices and criteria, examination variability, methods of

Based on this, we performed a nonsystematic hand-searching screening in the PUBMED data base using the terms: EAPD; MIH; limited to: at least 100 subjects and the data of study - after 2003 and the results could be found (Table 3). According to results, it was possible observed that at least one country in each continent already demonstrates concern for the impact of MIH regarding the condition of oral health of the population, which makes it a public health problem. Taking searching results of the more recent studies into account, the prevalence of MIH varies from 3.5% to 40.2%. This could be explained by methodological variability, by different socio-demographic-ethnical characteristics of samples and by the access to health services (favorable x unfavorable). It worthwhile mentions that only one population-based well designed study could be found and it highlights the prevalence of 3.5% for MIH in Southeast Sweden. (Fagrell et al., 2011) These results are also found in

**(n)** 

Argentina 15.9% 1,098 11.3 years

China 2.8% 2,635 11.0–14.0 years

Greece 10.2% 3,518 5.5-12 years

**Years age (mean + SD)** 

(11.08-11.39)

(12 years +0.6)

(8.17+1.38)

Herzegovina 12.3% 560 12 years Muratbegovic et al., 2008

Brazil 19.8% 918 6-12 years da Costa-Silva et al., 2010 (da

Brazil 40.2% 249 7-13 years Soviero et al., 2009 (Soviero et

Bulgaria 3.58% 2,960 7-14 years Kukleva et al., 2008 (Kukleva

Germany 14.3% 442 9 years Jasulaityte et al., 2008

Instanbul 14.9% 147 7-9 years Kusku et al., 2008

Iraq 21.5% 823 7-9 years Ghanim et al., 2011 (Ghanim

Jordan 17.6% 3,666 7-9 years Zawaideh et al., 2011

**Authors** 

Biondi et al, 2011 (Biondi et al., 2011)

(Muratbegovic et al., 2008)

Costa-Silva et al., 2010)

al., 2009)

et al., 2008)

Cho et al., 2008 (Cho et al., 2008)

(Jasulaityte et al., 2008)

Lygidakis et al., 2008 (Lygidakis et al., 2008)

(Kusku et al., 2008)

et al., 2011)

(Zawaideh et al., 2011)

Fig. 4. A to C – Mild defect opacities in right FPM (A). Atypical restorations in upper incisors (B) and in left lower FPM (C). Note the opacities in the vestibular surface of the right lower incisor (B), left upper FPM (B). Post restoration enamel fracture in lower right FPM (C).

Dental diseases have a detrimental effect on quality of life both in childhood and older age. (Moynihan & Petersen, 2004) Several authors have discussed whether developmental defects of enamel (DDE) are a public health problem. (Mathu-Muju & Wright, 2006) For a condition to be considered of public health significance, several criteria need to be reviewed, particularly the prevalence its impact on an individual in terms of symptoms, functioning, psychological and social should be considerate. (Marshman et al., 2009) Besides its clinical implications in the field of public health, MIH have taken on importance as strong predictors of dental caries. This result highlights the importance of establishing priority programs of prevention and early treatment for these groups of children both for aesthetic and functional reasons, as well as to minimize the increased risk of dental caries.

In view of MIH having a potentially large impact on treatment needs in child populations and a cost-effectiveness treatment from public or private health insurance, it is relevant to identify the prevalence of MIH in epidemiological studies, with the concern only studies using the MIH index as epidemiological criteria. (Weerheijm et al., 2003, Weerheijm et al., 2001, Weerheijm, 2003)

#### **4.2 Prevalence of MIH**

A first epidemiological study was carried out in Swedish children in the late 1970s, whose first permanent molars (FPM) called "cheese" molars, were described as creamy-white to yellow-brown enamel opacities; or with disintegration in severe cases (Koch et al., 1987)

Fig. 4. A to C – Mild defect opacities in right FPM (A). Atypical restorations in upper incisors (B) and in left lower FPM (C). Note the opacities in the vestibular surface of the right lower incisor (B), left upper FPM (B). Post restoration enamel fracture in lower right FPM (C).

Dental diseases have a detrimental effect on quality of life both in childhood and older age. (Moynihan & Petersen, 2004) Several authors have discussed whether developmental defects of enamel (DDE) are a public health problem. (Mathu-Muju & Wright, 2006) For a condition to be considered of public health significance, several criteria need to be reviewed, particularly the prevalence its impact on an individual in terms of symptoms, functioning, psychological and social should be considerate. (Marshman et al., 2009) Besides its clinical implications in the field of public health, MIH have taken on importance as strong predictors of dental caries. This result highlights the importance of establishing priority programs of prevention and early treatment for these groups of children both for aesthetic

In view of MIH having a potentially large impact on treatment needs in child populations and a cost-effectiveness treatment from public or private health insurance, it is relevant to identify the prevalence of MIH in epidemiological studies, with the concern only studies using the MIH index as epidemiological criteria. (Weerheijm et al., 2003, Weerheijm et al.,

A first epidemiological study was carried out in Swedish children in the late 1970s, whose first permanent molars (FPM) called "cheese" molars, were described as creamy-white to yellow-brown enamel opacities; or with disintegration in severe cases (Koch et al., 1987)

and functional reasons, as well as to minimize the increased risk of dental caries.

2001, Weerheijm, 2003)

C

**4.2 Prevalence of MIH** 

After that, epidemiological data comes from studies conducted in European countries and reported the prevalence of MIH had varied from 3.6 to 25%.(Weerheijm & Mejare, 2003) Lately, a systematic review showed a wide variation in the prevalence of MIH (2.4 - 40.2 %) and stated that the cross comparison of the results of the various studies were difficult because of use of different indices and criteria, examination variability, methods of recording and different age groups. (Jalevik, 2010)

Based on this, we performed a nonsystematic hand-searching screening in the PUBMED data base using the terms: EAPD; MIH; limited to: at least 100 subjects and the data of study - after 2003 and the results could be found (Table 3). According to results, it was possible observed that at least one country in each continent already demonstrates concern for the impact of MIH regarding the condition of oral health of the population, which makes it a public health problem. Taking searching results of the more recent studies into account, the prevalence of MIH varies from 3.5% to 40.2%. This could be explained by methodological variability, by different socio-demographic-ethnical characteristics of samples and by the access to health services (favorable x unfavorable). It worthwhile mentions that only one population-based well designed study could be found and it highlights the prevalence of 3.5% for MIH in Southeast Sweden. (Fagrell et al., 2011) These results are also found in China and Bulgaria epidemiological surveys.


Molar Incisor Hypomineralization:

teeth replacement with a bridge or implant.

**5.2 Clinical management of MIH** 

condition.

(Baroni & Marchionni, 2011)

Morphological, Aetiological, Epidemiological and Clinical Considerations 437

Phosphopeptide-Amorphous Calcium Phosphate (CCP-ACP) (Baroni & Marchionni, 2011) or the application of desensitizers (2 % potassium nitrate plus 2% sodium fluoride) or

Dental pain and the severity of hypomineralisation or enamel loss in molar-incisor hypomineralisation are major determinants for the choice of treatment. (William et al., 2006a) The most conservative interventional treatment consists of bonding a tooth colored material to the tooth to protect it from further wear or sensitivity although the nature of the enamel prevents formation of an acceptable bond. (William et al., 2006b) Less conservative treatment options, but frequently necessary include use of stainless steel crowns, permanent cast crowns or extraction of affected teeth in association with the orthodontic appliance or

In accordance with the European Academy of Pediatric Dentistry until now there are only a limited number of evidence based research papers on MIH affected teeth. (Lygidakis et al., 2010) Because of this, the guidelines diagram according to Scottish Intercollegiate Guidelines Network (SIGN) methodology (SIGN, 1999) is impossible to be made. However, treatment modalities in children with teeth affected by MIH were systematically reviewed by LYGIDAKIS, 2010. (Lygidakis, 2010) Thus, the clinical management of MIH was resumed by the present authors as seen in Figure 5. These clinical guidelines approach were organized considering the type of MIH affected teeth (permanent first molars or incisors) and the severity of defects. Then, it was also considered, the treatment management of the first permanent molars (FPM) without post eruptive breakdown (PEB) or with post-eruptive breakdown; as well as to the incisors with different levels of opacities (Figure 3). It worthwhile be emphasized the necessity of not only randomized controlled clinical trials but also the laboratory studies to support and better understand the specificities of MIH

Therefore, a detailed study under magnification of the unerupted molar and incisor crowns on any available radiographs should be done. (William et al., 2006a) During teeth eruption, when MIH is confirmed, it should be made a diet counseling for dietary modifications to avoid dental caries, dental erosion and dental sensitivity; It should be recommended a toothpaste with a fluoride or, in cases of dental sensitivity, aiming to produce a nonsensitivity and hypermineralized surface layer which provides a super saturated environment of calcium and phosphate on enamel surface, a desensitizing toothpaste with casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) should be indicated.

Fissure sealants should be applied early after molars eruption and before enamel breakdown. (Kilpatrick, 2009, Lygidakis et al., 2010, Lygidakis, 2010, William et al., 2006a, Crombie et al., 2008) Taking the morphological aspects of MIH affected teeth into account, for first permanent molars, highly viscosity glass ionomer cements can be considered as an alternative material of choice for fissure sealing due to its stable chemical adhesion on the substrate (Welbury et al., 2004) which ensures its clinical longevity even if disappeared

macroscopically in the follow-ups. (Frencken &Wolke, 2010)

sealers have been indicated. (Lygidakis et al., 2010, Lygidakis, 2010)


Table 3. Distribution of MIH in some countries in the world. Selected studies were conducted using only MIH index criteria as suggested by EAPD.

In spite of having still need of further investigation considering population-based samples, with standardization of methodology, it is clearly seen that different countries from different regions of the world are performing epidemiological surveys using MIH index. This is essential to ascertain the occurrence of the MIH and may otherwise be systematized not only strategies to MIH diagnosis, but also treatments and monitoring as well as outlining scientific researches considering this topic. Thus, it is essential to do well design clinical studies considering MIH pathology.
