Prevalence of Dental Enamel Defects, Aphthous-Like Ulcers and Other Oral Manifestations in Celiac Children and Adolescents: A Comparative Study.

Objectives: Celiac disease (CD) is an autoimmune disease with typical, atypical and asymptomatic forms, in which many oral manifestations have been recognized. This study aims to evaluate the prevalence of oral manifestations as well as explore if oral examination could be used as a first diagnostic screening tool for atypical or asymptomatic forms. Study Design: 45 CD patients, between 2 and 18 years (mean age 10.3) and 45 healthy subjects, age and gender-matched, were examined for hard and soft tissue lesions such as dental enamel defects (DED), dental caries, aphthous-like ulcers (ALU), atrophic glossitis, geographic tongue, median rhomboid glossitis. Results: Statistically significant differences between the two groups were observed for the prevalence of DED (in 64,4% CD and 24,46% control patients, p=0.001), their location in the teeth (incisal: p=0.0001, middle: p=0.002, cervical: p=0.007), as well as for the prevalence of ALU (in 40% CD as opposed to 4,44% control patients, p=0.001). Conclusion: The presence of DED and ALU could be used as a sign of alert for possible atypical and asymptomatic forms of CD.

Phenotypes of Enamel Hypomineralization and Molar Incisor Hypomineralization in Permanent Dentition: Identification, Quantification and Proposal for Classification.

OBJECTIVES: To report the extent, pattern, clinical presentation and phenotypes of enamel hypomineralization in permanent dentition Study Design: This cross sectional observational study recruited a random sample of 1726, 12-16 year olds. Enamel hypomineralization was scored on all teeth by a calibrated examiner using the EAPD 2003 criteria. Proportions of affected subjects (prevalence) with a minimum of one hypomineralization and Molar Incisor Hypomineralization (MIH) were calculated. Proportions of following phenotypes were quantified i.e. MH (only FPM hypomineralization), M+IH (concomitantly affected FPMs and permanent incisors without affecting any other tooth in the arch), MIHO (hypomineralization affecting at least one of the canines, premolars or 2(nd) molars and simultaneously including at least one FPM), IH (only permanent incisor's hypomineralization) and NoFPM (hypomineralization affecting at least one of the canines, premolars and 2(nd) molars but not FPM; incisors can be affected concomitantly). A comparative evaluation of extent and severity of enamel hypomineralization was performed amongst various phenotypes. Statistical measures employed t-test, chi square tests and ANOVA. RESULTS: Overall prevalence of affected subjects was 13.21% (228/1726) and 9.79% (169/1726) for enamel hypomineralization and MIH respectively. A total of 4.36±3.45 teeth/subject and 6.01±5.20 surfaces/subject were found to be affected with enamel hypomineralization. Most prevalent phenotype was M+IH while the least prevalent was IH. Maximum severity i.e. number of affected surfaces and surfaces with PEB were reported for MIHO (p<0.001). CONCLUSION: Enamel hypomineralization can manifest in any tooth in five phenotypic variations in permanent dentition with varying extent and severity.

Longitudinal Evaluation of the Structural Integrity of Teeth Affected by Molar Incisor Hypomineralisation.

The aim of this prospective cohort study was to evaluate the risk of posteruptive breakdown and the development of caries lesions in teeth with molar incisor hypomineralisation (MIH). A total of 367 permanent incisors and first molars, affected and not affected by MIH lesions, of 45 children with MIH from Araraquara, São Paulo, Brazil, were evaluated at intervals from 6 to 12 months by assessing the severity of MIH, the presence of tooth caries lesions and the treatment needed. During the study period, all patients received preventive care. The data were analysed using Fisher's exact test and actuarial method survival analysis. Significant associations were also found in teeth between the presence of MIH and a DMFT index >0 in all periods and also between the need for treatment and the presence of MIH. The teeth affected by MIH opacities were healthy in 99% of incisors and 93% of molars at the end of the 12-month period. Due to the high likelihood of maintaining the tooth structure in opacities, the complete or premature removal of the affected area is not justified.

Evaluation of internal consistency of the epidermolysis bullosa oropharyngeal severity score (EBOS).

OBJECTIVE: To evaluate the internal consistency of the epidermolysis bullosa oropharyngeal severity score (EBOS). MATERIALS AND METHODS: Data from 92 patients of varying EB types/sub-types already described in a previous multi-center study were re-analyzed via the coefficient Cronbach's α (CR-α). Additionally, the corrected item total correlation between each item and the items' overall score with Pearson's product-moment correlation (ρ) was calculated. RESULTS: The alpha coefficient for the mean total score of 17 items is 0.941. The inter-observer reliability for disease severity score was excellent for oral medicine specialist (α = 0.924) and dermatologist (α = 0.916) and the intra-observer reliability was good at Time 1 (α = 0.895) and Time 2 (α = 0.897). The analysis of CR-α per single item revealed that alpha was greater than 0.904 for disease activity and 0.743 for structural damage, after the elimination of four items for oral medicine specialist and greater than 0.898 for disease activity and 0.769 for structural damage after the elimination of five items for dermatologist. Similarly the analysis of the corrected items-EBOS correlation showed that the same items do not correlate very well (ρ < 0.4) with the overall EBOS. CONCLUSIONS: The EBOS turned out to have a strong and reliable internal consistency, as the majority of the EBOS' items were consistent with each other.

Distribution of Molar Incisor Hypomineralization in Malaysian Children Attending University Dental Clinic.

OBJECTIVES: Molar-Incisor Hypomineralization (MIH) is a condition of hypomineralized enamel of systemic origin affecting first permanent molars and frequently permanent incisors. It is considered a global problem and data from South-East Asian countries, including Malaysia are lacking. Hence the aim of this study were to investigate the distribution and severity of MIH in a group of children aged 7-12 year olds attending pediatric dental clinic at Faculty of Dentistry, Universiti Teknologi MARA (UiTM), Malaysia. STUDY DESIGN: Hundred and fifty four children age 7-12 year-old with mean age of 9.14 ±1.682 had their first permanent molars and permanent incisors were examined at Faculty of Dentistry, UiTM using European Academy of Paediatric Dentistry 2003 (EAPD) criteria for diagnosis of MIH. Children at least one first permanent molar affected were considered as having MIH. Data were recorded and statistically analysed using descriptive analysis and Chi square test. RESULTS: Twenty six of the total examined children (n=154) had MIH (16.9%). There was no statistical difference between males and females in the prevalence of MIH. However, a statistical significant difference was found by age groups. The first permanent molars were more frequently affected (58%) as compared to permanent incisors. Mandibular molars were to have the highest rate of MIH (15.5%). The right and left sides were equally affected. Mild defects were the most frequent lesion type (96.6%). CONCLUSIONS: This study revealed that MIH is a common condition (16.9%). Molars were more frequently affected than incisors with mild defects were the most common lesion status. Further studies on this defect amongst Malaysian children are worthwhile.

Challenges of Using Scoring Systems for the Assessment of Molar Incisor Hypomineralisation.

The dental professional is exposed to complex challenges daily, posed by molar incisor hypomineralisation (MIH). These range from understanding its etiology through to determining the most effective strategies for clinical management of the problem. Beyond any doubt, the choice of the diagnostic scoring system to be used for recording the condition is included among these challenges. To a certain degree, this is understandable since the development of specific diagnostic tools for recording the occurrence of MIH takes place parallel to the ongoing discoveries about the problem. Therefore, the aim of this chapter is to present different MIH scoring systems that have previously been proposed in the literature for detecting MIH and discuss their applications, advantages, and limitations.

Reconstruction of periodicity of repetitive linear enamel hypoplasia from perikymata counts on imbricational enamel among dry-adapted chimpanzees (Pan troglodytes verus) from Fongoli, Senegal.

Periodicity of repetitive linear enamel hypoplasia (rLEH) in apes from high latitudes with single wet and dry seasons annually has not been described. We reconstruct periodicity and duration of rLEH in canine teeth from three recently deceased chimpanzees from Fongoli, Senegal with a marked seven-month dry season. High-resolution dental molds were taken in the field for magnified imaging with digital microscopy. Photomontages allowed counting of perikymata between episodes of rLEH for reconstruction of periodicity and duration of physiological stress. Where rLEH spans the imbricational enamel, the number of events is consistent with years required to form canine imbricational enamel; i.e., periodicity of rLEH seems circannual. We predicted perikymata counts between rLEH events ranging from 52 to 61 based on reported "long counts" of 7-6 days. Counts ranged from 29.5 to 44, individual mean of 36.7. This discrepancy could be explained by recurrent stress with a periodicity of 7.2-8.4 months, or by long counts of 10 days per stria. Neither is supported in the literature. Since we find evidence of rLEH with circannual periodicity, we postulate the existence of non-emergent imbricational striae. Based on evidence that stress at Fongoli recurs annually, we reconstruct stress duration of 2-3 months, longer than reported for chimpanzees living in other habitats, which we attribute to heat stress and food shortage near shrinking waterholes. We conclude that canine teeth from a small mortality cohort of chimpanzees at Fongoli preserve a faithful record of dry season stress in an extreme environment.

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

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.

Comparison of enamel defects in the primary and permanent dentitions of children from a low-fluoride District in Australia.

PURPOSE: The purpose of this study was to compare developmental defects of enamel (DDE) in the primary and permanent dentitions of children from a low-fluoride district. METHODS: A total of 517 healthy schoolchildren were examined using the modified DDE criteria. RESULTS: The prevalence of DDE in the primary and permanent dentition was 25% and 58%, respectively (P<.001). The mean number of teeth with enamel opacity per subject was approximately threefold compared to that affected by enamel hypoplasia (3.1±3.8 vs 0.8±1.4, P<.001 in the primary dentition and 3.6±4.7 vs 1.2±2.2, P<.001 in the permanent dentition). Demarcated opacities (83%) were predominant compared to diffuse opacities (17%), while missing enamel was the most common type of enamel hypoplasia (50%), followed by grooves (31%) and enamel pits (19%) (P=.04). In the permanent dentition, diffuse and demarcated opacities were equally frequent, while enamel grooves were the commonest type of hypoplasia (52%), followed by missing enamel (35%) and enamel pits (5%; P<.001). CONCLUSIONS: In a low-fluoride community, developmental defects of enamel were twice as common in the permanent dentition vs the primary dentition. In the primary dentition, the predominant defects were demarcated opacities and missing enamel, while in the permanent dentition, the defects were more variable.

A retrospective study of a modified 1-minute formocresol pulpotomy technique part 2: effect on exfoliation times and successors.

PURPOSE: The purposes of this study were to evaluate the: effect of a 1-minute application of full-strength Buckley's formocresol with concur- rent hemostasis using the medicated cotton pledget in human primary teeth on their successors; and exfoliation times compared to the contralateral nonpulpotomized tooth. METHODS: Using a retrospective chart review, clinical and radiographic data were available for 557 primary molars in 320 patients. RESULTS: There was no difference between treated and control teeth in the number of enamel defects of succedaneous teeth (P<.45). Approximately 66% exfoliated at the same time as their contralateral counterpart and approximately 29% exfoliated earlier (P<.001). CONCLUSIONS: This 1-minute technique showed a tendency toward early exfoliation, but no effect on clinical management, and no increase in incidence of defects on succedaneous teeth was observed. The 1-minute full-strength formocresol technique may be considered an acceptable alternative to the 5-minute formocresol pulpotomy.

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

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.

Aetiology of molar-incisor hypomineralization: a critical review.

OBJECTIVE: The objective of this study was to assess the strength of evidence for the aetiology of molar-incisor hypomineralization (MIH), often as approximated by demarcated defects. METHOD: A systematic search of online medical databases was conducted with assessment of titles, abstracts, and finally full articles for selection purposes. The level and quality of evidence were then assessed for each article according to Australian national guidelines. RESULTS: Of 1123 articles identified by the database search, 53 were selected for review. These covered a variety of potential aetiological factors, some of which were grouped together for convenience. The level of evidence provided by the majority of papers was low and most did not specifically investigate MIH. There was moderate evidence that polychlorinated biphenyl/dioxin exposure is involved in the aetiology of MIH; weak evidence for the role of nutrition, birth and neonatal factors, and acute or chronic childhood illness/treatment; and very weak evidence to implicate fluoride or breastfeeding. CONCLUSION: There is currently insufficient evidence in the literature to establish aetiological factor/s relevant for MIH. Improvements in study design, as well as standardization of diagnostic and examination protocols, would improve the level and strength of evidence.

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.

Molar incisor hypomineralization: a study of aetiological factors in a group of UK children.

OBJECTIVES: The objectives were to investigate the aetiology of molar incisor hypomineralization (MIH), and to discuss previously published studies. SUBJECTS AND METHODS: One hundred and nine children attending the Department of Paediatric Dentistry at the Royal London Hospital were included in the study: 57 children with MIH and 52 controls. Their mothers completed a medical history interview. RESULTS: No significant associations were found with MIH and delivery and birth complications, breastfeeding, immunization history, other illnesses and allergies, general anaesthetics, fluoride history, and trauma or abscesses affecting the primary predecessors. A family history of enamel defects was more commonly reported for MIH children, but the association was not statistically significant. However, MIH was significantly more common among those whose mothers had experienced problems during pregnancy (P = 0.025), those who had chickenpox between the ages of 3 and 3.99 (P = 0.047), and those for whom amoxycillin was the only antibiotic they had received (P = 0.028). CONCLUSIONS: The aetiology of MIH remains unclear, and this study questions whether it is because of a lone aetiological insult. This study recommends further research looking at the links with chickenpox occurring around the third year of life and amoxycillin.

The Prevalence and Severity of Molar Incisor Hypomineralization and Molar Hypomineralization in Dubai, UAE.

Purpose: The purpose of this study was to evaluate the prevalence and severity of molar incisor hypomineralization (MIH) among schoolchildren in Dubai, UAE.Methods: A randomized cluster sample of 342 eight to 12-year-old schoolchildren had their permanent first molars and incisors evaluated for prevalence and severity of MIH using the European Academy of Paediatric Dentistry criteria.Results: The prevalence of MIH in Dubai was found to be 27.2 percent and was significantly higher in girls (32.6%) compared to boys (18.1%;P=0.002). The prevalence of molar hypomineralization (MH) was higher than MIH: of the 27.2 percent diagnosed children, 65.6 percent had only MH while 34.4 percent had MIH. MH prevalence in maxillary molars was 20.8 percent, significantly higher than 14.6 percent in mandibular molars (P≤0.005). Almost nine percent of maxillary incisors were affected by MIH compared to 0.9 percent of mandibular incisors (P≤0.001). The presence of demarcated opacities was significantly higher in females than males (P =0.002). Fifty-three percent of the children with MIH had mild defects, 17 percent had moderate defects, and 30 percent had severe defects.Conclusions: Despite the high prevalence of MIH in schoolchildren in Dubai, the severity was mild. The prevalence of MIH and MH was significantly related to sex and location of tooth in the oral cavity.

Enamel hypoplasia in children with renal disease in a fluoridated area.

The aim of this study was to compare the frequency of enamel hypoplasia in children with renal disease and healthy children, all of whom live in a fluoridated area. A cross-sectional study was made in 42 children divided into 2 groups. To describe enamel changes, 3 diagnostic criteria were applied: TSIF Index to describe dental fluorosis, Jackson-Al-Alousi Index to describe enamel hypoplasia, and Russell criteria to differentiate mild forms of dental fluorosis and enamel hypoplasia. The frequency of enamel hypoplasia in patients with renal disease was 38.09%. This frequency is smaller than that seen in other studies. There was no difference in the frequency of dental fluorosis between patients with renal disease and patients without renal disease. However the patients with renal disease presented more severe dental fluorosis than children without renal disease.

The Würzburg MIH concept: the MIH treatment need index (MIH TNI) : A new index to assess and plan treatment in patients with molar incisior hypomineralisation (MIH).

AIM: This was to create a new easy-to-use index for the treatment of MIH. METHODS: An international MIH working group developed a new MIH index as an epidemiological screening procedure for assessing MIH treatment needs (MIH-TNI), and also for the screening and monitoring of individuals by dental practitioners. RESULTS: The MIH TNI assesses in particular the extent of the destruction of tooth structure in combination with any hypersensitivity occurring in MIH. The MIH-TNI is suggested as a basis for individual dental examinations covering all MIH typical problems or treatment planning. In addition, this index shall be the basis for decision-making in any MIH therapy studies already planned. CONCLUSION: After the validation of the MIH TNI it may be possible to create a standardised approach for dental treatment for MIH.

Breast-feeding and other mother-child factors associated with developmental enamel defects in the primary teeth of Brazilian children.

PURPOSE: The purpose of this study was to examine the association between developmental defects in the enamel (DDE) of the primary teeth and low birth weight or prematurity. METHODS: A case-control study was carried out in Itajaí, Southern Brazil, involving 3- to 5-year-old children. The case group was composed of 102 children presenting at least 1 dental surface with DDE. The control group comprised 113 children without DDE matched by sex and age and enrolled in the same day care centers. All teeth were clinically examined using the Modified Index of Developmental Defects of Enamel. The outcome variable of the study was DDE in at least 1 dental surface, and the independent variables were: (1) birth weight; (2) gestational age; and (3) breast-feeding. Maternal schooling and health problems of the mother during pregnancy and of the child during the first year of life were collected as potential confounding factors. Simple and conditional multiple logistic regression analyses were performed, providing crude and adjusted odds ratio and 95% confidence intervals. RESULTS: Prematurity (OR=2.6; 95% CI=1.0-6.4) and children who did not breast-feed (OR=3.2; 95% CI=1.2-8.4) were associated with defects in tooth enamel after adjusting for possible confounding variables. CONCLUSIONS: In this study, premature children and those who did not breast-feed could be considered at risk for developing defects in tooth enamel.

Severity of MIH findings at tooth surface level among German school children.

AIM: This study was to investigate the distribution and clinical characteristics of teeth diagnosed with MIH at surface and defect type level in a cohort of German children. METHODS: The study cohort included 242 children diagnosed with MIH which had been recorded during the compulsory dental school examinations of 20 German primary schools. The subjects had been enrolled by cluster sampling. All children attended the second to fourth grade (age 7-10 years, mean 8.1 ± 0.8). The children were examined by five calibrated examiners (kappa = 0.9) after tooth brushing. The recording comprised teeth, surfaces, type and severity of MIH defects and was conducted using a portable light, mirrors and cotton rolls. MIH was registered according to the EAPD criteria. Defects <1 mm were not recorded. Statistical analysis included descriptive statistics and Spearman's correlation. RESULTS: Most affected teeth were first permanent molars (71.4 %) followed by the maxillary central incisors (15.6 %). The most common defects were demarcated opacities (82.2 %), while the remaining 17.8 % of the affected teeth exhibited severe enamel defects. The most frequently affected surface in molars was the occlusal surface (72.4 %); in incisors, it was the buccal surface (73.5 %). There were no atypical restorations in the affected incisors. Different types of MIH defects at various surfaces of the same tooth were common. The number of affected tooth surfaces was positively correlated with the severity of MIH at child (p < 0.001). CONCLUSIONS: The study demonstrates severe enamel defects involving in almost one-fifth of all MIH teeth. The knowledge of the intra-oral distribution and severity of MIH findings at the enamel surface level is important for assessing the treatment needs.

The prevalence of incisor hypomineralisation and its relationship with the prevalence of molar incisor hypomineralisation.

AIM: To establish the prevalence of incisor hypomineralisation (IH) in a cohort of 12-year-old children in Northern England and to relate the prevalence to gender, socioeconomic status, and the prevalence of molar incisor hypomineralisation (MIH). METHOD: The study population comprised 12-year-old children participating in the 2008-2009 National Dental Epidemiological Programme in five regions in Northern England. Participating dentists were trained and calibrated in the use of the modified Developmental Defects of Enamel Index. Children were examined at school under direct vision with the aid of a dental mirror. First permanent molars and incisors were recorded for the presence and type of enamel defects greater than 2 mm. A diagnosis of MIH was ascribed to any child with a demarcated defect in any first permanent molar. A diagnosis of IH was ascribed to any child with a demarcated defect in an incisor but with molar sparing. RESULTS: 3,233 children were examined. The prevalence of IH was 11.0 % (95 % CI 11.0-12.2 %). There was a strong positive correlation between the prevalence of MIH and IH in different regions which reached significance (r = 0.9, p = 0.037) according to Spearman's rho test of correlation. There was a similar pattern of prevalence in the different socioeconomic quintiles although this correlation did not reach significance. The most common teeth affected in IH were the maxillary central incisors, followed by the maxillary lateral incisors and followed by the mandibular incisors. There was no difference in the prevalence of IH by gender. CONCLUSIONS: The prevalence of IH was 11.0 %. The variation of prevalence between regions and socioeconomic groups and the distribution of lesions in the teeth were very similar to observations seen in MIH children from the same cohort.