Does molar-incisor hypomineralization (MIH) affect only permanent first molars and incisors? New observations on permanent second molars

Molar-Incisor Hypomineralisation: Severity, caries and hypersensitivity

OBJECTIVES

To investigate distribution of affected teeth and severity of molar-incisor hypomineralisation (MIH) in 8-9-year-old children. A second aim was to study association between severity of MIH and hypersensitivity, caries, and affection of incisors and second primary molars (SPM).

METHODS

A total of 3013 children in one age cohort participated in a cross-sectional study, of which 851 children were diagnosed with MIH. A majority of these children were re-examined and MIH diagnosis based on the European Academy of Paediatric Dentistry criteria was confirmed in 538 children. The re-examinations were undertaken at the local clinics by one calibrated dentist. Data were tested with bivariate logistic regression analysis. Results were reported using frequencies, proportions, odds ratios (OR) and confidence intervals (CI).

RESULTS

Almost half of the children with MIH (46.8 %) had at least one severely affected molar. Incisors were affected in 51.9 % of children with MIH, and the prevalence was higher in children with severe affection (57.4 %, p < 0.01). Among children with MIH, second primary molars were affected in 29.6 %, hypersensitivity in at least one first permanent molar was reported by 25.8 and 30.8 % had caries extending to dentine. Children classified with severe MIH were more likely to suffer from hypersensitivity (OR 5.62, 95 % CI 3.61-8.74) and dentine caries (OR 10.32, 95 % CI 6.46-16.50) than children with mild MIH.

CONCLUSION

Prevalence of hypomineralised incisors and SPM were high in the studied children with MIH. Children with severe MIH had higher probability of incisor affection, dentin caries and hypersensitivity.

CLINICAL SIGNIFICANCE

This study highlights the importance of understanding the association between MIH, caries and hypersensitivity, especially in children with severe MIH. These children need extensive and individualized care in the dental services to prevent caries and pain.

Why orthodontists need to know about molar incisor hypomineralization

Molar incisor hypomineralization (MIH) is a systemic developmental qualitative defect of the enamel that affects 1-4 first permanent molars with or without incisor involvement. Enamel hypomineralization is identified visually as a demarcated opacity with a clear border with varying extensions and can be white, yellow, or brown. This opacity is characterized by a reduced quality of enamel that is of normal thickness but not fully mineralized. It is very common for the affected teeth to present with posteruptive breakdown, making them susceptible to caries, leading to their subsequent loss. Thus, MIH is a significant dental problem with clinical, economic, and psychosocial implications. The planned extraction of compromised teeth is a valid alternative to complex restorative treatment. Orthodontists' involvement is essential in developing effective treatment strategies for children affected by MIH, contributing to their oral health and well-being.

Is there a rise of prevalence for Molar Incisor Hypomineralization? A meta-analysis of published data

Since Molar Incisor Hypomineralization was first described as a pathologic entity, public perception often suggests a considerable rise in prevalence of the respective disease. Since there are still considerable doubts regarding the etiology and-accordingly-prevention of MIH and respective therapeutic approaches are difficult this question is of considerable clinical and public interest. Accordingly, a systematic literature search in accordance with the PRISMA guidelines for systematic reviews on Medline, Cochrane Database, EMBASE, LILACS, Web of Science, Google scholar, Scopus was performed to retrieve original articles reporting the prevalence of MIH as defined by the European Academy of Pediatric Dentistry (EAPD). From initially 2360 retrieved titles, 344 full texts were assessed for possible inclusion and finally 167 articles of mainly moderate to high quality and based on data of 46'613 individuals were included in the meta-analysis. All studies published before 2001 had to be excluded since it was not possible to align the findings with the EAPD classification. Studies varied considerably regarding cohort size (25 to 23'320, mean 1'235)) and age (5.6-19 y, mean 9.8 y). Over all studies, the weighted mean for the prevalence for MIH was 12.8% (95% CI 11.5%-14.1%) and no significant changes with respect to either publication year or birthyear were found. A sub-analysis of eleven studies reporting on the prevalence in different age groups, however, revealed strong evidence for an increasing prevalence between the years 1992 (3%) and 2013 (13%).Therefore, based on data from cross-sectional studies a possible rise in prevalence of MIH remains unclear. Future prospective large-scale studies under standardized examination conditions with an emphasis on examiner calibration are needed to gain better understanding in the evolution of the prevalence of MIH.

Characterization of enamel developmental defects in patients with orofacial clefts and their relationship to surgical procedures

AIMS

This study aimed to characterize the prevalence of development defects of enamel (DDE) in patients with cleft based on the cleft phenotype and explore the relationship between surgical procedures and different types of DDE.

MATERIAL AND METHODS

In this cross-sectional study, 290 standardized orthodontic documentation and medical records from a reference hospital were evaluated, which treated patients with: cleft lip (CL), cleft lip with alveolar bone involvement (CLa), cleft lip and palate (CLP), cleft palate (CP), cleft median (CM), and considering laterality as unilateral or bilateral. DDE was assessed using the Ghanim Index (2015). Information on surgical intervention periods was obtained from medical records. Statistical analyses were performed using prevalence ratio (PR) for DDE comparisons between cleft phenotypes and surgical procedures.

RESULTS

The prevalence of DDE was 77.2%. Demarcated hypomineralization was associated with CP and CLP, while hypoplasia was associated with CLa, especially when bilateral. Hypoplasia was also associated with the labial adhesion surgery.

CONCLUSION

Demarcated hypomineralization was the most common DDE in this population, and the cleft phenotype influenced the type of DDE manifested. The lip adhesion surgery increased the chances of hypoplasia manifestation.

CLINICAL RELEVANCE

The type of DDE in patients with cleft depends on the cleft phenotype. Understanding this susceptibility enables the multidisciplinary team to monitor dental development, thus allowing early diagnosis and timely referral to the pediatric dentist and better prognoses.

Comparison between two molar incisor hypomineralization detection criteria in epidemiological surveys

BACKGROUND

There is no consensus on which molar incisor hypomineralization (MIH) indices are more suitable for epidemiological surveys.

AIM

To compare the operational aspects and diagnostic ability of the MIH index (simplified/MIH_s and extended/MIH_e) with the MIH-Severity Scoring System (MIH-SSS) in classifying and diagnosing MIH.

DESIGN

This cross-sectional study assessed the indices in a homogeneous group of 680 6- to 10-year-old schoolchildren in Bauru, Brazil, who had at least one first permanent molar, ensuring consistent conditions. Followed by toothbrushing, the children seated on school chairs were examined by the two calibrated researchers under artificial lighting, using mouth mirror and WHO probe, and chronometer recording the duration of examinations.

RESULTS

The prevalence of MIH was 24.7%. The most common characteristic of MIH was demarcated opacity, with a prevalence of 81.7% and 85.45% according to the MIH_s and the MIH-SSS, respectively. A positive association was observed among the MIH_s, the MIH_e, and the MIH-SSS (chi-squared test; p < .01). The MIH-SSS demonstrated a shorter average application time than both versions of the MIH index (ANOVA/Tukey; p < .05). Additionally, fluorosis was found to be the most prevalent among other developmental defects of enamel, with a prevalence of 38.38%.

CONCLUSION

All systems effectively diagnosed MIH and its characteristics.

Predictive Value of Hypomineralization of Second Primary Molars for Molar Incisor Hypomineralization and Other Relationships between Both Developmental Defects of Dental Enamel

Molar incisor hypomineralization (MIH) and hypomineralized second primary molars (HSPM) are dental enamel developmental defects with significant prevalence and psychophysical impact, posing a public health concern. We examined the relationship between HSPM and MIH in 426 children aged 7 to 10 years (213 with MIH, 213 without MIH). The frequency of HSPM was higher in children with MIH (37.1% vs. 11.3%, p < 0.001). However, there was no correlation between MIH severity and presence of HSPM (p = 0.296). In patients with both defects (n = 79), 90% of severe MIH cases were associated with severe HSPM, while 87.8% of mild MIH cases were associated with mild HSPM (p < 0.001). The involvement of permanent incisors by MIH was not influenced by the presence of HSPM or HSPM severity. HSPM exhibited a positive predictive value of 76.7, negative predictive value of 58.8, sensitivity of 37.1% (95% CI = 30.6-43.6%), and specificity of 88.7% (95% CI = 84.5-93%). The odds ratio for MIH based on HSPM was 4.64 (95% CI). HSPM may serve as a predictor of MIH, but its absence does not rule out the occurrence of MIH. The results highlight the need for surveillance programs in children presenting with HSPM to facilitate early diagnosis and preventive measures for MIH-related complications.

Association of dental hypersensitivity and anxiety in children with molar-incisor hypomineralisation (MIH)

AIM

The objective of this study was to investigate whether dental hypersensitivity and dental fear were linked to the presence and severity of MIH.

METHODS

For this cross-sectional study, 1830 students between the ages of 6 and 12 years were recruited from four randomly selected schools. The Children's Fear Survey Schedule-Dental Subscale questionnaire was used to assess dental anxiety and fear. The children's self-reported dental hypersensitivity resulting from MIH was evaluated using the Wong-Baker Facial Scale and the Visual Analog Scale (VAS).

RESULTS

MIH was correlated with tooth hypersensitivity, particularly in severe cases. Dental fear was present in 17.4% of the children with MIH, but it was not associated with dental hypersensitivity, gender, or age.

CONCLUSION

No association was found between dental fear and dental hypersensitivity in children with MIH.

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.

Eruption Pattern of Third Molars in Orthodontic Patients Treated with First Permanent Molar Extraction: A Longitudinal Retrospective Evaluation

The aim of this study was to evaluate angular and positional changes in the second (M2) and third molars (M3) of orthodontically treated patients undergoing a first molar (M1) extraction. A retrospective longitudinal study with a sample of 152 pre- and post-treatment panoramic radiographs was conducted. Thirty-nine patients (51.3%) were orthodontically treated with M1 extraction and thirty-seven (48.7%) were treated without extraction. Angulations of M2 and M3 relative to the infraorbital (IOP) and the palatal planes (PP) were measured and compared between the groups before orthodontic treatment (T1) and after the completion of orthodontic space closure (T2). The prognosis of M3 eruptions was evaluated by assessing their horizontal and vertical position (inclination) using different classification systems. The angular (p < 0.001) and inclination improvement (p < 0.01) of the maxillary M3 was significant for the M1 extraction group. The mandibular M3 inclination significantly improved (p < 0.01), whereas the groups' angulation and vertical position were not significantly different. These findings suggest that extraction therapy has a favorable effect on the maxillary M2 and M3 angulation, but not on the mandibular. M1 extraction showed a signi- ficant effect on the horizontal position of M3 and thus may improve the eruption space and prognosis.

Molar-Incisor Hypomineralization: Prevalence Comparative Study in 6 Years of Interval

The aim of this study was to evaluate the prevalence evolution rate of MIH (molar-incisor hypomineralization) after a 6-year period in Araraquara/SP, Brazil. This population-based study evaluated MIH in 545 schoolchildren (6–12 years of age) and other associated alterations, dental caries and dental fluorosis (DF). A semistructured questionnaire was sent to the schoolchildren’s parents/guardians with the purpose of identifying the socioeconomic profile. Associations between MIH and the clinical characteristics were analyzed by the Poisson analysis of regression with robust variance, estimating the RPc (crude prevalence ratio) with CI 95%. The level of significance of 5% was adopted. The MIH prevalence in Araraquara/SP in 2016 was 14.3% (n = 78), and at this time, an increase of 2% was observed, in comparison with the data of the first prevalence study conducted in 2010 (12.3%). The mild degree compromise was the most prevalent diagnosis in the affected teeth (82.0%). Among children with MIH, the mean number of affected teeth was 2.78. Of the total number of children with MIH, 32.0% presented alterations in both first permanent molars and permanent incisors. There is no significant association between MIH and dental caries experience on permanent dentition (PRc = 1.141; CI 95% 0.709–1.835) or on primary dentition (PRc = 1.132; CI 95% 0.749–1.709). Children with MIH presented significantly less prevalence of dental fluorosis (PRc = 0.505; CI 95% 0.268–0.950). There is no association between MIH and monthly Brazilian minimal wage income (PRc = 1.130; CI 95% 0.655–1.949). It was concluded that the number of MIH cases had increased, revealing a greater need for defining the etiological factors and establishing a correct diagnosis to make it possible to institute early intervention.

Clinical Management of Molar Incisor Hypomineralization Affected Molars in a Pediatric Patient Including Endodontic Treatment, Case Report and Review of the Literature

The term molar incisor hypomineralization (MIH) describes the clinical manifestation of enamel hypomineralization of systemic origin affecting one or more permanent first molars and incisors. The purpose of this case report is to discuss the management of two mandibular molars with hypomineralization and to emphasize endodontic treatment for pediatric patients. An 8-year-old girl was referred to the pediatric dental clinic for restorations of multiple carious teeth. Upon clinical examination, based on the pattern of enamel hypomineralization and posteruptive breakdown presented, the diagnosis of MIH was established. As a part of the comprehensive treatment, one molar was restored with resin-based composite restorations. The other was endodontically involved and was treated with apexification and then covered with a stainless-steel crown. A two-year recall appointment revealed both molars to be free from signs and symptoms of inflammation. Management of MIH-affected molars should follow a conservative approach and endodontic treatment should be considered.

Molar-incisor hypomineralisation: an updated view for aetiology 20 years later

BACKGROUND

The term Molar-Incisor Hypomineralisation (MIH) was introduced in 2001 by Weerheijm, Jälevik and Alaluusua, and describes a defect of systemic origin that affects one to four first permanent molars, often associated with permanent incisors. In the past 20 years, this definition dictated the work regarding MIH prevalence, associated risk factors, association with dental caries, impact on quality of life, and therapeutic options.

PURPOSE

In this report, we offer an updated and comprehensive view of MIH centred on the patient and the tooth.

CONCLUSION

MIH today is globally recognized as a potential public health problem and it is not a defect of purely systemic origin but rather a condition with complex aetiology that in some instances may be the result of gene-environmental interactions.