Reabilitação de dente com hipoplasia de Turner: relato de caso / Rehabilitation of tooth with Turner's hypoplasia: case report

Os defeitos de esmalte são alterações qualitativas ou quantitativas na estrutura dentária, que originam-se de fatores sistêmicos, locais ou genéticos. A hipoplasia de Turner é um defeito na espessura do esmalte localizado cuja etiologia decorre de um traumatismo ou infecção periapical presente no dente decíduo predecessor, afetando o desenvolvimento do dente permanente. O objetivo do presente estudo foi apresentar um caso clínico de paciente infantil com dente hipoplásico de Turner em pré-molar, que tornou-se não vital sem que houvesse lesão de cárie ou trauma adicional. Em razão das características clínicas e radiográficas do dente afetado, bem como do risco de cárie e do comportamento cooperador da paciente, optou-se pela reabilitação do elemento afetado por meio de tratamento endodôntico e de restauração semidireta em resina composta. Torna-se de fundamental importância o conhecimento da etiologia e a realização de um exame clínico e radiográfico minucioso visando ao diagnóstico precoce e à elaboração de um plano de tratamento adequado para todos os defeitos de desenvolvimento do esmalte, incluindo-se a hipoplasia de Turner, cujo tratamento dependerá da severidade da alteração, do comportamento do paciente e do risco de cárie. Sugere-se a realização de estudos que associem a microestrutura do esmalte hipoplásico com a ausência de vitalidade pulpar.

Enamel defects are qualitative or quantitative changes in the tooth structure originating from systemic, local, or genetic factors. Turner's hypoplasia is a defect in the thickness of the localized enamel whose etiology arises from trauma or periapical infection in the predecessor deciduous tooth, affecting the permanent tooth's development. The objective of the present study was to present a clinical case of a child patient with a hypoplastic Turner premolar tooth, which became non-vital without the occurrence of caries, or additional trauma. Due to the affected tooth's clinical and radiographic characteristics, the risk of cavities, and the patient's cooperative behavior, it was decided to rehabilitate the affected element through endodontic treatment and semidirect restoration in composite resin. It is of fundamental importance to know the etiology and carry out a thorough clinical and radiographic examination aiming at early diagnosis and the development of an adequate treatment plan for all enamel developmental defects, including Turner's hypoplasia, whose treatment will depend on the severity of the change, the patient's behavior and the risk of caries. Studies are suggested to be carried out that associate the microstructure of hypoplastic enamel with the absence of pulp vitality.

Developmental Defects of Enamel.

Amelogenesis, the intricate process governing enamel formation, is susceptible to a range of genetic, systemic, and environmental influences, resulting in distinct developmental defects of enamel (DDE), such as molar incisor hypomineralisation (MIH), enamel hypoplasia, dental fluorosis, and amelogenesis imperfecta (AI). This chapter aims to provide a comprehensive overview of amelogenesis and DDE, establishing correlations between histopathological findings and clinical manifestations. MIH, a qualitative enamel defect, occurs during the mineralisation and maturation phases, affecting first permanent molars and eventually incisors. Diagnostic challenges in MIH arise from the disorder's unique features, including variable tooth involvement and severity, influenced by a complex interplay of genetic, systemic, and environmental factors. Enamel hypoplasia, a quantitative defect, manifests in any tooth during enamel matrix secretion. Etiological factors include local, systemic, environmental, and genetic influences, with variable enamel matrix abnormalities depending on the stage of amelogenesis when aggression occurred. Dental fluorosis, a toxicological concern from chronic and excessive fluoride exposure, affects ameloblasts and compromises crystal growth of the homologous teeth during enamel development. Lastly, AI, an inherited condition, encompasses diverse phenotypes in enamel development. AI phenotypes, whether hypoplastic or hypomineralised, entail mutations in genes, such as AMELX, ENAM, MMP20, KLK4, WDR72, FAM83H, C4ORF26, amelotin, GPR68, and ACPT. Diagnosing AI involves considering family history and clinical observation. In conclusion, navigating the intricacies of amelogenesis, from MIH to AI, underscores the critical importance of accurate diagnosis for proper clinical management of DDE.

Restorative Therapy of MIH-Affected Molars.

One fourth of teeth affected by molar incisor hypomineralisation (MIH) have required or will require treatment due to pain, sensitivity, or posteruptive breakdown. Restorative treatment becomes necessary in cases of severe MIH, characterized by posteruptive breakdown, which exhibits a wide range of clinical characteristics. Until approximately 20 years ago, all techniques, materials, and research were developed for treating caries lesions, not hypomineralisation. Research attempting to evaluate approaches to MIH treatment is recent and inconclusive. Therefore, there is still insufficient high-quality scientific evidence to establish a definitive clinical protocol for treating this condition. Recommendations based on best clinical practices can be provided rather than conclusions supported by a high level of evidence. To assist in clinical judgment regarding the best treatment strategy, eligible therapeutic options for restoring MIH-affected molars will be presented based on the strength and adhesive potential of the remaining hypomineralised enamel. The literature presents options for restorative materials ranging from direct alternatives such as glass ionomer cement and resin composite, through prefabricated devices, such as stainless-steel crowns and orthobands, to indirect restoration alternatives. However, it is essential to understand the indications of each restorative alternative and to know the restorative techniques, many of which are specifically developed to mitigate the difficulties encountered with the use of conventional techniques. Emphasis will be placed on the importance of adopting a personalized approach to restorative decision-making, considering the philosophy of minimal intervention dentistry and potential benefits for the patient's well-being and the family's needs.

MIH-Affected Substrate: An Overview of Adhesive Challenges to the Dental Structures.

Based on the current state of the art regarding molar incisor hypomineralisation (MIH)-affected enamel, bonding systems are expected to play a relevant role on the restorative procedures when required. MIH-affected enamel is often subjected to posteruptive breakdown combined or not with carious lesions, predominantly on molars, and may also affect the aesthetics of anterior teeth. As unbalanced mineral and protein contents occur, understanding these alterations is essential before selecting the most appropriate adhesive systems, while bearing in mind their limitations. In particular, when dentin is involved due to enamel breakdown, the use of functional monomer-based bonding systems present in self-etching and universal systems produce a chemical interaction that enhance the bonding. So far, the overall recommendation relies on placing the margin of the restoration on clinically sound enamel, regardless of the category of the adhesive system.

Factors Associated with Hypersensitivity, Management, and Treatment Options for Teeth with Molar Incisor Hypomineralisation.

Tooth hypersensitivity is a common symptom in molar incisor hypomineralisation (MIH) patients and can affect children's quality of life. During daily routine, children with MIH often report sensitivity to various thermal and mechanical stimuli, and difficulty in achieving effective analgesia is a common issue becoming a challenge for dentists. Research has focused on the possible pathophysiological mechanisms behind this phenomenon, which, in turn, have not been determined. Even with the apparently intact enamel of MIH-teeth, the porosity of the hypomineralised enamel acts as an open door for the invasion of oral microorganisms, which reach the dentinal tubules, and stimulate subclinical inflammatory reactions in the pulp. Tissue inflammation may, in turn, lead to morphological and cytochemical changes within sensory neurons, resulting in sensitization of these nerve fibers. This phenomenon is complex, and the treatment modalities focus on inflammation management followed by tubule obliteration by using different materials and technologies. In conclusion, this chapter reviews the concept and etiology of hypersensitivity in teeth with MIH and summarizes the clinical management according to the best evidence available.

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.

Molar Incisor Hypomineralisation Patient Assessment: Comprehensive Oral, Clinical Records and Behavior Evaluation.

Comprehensively evaluating molar incisor hypomineralisation (MIH) involves the integration of anamnesis and clinical data to diagnose, create a care plan, and predict prognoses. Anamnesis reveals relationships between defects and time, patient expectations, and impacts on the quality of life. Clinical studies emphasize posteruptive breakdown in yellow-brown opacities, highlighting the importance of identifying risk factors. The classification and recording of the clinical features associated with MIH are essential and allow for the longitudinal follow-up of the patient. Assessment of dental caries lesions, oral hygiene, and pain guides the care plan. Depending on the severity of MIH and associated symptoms, intraoral radiographs and cone beam computed tomography may be necessary. In cases of scheduled extractions, extraoral radiographs, photographs, and study models are indicated. Evaluations of the quality of life, aesthetic perception, and dental fear and anxiety provide valuable insights into the patient's emotional status and guide empathetic practice. A positive dental experience is based on communication with the patient, trust, and the proper use of behavior guidance techniques.

Implications of Histological and Ultrastructural Characteristics on the Chemical and Mechanical Properties of Hypomineralised Enamel and Clinical Consequences.

Molar incisor hypomineralisation (MIH) is a qualitative type of enamel defect, which occurs due to a failure in the biomineralisation process of the enamel organic matrix during amelogenesis. The tooth enamel affected by MIH shows changes in its chemical, structural, and mechanical properties, leading to different clinical repercussions. The color of MIH opacities varies from opaque white to yellow/brown, and elemental analyses of these lesions show a lower calcium and phosphate content, minerals that are more abundant in sound enamel. Furthermore, the incorporation of other molecules occurs, such as carbonate, a component that provides a greater degree of solubility, thus making hypomineralised enamel more susceptible to posteruptive fractures. At a structural level, the layer of hydroxyapatite crystals appears to be disorganized, with morphological changes, implying a greater degree of porosity in the structure. The increase in porosity of the structure may be associated with dental hypersensitivity, a common clinical repercussion among patients with MIH. Among the mechanical properties, a decrease in hardness and modulus of elasticity occurs, and this also makes the enamel more fragile. Deficiency in biomineralisation can be caused by changes in the function of ameloblasts or by failures at the intercellular junction that result in lower activity of proteases such as MMP-20 and KLK4. The increase in proteins in the organic matrix of enamel impairs the growth and incorporation of minerals into the hydroxyapatite crystals, so that the enamel becomes hypomineralised and has larger organic content, thus having an impact on its properties. These changes present in the enamel with MIH help to explain the clinical repercussions caused by this condition.

Uses of Internet for Obtaining and Sharing MIH-Related Information.

The Internet's increasing prevalence, along with the user-friendly nature of smartphones and the ease of access to virtual spaces, creates a vast and practical domain for digital communication. In this context, obtaining online information plays a crucial role in promoting health and preventing disease, facilitating individual and collaborative decision-making between patients and dental professionals. Digital information resources play a crucial role in providing guidance, support, and knowledge to the public and health care experts on molar incisor hypomineralisation (MIH). This chapter explores various dimensions related to MIH digital information, including a diverse array of digital platforms and the multifaceted landscape of health information-seeking behaviors. This chapter emphasizes the importance of accurate and reliable information dissemination in the digital era. It also sheds light on how understanding the dynamics of digital communication and health information-seeking behavior can improve accessibility and information quality for individuals facing the challenges of MIH.

Deciduous Teeth Hypomineralisation and Perinatal Risk Factors.

Hypomineralisation defects with demarcated opacities are also observed in the deciduous dentition and have been found to be a predictive factor for hypomineralisation defects in the permanent dentition. Deciduous molar hypomineralisation (DMH) represents a qualitative enamel defect primarily afflicting deciduous second molars, albeit its presence is not limited solely to deciduous second molars, as it can manifest in deciduous canines and first molars. Thus, the presence of demarcated hypomineralisation defects in deciduous teeth could be called as deciduous teeth hypomineralisation. Clinically, these defects are characterized by demarcated opacities, posteruptive enamel breakdown, atypical caries lesions, and atypical restorations. The accurate diagnosis of DMH continues to present a clinical challenge, and the reported prevalence of this defect exhibits notable variability across different countries. Its precise etiology remains elusive; however, there is a prevailing suspicion that events occurring during the prenatal, perinatal, or early postnatal periods, particularly those unfolding during the perinatal phase, are intricately linked to DMH development. Factors such as delivery complications, neonatal complications, prematurity, and low birth weight have been associated with DMH. Notably, there exists a possibility that, the more health-related events occur during this critical period, the greater the likelihood of a child presenting with this enamel defect. Nevertheless, the establishment of these associations warrants further investigation through prospective studies. Acquiring knowledge regarding the factors associated with this defect holds paramount importance for effective diagnosis, guidance for families with affected children, and the formulation of strategies to mitigate the incidence of these contributory factors.

Understanding the Enamel Disintegration and Posteruptive Breakdown of Demarcated Opacities on Molar Incisor Hypomineralisation.

This review aims to present scientific knowledge regarding the demarcated opacities of molar incisor hypomineralisation (MIH) and factors that clarify the occurrence of posteruptive enamel breakdown. The demarcated opacities have distinct boundaries with the adjacent nonaffected enamel and may vary in color among white, creamy, yellow, and brownish. The hypomineralised enamel is more porous and less organized than the nonaffected enamel. As a result of the reduced mineral content and higher protein content, the hypomineralised enamel shows a progressive reduction in its mechanical properties according to the opacity feature. Chemically, the protein content of MIH opacities is abnormally high, mainly composed by albumin, which is a serum protein usually not found in mature enamel. The highest protein content is seen in brown opacities, followed by yellow and white opacities, both with higher protein content than nonaffected enamel. The fact that the hypomineralised enamel is more fragile than the nonaffected enamel is supported not only by laboratorial findings but also by clinical prospective studies that observed an aggravation of MIH over time, as well as the correlation between the color of the demarcated opacities and the risk of posteruptive enamel breakdown. A better understanding about the microstructure of the hypomineralised enamel has relevant implications for the clinical approach of the condition. In the clinic, besides a comprehensive assessment of anamnesis and clinical data, it is advisable to record the color and the location of the opacities by tooth surface in order to support the treatment decisions and estimate a prognosis for MIH patients.

Re-Establishing the Esthetics of Incisors in Patients with Molar Incisor Hypomineralisation.

The awareness of molar incisor hypomineralisation (MIH) has led to its increased clinical detection, consequently drawing more attention to its associated complications. This text offers an overview of the esthetic management of anterior teeth affected by MIH, a condition characterized by enamel defects that present significant cosmetic challenges. The focus is on the clinical presentation of MIH characteristics, considering the depth of lesions and the clinical aspects, and the treatment protocols available, despite a lack of extensive scientific evidence. To the best of the current scientific knowledge, the text evaluates the potential of minimally invasive procedures, as well as the use of traditional composite resin techniques and their possible combinations, highlighting the critical role of esthetic considerations for the impacted anterior teeth. The chapter is augmented with five illustrative clinical cases that display the practical application of these treatment approaches. These examples articulate the clinical decision-making process and personalized restorative strategies, aiming to balance function with enhanced esthetic results. The described cases act as a roadmap for clinicians tackling the complexities of MIH treatment in the context of limited empirical evidence, providing insights into achieving both satisfactory and esthetically pleasing outcomes for patients suffering from this condition.

Systemic and Environmental Risk Factors Associated with Molar Incisor Hypomineralisation.

The etiology of molar incisor hypomineralisation (MIH) has been attributed to systemic and environmental factors since 2001. The identification of MIH etiology is fundamental to better understand this condition, for differential diagnosis, and to identify the patient group at risk of MIH. Although the etiology of MIH is still unclear, it is stated as a multifactorial origin, with an overlap of systemic and genetic risk factors. The aim of this chapter was to discuss the systemic and environmental factors associated with MIH according to scientific evidence in the literature, relating it to the basic knowledge of amelogenesis and tooth development chronology. In this chapter, amelogenesis is described and illustrated in detail. Some characteristics of the amelogenesis process could explain some clinical features of the developmental defect of enamel, especially MIH. The chronology of tooth development was also referred to as a characteristic for the occurrence of MIH. Finally, the literature about systemic and environmental risk factors was revised, and the prenatal, perinatal, and postnatal factors associated with MIH were discussed. During the prenatal period, maternal health status, including illnesses during pregnancy and maternal smoking, are the main investigated factors associated with MIH. Prematurity (<37 weeks), low birth weight, and cesarean delivery are the factors associated with MIH during the perinatal period. Moreover, postnatal factors, such as common childhood illnesses, respiratory disease, infections, and antibiotic use, have been associated with MIH. New longitudinal studies that consider the synergy between exposure to environmental factors and biological susceptibility are likely to provide a new understanding of the etiology of MIH.

Impact of Molar Incisor Hypomineralisation on Quality of Life.

Oral health-related quality of life (OHRQoL) is a multifaceted concept that surpasses an exclusively clinical perception and includes functional, social, emotional, and environmental issues. The measure of OHRQoL represents a holistic approach for research and clinical practice. Negative impacts of oral conditions on OHRQoL in childhood can reflect on health development, especially in a life stage marked by social and cognitive maturation. Therefore, such problems can impact negatively on the daily lives of the individuals and their families. Individuals with molar incisor hypomineralisation (MIH) experience more frequent posteruptive breakdown, an elevated risk of tooth decay, filling failures, the need for recurrent dental treatment, and a higher prevalence of dental hypersensitivity. Children with severe MIH may struggle with everyday activities, such as brushing their teeth, speaking, smiling, chewing, and consuming hot or cold foods. MIH-affected incisors may exhibit opacities that can impact the aesthetics of their smiles. This condition may discourage children from smiling and can indirectly affect their parents as well. The management modalities are focused on solving functional, aesthetic, and hypersensitivity problems and to evaluate OHRQoL values before and after therapies. Therefore, this chapter aims to discuss how MIH affects the OHRQoL of children and the questionnaires that can be used to evaluate that impact.

Molar Incisor Hypomineralisation: A Recent Condition or a New Perception?

The condition known as molar incisor hypomineralisation (MIH) has been featured in the dental literature for some time. However, the condition itself, characterized by demarcated opacities, had been observed and documented in various forms before the official terminology was coined. The awareness and understanding of MIH have increased over the years, and there has been ongoing research to explore its prevalence, etiology, clinical implications, care, and treatment. In summary, MIH is not a recent condition, but the terminology and recognition of this dental phenomenon have been refined and formalized in the relatively recent past. This chapter reflects on our clinical experience, juxtaposing it with information from scientific literature and personal insights, as well as identifying gaps in understanding this enamel defect. Furthermore, another aim was to foster contemplation for potential research advancements in the MIH field.

Is It Possible to Remineralise Hypomineralised Enamel Lesions in Patients with Molar Incisor Hypomineralisation?

Molar incisor hypomineralisation (MIH) is characterized with reduced enamel mineral quantity, especially in the calcium and phosphate content, with increases in the carbonate and protein contents. Albumin is the main protein that accumulates pre-eruptively, leading to defective initiation of mineralisation. Other oral-fluid proteins are found in cases of posteruptive enamel surface breakdown. Most of the lesions extend through the full thickness of enamel. Due to the lower mineral quantity and increased carbon and protein content, MIH teeth are more prone to fractures once exposed to mastication. In addition, susceptibility to dental caries is increased and hypersensitivity is common in MIH patients. For these reasons, MIH-affected teeth might benefit from exposure to remineralising agents that will decrease caries susceptibility and reduce sensitivity. Several in vitro, in situ, and in vivo studies have shown that improving the mineralisation of MIH teeth after eruption is possible, especially at the surface. However, complete resolution is difficult due to the depth/thickness of these lesions. In fact, the process is similar to posteruptive maturation. Thus, this nomenclature should be used instead of remineralisation. The evidence available so far indicates that among the several available remineralising agents, casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) cream and fluoride (F) varnish show the best results and are equally effective in remineralising MIH-affected teeth. Fluoride varnish demands no patient adherence, while CPP-ACP cream can be applied at home. However, it is important to consider that fluoride varnish is generally more economical than CPP-ACP cream. Consequently, the choice between these agents can be tailored to the patient's specific requirements.

Perceptions, attitudes, and clinical experiences of Brazilian dental practitioners towards molar incisor hypomineralisation: a cross-sectional study.

PURPOSE: To evaluate perceptions, attitudes, and clinical experience of Brazilian dental practitioners regarding molar incisor hypomineralisation (MIH). METHODS: An online survey with 27 questions, covering professional profile data, perceptions, and knowledge on clinical management of MIH, was employed. Descriptive analyses, chi-square, Fisher's exact, and Cramer's V tests were used. RESULTS: Sample comprised 100 participants, equally distributed between those working in private or public sectors. Most private sector practitioners had 21-30 years of clinical experience (28%) and master's degree (50%), while most public sector practitioners had 11-20 years of clinical experience (32%) and a PhD degree (32%). Most participants (86%) recognized MIH in their practice. Statistically significant differences were observed in frequency (p = 0.001), incidence (p = 0.039), and lesion type (p = 0.043) between practitioners from both sectors. Uncertainly in management was reported by 49%, mainly in public sector. For mild MIH in incisors, no treatment was chosen (43%), and the treatment longevity was the only significant factor reported (p = 0.012). In cases of mild MIH in first permanent molars (FPMs), 51% of respondents opted to keep the affected tissue and apply fissure sealant. Glass ionomer (GI) restoration was commonly indicated for FPMs with severe MIH with moderate loss of structure and sensitivity (38%). In cases with substantial structural loss and pulpal involvement, the most chosen treatment was endodontic intervention combined with preformed crowns. CONCLUSION: Brazilian dental practitioners face MIH in clinical practice. Although, public sector professionals are less confident in diagnosis and treatment, no significant differences in treatment preferences between public and private sector dental practitioners were identified.

Cost-Effectiveness of Managing MIH Teeth.

Numerous therapeutic approaches are available for managing molar incisor hypomineralisation (MIH); however, the cost-effectiveness of these strategies is underexplored. Economic evaluations are crucial for determining the optimal treatment approach to individual patients' requirements. We systematically reviewed the literature on the topic to have a more comprehensive discussion about these issues. Systematic searches were carried out. After a two-stage selection, 11 studies were included for synthesis. These studies could be divided into three groups according to the type of information given on costs: assumptions or deductions based on the literature (n = 6), cost collection on the available sources (n = 3), and cost-effectiveness evaluations (n = 2). The economic evidence on MIH management is still scarce and incipient. However, some important findings were produced for this evidence synthesis. A database of costs valuable in different contexts for therapeutic approaches related to MIH and its consequences was created. Furthermore, compiling and digesting the evidence on the cost-effectiveness of different approaches for managing severe MIH cases points out possible directions to be considered in decision-making that should consider these economic outcomes in different contexts and their powers of generalizability and also other aspects of evidence-based practice (e.g., professional and patients' preferences). Finally, there is an imminent need for economic evaluations focused on investigating the potential efficiency of preventive approaches for managing minor-compromised MIH teeth to postpone/avoid the severe consequences, which are more critical, complex, and costly to treat.

An inverse relationship between dental fluorosis and Molar Incisor Hypomineralization in Mexican schoolchildren in an area with a high concentration of fluoride in drinking water: A cross-sectional study.

AIM: To evaluate the association between the frequency and severity of dental fluorosis and Molar Incisor Hypomineralization (MIH) in 8-12-year-old schoolchildren living in an area with a high concentration of fluoride in the drinking water. METHODS: The present cross­sectional study was conducted on Mexican children (n = 573) selected from one community presenting a drinking water fluoride concentration of 1.39 ppm/F. The prevalence of dental fluorosis was ascertained using the Thylstrup and Fejerskov Index (TFI). The presence and severity of MIH was evaluated using the European Academy of Pediatric Dentistry (EAPD) criteria. A multinomial regression model was used to estimate the odds ratio (OR) and the 95% confidence intervals (CI), using the severity of MIH as the result. RESULTS: The prevalence of MIH was 37.7% and, by severity, was 16.1% mild, 14.3% moderate, and 7.3% severe. The prevalence of dental fluorosis in permanent dentition was 70.9% (TFI ≥1) and, by severity, was 29.2% (TFI = 0), 45.6% (TFI 1-3) and 25.3% (TFI ≥4), while 54.5% of subjects were found to have poor oral hygiene. Schoolchildren with fluorosis (TFI ≥4) were 49% less likely [OR = 0.51; p = 0.025] to present mild MIH than children with fluorosis (TFI <4). Similarly, children with fluorosis (TFI ≥4) were 53% [OR = 0.47; p = 0.019] and 62% [OR = 0.38; p = 0.036] less likely to present moderate and severe MIH than children with fluorosis (TFI <4). CONCLUSION: An inverse relationship between the presence of fluorosis and MIH was found. The results obtained by the present study may contribute to both the early identification of disorders affecting the enamel and the creation and implementation of long-term oral health prevention, promotion, and intervention programs in the affected population.

Prevalence of hypomineralized second primary molars and association with socioeconomic characteristics and dental caries in a Brazilian population of preschoolers: a cross-sectional study.

OBJECTIVE: To analyze the prevalence of hypomineralized second primary molar (HSPM) and its association with socioeconomic characteristics and dental caries in a Brazilian population of preschoolers. MATERIAL AND METHODS: 603 preschoolers, enrolled in public preschools in Itajaí (state of Santa Catarina, Brazil), took part in the study. To assess the participants' socio-economic characteristics, an original questionnaire was formulated and sent to the children's parents. The clinical evaluation was carried out by a calibrated examiner using the deft/DMFT index for dental caries and Ghanim et al. (Ghanim et al., Eur Arch Paediatr Dent, 2015) criteria for HSPM. The data were analyzed through Poisson regression, using STATA statistical software, and the association analyses were presented by prevalence ratios (PR). RESULTS: The prevalence of at least one HSPM-affected second molar was 24.5%. The prevalence of HSPM was associated to the city's geographical regions of the Educational hubs (p < 0.001). A significant association was found between dental caries and HSPM (p = 0.003; PR: 1.31; 95% CI 1.09-1.56). Children with HSPM were 31% more likely to experience dental caries than children without HSPM. Geographical regions of educational hubs were also significantly associated with HSPM (p < 0.001). None of the socioeconomic characteristics was associated with HSPM (p > 0.05). CONCLUSION: HSPM is a common developmental defect of enamel in children in our study. The HSPM distribution was associated with the city's geographic regions. Children with HSPM are more likely to experience dental caries. Socioeconomic characteristics were not associated with HSPM.