Molar incisor hypomineralization: prevalence,severity and clinical consequences in Brazilian children

International Journal of Paediatric Dentistry 2010; 20: 426–434 Background. The prevalence of molar incisor hypomineralization (MIH) varies considerably around the world; however, few studies have examined MIH in South American countries. Objective. To evaluate the prevalence, severity, and clinical consequences of MIH in Brazilian children residing in rural and urban areas of the municipality of Botelhos, Minas Gerais, Brazil. Methods. Children aged 6 to 12 years (n = 918) with all four‐first permanent molars erupted had these teeth evaluated according to the European Academy of Paediatric Dentistry (EAPD) criteria. The examinations were conducted by two previously trained examiners, and the dental impact caused by MIH was evaluated with the Decayed, Missing and Filled Teeth (DMFT) index (WHO). Results. Molar incisor hypomineralization was present in 19.8% of the 918 children, with a higher prevalence in rural areas. The majority of the defects presented were demarcated opacities without post‐eruptive structural loss, which has been considered as mild defects. Children with MIH had higher DMFT values. Conclusion. Despite the high prevalence of MIH, the severity of the defects was mild. The results indicate a positive association between MIH and the presence of dental caries.     

Factors increasing the caries risk of second primary molars in 5‐year‐old Dutch children

International Journal of Paediatric Dentistry 2010; 20: 151–157 Background. Caries is still a prevalent condition in 5‐year‐old children. At present, knowledge regarding some aetiological factors, like deciduous molar hypomineralization (DMH), is limited. Aim. To investigate aetiological factors both directly and indirectly associated with caries in second primary molars. Design. Of 974 children invited to participate in the study, 386 children were examined clinically with visual detection of caries. Only carious lesions determined to have reached the dentine were recorded. Information about tooth brushing frequency, education level of the mother, and country of birth of mother and child, was collected by means of a multiple‐choice questionnaire. Parents of 452 children filled in the questionnaire. Complete clinical and questionnaire data were available for 242 children. Statistical analysis of the effect of the independent variables was undertaken using the Pearson’s chi‐squared test. Results. Deciduous molar hypomineralization (P = 0.02) and the country of birth of the mother (P < 0.001) were positively associated with caries prevalence. Conclusions. Deciduous molar hypomineralization and the country of birth of the mother play a role in the prevalence of dental caries. These aetiological factors associated with childhood dental caries need to be investigated further in longitudinal clinical trials.     

Hypomineralized second primary molars: prevalence data in Dutch 5-year-olds

The aim of this cross-sectional observational study was to report on the prevalence of hypomineralizations in second primary molars in 5-year-old Dutch children. In the study 386 (45% girls) 5-year-old Dutch children, all insured by a Health Insurance Fund, participated. Scoring criteria for molar incisor hypomineralization molars were adapted to score second primary molars. The prevalence of hypomineralized second primary molars (HSPM) was 4.9% at child level and 3.6% at tooth level. Most HSPMs (87%) showed demarcated opacities, followed by posteruptive enamel loss (40%).     

An in vivo investigation of salivary properties,enamel hypomineralisation,and carious lesion severity in a group of Iraqi schoolchildren

International Journal of Paediatric Dentistry 2013; 23: 2–12 Background. Hypomineralised enamel is a prevalent, congenital defect vulnerable to deteriorate post‐eruptively particularly in the presence of an unfavourable oral environment. Aims. To assess the influence of salivary characteristics on the clinical presentation of hypomineralisation lesions diagnosed in first permanent and second primary molars and to evaluate caries severity in relation to the defect’s clinical presentation. Design. Recruitment consisted of 445 seven‐ to nine‐year‐old participants, of whom 152 were diagnosed as having molar hypomineralisation (MH); the remaining unaffected subjects (N = 293) were considered their controls for saliva analysis. Dental caries status was assessed in 300 subjects of saliva sub‐sample, equally divided as MH‐affected and non‐affected children. The International Caries Detection and Assessment System was used for caries detection. Salivary flow rates, viscosity, pH, and buffering capacity were determined. Results. Molar hypomineralisation‐affected children have significantly higher mean caries scores compared to the non‐affected group. Dentinal carious lesions were ten times more frequent in teeth with post‐eruptive breakdown (PEB) than with teeth with opacities only. Low salivary flow rates (LSFR), moderately viscous saliva, and low pH were significantly more common in the affected group. LSFR and moderate and highly acidic saliva were more likely associated with PEB. Conclusion. Demarcated hypomineralised enamel is a dynamic defect highly influenced by individual characteristics of the oral environment.     

浙江省温州市鹿城区6～11岁儿童磨牙-切牙釉质矿化不全调查

目的:了解浙江省温州市鹿城区6～11岁儿童磨牙-切牙釉质矿化不全(molar-incisor hypomineralization,MIH)的患病情况 方法:选取4个第一恒磨牙都已完全萌出的6～1 1岁儿童988名,按年龄分为6组,依据欧洲儿童牙科协会制定的标准对其进行诊断,详细记录MIH患牙的牙位及严重程度.采用SPSS13.0软件包对数据进行统计学分析,各年龄组间MIH严重程度比较及上、下颌第一恒磨牙及恒切牙MIH患病率的比较均采用Kruskal-Wallis检验,MIH严重程度与年龄的相关关系采用Spearman相关分析结果:MIH患病率为25.5％,轻症MIH为最主要病损各年龄组间MIH严重程度有显著差异(P＜0.05),MIH严重程度与年龄之间呈正相关关系,相关关系密切(rp=0.534)各MIH患牙在上、下颌的分布无显著差异(P＞0.05).结论:浙江省温州市鹿城区6～11岁儿童具有较高的MIH患病率,但以轻症病损为主.MIH的严重程度有随着年龄增加而加重的趋势.     

Nonfluoride hypomineralizations in the permanent first molars and their impact on the treatment need

To determine the prevalence of nonfluoride enamel hypomineralization in the permanent first molars, we examined 488 7- to 13-year-old children. We further examined the impact of such defects on the treatment need by evaluating the number of caries lesions, restorations and extractions of the target teeth. Nonfluoride hypomineralization(s) were seen in 94 children (19.3%). The severity of defects varied from mild lesions with local color change to more severe ones where the hypomineralized tissue had been replaced by a restoration or the tooth had been extracted. Further examination of 65 children with nonfluoride hypomineralization showed that the defects had significantly increased the treatment need of the target teeth compared with the age- and sex-matched controls (p<0.001). Consequently, also the DMFT index of the whole dentition was higher in the children with hypomineralizations than in the controls (p<0.05). The results indicate that nonfluoride hypomineralizations have a significant impact on treatment need in the present child population with low caries activity.     

Is there a positive relationship between molar incisor hypomineralisations and the presence of dental caries?

International Journal of Paediatric Dentistry 2013; 23: 116–124 Objective This epidemiological study aimed to compare the caries experience in 10‐year‐olds with and without molar incisor hypomineralisation (MIH). Methods About 693 children from an ongoing birth cohort study (GINIplus10) were examined for caries lesions to determine the DMF index. Furthermore, enamel hypomineralisation (EH) was scored on all permanent teeth/surfaces, according to the criteria of the European Academy of Paediatric Dentistry. Children with EH were categorised into those with a minimum of one EH in the permanent dentition (MIH/1), with EH on at least one‐first permanent molar (MIH/1A), on at least one‐first permanent molar and permanent incisor (MIH/1B), and on other permanent teeth (MIH/1C). Results The mean caries experience was 0.4 (SD 0.9) DMFT. Existence of MIH/1, MIH/1A, MIH/1B, and MIH/1C was determined in 36.5%, 14.7%, 9.4%, and 21.8% of all children. The corresponding DMFT values were the following: no MIH: 0.3 (SD 0.8); MIH/1: 0.5 (SD 0.9); MIH/1A: 0.5 (SD 0.9); MIH/1B: 0.4 (SD 0.9); and MIH/1C: 0.4 (SD 0.9) DMFT. No significant differences were found between all groups. Conclusions There was no relationship between the presence of EH/MIH and caries in 10‐year‐olds. A ratio of one EH‐associated defect to two caries lesions indicates that both conditions are prevalent and influence the oral health status of 10‐year‐old children from Munich, Germany.     

Molar incisor hypomineralization and pre-eruptive intracoronal lesions in dentistry-diagnosis and treatment planning

The aim of this study is to report the diagnostic features, prevalence, mineral content, clinical significance and treatment options of molar incisor hypomineralization (MIH) and pre-eruptive intracoronal lesions (PEIR), in order to minimize miss-treatment of primary and permanent teeth in young children. MIH was defined as the occurrence of hypomineralization of one up to four permanent first molars from a systemic origin and frequently associated with affected incisors. PEIR are lesions that are located in the occlusal portion of the crown of unerupted permanent or primary teeth. The prevalence of MIH was reported between 2.5%-40% in the permanent first molars and 0%-21.8% in primary second molars. PEIR was observed in 2%-8% of children, mainly in mandibular second premolars and second and third permanent molars. A number of possible causes for MIH were mentioned, including environmental changes, diet and genetics in prenatal and postnatal periods, but all are questionable. In PEIR, the resorption of the intracoronal dentine begins only after crown development is complete and is caused by giant cells resembling osteoclast observed histologically on the dentine surface close to the pulp. The mineral content in MIH is reduced in comparison to normal enamel and dependent on the severity of the lesion. In PEIR the resorbed surface of enamel showed less mineral content. The hypomineralized enamel in MIH is not suitable for restorations with amalgam or composite materials, and the best material should be based on remineralization material like glass-ionomers. Similar, the resorbed dentin surface in PEIR should be covered by the biocompatible and re-mineralizing glass-ionomer cement.     

Impact of caries onset on number and distribution of new lesions in preschool children

International Journal of Paediatric Dentistry 2013; 23: 39–47 Background. Caries in preschool children remains an important public health issue. Aim. To determine (i) which teeth and tooth surfaces are most susceptible to dental caries by age 3, (ii) where do caries lesions develop during 2‐year follow‐up, and (iii) to evaluate the impact of caries onset on the distribution of new caries experience. Design. One thousand and fifty seven consecutively born children were recruited in Flanders (Belgium). Parents completed validated questionnaires on oral health‐related behaviour and trained dentists examined the children at ages 3 and 5. Results. Children with visible caries experience at age 3 were significantly more vulnerable in developing additional caries during follow‐up. In this group, new caries experience developed primarily in the occlusal and distal surfaces of the mandibular first molars and the occlusal surfaces of the maxillary second and first molars, whereas in the caries‐free group, the occlusal surfaces of both mandibular and maxillary second molars ranked first. Conclusions. This paper confirms the higher vulnerability for further caries development in those children with caries experience at age 3. Visible caries develops most frequently in the occlusal surfaces of the second molars: in high‐risk children already by age 3 and in children who were caries free at baseline by age 5.     

Molar-incisor hypomineralisation: prevalence and defect characteristics in Iraqi children

BACKGROUND. Little prevalence data relating to molar incisor hypomineralisation (MIH) exist for Middle East populations. AIM. To evaluate the prevalence and the clinical features of MIH in school-aged children residing in Mosul City, Iraq. DESIGN. A cluster sample of 823 7- to 9-year-old children had their first permanent molars and incisors (index teeth) evaluated using the European Academy of Paediatric Dentistry (EAPD) criteria for MIH. The examinations were conducted at schools by a calibrated examiner. RESULTS. Of the children examined, 177 (21.5%) had hypomineralisation defects in at least one index tooth, 153 (18.6%) had at least one affected first molar or first molars and incisors and were considered as having MIH. The most commonly affected teeth were maxillary molars. Demarcated creamy white opacities were the most frequent lesion type. Dental restorations and tooth extraction because of MIH were uncommon. Children with three or more affected teeth were 3.7 times more likely to have enamel breakdown when compared with those children having only one or two affected teeth. CONCLUSIONS. Molar incisor hypomineralisation was common amongst Iraqi children. Demarcated opacities were more prevalent than breakdown. The severity of the lesions increased with the number of affected teeth. The more severe the defect, the greater the involved tooth surface area.     

Risk factors in the occurrence of enamel defects of the first permanent molars among schoolchildren in Western Australia

Abstract – Background: The prevalence of enamel defects in the first permanent molars among children in Western Australia is higher than that reported for some European countries. The cause(s) of the defects, both white diffuse opacities and demarcated opacities, with or without hypoplasia, continue to be investigated. A recent review identified childhood illnesses and exposure to environmental toxins as putative causal factors for the occurrence of demarcated opacities (usually in association with hypoplasia). Diffuse opacities have been reported to be associated with exposure to the antibiotic amoxicillin, adjusted for otitis media and fluoride. The aim of this study was to examine the possible risk factors for enamel defects in the first permanent molars among children in Western Australia. Methods: Children attending pre‐primary schools (1999–2000 year of birth) in metropolitan Perth, Western Australia, were invited to participate in the study. In 2005, before the child’s first permanent molars had erupted, parents completed a questionnaire about the mother’s health during pregnancy, and their child’s health for the first 3 years. The first permanent molars were classified for type and extent of enamel defects using the modified Developmental Defects of Enamel (DDE) index. Caries experience and the presence of enamel defects on the deciduous molars and canines were also recorded using the WHO criteria. Bivariate, multinomial logistic and logistic regression analyses were used to test the factors for their influence on the occurrence of the enamel defects. Results: Five hundred and fifty children were examined for the occurrence of enamel defects on the first permanent molars. Multinomial logistic regression indicated that neonatal health conditions, prematurity (OR 2.75) and other health conditions (OR 2.40) were significant risk factors for the occurrence of diffuse enamel defects. Infection during the neonatal period was a strong risk factor for the occurrence of demarcated enamel defects (OR 6.88). Increased deciduous tooth caries experience increased the risk of demarcated enamel defects by 10% (OR 1.10) and living further from a heavy industrial area increased the risk of diffuse enamel defects nearly twofold (OR 1.93). Conclusions: Neonatal health factors were found to be important risk factors for the occurrence of enamel defects in first permanent molars. The effects of residential location and the association between deciduous tooth caries experience and enamel defects require further investigations.     

Oral features and dental health in Hurler Syndrome following hematopoietic stem cell transplantation

International Journal of Paediatric Dentistry 2010; 20: 322–329 Background. Hurler Syndrome is associated with a deficiency of a specific lysosomal enzyme involved in the degradation of glycosaminoglycans. Hematopoietic stem cell transplantation (HSCT) in early infancy is undertaken to help prevent the accumulation of glycosaminoglycans and improve organ function. Aim. To investigate the oral features and dental health of patients with Hurler Syndrome who have undergone successful HSCT. Materials and methods. Twenty‐five patients (median age 8.6 years) post‐HSCT (mean age 9.4 months) underwent oral assessment (mean of 7.5 years post‐HSCT). Results. Dental development was delayed. Numerous occlusal anomalies were noted including: open‐bite, class III skeletal base, dental spacing, primary molar infra‐occlusion and ectopic tooth eruption. Dental anomalies included hypodontia, microdontia, enamel defects, thin tapering canine crowns, pointed molar cusps, bulbous molar crowns and molar taurodontism. Tooth roots were usually short/blunted/spindle‐like in permanent molars. The prevalence of dental caries was low in the permanent dentition (mean DMFT 0.7) but high in the primary dentition (mean dmft 2.4). Oral hygiene instruction with plaque and or calculus removal was indicated in 71% of those that were dentate. Conclusion. Patients with Hurler Syndrome post‐HSCT are likely to have delayed dental development, a malocclusion, and dental anomalies, particularly hypodontia and microdontia.     

Prevalence and possible aetiological factors of molar incisor hypomineralisation in Saudi children: A cross-sectional study

BackgroundA new charting system for molar incisor hypomineralisation (MIH) was recently published and is based on the European Academy of Paediatric Dentistry (EAPD) criteria. This charting system aims to standardise MIH data collection. Therefore, there is a need for new MIH prevalence studies using the currently recommended charting-form.AimTo investigate the prevalence and possible aetiological factors of MIH in randomly selected Saudi schoolchildren aged 8–12 years in Riyadh.DesignA randomly selected sample of Saudi schoolchildren aged 8–12 years attending elementary schools in Riyadh was examined using the EAPD short-form charting, which was recently recommended for the standardised collection of epidemiological data on MIH. To investigate possible aetiological factors of MIH, we collected demographic, pregnancy, and medical history using a questionnaire.ResultsA total of 1,562 children participated in the study (48.8% girls, 51.2% boys). The prevalence of MIH was 15.2%, without a significant difference in the prevalence between the sexes. Among those with MIH, 79.4% had affected incisors and 55.9% had hypomineralised second primary molars. The most prevalent clinical defect was demarcated opacities, and the maxillary arch was more affected. Permanent incisors were more affected in boys than in girls. Defects of the first permanent molars were more severe in terms of clinical status and lesion extent than defects of the permanent incisors. MIH was significantly more prevalent in children with a history of early childhood ear infections, respiratory distress, and tonsillitis.ConclusionsMIH is common in Saudi schoolchildren living in Riyadh, with no gender predilection. Hypomineralised second primary molars can be used to predict MIH. MIH was significantly associated with childhood illness during the first three years of life, including ear infection, respiratory distress, and tonsillitis.     

Risk factors in the occurrence of molar–incisor hypomineralization amongst a group of Iraqi children

International Journal of Paediatric Dentistry 2013; 23: 197–206 Background. Despite the worldwide increasing interest in the prevalence studies of molar–incisor hypomineralization (MIH), there is still insufficient evidence to verify the aetiological factors of this condition. Aims. To investigate risk factors involved in the development of MIH in a group of school‐aged Iraqi children. Design. Seven‐ to nine‐year‐old school children (823 of 1000 eligible, response rate of 82.3%) had their first permanent molars and incisors evaluated using the European Academy of Paediatric Dentistry evaluation criteria for MIH. Mothers completed a medical history questionnaire‐based interview performed in the schools by a trained examiner. Results. For children with MIH, 6% reported no relevant medical history; the remaining 94% reported various medical conditions putatively associated with MIH compared with 70% for the non‐affected group. Post‐natal medical conditions (33.3%) were most frequently reported. When data were split into the possible risk effect groups, maternal psychological stress (OR, 3.24), frequent exposure to ultrasonic scans during the last gestational trimester (OR, 2.51) and birth order as a fourth sibling or later (OR, 3.17 and 5.73, respectively) were previously unreported significant risk factors and postulated as contributing to, or causing the defect. Conclusions. Children with MIH had experienced a greater number of medical conditions than their unaffected peers with no single health event identified as a risk factor.     

A prospective cohort study on emergence of permanent teeth and caries experience in Korean children

International Journal of Paediatric Dentistry 2011; 21: 254–260 Objectives. The objectives of this study were to investigate permanent tooth emergence during a 9‐year longitudinal study and to assess the effect of dental caries in primary teeth on the emergence of permanent teeth. Methods. Data on caries occurrence in primary teeth were obtained at the baseline by a trained dentist. Permanent tooth emergence data of 539 students from 16 elementary schools in Yeoncheon were examined annually from 1995 to 2003 using dental casts. The median age at emergence of the teeth was calculated using a linear logistic regression model. A multiple linear regression model was used to evaluate the effect of caries on the emergence of permanent teeth. Results. The age of permanent tooth emergence was different between boys and girls, but the difference was not statistically significant at the 5% level. Having ‘decayed teeth’ hastened the emergence of most second premolars and second molars, whereas the regression coefficients ranged from ?1.23 to ?0.82. The number of ‘filled teeth’ showed a correlation with maxillary second premolars and mandibular first premolar, and the regression coefficients ranged from ?1.92 to ?3.25. Conclusions. Having dental caries in primary teeth can be a strong predictor of earlier emergence of permanent teeth.     

Perception of molar-incisor hypomineralisation (MIH) by Iraqi dental academics

International Journal of Paediatric Dentistry 2011; 21: 261–270 Background. The understanding and detection of molar‐incisor hypomineralisation (MIH) is linked to its recognition by clinicians. No study has investigated dental clinicians’ level of perception regarding MIH in the Middle East region including Iraq. Aim. To determine the perception of Iraqi academic clinicians about MIH prevalence, severity and aetiological factors. Design. A questionnaire, based on previous European and Australian/New Zealand studies was administered to the academic dental staff of Mosul University. Results. A response rate of 77.7% was reported. General dental practitioners represented 30.8% of the total respondents, whilst 65.1% were dentists with post‐graduate qualification. The majority of the respondents (81.2%) encountered MIH in their clinical activities and 37.3% of them identified that the prevalence appeared to have increased in recent years. Fewer than half of the respondents observed MIH affected teeth on a monthly basis. The condition was less commonly seen in primary second molars than the first permanent molars. A variation in views was recorded about MIH specific aetiological factor/s. Respondents advocated the need for clinical training regarding MIH‐aetiological and therapeutic fields. Conclusions. Molar‐incisor hypomineralisation is a condition commonly diagnosed by Iraqi dental academics. No apparent consensus existed between the general and specialist dentists regarding the anticipated prevalence, severity and aetiology of this condition.     

Prevalence of developmental enamel defects of the first permanent molars among school children in Western Australia

BACKGROUND: The prevalence of enamel defects in the first permanent molars among children has been reported to be high and may be on the increase, particularly in the European countries. Little information is available on the prevalence of enamel defects in the first permanent molars among children in Australia. The aim of this study was to describe the prevalence of enamel defects in the first permanent molars among school children in Western Australia. METHODS: Informed consent was obtained from parents of children attending pre-primary schools within an administrative area of the School Dental Service of Western Australia in metropolitan Perth to participate in the study in 2005. Parents completed a questionnaire about the mother's health status during pregnancy, and their child's health status for the first three years. Participating children were examined during 2006 and 2007 by one examiner. Teeth were classified on the type and extent of enamel defects using the modified DDE index, and deciduous tooth caries experience of molars and canines was recorded using the WHO criteria. RESULTS: Parents of 634 children out of the eligible 1135 (56 per cent participation) completed the questionnaire. Five hundred and eleven children with at least one erupted first permanent molar were examined (mean age 7.1 years, SD 0.5). Of the first permanent molars, 42 per cent upper right; 37 per cent upper left; 47 per cent lower left; and 45 per cent lower right were without enamel defects. White diffuse opacities were the predominant enamel defects found with 46 per cent upper right; 47 per cent upper left; 40 per cent lower left and 41 per cent lower right molars affected. Demarcated opacities alone or in association with other defects affected 11 per cent upper right; 14 per cent upper left; 10 per cent lower left and 9 per cent lower right molars. At the individual level, 71 per cent had permanent molars with enamel defects; 47 per cent with white diffuse opacities and 22 per cent with demarcated opacities. CONCLUSIONS: Prevalence of enamel defects among this school population is high. Majority of defects were white diffuse opacities and the prevalence of demarcated opacities is at the high end of that reported for some European countries. Possible risk factors for enamel defects remains to be tested.     

Effect of computerized delivery intraligamental injection in primary molars on their corresponding permanent tooth buds

International Journal of Paediatric Dentistry 2010; 20: 270–275 Objective. To evaluate the prevalence of developmental disturbances in permanent teeth in which buds were exposed to intraligamental injection (ILI) delivered by a computer controlled local anaesthetic delivery (C‐CLAD). Methods. The study population consisted of 78 children (age 4.1–12.8 years) who received ILI–C‐CLAD to 166 primary molars. A structured form was designed to include information regarding age at treatment, gender, type of treated tooth, tooth location, type of dental treatment, and type of developmental disturbance(s) present in the associated permanent tooth. Teeth, which received regular anaesthesia or were not anaesthetized by local anaesthesia, served as controls. Results. Five children had developmental defects. In C‐CLAD–ILI exposed teeth, one child had two hypomaturation defects. The corresponding primary teeth were extracted. No defects were found on the control side. In two children, hypoplastic defects were found only in the control teeth (one in each child). One suffered from a dentoalveolar abscess in the corresponding primary tooth. Diffuse hypomaturation defects were found in two children on both the C‐CLAD‐ILI exposed and control sides. Conclusion. In the primary dentition, C‐CLAD–ILI does not increase the danger of developmental disturbances to the underlying permanent dental bud.     

Proportion and extent of manifestation of molar‐incisor‐hypomineralizations according to different phenotypes

Objective: This epidemiological study aimed to assess the proportion and extent of manifestation of enamel hypomineralization, including molar‐incisor‐hypomineralization (MIH), in the permanent and primary dentition. Methods: A total of 693 children enrolled in an ongoing birth cohort study (GINIplus‐10) were examined at their 10‐year follow‐up. Enamel hypomineralization was scored in the primary and permanent dentition on a tooth‐ and surface‐related level based on the criteria of the European Academy of Paediatric Dentistry (EAPD). Children were grouped according to their distribution pattern of enamel hypomineralization: children with a minimum of one hypomineralized tooth in the primary dentition (ht ≥ 1) and permanent dentition (HT ≥ 1); with a minimum of one hypomineralization on at least one first permanent molar (MIH); and with hypomineralization on at least one first permanent molar and permanent incisor (M + IH). For each group, the mean values of hypomineralized primary teeth (ht), permanent teeth (HT), and permanent surfaces (HS) were calculated. Results: The proportion of affected children was 36.5 percent (HT ≥ 1), 14.7 percent (MIH), and 9.4 percent (M + IH); 6.9 percent of the subjects had a minimum of one affected primary tooth (ht ≥ 1). The mean number of hypomineralized permanent teeth and surfaces were 2.3HT/2.9HS (HT ≥ 1), 3.4HT/4.8HS (MIH), and 4.2HT/5.9HS (M + IH). The mean number of hypomineralized primary teeth amounted to 0.1ht in the entire study population. Conclusions: Enamel hypomineralization can be detected frequently in this study sample. Children with M + IH showed the highest number of affected teeth and surfaces followed by those with MIH.