Evaluation of the effectiveness of the Chronological Dental Mineralization Table of Permanent Teeth among Brazilians in the city of Belo Horizonte

The knowledge of an individual age, especially children and young people, is important in civil and criminal cases, such as adoption and when is important determining criminal imputability. To estimate this age, when there are no suitable documents to prove it, body development factors are used, especially those that show the stages of mineralization of the teeth. To this estimation, numerous tables have been developed in the most diverse regions. The aim of this study was to analyze the accuracy of the Chronological Table of Mineralization of Permanent Teeth among Brazilians in a region different from that in which the method was developed, namely, Vale do Paraíba (SP - Brazil). For this purpose, 442 panoramic radiographs of individuals aged 5 years to 20 years and 4 months, taken in the central region of the city of Belo Horizonte (MG), were used. After applying the table, with the determination of the stages of each tooth present in the radiograph and an average between them, using the data developed by the authors, the total average percentage of correct answers was 63.5%, showing a low number, especially in the age range of 14 to 17 years. When the estimate was analyzed for sexual dimorphism, no significant differences were found. Through this study, one can perceive a need for standardization and detailing in the methodology, besides its updating and complementation with data that encompass dental development in the different regions of the country.

Prevalence of low alkaline phosphatase activity in laboratory assessment: Is hypophosphatasia an underdiagnosed disease?

Background Tissue-nonspecific alkaline phosphatase (TNSALP) encoded by the ALPL gene is of particular importance for bone mineralization. Mutation in the ALPL gene can lead to persistent low ALP activity resulting in the rare disease Hypophosphatasia (HPP) that is characterized by disturbed bone and dental mineralization. While severe forms are extremely rare with an estimated prevalence of 1/100.000, recent studies suggest that moderate form caused by heterozygous mutations are much more frequent with an estimated prevalence of 1/508. The purpose of this study was to estimate the prevalence of low AP levels in the population based on laboratory measurements. Methods In this study, the prevalence of low AP activity and elevated pyridoxal-5-phosphate (PLP) levels was analyzed in 6.918.126 measurements from 2011 to 2016 at a single laboratory in northern Germany. Only laboratory values of subjects older than 18 years of age were included. Only the first measurement was included, all repeated values were excluded. Results In total, 8.46% of the measurements of a total of 6.918.126 values showed a value < 30 U/L. 0.59% of the subjects with an ALP activity below 30 U/L had an additional PLP measurement. Here, 6.09% showed elevated pyridoxal-5-phosphate (PLP) levels. This suggest that 0.52% (1:194) of subjects show laboratory signs of HPP. Conclusion These data support the genetic estimation that the prevalence of moderate forms of HPP may be significantly higher than expected. Based on these data, we recommend automatically measurement of PLP in the case of low ALP activity and a notification to the ordering physician that HPP should be included in the differential diagnosis and further exploration is recommended.

TNAP: A New Multitask Enzyme in Energy Metabolism

Tissue-nonspecific alkaline phosphatase (TNAP) is mainly known for its necessary role in skeletal and dental mineralization, which relies on the hydrolysis of the mineralization inhibitor inorganic pyrophosphate (PPi). Mutations in the gene encoding TNAP leading to severe hypophosphatasia result in strongly reduced mineralization and perinatal death. Fortunately, the relatively recent development of a recombinant TNAP with a bone anchor has allowed to correct the bone defects and prolong the life of affected babies and children. Researches on TNAP must however not be slowed down, because accumulating evidence indicates that TNAP activation in individuals with metabolic syndrome (MetS) is associated with enhanced cardiovascular mortality, presumably in relation with cardiovascular calcification. On the other hand, TNAP appears to be necessary to prevent the development of steatohepatitis in mice, suggesting that TNAP plays protective roles. The aim of the present review is to highlight the known or suspected functions of TNAP in energy metabolism that may be associated with the development of MetS. The location of TNAP in liver and its function in bile excretion, lipopolysaccharide (LPS) detoxification and fatty acid transport will be presented. The expression and function of TNAP in adipocyte differentiation and thermogenesis will also be discussed. Given that TNAP is a tissue- and substrate-nonspecific phosphatase, we believe that it exerts several crucial pathophysiological functions that are just beginning to be discovered.

Age estimation by analysis of dental mineralization and its forensic contribution

Age is an important factor in the formation of the uniqueness of individuals. The procedure for assessing age in situations that cannot determine chronological age, especially in court cases, is mandatory. The literature presents different methods to estimate the age of individuals because civil and criminal majority at 18 years is a milestone in Brazil and other countries. Thus, age estimation through the analysis of dental mineralization stages is important, as it is rarely affected by exogenous or endogenous factors. This study evaluates different methods used to estimate age through dental mineralization and its forensic contribution. The following databases were used: PubMed, Medline, Scopus, Web of Science, and Google Scholar, using the descriptors "age estimation", "dental age estimation", and "forensic dentistry", both isolated and combined. It was verified the reliability of the analysis of dental mineralization stages for age estimation. Some of the methods used for this purpose have not been tested in Brazilian individuals. There are no up-to-date data on mineralization stages of permanent teeth for this population. Thus, current and specific data from the Brazilian population are required because the results to be obtained from new studies could benefit society, assisting the clarification of Justice in real-life situations.

Correlation between different methods of assessing bone maturation

<p><strong>Introduction</strong>: the skeletal maturity of na individual can be evaluated through different methods and it is an important tool to the<br />diagnostic and treatment in othodontics. <strong>Objective</strong>: to verify the correlation between different methods of assessing bone maturation:<br />Carpal Maturation Index (CMI), Cervical Vertebrae Maturation Stages (CVM) and Dental Mineralization Stages (DM). <strong>Methodology</strong>:<br />the sample consisted of digitalized images of cephalometric, panoramic and hand and wrist radiographs of 73 patients. 50 were<br />selected for analysis. Two examiners were properly calibrated, through images analysis from another database. Inter and intraexaminer<br />reliability was measured by Kappa coefficient. The images were assessed according to Fishman (1982), Baccetti, Franchi and<br />McNamara Junior (2002) and Nolla (1960) methods. All images were coded and data of all analyzes was transferred to spreadsheets.<br />The data was processed in Matlab program for Windows, version 7.10.0, and analyzed using descriptive and inferential statistics.<br /><strong>Results</strong>: the results demonstrated a positive correlation among bone maturity methods (CMI, CVM and DM), as well as between those<br />methods and chronological age. Females showed precocity in reaching the stages of skeletal maturation indicators and CVM compared<br />to males. It was observed that there was a correspondence between maturation methods for both genders. <strong>Conclusion</strong>: there was<br />a correlation between skeletal maturation assessment methods and dental mineralization in patients. Significant differences were<br />observed between genders for skeletal maturity assessment methods. There was a relation between the methods used for skeletal<br />maturation and dental mineralization, as well as chronological age.</p>

TNAP as a therapeutic target for cardiovascular calcification: a discussion of its pleiotropic functions in the body

Cardiovascular calcification (CVC) is associated with increased morbidity and mortality. It develops in several diseases and locations, such as in the tunica intima in atherosclerosis plaques, in the tunica media in type 2 diabetes and chronic kidney disease, and in aortic valves. In spite of the wide occurrence of CVC and its detrimental effects on cardiovascular diseases (CVD), no treatment is yet available. Most of CVC involve mechanisms similar to those occurring during endochondral and/or intramembranous ossification. Logically, since tissue-nonspecific alkaline phosphatase (TNAP) is the key-enzyme responsible for skeletal/dental mineralization, it is a promising target to limit CVC. Tools have recently been developed to inhibit its activity and preclinical studies conducted in animal models of vascular calcification already provided promising results. Nevertheless, as its name indicates, TNAP is ubiquitous and recent data indicate that it dephosphorylates different substrates in vivo to participate in other important physiological functions besides mineralization. For instance, TNAP is involved in the metabolism of pyridoxal phosphate and the production of neurotransmitters. TNAP has also been described as an anti-inflammatory enzyme able to dephosphorylate adenosine nucleotides and lipopolysaccharide. A better understanding of the full spectrum of TNAP’s functions is needed to better characterize the effects of TNAP inhibition in diseases associated with CVC. In this review, after a brief description of the different types of CVC, we describe the newly uncovered additional functions of TNAP and discuss the expected consequences of its systemic inhibition in vivo.

Expression of Phosphate Transporters during Dental Mineralization

The importance of phosphate (Pi) as an essential component of hydroxyapatite crystals suggests a key role for membrane proteins controlling Pi uptake during mineralization in the tooth. To clarify the involvement of the currently known Pi transporters (Slc17a1, Slc34a1, Slc34a2, Slc34a3, Slc20a1, Slc20a2, and Xpr1) during tooth development and mineralization, we determined their spatiotemporal expression in murine tooth germs from embryonic day 14.5 to postnatal day 15 and in human dental samples from Nolla stages 6 to 9. Using real-time polymerase chain reaction, in situ hybridization, immunohistochemistry, and X-gal staining, we showed that the expression of Slc17a1, Slc34a1, and Slc34a3 in tooth germs from C57BL/6 mice were very low. In contrast, Slc34a2, Slc20a1, Slc20a2, and Xpr1 were highly expressed, mostly during the postnatal stages. The expression of Slc20a2 was 2- to 10-fold higher than the other transporters. Comparable results were obtained in human tooth germs. In mice, Slc34a2 and Slc20a1 were predominantly expressed in ameloblasts but not odontoblasts, while Slc20a2 was detected neither in ameloblasts nor in odontoblasts. Rather, Slc20a2 was highly expressed in the stratum intermedium and the subodontoblastic cell layer. Although Slc20a2 knockout mice did not show enamel defects, mutant mice showed a disrupted dentin mineralization, displaying unmerged calcospherites at the mineralization front. This latter phenotypical finding raises the possibility that Slc20a2 may play an indirect role in regulating the extracellular Pi availability for mineralizing cells rather than a direct role in mediating Pi transport through mineralizing plasma cell membranes. By documenting the spatiotemporal expression of Pi transporters in the tooth, our data support the possibility that the currently known Pi transporters may be dispensable for the initiation of dental mineralization and may rather be involved later during the tooth mineralization scheme.