Molar Incisor Hypomineralization in adolescents and adults and its association with facial profile and occlusion.

OBJECTIVES: To date, there are no data available in the scientific literature about the diagnosis of Molar Incisor Hypomineralization (MIH) in adults. We aimed to assess the MIH prevalence and clinical characteristics in adolescents and adults and its association with facial profile and occlusion. MATERIALS AND METHODS: In this cross-sectional study, permanent teeth were evaluated in 275 patients between the ages of 12 and 49 at a dental clinic, using intraoral photographs. A calibrated examiner classified enamel hypomineralization using the MIH index. Statistical analyses were performed using chi-square, Fisher's tests, and ordinal logistic regression. RESULTS: MIH was observed in 12.73% of all patients. The most commonly affected teeth were permanent molars, while incisors, premolars, and canines were less affected. MIH usually appears as demarcated opacities, with less than one-third of the tooth affected. There was no association between severe defects and facial profile and occlusion, but rather with the higher age of the participants. CONCLUSION: Enamel hypomineralization mainly affects the first and second permanent molars, but it could also be observed in the third molars, although it is not associated with the orthodontic characteristics investigated. CLINICAL RELEVANCE: This is the first study to highlight the prevalence of MIH in adults. This result showed the importance of other specialists beyond Pediatric Dentistry in the diagnosis of this defect. In addition, hypomineralization of other permanent teeth (canines, premolars, and second molars) has been described previously in other studies, but this is the first to identify MIH in third molars.

Enamel opacities in all other than Molar Incisor Hypomineralisation index teeth of adolescents.

BACKGROUND: There are scarce data on the hypomineralisation of other permanent teeth (HOPT) than the index teeth of Molar Incisor Hypomineralisation (MIH). AIM: To report on the prevalence and surface pattern of HOPT and seek associations with MIH. DESIGN: Representative samples of urban Greek 14-year-olds were examined in classroom with a dental mirror. Their enamel defects were recorded using EAPD criteria for MIH. Descriptive statistics and correlation tests for HOPT vs previously reported MIH findings in the same samples were applied. RESULTS: HOPT prevalence in 1156 consented adolescents was 22.9%. 148 (16.2%) of 912 no-MIH children had HOPT; 117 (48.1%) of the 244 MIH children had HOPT too (OR 3.0, 95% CI 2.4-3.6). There were more HOPT teeth per child in the MIH vs no-MIH children (P < .001). HOPT tooth frequency was as follows: second molar 33.7%, canine 25.7%, first premolar 23.6%, and second premolar 17.0%. Enamel breakdown was seen in 5.3% HOPT children. Vestibular to intraoral surface defect ratio differed between jaws (maxilla 187/88, mandible 149/17, P < .05). CONCLUSIONS: Hypomineralisation defects in the MIH non-index teeth collectively had comparable prevalence and tooth surface patterns to MIH, but much lower severity. MIH was predictor for HOPT.

The severity and degree of hypomineralisation in teeth and its influence on oral hygiene and caries prevalence in children.

AIM: The purpose of this study was to investigate the relationship between the severity of hypomineralised teeth, plaque accumulation, hypersensitivity, associated caries risk, and oral health-related quality of life limitations of affected children. MATERIALS AND METHODS: A total of 250 children (mean age 9.0 years) presenting with at least one hypomineralised molar or incisor were included in the study. The hypersensitivity of the teeth was evaluated using the Schiff Cold Air Sensitivity Scale and the Wong-Baker Faces Scale. Furthermore, the Decayed, Missing, and Filled Teeth Index was documented, the Quigley Hein Index was obtained, and personal questioning was used to document the patients' limitations with intake of food. These data were analysed using general linear models that control influencing factors such as age and sex. RESULTS: The Quigley Hein Index increased with the severity of the hypomineralised teeth (1.64 in the unaffected, 2.77 in the moderately, and 3.63 in the severely affected teeth). Problems with intake of food were only observed in subjects with severe hypomineralisation. There was no immediate effect on dental caries. CONCLUSION: Increased severity of tooth hypomineralisation leads to increased hypersensitivity, which resulted in inadequate oral hygiene among children and limitations to their daily life.

The prevalence and morphological types of non-carious cervical lesions (NCCL) in a contemporary sample of people.

Non-carious cervical lesions (NCCLs) were examined in 6541 extracted human teeth and classified based on the morphology of the lesions. As a result, NCCLs were found on 38.7% of teeth (41.6% on maxillary teeth and 36.0% on mandibular teeth), and were most frequent on canines and first premolars. According to the new method of classification, the morphology of NCCLs was classified both by the surface contour (SC) and by the cross-sectional contour (CC). Three types of NCCLs appeared to be dominant. The causes of these NCCLs were discussed based on their morphologies, positions where these NCCLs were frequently found, and the results of previous studies. NCCLs with a horizontal oval SC and a round CC (Type I), which were frequent on the labial surfaces of maxillary canines and buccal surfaces of maxillary first premolars, may be associated with wear by friction and chemical degradation. NCCLs with a vertical oval SC and a round CC (Type II), which were frequent on the lingual surfaces of mandibular incisors and canines, might be mainly related to chemical degradation. NCCLs with a horizontal oval SC and a wedge shape CC (Type III), which were extensively found on the buccal surfaces of maxillary premolars, had formed most probably due to wear by friction and microstructural loss by stress. This new method can classify the morphology of NCCLs more precisely and deduce the mechanisms of the formation of NCCLs more clearly than former methods.

How serious is Molar Incisor Hypomineralisation (MIH) among 8- and 9-year-old children in Bosnia-Herzegovina? A clinical study.

AIM: To determine the prevalence of MIH in 8- and 9 year-old children in the city of Kljuc, Bosnia-Herzegovina, and to describe the distribution and severity of the affected teeth. MATERIALS AND METHODS: Study design: All 8- and 9-year-olds (n=104) living in Kljuc (born 2004/2005) were invited to participate, and 103 were examined by a calibrated clinician. Written, informed consent was obtained from all participants' relatives, as well as a questionnaire designed to assess potential risk indicators. Index teeth were all permanent first molars and incisors (12 teeth). Opacities (>1mm), post eruptive breakdown (PEB), atypical restorations and previous extractions caused by MIH were registered. RESULTS: The prevalence of MIH was 11.7% (n=12), significantly higher for girls than for boys (14.6% vs. 9.7%; p<0.05). The maxillary first molars and incisors were 1.8 (p<0.02) and 2.3 (p<0.05) times more frequently affected than the mandibular ones, respectively. Seven (30%) of the affected molars had opacities, 8 (35%) had PEB and 8 (35%) atypical restorations. No molars had been extracted due to MIH. The use of penicillin due to adenoid infections in the first 5 years was associated with a higher prevalence of MIH (41.7% vs. 19.6%). CONCLUSIONS: The prevalence of MIH (11.7%) supports the data previously published from Bosnia-Herzegovina. Girls had higher prevalence of MIH than boys; first molars and incisors in the maxilla were almost twice as often affected as in the mandible. Use of penicillin in the first 5 years was associated with a higher prevalence.

The influence of different types of brackets and efficacy of two chlorhexidine mouthwashes on oral hygiene and the incidence of white spot lesions in adolescents during the orthodontic therapy.

BACKGROUND: To detect the effect of two different types of brackets (ceramic and stainless steel) and investigate the effectiveness of two chlorhexidine mouthwashes 0.2% (CHX) on oral hygiene status and incidence of white spot lesions (WSLs) in adolescents wearing fixed orthodontic appliance. SUBJECTS AND METHODS: One hundred and twenty subjects (aged 11 to 18 years, mean age 14.5 years) were divided into six equal groups according to brackets type and to different mouthwashes: Group 1: metal brackets and conventional CHX, Group 2: metal brackets and CHX with anti-discoloration system (CHX-ADS), Group 3: ceramic brackets and conventional CHX, Group 4: ceramic brackets and CHX-ADS, Group 5: metal brackets and water correction flavors mouthwash (placebo), Group 6: ceramic brackets and placebo. Four weeks after the placement of fixed orthodontic appliance the subjects were provided with three different mouthwashes for use during the next two weeks. Assessment was carried out according to oral hygiene index-simplified (OHI-S) and WSL index performed: prior to placement of the appliance (baseline), four weeks, six weeks, eighteen weeks, and thirty weeks after the placement. The data were then subjected to statistical analysis. RESULTS: Group 4 showed reduction in the OHI-S scores when compared to the Group 5 (in the 6th week), and Group 6 (in the 6th and 18th week), which was statistically significant, P<0.05. Group 4 showed decrease in the WSLs scores when compared to the Group 1 (in the 4th, 6th, 18th and 30th week), Group 5 (in the 18th and 30th week) and Group 6 (in the 6th, 18th and 30th week), which was statistically significant, P<0.05. CONCLUSION: The ceramic brackets and the usage of CHX-ADS resulted in better oral hygiene status and lower incidence of WSLs.

Incidence of white spot lesions among patients treated with self- and conventional ligation systems.

OBJECTIVES: The aim of this study was to investigate the incidence of white spot lesions (WSLs) and its relationship with various patient and treatment variables, in patients treated with self-ligation and conventional ligation orthodontic bracket systems. METHODS: Two-hundred randomly selected patient records (136 female, 64 male) for self-ligation and (108 female, 92 male) for conventional ligation groups were examined to determine WSL development. In the self-ligation group, Damon 3MX (Ormco, Glendora, Calif) brackets had been used, and in the conventional ligation group, Equilibrium 2 (Dentaurum, Phorzeim, Germany) had been used. Labial surfaces of 24 teeth in the pre- and post-treatment photographic records were scored using the WSL index. RESULTS: The prevalence of patients who developed at least 1 WSL before treatment was 19%, whereas after treatment, it was 49% in the self-ligation and 54% in the conventional ligation groups. Before treatment, the patients had only mild WSL, but after treatment, severe WSL and cavitation were observed in both groups. Bracket type, age, and hygiene care were significantly associated with new WSL development (P = 0.008, P = 0.004, P = 0.013, respectively). CONCLUSION: Bracket type and more importantly, the hygiene care therapy provided appeared to influence the development of new WSLs. Ligation can promote plaque accumulation and thereby new WSL development in conventional bracket systems. CLINICAL RELEVANCE: This article investigates the incidence of WSLs in patients treated with self-ligation and conventional ligation. The present study showed that incidence of WSL less in the self-ligation than in the conventional ligation but hygiene care was mostly important factor in developed WSL.

Oral manifestations of suspected eating disorders among women of 20-25 years in Bangalore City, India.

To detect the presence of eating disorders (EDs) and clinical findings in 20-25 years old women residing in professional college hostels in Bangalore city, India, a cross-sectional study was conducted. One hundred seventeen women of the 128 selected randomly participated in the study. SCOFF [Sick, Control, One-stone (14 lbs/6.5 kg), Fat, Food] Questionnaire was used for screening suspected cases of anorexia nervosa (AN) and bulimia nervosa (BN). Examination was done for systemic findings, extra-oral and intra-oral manifestations of EDs. Data obtained were analyzed using SPSS (version 13.0). The response rate was 71.3%, of which 42.7% were suspected to have EDs by SCOFE Examination showed significantly higher prevalence of periomylolysis (p = 0.004), dental caries (p = 0.004), and tooth sensitivity (p = 0.001) in suspected cases. The study succeeded at 'case-finding' of EDs with a significant prevalence of oral manifestations in suspected cases. Thus, dentists play a major role for early detection and prompt further referral of co-morbid disorders, like EDs.

Assessment of non-cavitated and cavitated carious lesions among 12- to 15-year-old government and private school children in Pune, Maharashtra, India.

PURPOSE: The present cross-sectional study was conducted to assess and compare the mean number of non-cavitated (initial lesions, IL) and cavitated carious lesions (WHO criteria) per child in the permanent dentition and to correlate it with the plaque index among 12- to 15-year-old government and private school children. MATERIALS AND METHODS: 481 schoolchildren aged 12-15 years were selected randomly by multistage random sampling from two government and two private schools. Demographic details were collected at the time of examination. Baseline plaque scores were recorded using the Silness and Löe plaque index. Immediately after brushing and drying the teeth, cavitated lesions were recorded based on WHO recommendations and non-cavitated lesions were recorded using the IL criteria of Nyvad et al and Fyffe et al. RESULTS: The mean number of surfaces with cavitated and non-cavitated lesions for government school children was 2.13 ± 2.98 and 3.21 ± 2.97, respectively, and 1.24 ± 1.86 and 3.08 ± 2.33 for private school children, respectively. WHO + IL surfaces among private school children were 4.33 ± 3.48 and in government school children 5.35 ± 4.45. There was a positive correlation of plaque score with IL (r = 0.63) and WHO+IL (r = 0.73). CONCLUSION: Non-cavitated lesions are about twice as common as cavitated carious lesions in school children. Government school children had a higher number of cavitated and non-cavitated carious lesions when compared with private school children.

Prevalence of demarcated hypomineralisation defects in second primary molars in Iraqi children.

BACKGROUND: Demarcated hypomineralization lesions are not uncommon in second primary molars. Data on the prevalence of hypomineralized second primary molars (HSPM) are scarce. AIM: To investigate the prevalence of HSPM, assess the relationship between HSPM and first permanent molars previously diagnosed with demarcated lesions and to determine the severity of HSPM in relation to dental caries severity. DESIGN: A cluster sample of 809, 7- to 9-year-old children was examined. The scoring criteria proposed by the European Academy of Paediatric Dentistry for hypomineralization in permanent dentition were adapted to score HSPMs. The International Caries Detection and Assessment System was used to assess caries status in the second primary molar of the children diagnosed with demarcated defects. The examination was carried out in schools by a calibrated dentist. RESULTS: Of the children examined, 53 (6.6%) had hypomineralization defects in at least one second primary molar. Combinations of affected first permanent and second primary molars were reported in 21 (39.6%) of cases. Severe carious lesions were found mostly in teeth with enamel breakdown. CONCLUSIONS: The prevalence of HSPM was 6.6%. Over one-third of affected second primary molars were associated with demarcated lesions in the first permanent molars. The chance of severe caries increased with the increase in the demarcated lesion severity.

Insights into molar-incisor hypomineralisation in past populations: A call to anthropologists.

OBJECTIVE: Molar incisor hypomineralisation (MIH) is a developmental defect of enamel affecting the first permanent molars and often the incisors and affecting approximately 13% of the current population worldwide. Here, we aim to highlight potential differential diagnoses of MIH in archaeological collections (taphonomic discoloration, amelogenesis imperfecta, fluorosis, rachitic teeth, etc.). METHODS: Causative factors of dental discolourations are identified through a literature review. RESULTS: In an archaeological context, the sediments contained in the burial soil can lead to tooth discoloration. Taphonomic staining of the dentition may have a similar appearance to enamel hypomineralisation, and thus is a confounding factor that has the potential to cause miscalculation of the true prevalence of MIH within archaeological collections. Some rare medieval cases are reported in the modern literature but without microanalysis, misdiagnosis is possible. The aetiological factors of MIH are unknown but probably follow the multifactorial model involving systemic medical and genetic factors. CONCLUSIONS: Systematic detection and diagnosis of MIH during anthropological studies is therefore of great interest. SIGNIFICANCE: The hypotheses that only contemporary agents are causative factors of MIH could be refuted by the discovery of individuals living before medication or pollutants. The identification of MIH in a group of individuals also provides information regarding the health status of a population and reflects stress occurring during the period of mineralisation of the first permanent molars after secretion of the enamel matrix. LIMITATIONS: Taphonomic alterations of archaeological remains prevent MIH diagnosis. SUGGESTIONS FOR FUTURE RESEARCH: MIH diagnosis can be difficult in archaeological series and further non-destructive methods (microtomography, elemental analyses, etc.) are required.

Evaluation of tooth demineralization using laser-fluorescence in dental school patients undergoing orthodontic treatment: A clinical study.

BACKGROUND: Adverse effects can occur during orthodontic treatment. OBJECTIVE: To evaluate the relationship between prevalence and severity of enamel demineralization using a laser-fluorescence device, with length of orthodontic treatment time. METHOD: A cross-sectional study was conducted in 60 patients in a university orthodontic clinic. A clinical examination to establish demineralization at four sites on each tooth (premolar to premolar) was performed using the DIAGNOdent pen. The dependent variable was enamel demineralization, from which the prevalence (at least one affected site), extension (percentage of affected teeth) and adjusted average (average of the mean DIAGNOdent values per tooth) were calculated. The length of time for orthodontic treatment was determined in months. Various sociodemographic and clinical covariates were included. RESULTS: Average number of months under orthodontic treatment was 26.37 ± 24.81 months. Prevalence of enamel demineralization was 80.0%, its extension was 21.9% ± 17.2 and adjusted average of DIAGNOdent values was 6.09 ± 1.75. By quadrant, the teeth most affected were 14 (34.4%), 24 (25.0%), 31 (30.2%) and 44 (33.3%). No significant relationship (p> 0.05) was observed between enamel demineralization and length of time under orthodontic treatment. CONCLUSIONS: A high prevalence of dental demineralization was observed. In this sample, no relationship was observed between months under treatment and dental demineralization, or with other variables included in the study.

Hypophosphatasia.

Hypophosphatasia (HPP) is a group of inherited disorders characterised by the impaired mineralisation of bones and/or teeth and low serum alkaline phosphatase (ALP) activity. It is caused by a mutation in the ALPL gene encoding the tissue-non-specific isoenzyme of ALP (TNSALP) resulting in a loss of function. The disease is highly heterogenous in its clinical expression ranging from stillbirth without mineralised bone to the mild form of late adult onset with symptoms and signs such as musculoskeletal pain, arthropathy, lower-extremity fractures, premature loss of teeth or an incidental finding of reduced serum ALP activity. A classification based on the age at diagnosis and the presence or absence of bone symptoms was historically used: perinatal, prenatal benign, infantile, childhood, adult and odontohypophosphatasia. These subtypes are known to have overlapping signs and complications. Three forms of HPP distinguishable by their genetic characteristics have been described: severe, moderate and mild. Severe forms of HPP (perinatal and infantile severe) are recessively inherited, whereas moderate HPP may be dominantly or recessively inherited. The biochemical hallmark of HPP is persistently low serum ALP for age and increase in natural substrates of TNSALP, pyridoxal 5'-phosphate and phosphoethanolamine supported by radiological findings. The diagnosis is confirmed by ALPL sequencing. A multidisciplinary team of experts is essential for the effective management. Calcium restriction is recommended in infants/children to manage hypercalcaemia. A targeted enzyme replacement therapy for HPP has become available and correct diagnosis is crucial to allow early treatment.

Prevalence of Molar-Incisor Hypomineralization and Caries in Eight-Year-Old Children in Croatia.

The aim of this study was to detect molar-incisor hypomineralization (MIH) and caries prevalence in eight-year-old children with early mixed dentition in Eastern Croatia. There is a lack of data on MIH in Croatia. There were 729 children examined in total: 356 (48.83%) were female and 373 (51.16%) were male. The presence of MIH was found in 95 children, the prevalence of MIH was 13%, and the remaining 634 (87%) did not have any changes associated with MIH. The prevalence of caries overall in the population of examined children was 11.48%. In the group of children with MIH, the prevalence of caries was 24.14%, while in the group of children with no MIH, the prevalence of caries was 11.18%. Teeth had a Decayed, Missing, and Filled Teeth (DMFT) index of 1.2, the value of the SiC index was 1.4, and the decayed, missing, and filled teeth (dmft) index for deciduous teeth was 5.8. Children with MIH had a caries index of DMFT 2.1, and the value of the SiC index was 2.6. The index of caries for non-MIH children was DMFT 1.1 and the SiC index was 1.2. MIH prevalence in Croatia is more common in girls than in boys. MIH has a significant impact on children's development and is a major factor in the occurrence of caries.

ORAL HYGIENE IN CHILDREN WITH DISTURBANCES IN TOOTH FORMATION WHO WERE AFFECTED AS A CONSEQUENCE OF THE ChNPP ACCIDENT. / STAN GIGIIeNY POROZhNYNY ROTA U DITEI Z PORUShENNIaMY FORMUVANNIa ZUBIV, POSTRAZhDALYKh VNASLIDOK AVARIÏ NA ChAES.

OBJECTIVE: evaluation of oral hygiene to enhance the prophylaxis of complications specifically of dental caries inchildren with disturbances in tooth formation (DTF) who live on radiologically contaminated territories after theChornobyl NPP (ChNPP) accident. MATERIALS AND METHODS: Children aged 6-14 years (n = 1470) with DTF were the study subjects examined in 2012-2016. Among them there were (n = 528) residents of the zones III and IV of radiological contamination after theChNPP accident with 137Cs soil contamination density 1-15 Ci/km2. The effective radiation dose in them was notexceeding 1 mSv/year. The Green-Vermillion and Silness-Loe oral hygiene indices were assesses within clinicalexamination methods. RESULTS: The worth oral hygiene was revealed in children having got the DTF, compensated chronic diseases oforgans and systems, and in those with burdened radiation history. The Green-Vermilion and Silness-Loe indices were1.7 ± 0.51 and 1.65 ± 0.46 respectively. CONCLUSIONS: A significant deterioration in oral hygiene confirmed by the highest values of the Green-Vermillion index (1.7 ± 0.51; p < 0.001 - «unsatisfactory oral hygiene¼ criterion) and Silness-Loe index (1.65 ± 0.46; p < 0.001 -«poor oral hygiene¼ criterion) was found in children with DTF aged 6-14 years being residents of contaminated areasas a result of the Chernobyl accident. The revealed deterioration may be due to a set of negative factors, includingthe impact of ionizing radiation in low doses and peculiarities of social status. Results of the questioning of surveyed pediatric contingents both having got an DTF and with no defects of the hard tissues of teeth indicate aninsufficient level of knowledge and skills in hygienic care of oral cavity regardless of the area of residence.Development of a set of measures to prevent the DTF complications in children should be carried out taking intoaccount the state of oral hygiene, level of knowledge and skills in oral care, and include the use of hygiene products, namely toothpastes and anti-caries mouthwashes.

Prevalence and distribution of demarcated opacities and their sequelae in permanent 1st molars and incisors in 7 to 13-year-old Brazilian children.

OBJECTIVE: To determine the prevalence of demarcated opacities in permanent 1st molars and incisors in 7 to 13-year-old Brazilian children. MATERIAL AND METHODS: The study population comprised 292 children from a middle social class public school in Rio de Janeiro, Brazil. Children with all 1st permanent molars erupted were eligible for participation. Clinical examination was performed by two calibrated examiners who recorded demarcated opacities, post-eruptive breakdown, atypical restorations, and extractions due to demarcated opacities. Forty-three children had at least one molar that could not be examined, which left 249 children for the data analysis. RESULTS: One hundred children (40.2%) had one or more 1st molars with demarcated opacities with a mean number of 1.98 (SD 1.09) affected molars. The number of affected incisors increased with increasing number of affected molars. Twenty-two (18.6%) of 118 children with unaffected 1st molars had affected incisors. Demarcated opacities were the most frequent defect, and 1st molars and upper central incisors were the most frequently affected teeth. Among children with demarcated opacities in 1st molars, 20 (20%) had post-eruptive breakdown. CONCLUSIONS: A high prevalence of demarcated opacities, possibly resulting in disintegration of the tooth crown, has been found in Brazilian children.

Japanese nationwide survey of hypophosphatasia reveals prominent differences in genetic and dental findings between odonto and non-odonto types.

Hypophosphatasia (HPP) is a rare and intractable metabolic bone disease caused by mutations in the ALPL gene. Here, we undertook a nationwide survey of HPP in Japan, specifically regarding the prominent genetic and dental manifestations of odonto (n = 16 cases) and other (termed "non-odonto") (n = 36 cases) types. Mean serum alkaline phosphatase (ALP) values in odonto-type patients were significantly greater than those of non-odonto-type patients (P<0.05). Autosomal dominant and autosomal recessive inheritance patterns were detected, respectively, in 89% of odonto-type and 96% of non-odonto-type patients. The ALPL "c.1559delT" mutation, associated with extremely low ALP activity, was found in approximately 70% of cases. Regarding dental manifestations, all patients classified as odonto-type showed early exfoliation of the primary teeth significantly more frequently than patients classified as non-odonto-type (100% vs. 56%; P<0.05). Tooth hypomineralisation was detected in 42% of non-odonto-type patients, but not in any odonto-type patients (0%; P<0.05). Collectively, these results suggest that genetic and dental manifestations of patients with odonto-type and non-odonto-type HPP are significantly different, and these differences should be considered during clinical treatment of patients with HPP.

Molar incisor hypomineralization: Analysis of asymmetry of lesions.

Clinically, Molar-Incisor Hypomineralization (MIH) lesions are not distributed symmetrically, and their severity varies even within the same arcade. AIM: To estimate the frequency of asymmetries in hypomineralized lesions on permanent molars and incisors of children with MIH. METHODS: Three pediatric dentists, calibrated following the diagnostic criteria of Mathu-Muju and Wright (2006) (Kappa 0.87) identified presence and severity of opacities on molars and incisors of patients with MIH. Six pairs of teeth (permanent maxillary and mandibular first molars, central and lateral incisors) were evaluated in each patient. Degree of lesion severity (0-none, 1-mild, 2-moderate, 3-severe) was recorded for each tooth. For each pair containing any affected teeth, asymmetry of presence (one tooth in the pair with lesion and the other intact), asymmetry of severity (both teeth with lesions but with different degrees of severity) or symmetry of severity (both affected teeth with the same degree of severity) were evaluated. The recorded values were entered into a database to calculate percentages, 95% confidence intervals and Chi-Square test for comparisons. RESULTS: The sample consisted of475 of the 1032 pairs of teeth evaluated in the 172 patients included in the study, mean age 11±2.2 years, and 50% female. Asymmetry was found for 67.5% (63.1 - 71.7) of the pairs of the studied teeth. There was a significant relationship between asymmetries and symmetries (p=0.038). A total 50.1% of the pairs were asymmetrical for presence of opacities. Of these, 62.2% scored severity 1 (mild). Symmetry of severity was found for 32.5% of the lesions. Among the pairs of affected teeth, the most frequently observed degrees of lesion severity were mild and moderate, with the exception of lower molars, in which 49% had severe lesions. CONCLUSIONS: In this study, MIH lesions were asymmetrical both in presence and severity for all tooth types.

Clínicamente las lesiones de Hipomineralización Molar Incisiva (HMI) no tienen una distribución simétrica variando su severidad inclusive en la misma arcada. Objetivo: Estimar la frecuencia de asimetrías en lesiones de hipomineralización en molares e incisivos permanentes de niños afectados con HMI. Métodos: Tres odontopediatras calibrados (Kappa 0,87) según los criterios de diagnóstico de Mathu-Muju y Wright (2006), registraron presencia y severidad de opacidades en molares e incisivos de pacientes con HMI. En cada paciente se evaluaron 6 pares de piezas dentarias permanentes: primeros molares, incisivos centrales y laterales de ambos maxilares. Para cada una de las piezas se registró el grado de severidad de la lesión (0-intacto, 1-leve, 2-moderado, 3-severo). Para cada par con alguna de sus piezas afectadas, se analizó si presentaba asimetría de presencia (una pieza del par con lesión y la otra intacta), asimetría de severidad (ambas piezas con lesión pero con distinto grado de severidad) o simetría (ambas piezas afectadas con el mismo grado de severidad en la lesión). Se calcularon porcentajes, I.C. del 95% y CHI2 para las comparaciones. Resultados: La muestra quedó conformada por los 475 pares de piezas dentarias que presentaron lesión entre un total de 1032pares de piezas analizadas en los 172 pacientes incluidos en el estudio (edad media 11 ± 2,2 años, 50% género femenino). El 67,5% (63,1- 71,7) de los pares de piezas dentarias estudiados presentaron relación de asimetría. La relación entre frecuencia de asimetrías y simetrías fue significativa (p= 0,038). Del 50,1% de los pares que presentó asimetrías en presencia, un 62,2% mostró grado de severidad 1(leve) en una de sus piezas. Entre los pares afectados, las lesiones leves y moderadas fueron las más observadas en todos los grupos dentarios, a excepción de los molares inferiores que revelaron un 49% de lesiones severas. Conclusiones: En este estudio las lesiones de HMI presentaron, en su mayoría, algún tipo de asimetría (de presencia o de severidad) en todos los grupos dentarios.

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%).

Molar incisor hypomineralization in Hong Kong Chinese children.

BACKGROUND: Most prevalence studies on molar incisor hypomineralization (MIH) were carried out in European countries, and data from the East-Asian populations were lacking. AIM: This study aimed to investigate the prevalence of MIH in Hong Kong Chinese children. DESIGN: Since 2006, charting of teeth with MIH was included into the routine dental examination in a school dental clinic. The dental records of grade 6 primary school children who attended annual check-up in this clinic in 2006 were subsequently reviewed retrospectively. The records were selected for this study if the charting indicated that the children were affected by MIH. RESULTS: A total of 2635 records were reviewed and 73 cases of MIH were identified. The prevalence of MIH in this group of children was 2.8%. Their mean age was 12, and the male-to-female ratio was 1 : 1.2. The mean decayed, missing, or filled permanent teeth value of those affected was 1.5, which was higher than that of the general Hong Kong Chinese children aged 12 years old (0.8). A total of 192 teeth were affected. The most commonly affected teeth were permanent maxillary first molars, followed by mandibular first molars and maxillary central incisors. Dental fillings and fissure sealants were found in 52 (38%) and 65 (47%) permanent first molars with hypomineralization, respectively. Medical histories were unremarkable in 60 children, whereas early childhood diseases were reported in 13 cases. CONCLUSIONS: The prevalence of MIH in the permanent dentition of Hong Kong Chinese children was 2.8%. Children with MIH showed higher caries experience in the permanent dentition than the general population of similar age.