Monographs in oral science最新文献

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.

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.

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.

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.

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.

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.

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.

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.

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.