Aspectos clínicos y forenses del color rosa de los dientes: reporte de un caso / Clinical and forensic aspects of the pink color of teeth: report of a case

La coloración rosa de los dientes puede originarse por diferentes factores. En el ámbito forense se ha descrito al fenómeno denominado post mortem pink teeth como un signo asociado a muertes violentas de etiología diversa. En la práctica clínica también es posible observar pacientes con dientes rosados, fre-cuentemente ocasionados por traumatismos o iatro-genia proveniente de ortodoncia, cuyo mecanismo de producción obedece a distintas etiopatogenias, destacándose las reabsorciones dentinarias inter-nas, cemento-dentinarias externas y calcificaciones dentinarias. El presente artículo expone el caso de un individuo adulto con antecedente de trauma óseo-dentario por accidente vial que, luego de un prolon-gado tiempo, asiste al Servicio de Urgencias Odon-tológicas y Orientación de Pacientes de la Facultad de Odontología de la Universidad de Buenos Aires, en donde se le detecta, a modo de hallazgo exploratorio, una ostensible coloración rosada en el canino infe-rior derecho. La situación motivó un pormenorizado abordaje clínico y radiográfico, indagando respecto a los probables factores que intervinieron en su ge-neración y desarrollo (AU)

The pink coloration of the teeth can be caused by dif-ferent factors. In the forensic field, the phenomenon called post mortem pink teeth has been described as a sign associated with violent deaths of various etiology. In clinical practice, it is also possible to ob-serve patients with pink teeth, frequently caused by trauma or iatrogenesis from orthodontics, whose production mechanism is due to different etiopatho-genesis, highlighting internal dentin resorption, ex-ternal cemento-dentinal resorption and dentin calci-fications. This article presents the case of an adult individual with a history of bone-dental trauma due to a road accident who, after a long time, attends the Dental Emergency and Patient Guidance Service of the Faculty of Dentistry of the University of Bue-nos Aires, where an ostensible pink coloration was detected in the lower right canine as an exploratory finding. The situation motivated a detailed clinical and radiographic approach, inquiring about the probable factors that intervened in its generation and development (AU)

Relationship between cervical vertebral maturation and dental development in a sample of yemeni children and adolescents / Relación entre la maduración vertebral cervical y el desarrollo dental en una muestra de niños y adolescentes yemeníes

Objective: This study was conducted to investigate the relationship between dental development and cervical vertebral maturation stages in a group of Yemeni children and adolescents. Materials an Methods: The study included digital panoramic radiographs and lateral skull cephalograms obtained from 207 Yemeni subjects­122 females and 85 males aged between 8 to 18 years. Dental maturity was evaluated according to the method of Demirijian et al., calcification stages of the left mandibular canines, first and second premolars and second molars were assessed. Skeletal maturity was assessed by the cervical vertebral maturation (CVM) stages according to the method of Baccetti et al. Correlation between CVM and dental maturation was evaluated by Spearman rank-order correlation coefficient (SROCC). Results: CVM and dental calcification stages were highly correlated (p<0.001) in both genders, ranging from 0.686 to 0.873 for females and 0.787 to 0.871 for males. Calcification stages of the second molars showed the strongest correlation with CVM. Conclusion: Calcification stages of the second molar may be used as a reliable maturation indicator. Dental maturation may be applied to determine the skeletal maturity status of Yemeni children and adolescents.

Objetivo: Este estudio se realizó para investigar la relación entre el desarrollo dental y las etapas de maduración vertebral cervical en un grupo de niños y adolescentes yemeníes. Material y Métodos: El estudio incluyó radiografías panorámicas digitales y cefalogramas laterales del cráneo obtenidos de 207 sujetos yemeníes: 122 mujeres y 85 hombres de entre 8 y 18 años. La madurez dental se evaluó de acuerdo con el método de Demirijian et al. Se evaluaron las etapas de calcificación de los caninos mandibulares izquierdos, primer y segundo premolares y segundos molares. La madurez esquelética se evaluó mediante las etapas de maduración vertebral cervical (CVM) de acuerdo con el método de Baccetti et al. La correlación entre la CVM y la maduración dental se evaluó mediante el coeficiente de correlación de orden de rango de Spearman (SROCC). Resultado: Las etapas de CVM y calcificación dental estuvieron altamente correlacionadas (p<0.001) en ambos sexos, con un rango de 0.686 a 0.873 para las mujeres y 0.787 a 0.871 para los hombres. Las etapas de calcificación de los segundos molares mostraron la correlación más fuerte con CVM. Conclusión: las etapas de calcificación del segundo molar pueden usarse como un indicador de maduración confiable. La maduración dental puede aplicarse para determinar el estado de madurez esquelética de los niños y adolescentes yemeníes.

Assessment of skeletal maturity using the calcification stages of permanent mandibular teeth.

INTRODUCTION: Knowledge of the growth status of patients is essential to formulate and initiate a precise treatment plan. This study aimed at determining the role of calcification of permanent mandibular teeth for the assessment of skeletal maturity. METHODS: A cross-sectional study was conducted using lateral cephalograms and dental panoramic radiographs of 360 patients (ages 7-18 years) equally divided into six groups according to cervical vertebral maturation stages. Skeletal age was determined using Baccetti et al. method and dental age was calculated using Nolla and Demirjian methods. RESULTS: Mean chronological stage at CS5 revealed a significant difference between male and female subjects (p= 0.003), which showed that the latter achieved skeletal maturity one year earlier than the former. A significant difference (p= 0.007) was found for dental age using Nolla's stages at CS3, which showed females demonstrated a dental age of 1.4 years less than males. Mandibular canine showed the highest correlation with Demirjian index (DI) in males (rho = 0.818) and females (rho = 0.833). Mandibular second premolar showed the highest correlation with Nolla's stages in males (rho = 0.654) and females (rho = 0.664). CONCLUSION: Comparisons between sexes revealed that females are skeletally and dentally advanced. The DI indicated stage F and Nolla's stages identified stages 9, 10 to be indicative of CS2-3 for the mandibular canine and stages F and G and 9-10 for CS2-3 for the first premolars, second premolars and second molars, respectively.

Assessment of skeletal maturity using the calcification stages of permanent mandibular teeth

Abstract Introduction: Knowledge of the growth status of patients is essential to formulate and initiate a precise treatment plan. This study aimed at determining the role of calcification of permanent mandibular teeth for the assessment of skeletal maturity. Methods: A cross-sectional study was conducted using lateral cephalograms and dental panoramic radiographs of 360 patients (ages 7-18 years) equally divided into six groups according to cervical vertebral maturation stages. Skeletal age was determined using Baccetti et al. method and dental age was calculated using Nolla and Demirjian methods. Results: Mean chronological stage at CS5 revealed a significant difference between male and female subjects (p= 0.003), which showed that the latter achieved skeletal maturity one year earlier than the former. A significant difference (p= 0.007) was found for dental age using Nolla's stages at CS3, which showed females demonstrated a dental age of 1.4 years less than males. Mandibular canine showed the highest correlation with Demirjian index (DI) in males (rho = 0.818) and females (rho = 0.833). Mandibular second premolar showed the highest correlation with Nolla's stages in males (rho = 0.654) and females (rho = 0.664). Conclusion: Comparisons between sexes revealed that females are skeletally and dentally advanced. The DI indicated stage F and Nolla's stages identified stages 9, 10 to be indicative of CS2-3 for the mandibular canine and stages F and G and 9-10 for CS2-3 for the first premolars, second premolars and second molars, respectively.

Resumo Introdução: o conhecimento acerca do status de crescimento dos pacientes é essencial para se formular e iniciar um plano de tratamento preciso. Esse estudo teve como meta determinar a correlação entre a calcificação dos dentes inferiores permanentes e a avaliação da maturação esquelética. Métodos: um estudo transversal foi conduzido utilizando-se radiografias laterais e panorâmicas das arcadas de 360 pacientes (idades entre 7 e 18 anos), igualmente divididos em seis grupos, de acordo com os estágios de maturação esquelética das vértebras cervicais. A idade esquelética foi determinada utilizando-se o método de Baccetti, e a idade dentária foi calculada utilizando-se os métodos de Nolla e Demirjian. Resultados: o estágio cronológico médio em CS5 revelou uma diferença significativa entre os indivíduos do sexo masculino e do feminino (p= 0,003), demonstrando que as meninas alcançavam a maturação esquelética um ano antes dos meninos. Encontrou-se uma diferença significativa (p= 0,007) para a idade dentária utilizando-se os estágios de Nolla em CS3, o que revelou que as meninas exibiam uma idade dentária 1,4 anos inferior à dos meninos. Os caninos inferiores demonstraram a maior correlação com o índice de Demirjian (DI) tanto em indivíduos do sexo masculino (rho = 0,818) quanto do feminino (rho = 0,833). Já os segundos pré-molares inferiores revelaram a maior correlação com os estágios de Nolla, tanto em meninos (rho = 0,654) quanto em meninas (rho = 0,664). Conclusão: as comparações entre os sexos revelaram que as mulheres são mais precoces tanto no desenvolvimento dentário quanto no esquelético. O DI indicou o estágio F, e o método de Nolla identificou os estágios 9 e 10 como indicativos de CS2-3, para os caninos inferiores; e os estágios F e G, e 9 e 10 para CS2-3, para os primeiros e segundos pré-molares, e segundos molares, respectivamente.

Accuracy of dental development for estimating the pubertal growth spurt in comparison to skeletal development: a systematic review and meta-analysis.

OBJECTIVES: This study aimed to search for scientific evidence concerning the accuracy of dental development for estimating the pubertal growth spurt. METHODS: It was conducted according to the statements of PRISMA. An electronic search was performed in six databases, including the grey literature. The PICOS strategy was used to define the eligibility criteria and only observational studies were selected. RESULTS: Out of 1,416 identified citations, 10 articles fulfilled the criteria and were included in this systematic review. The association between dental development and skeletal maturity was considered strong in seven studies, and moderate in two, although the association with the pubertal growth spurt had been verified in only four articles. According to half of the studies, the tooth that provided the greater association with the ossification centres was the lower canine. The meta-analysis performed also indicated a positive association, being stronger in females [0.725 (0.649-0.808)]. However, when the method used for dental evaluation was considered, it was possible to verify greater correlation coefficients for Nolla [0.736 (0.666-0.814)] than for Demirjian [0.631 (0.450-0.884)], at the boys sample. The heterogeneity test reached high values (Q = 51.00), suggesting a potential bias within the studies. CONCLUSIONS: Most of individual studies suggested a strong correlation between dental development and skeletal maturation, although the association with the peakof pubertal growth spurtwas clearly cited only in some of them. However, due to the high heterogeneity found among the studies included in this meta-analysis, a pragmatic recommendation about the use of dental stages is not possible.

Relationship between dental calcification and skeletal maturation in a Peruvian sample.

OBJECTIVE:: the objective of the study was to determine the relationship between dental calcification stages and skeletal maturation in a Peruvian sample. METHODS:: panoramic, cephalometric and carpal radiographs of 78 patients (34 girls and 44 boys) between 7 and 17 years old (9.90 ± 2.5 years) were evaluated. Stages of tooth calcification of the mandibular canine, first premolar, second premolar, and second molar and the skeletal maturation with a hand-wrist and a cervical vertebrae method were assessed. The relationships between the stages were assessed using Spearman's correlation coefficient. Additionally, the associations of mandibular and pubertal growth peak stages with tooth calcification were evaluated by Fisher's exact test. RESULTS:: all teeth showed positive and statistically significant correlations, the highest correlation was between the mandibular second molar calcification stages with hand-wrist maturation stages (r = 0.758, p < 0.001) and with vertebrae cervical maturation stages (r = 0.605, p < 0.001). The pubertal growth spurt was found in the G stage of calcification of the second mandibular molar, and the mandibular growth peak was found in the F stage of calcification of the second molar. CONCLUSION:: there was a positive relationship between dental calcification stages and skeletal maturation stages by hand-wrist and cervical vertebrae methods in the sample studied. Dental calcification stages of the second mandibular molar showed the highest positive correlation with the hand-wrist and cervical vertebrae stages.

Relationship between dental calcification and skeletal maturation in a Peruvian sample

ABSTRACT Objective: the objective of the study was to determine the relationship between dental calcification stages and skeletal maturation in a Peruvian sample. Methods: panoramic, cephalometric and carpal radiographs of 78 patients (34 girls and 44 boys) between 7 and 17 years old (9.90 ± 2.5 years) were evaluated. Stages of tooth calcification of the mandibular canine, first premolar, second premolar, and second molar and the skeletal maturation with a hand-wrist and a cervical vertebrae method were assessed. The relationships between the stages were assessed using Spearman's correlation coefficient. Additionally, the associations of mandibular and pubertal growth peak stages with tooth calcification were evaluated by Fisher's exact test. Results: all teeth showed positive and statistically significant correlations, the highest correlation was between the mandibular second molar calcification stages with hand-wrist maturation stages (r = 0.758, p < 0.001) and with vertebrae cervical maturation stages (r = 0.605, p < 0.001). The pubertal growth spurt was found in the G stage of calcification of the second mandibular molar, and the mandibular growth peak was found in the F stage of calcification of the second molar. Conclusion: there was a positive relationship between dental calcification stages and skeletal maturation stages by hand-wrist and cervical vertebrae methods in the sample studied. Dental calcification stages of the second mandibular molar showed the highest positive correlation with the hand-wrist and cervical vertebrae stages.

RESUMO Objetivo: o objetivo do presente estudo foi determinar a correlação entre o estágio de calcificação dentária e a maturação esquelética, em uma amostra de indivíduos peruanos. Métodos: radiografias panorâmicas, cefalométricas e carpais de 78 pacientes (34 meninas e 44 meninos) com idades entre 7 e 17 anos (média = 9,90 ± 2,5 anos) foram avaliadas. Nelas, avaliaram-se os estágios de calcificação dentária (canino, primeiro pré-molar, segundo pré-molar e segundo molar inferiores) e de maturação esquelética, pelas avaliações radiográficas da mão e punho e das vértebras cervicais. As correlações entre esses estágios foram avaliadas usando-se o coeficiente de correlação de Spearman. Adicionalmente, a associação entre os estágios em que ocorreram os picos de crescimento mandibular e de crescimento puberal e o grau de calcificação dentária foi avaliada pelo teste exato de Fisher. Resultados: todos os dentes demonstraram correlações positivas e estatisticamente significativas. A correlação mais elevada foi verificada entre o estágio de calcificação do segundo molar inferior e o estágio de maturação esquelética da mão e do punho (r= 0,758, p < 0,001) e o estágio de maturação das vértebras cervicais (r = 0,605, p < 0,001). O surto de crescimento puberal foi identificado no estágio G de calcificação do segundo molar inferior, e o pico de crescimento mandibular foi detectado no estágio F de calcificação do segundo molar. Conclusão: na amostra estudada, houve uma correlação positiva entre os estágios de calcificação dentária e os estágios de maturação esquelética avaliada nas radiografias de mão e punho e das vértebras cervicais. Os estágios de calcificação dentária do segundo molar inferior demonstraram a mais alta correlação positiva com os estágios de maturação da mão e punho e das vértebras cervicais.

Avaliação da mineralização dos segundos molares inferiores como parâmetro para a classificação da idade biológica / Evaluation of the mineralization of permanent second molars as a parameter to classify the biological age of the individual

O presente trabalho teve como objetivo avaliar se a mineralização dos segundos molares inferiores permanentes pode ser usado como parâmetro para classificar a idade biológica do indivíduo. A amostra foi constituída por 129 radiografias panorâmicas, sendo 71 indivíduos do sexo feminino e 58 indivíduos do sexo masculino, na faixa etária de 7 anos à 12 anos e 1 mês. Para a análise da mineralização dental foi utilizada a tabela proposta por Nolla (1960). Os resultados da análise foram documentados numa planilha do programa Microsoft Excel 2010 contendo o nome completo, data de nascimento, data da tomada radiográfica, idade em anos e meses, número do prontuário, estágio de Nolla (1960) lado direito e lado esquerdo. Foi realizada a análise estatística (Mann-Whitney, Wilcoxon e correlação de Spearman) e pôde-se concluir que na amostra estudada não foi encontrado dimorfismo sexual, que a mineralização dentária ocorre de forma similar do lado direito e esquerdo, e que a mineralização dos segundos molares inferiores permanentes podem ser usadas como parâmetro para estimar a idade biológica e cronológica de um indivíduo.(AU)

This paper aimed to evaluate if the mineralization of permanent second molars can be used as a parameter to classify the biological age of the individual. The sample was composed of 129 panoramic radiographs, being 71 females and 58 males, aged 7 years and 12 years and 1 month. For the analysis of dental mineralization it was used a table proposed by Nolla (1960) with X-rays on the negatoscope (light box). The analysis results were documented in a Excel spreadsheet containing the full name, date of birth, date of the radiographic procedure, age in years and months, medical record number, stage of Nolla (1960) right and left side. Performed a statistical analysis, we concluded in our survey that the tooth mineralization occurs similarly in the right and left side, there is a certain precocity when compared to chronological age and the stage of mineralization in females compared to males. We also conclude that within the same chronological age, girls and boys have different mineralization stages, indicating that the dental mineralization can be used to identify the biological age, and the same is poorly correlated with chronological age.(AU)

Enamel and dentin mineralization in familial hypophosphatemic rickets: a micro-CT study.

OBJECTIVES: The aim of the present study was to analyse the mineralization pattern of enamel and dentin in patients affected by X-linked hypophosphatemic rickets (XLHR) using micro-CT (µCT), and to associate enamel and dentin mineralization in primary and permanent teeth with tooth position, gender and the presence/absence of this disease. METHODS: 19 teeth were collected from 5 individuals from the same family, 1 non-affected by XLHR and 4 affected by XLHR. Gender, age, tooth position (anterior/posterior) and tooth type (deciduous/permanent) were recorded for each patient. Following collection, teeth were placed in 0.1% thymol solution until µCT scan. Projection images were reconstructed and analysed. A plot profile describing the greyscale distance relationship in µCT images was achieved through a line bisecting each tooth in a region with the presence of enamel and dentin. The enamel and dentin mineralization densities were measured and compared. Univariate ANOVA and post hoc Tukey tests were used for all comparisons. RESULTS: Teeth of all affected patients presented dentin with a different mineralization pattern compared with the teeth of healthy patients with dentin defects observed next to the pulp chambers. Highly significant differences were found for gray values between anterior and posterior teeth (p < 0.05), affected and non-affected (p < 0.05), as well as when position and disease status were considered (p < 0.05). CONCLUSIONS: In conclusion, the mineralization patterns of dentin differed when comparing teeth from patients with and without FHR, mainly next to pulp chambers where areas with porosity and consequently lower mineral density and dentin defects were found.

Accuracy in the legal age estimation according to the third molars mineralization among Mexicans and Columbians.

OBJECTIVES: This study aims to assess the accuracy of age estimation according to two cut-off points of Demirjian's developmental stages (G and H) in the wisdom teeth, using panoramic radiographs from Colombian and Mexican teenagers. STUDY DESIGN: The degree of maturation of the third molars was classified according to Demirjian in 8 stages (from A to H) by a blinded trained assessor. The sensitivity, specificity and efficacy of two cut-off points (G and H) were calculated for both samples. RESULTS: The orthopantomographies of 316 subjects, 171 Colombians (54.1%) and 145 Mexicans (45.9%), were analyzed. The stage H was found to be the best threshold for detecting juveniles (because the high specificity) in all the third molars assessed. The specificity was higher for lower third molars than for upper third molars, but no asymmetrical discrepancy was noted. CONCLUSIONS: The stage H is the best cut-off point for detecting the adulthood when a high-specificity test is required.

Microstructure of mineralized tissues in human primary teeth.

UNLABELLED: The aim of this study was to analyze the structural characteristics of the mineralized dental tissues--enamel, dentin and cementum--in primary teeth and to correlate the histological aspects observed in function of the dental type--single-rooted or multi-rooted. METHOD: Eighteen human primary noncarious teeth were sectioned in facial-lingual (single-rooted) and mesio-distal direction (multi-rooted). One to three samples from each tooth were obtained. The samples were prepared by the ground technique and analyzed under light microscopy at different magnifications. A quantitative and descriptive analysis of the morphology of the mineralized tissues was performed. RESULTS: Spindles, tufts and lamellae were consistently observed mainly in the occlusal surface of the primary molars. The scalloped pattern of the dentinoenamel junction was not always present. The same was seen for zones of interglobular dentin. Dead tracts in dentin and tertiary dentin were observed mainly in single-rooted teeth below areas of dental attrition. Areas of cellular and acellular cementum were observed in the two dental types. CONCLUSIONS: Primary teeth have some structural peculiarities and these should be investigated concerning the clinical repercussion.

Influence of the degree of dentine mineralization on pulp chamber temperature increase during resin-based composite (RBC) light-activation.

OBJECTIVES: To analyse the influence of the degree of dentine mineralization on the pulp chamber temperature increase during composite light-activation. METHODS: Dentine discs (2mm thick) obtained from recently extracted teeth or those with extensive dentine sclerosis were analysed by FT-IR spectrometry in order to choose the two discs with the greatest difference in the degree of mineralization. A model tooth was set up with the dentine discs between a molar with the pulp chamber exposed and a crown with a standardized class II cavity. A K-type thermocouple was introduced into the molar root until it came into contact with the dentine discs and the cavity was filled with P60 resin composite. The temperature rise was measured for 120s after light-activation began: Standard (S) 600 mW/cm(2)/40s; Ramp (R) 0-->800 mW/cm(2)/10s+800 mW/cm(2)/10s; Boost (B) 85 0mW/cm(2)/10s and LED (L) 1.300 mW/cm(2)/40s (n=10). The same protocol was repeated after grinding the dentine discs to 1.0 and 0.5mm thickness. RESULTS: The temperature increase was significantly higher in dentine with high degree of mineralization (p<0.05). With respect to the dentine thickness, the following result was found: 2mm<1mm<0.5mm (p<0.05). The light-activation mode also presented significant difference as follows: S>R=L>B (p<0.05). CONCLUSIONS: The higher the degree of dentine mineralization the greater the increase in pulp chamber temperature. The temperature increase was influenced by the light-polymerization mode and dentine thickness.

Enamel remineralization: controlling the caries disease or treating early caries lesions?

The emphasis currently given to new technologies for enamel remineralization suggests that the changes in the understanding of the dental caries disease, which occurred in the last century, were either not yet adopted or were forgotten. Just like in the past, when the disease was "treated" by restoring cavities, there is presently a misunderstanding on the concept of incipient lesion remineralization. The aim of this paper was to review some concepts about caries, the natural phenomenon of enamel remineralization and the effect of fluoride (F) on it, and also to discuss the clinical relevance of remineralizing products recently launched in the marketplace aiming to "treat early caries lesions".

Enamel mineralization in the absence of maturation stage ameloblasts.

The role of maturation stage ameloblasts is not clear yet. The aim of this study was to verify to which extent enamel mineralizes in the absence of these cells. Maturation stage ameloblasts and adjacent dental follicle cells from rat lower incisors were surgically removed and the limits of this removal were marked by notches made in the enamel. Histological analysis confirmed that the ameloblasts had been removed within the limits of the notches. The teeth erupted and when the notches appeared in the mouth, the enamel in the experimental teeth was hard but whitish compared to the yellowish colour of the contralateral incisors used as control. SEM images revealed similar enamel rod arrangement in both groups. Decreased mineral content was observed in some specimens by polarized light microscopy, and microhardness values were much lower in the experimental teeth. FTIR analysis showed that higher amounts of protein were found in most experimental teeth, compared with the control teeth. Enamel proteins could not be resolved on 15% SDS-PAGE gels, suggesting that most of them were below 5kDa. These results suggest that the enamel matured in the absence of ameloblasts has increased protein content and a much lower mineral content, suggesting that maturation stage ameloblasts are essential for proper enamel mineralization.

Enamel remineralization: controlling the caries disease or treating early caries lesions?

The emphasis currently given to new technologies for enamel remineralization suggests that the changes in the understanding of the dental caries disease, which occurred in the last century, were either not yet adopted or were forgotten. Just like in the past, when the disease was "treated" by restoring cavities, there is presently a misunderstanding on the concept of incipient lesion remineralization. The aim of this paper was to review some concepts about caries, the natural phenomenon of enamel remineralization and the effect of fluoride (F) on it, and also to discuss the clinical relevance of remineralizing products recently launched in the marketplace aiming to "treat early caries lesions".

Influence of aging on biological properties of periodontal ligament cells.

The majority of patients eligible for periodontal regenerative therapies are aged subjects. Since periodontal ligament cells (PDLC) are essential for periodontal regeneration, the aim of the present study was to determine the effect of cellular aging on PDLC, including genes associated with extracellular matrix metabolism and growth-associated factors. PDLC cultures were obtained from subjects aged 15 to 20 years and subjects aged more than 60 years. Proliferation, cell viability, mineralization assays, and mRNA levels were assessed for type I and III collagen, platelet-derived growth factor (PDGF)-1, basic fibroblast growth factor (bFGF), metalloproteinase (MMP)-2 and-8, and tissue inhibitor of metalloproteinases (TIMP)-1 and-2. Data analysis demonstrated that aging negatively influenced cell proliferation and mineral nodule formation (p < 0.05). Gene expression analysis further showed that mRNA levels for bFGF, PDGF-1, and TIMP-2 were not affected by aging (p > 0.05). In addition, mRNA levels for type I and III collagen were significantly lower in aged cells (p < 0.05), whereas MMP-2 and-8 and TIMP-1 mRNA levels were higher (p < 0.05). Within the limits of the present study, data analysis suggests that aging modulates important biological properties of periodontal ligament cells, diminishes the potential for mineral nodule formation, and favors extracellular matrix degradation.

Immunology of root resorption: a literature review.

Root resorption seems to be related to a complex combination of mechanical factors and biological activity, which comprehends the role of immunologic structures including specialized cells. The aim of this research was to explain the development of the process--from mineralization to the destruction of hard tissues--and the possible relationship between root resorption and immunology, along with discussing current concepts described in the literature.

Radiographic evaluation of the chronological development of permanent dentition in children infected with HIV.

The objective of this study is to determine if there is an association between HIV infection in children and alterations in the chronological development of permanent dentition detectable by radiographic examination. The sample comprised two groups of children: (1) 50 children infected with HIV by vertical transmission and (2) 50 healthy children. The groups were paired according to age, sex, race, and socioeconomic level. After obtaining a panoramic radiograph, the stages of tooth calcification and the frequency of subjects showing alveolar eruption of the first and second mandibular permanent molars were determined. There was no significant difference in stages of tooth calcification and frequency of subjects showing alveolar eruption of the permanent molars between the groups (P > 0.05). Children infected with HIV by the vertical route showed upon radiographic examination stages of tooth calcification and alveolar eruption compatible with normal patterns. There is no association between HIV infection and alterations in the chronological development of the permanent teeth, detectable radiographically, in children infected by vertical transmission.

Characterization of glycosaminoglycans during tooth development and mineralization in the axolotl, Ambystoma mexicanum.

Glycosaminoglycans (GAGs) involved in the formation of the teeth of Ambystoma mexicanum were located and characterized with the cuprolinic blue (CB) staining method and transmission electron microscopy (TEM). Glycosaminoglycan-cuprolinic blue precipitates (GAGCB) were found in different compartments of the mineralizing tissue. Various populations of elongated GAGCB could be discriminated both according to their size and their preferential distribution in the extracellular matrix (ECM). GAGCB populations that differ in their composition could be attributed not only to the compartments of the ECM but also to different zones and to different tooth types (early-larval and transformed). Larger precipitates were only observed within the dentine matrix of the shaft of the early-larval tooth. The composition of the populations differed significantly between the regions of the transformed tooth: pedicel, shaft and dividing zone. In later stages of tooth formation, small-sized GAGCBs were seen as intracellular deposits in the ameloblasts. It is concluded that the composition of GAGCB populations seems to play a role in the mineralization processes during tooth development in A. mexicanum and influence qualitative characteristics of the mineral in different tooth types and zones, and it is suggested that GAGs might be resorbed by the enamel epithelium during the late phase of enamel formation.

Calcificaciones en los folículos de dientes retenidos / Calcifications in the follicles of impacted teeth

Los sacos foliculares, representan una estructura de frecuente manejo quirúrgico por parte de los odontólogos. La relativa escasa información de los mismos, así como su reconocida relación con neoformaciones de diferentes complejidades biológicas, conforman el propósito general del presente trabajo. Con el objetivo de precisar la relación existente entre las calcificaciones observadas en los SF y diferentes variables tales como la edd, sexo, localización anatómica y la presencia de restos epiteliales, se estudiaron 75 especímenes de acuerdo a un conjunto de criterios de exclusión. Los mismos fueron procesados por la técnica de inclusión en parafina y coloreados con hematoxilina y eosina, PAS y von Kossa. Los datos obtenidos fueron volcados en gráficos confeccionados al efecto para su ulterior análisis matemático. Se plantea una discusión sobre la presencia de las calcificaciones en estas estructuras como resultado de un fenómeno distrófico o metaplásico. Del mismo modo, se presentan ilustraciones que describen las más frecuentes formas de presentación de estas calcificaciones inmersas en los SF. Es de destacar que el procedimiento estadístico evidenció dependencia entre la variable localización anatómica y las calcificaciones