Evaluation of Pediatric Patient's Age, Behaviors, and Reasons for the First Dental Visit in Edirne, Turkey: a Cross-Sectional Study / Evaluación de la edad, los comportamientos y las razones de la primera visita dental del paciente pediátrico en Edirne, Turquía: un estudio transversal

ABSTRACT: Oral and dental health are vital parts of general baby health, and early dental visits provide significant prevention-focused intervention and parental counseling regarding oral health. Evaluating the age and main complaints of children is therefore important during their first dental visit (FDV). The purposes of this study were to determine the age, reason for the visit, behavioral response, and caries status at the FDV and to evaluate the factors affecting these parameters. Parents of 325 pediatric patients (159 males; 166 females; mean age 7.20±2.78 years) at their FDV were asked to fill out a questionnaire requesting sociodemographic information and their child's medical history, brushing habits, and reasons for attending dental consultation. The decayed-missing-filled-teeth (dmft/DMFT) scores were also recorded. The child's behavioral responses during the FDV were evaluated according to Frankl's Behavior Rating Scale (FBRS). Higher maternal education level and dmft/DMFT score were associated with earlier FDV age. The most common reason for the FDV was dental caries in 33.5% of patients, followed by toothache (29.5%). Most of the children showed positive behavior (46.7%), with positive behavior affected by age and negative behavior affected by the dmft/DMFT score and distance from home. The mean dmft/ DMFT score was 8.1±4.4 and was negatively affected by toothbrushing frequency and family income. These study results indicate that Turkish children living in Edirne present at a late age for the FDV. Raising awareness in terms of dental health care among parents is important to ensure that children attend their FDV at an early age.

RESUMEN: La salud oral y dental son partes vitales de la salud general del bebé, y las visitas dentales tempranas brindan una importante intervención centrada en la prevención y asesoramiento a los padres sobre la salud bucal. Por lo tanto, evaluar la edad y las principales quejas de los niños es importante durante su primera visita al dentista (FDV por sus siglas en inglés). El propósito de este estudio fue determinar la edad, motivo de visita, respuesta conductual y estado de caries en la FDV y evaluar los factores que afectan estos parámetros. A los padres de 325 pacientes pediátricos (159 hombres; 166 mujeres; edad media 7,20±2,78 años) en su FDV se les pidió que llenaran un cuestionario solicitando información sociodemográfica y el historial médico de su hijo, hábitos de cepillado y motivos de presentación a la consulta dental. También se registraron las puntuaciones de dientes cariados-faltantes-obturados (dmft/DMFT). Las respuestas conductuales del niño durante la FDV se evaluaron de acuerdo con la escala de calificación de conducta de Frankl (FBRS). Un mayor nivel de educación materna y una puntuación de dmft/DMFT se asociaron con una edad más temprana de la FDV. La causa más común de la FDV fue la caries dental en el 33,5% de los pacientes, seguida del dolor de muelas (29,5%). La mayoría de los niños mostró un comportamiento positivo (46,7%), con un comportamiento positivo afectado por la edad y un comportamiento negativo afectado por el puntaje dmft/DMFT y la distancia del hogar. La puntuación media de dmft/DMFT fue de 8,1±4,4 y se vio afectada negativamente por la frecuencia de cepillado de dientes y los ingresos familiares. Los resultados de este estudio indican que los niños turcos que viven en Edirne se presentan a una edad avanzada para la FDV. Es importante concienciar a los padres sobre el cuidado de la salud dental para garantizar que los niños asistan a su FDV a una edad temprana.

Crown formation times of deciduous teeth and age at death in neolithic newborns / Tiempos de formación de la corona de los dientes deciduos y edad al morir en neonatos neolíticos

SUMMARY: The aim of the present study was to investigate the possibility of estimating crown formation times of immature deciduous teeth and age at death in Neolithic newborns. In the Neolithic-Mesolithic transition, the health of the population deteriorated. Leaving the intrauterine environment for the newborn is the first obstacle in the process of adaptation and survival in the outside world. The fetus is protected by the mother's immune system and receives the necessary nutrients through the umbilical cord, but external factors indirectly affect its development. At birth deciduous teeth are not fully formed and are only partially mineralized. Variations in the rhythmic activity of ameloblasts and the secretion of the enamel matrix lead to the formation of incremental lines in the enamel. The sample consisted of unerupted deciduous teeth removed from the baby jaws from Neolithic archaeological graves, LepenskiVir Serbia. The skeletal age of the babies was from 38 to 40 gestational weeks. The daily enamel apposition rate was obtained for each tooth. The age of individuals was estimated using crown formation time. The average value of daily secretion rates for the primary teeth from the Neolithic age was 3.78 µm. There was no statistically significant difference in age at death determined by skeletal age assessment and crown formation time. Three babies were born preterm. The results of the present study show that the calculation of the time required for the formation of deciduous tooth enamel is applicable to archaeological samples of newborns.The age estimation using crown formation time together with the analysis of other anthropological parameters, can contribute to a more accurate determination of neonatal death in anthropological, archaeological and forensic contexts.

RESUMEN: El objetivo del estudio fue investigar la posibilidad de estimar el tiempo de formación de la corona de los dientes deciduos inmaduros y la edad, al momento de la muerte en neonatos neolíticos. Durante la transición Neolítico-Mesolítico, la salud de la población deterioró significativamente. Para el recién nacido dejar el medio intrauterino es el primer obstáculo en el proceso de adaptación y supervivencia en el mundo exterior. El feto está protegido por el sistema inmunológico de la madre y recibe los nutrientes necesarios a través del cordón umbilical, pero factores externos afectan indirectamente su desarrollo. Al nacer, los dientes deciduos no están completamente formados y solo están parcialmente mineralizados. Las variaciones en la actividad rítmica de los ameloblastos y la secreción de la matriz del esmalte conducen a la formación de líneas incrementales en el esmalte. La muestra consistió en dientes sin erupción extraídos de las mandíbulas de neonatos de tumbas arqueológicas neolíticas, LepenskiVir Serbia. La edad esquelética de los bebés fue de 38 a 40 semanas de gestación. Se obtuvo la tasa diaria de aposición de esmalte para cada diente. La edad de los individuos se estimó utilizando el tiempo de formación de la copa. El valor promedio de las tasas de secreción diaria para los dientes temporales del Neolítico fue de 3,78µm. No hubo diferencia estadísticamente significativa en la edad al momento de la muerte determinada por la evaluación de la edad esquelética y el tiempo de formación de la corona. Tres bebés nacieron prematuros. Los resultados del presente estudio muestran que el cálculo del tiempo requerido para la formación del esmalte dental deciduo es aplicable a muestras arqueológicas de recién nacidos. La estimación de la edad utilizando el tiempo de formación de la corona junto con el análisis de otros parámetros antropológicos, puede contribuir a una mayor determinación precisa de la muerte neonatal en contextos antropológicos, arqueológicos y forenses.

Orden y cronología de brote de dientes temporales / Order and chronology of temporary teeth breaking

El orden y cronología del brote dentario temporal es una expresión del crecimiento del niño e influye en su posterior desarrollo dental y maxilofacial. Tener un conocimiento sobre la edad promedio de brote de cada diente es útil para establecer un diagnóstico, prevención y tratamiento de maloclusiones por lo cual el objetivo de esta investigación es caracterizar el patrón de brote de la dentición temporal en niños y niñas del municipio Cerro, La Habana, Cuba. Para ello se diseñó un estudio observacional descriptivo en 370 niños de ambos sexos entre 0 a 36 meses de edad, el estudio se desarrolló entre septiembre de 2017 a enero de 2020. Se estudiaron las variables: edad, sexo, diente, hemiarcada y cronología del brote dentario. Se realizaron distribuciones de frecuencia a todas las variables en estudio y se presentan los resultados en tablas estadísticas. Se utilizó la prueba t-Student para verificar las diferencias significativas. Los resultados principales obtenidos fueron que los dientes de maxilares brotaron antes que los mandibulares, a excepción de los incisivos centrales y el incisivo lateral inferior izquierdo. A pesar de que el brote dentario comenzó primero en individuos de sexo masculino en ambas arcadas (5,86 meses en el maxilar, ± 0,92; y en la mandíbula 4,92 meses ± 1,09), el período de tiempo de brote fue algo más rápido en el sexo femenino (19,83 meses en el maxilar y 21,64 meses en la mandíbula ) y los masculinos (20,26 meses y 22,16 meses), pero sin diferencias significativas (p<0,05). Se concluye que el patrón de brote fue similar al descrito en la literatura, excepto por discreto adelanto para los incisivos centrales y retraso en segundos molares temporales

The order and chronology of the temporary tooth eruption is an expression of the child's growth and influences his later dental development. Having knowledge about the average age of emergence of each tooth is useful to establish a diagnosis, prevention and treatment of malocclusions, for which the objective of this research is to characterize the pattern of emergence of primary dentition in children in Cerro district, Havana, Cuba. For this, a descriptive observational study was designed in 370 children of both sexes between 0 and 36 months of age, in said clinic during September / 2017 to January / 2020. The variables were studied: age, sex, tooth, hemiarcade and chronology of the dental outbreak. Frequency distributions were made to all the variables under study and the results are presented in statistical tables. The t-Student test was used to verify significant differences. The main results obtained were that the teeth of the maxillary arch erupted before those of the mandibular, except for the central incisors and the lower left lateral incisor. Although the fact that the dental flare began first in males in both arches (5,86 months in the maxilla, ± 0,92; and in the mandible 4,92 months ± 1,09), the time period of outbreak was somewhat faster in females (19,83 months in the maxilla and 21,64 months in the mandible) and males (20,26 months and 22,16 months), but without significant differences (p <0, 05). It is concluded that the eruption pattern was similar to that described in the literature, except for slight advancement for the central incisors and delay in second primary molars

Assessment of physiological disturbances during pre- and early postnatal development based on microscopic analysis of human deciduous teeth from the Late Epipaleolithic site of Shubayqa 1 (Jordan).

OBJECTIVES: To study pre- and early postnatal tooth formation and to analyze the effects of physiological disturbances on enamel and dentin formation in deciduous teeth of infants from the Late Epipaleolithic (Natufian) site Shubayqa 1. MATERIALS AND METHODS: Ten deciduous teeth from six infants (ages at death between 21 and 239 days) were analyzed by light and scanning electron microscopy. RESULTS: Marked prism cross-striations and an abnormal wavy course of the prisms were recorded in pre- and postnatal enamel of all analyzed teeth. Single or multiple accentuated incremental lines were observed in prenatal enamel of nine teeth and in postnatal enamel of eight teeth. Accentuated Andresen lines and broader zones exhibiting an enhanced calcospheritic pattern were recorded in the pre- and postnatally formed dentin of nine teeth. DISCUSSION: The structural abnormalities in the pre- and postnatally formed enamel of the infants are considered indicative of chronic stress that negatively affected the activity of secretory ameloblasts. The structural aberrations in pre- and postnatal dentin denote that odontoblasts were also affected by this stress. The presence of single or multiple accentuated incremental lines in pre- and postnatal enamel is interpreted as reflecting (short-term) impacts of higher intensity superimposed on the chronic stress. Our findings suggest compromised maternal health affecting the late fetus and compromised health in newborns. Although limited by the small number of analyzed individuals, the present study contributes to the knowledge of maternal and early infant health conditions in Late Epipaleolithic populations.

Variation in the timing of enamel formation in modern human deciduous canines.

OBJECTIVES: Deciduous canines are now used increasingly in archaeological and forensic studies to establish the time of birth and as a retrospective source of trace elements incorporated into enamel before and after birth. However, data on the variability of deciduous enamel formation times are scarce. Our objectives were to use daily incremental markings to estimate daily secretion rates, the timing of prenatal, postnatal and total enamel formation and any changes in enamel coverage or prism and stria orientation that occur during enamel formation. MATERIALS AND METHODS: Longitudinal ground sections of 81 deciduous canines were studied with transmitted light microscopy. High-resolution digital images were imported from an Olympus VS-120 virtual slide scanning system into a geographic information system (ArcGIS, ESRI USA) for quantitative and statistical analyses of linear, angular and area measurements of buccal enamel. RESULTS: Daily rates of enamel secretion close to the EDJ were faster than in permanent enamel (3.23 µm/day, SD = 0.54). Prism and stria angles subtended to the EDJ both increased through crown formation. Enamel coverage was low in the cusp and cervix but maximal ∼150 days after birth. The mean prenatal enamel formation time was 118 days (range 60-150, SD, 29.2, n = 24). The overall mean postnatal enamel formation time was 319 days (range 210-420, SD 50.6, n = 67). CONCLUSIONS: Daily enamel secretion rates compared well with previous studies of deciduous enamel, however, enamel extension rates in deciduous cuspal enamel were notably lower. The variability of both prenatal and postnatal deciduous enamel formation times was greater than previously reported.

Developmental origins and homologies of the hyracoid dentition.

Understanding the origins of morphological specializations in mammals is a key goal in evolutionary biology. It can be accomplished by studying dental homology, which is at the core of most evolutionary and developmental studies. Here, we focused on the evolution and development of the specialized dentition of hyraxes for which dental homologies have long been debated, and could have implications on early placental evolution. Specifically, we analysed dental mineralization sequences of the three living genera of hyraxes and 17 fossil species using X-ray computed microtomography. Our results point out the labile position of vestigial upper teeth on jaw bones in extant species, associated with the frequently unusual premolar shape of deciduous canines over 50 Ma of hyracoid evolution. We proposed two evolutionary and developmental hypotheses to explain these original hyracoid dental characteristics. (a) The presence of a vestigial teeth on the maxilla in front of a complex deciduous canine could be interpreted as extra-teeth reminiscent of early placental evolution or sirenians, an order phylogenetically close to hyracoids and showing five premolars. (b) These vestigial teeth could also correspond to third incisors with a position unusually shifted on the maxilla, which could be explained by the dual developmental origin of these most posterior incisors and their degenerated condition. This integrative study allows discussion on the current evolutionary and developmental paradigms associated with the mammalian dentition. It also highlights the importance of nonmodel species to understand dental homologies.

Morphometric characterization of the very young child mandibular growth pattern: What happen before and after the deciduous dentition development?

OBJECTIVES: Numerous tools have been developed to characterize the morphometry of 3D models. The aim of this study was to apply these techniques to better understand the morphometric growth pattern of healthy children's mandibles. MATERIAL AND METHODS: The study sample was composed of 480 very young children aged from 36 gestational weeks to 7 years old. The sample was divided into three subsamples according to the development stages of their deciduous dentition. Several biometric data were collected on 3D mandibular models. RESULTS: There was homothetic growth during the first years of life. Once all deciduous teeth were fully erupted, the mandibular corpus warped more independently of the ramus, and the inter-individual variability was more pronounced. Throughout the growth period, several subgroups could be identified, highlighting the morphological growth pattern of the mandible. CONCLUSIONS: A particular morphogenesis of the mandible during the growth period was observed, which was correlated with deciduous dentition development. In younger individuals, this morphological pattern was mainly characterized by the progressive closure of the chin symphysis and ramus growth. The tongue movements in the oral space, depending on whether the child was bottle- or breast-fed, may explain this result. As the children grew older, the mandible widened to create sufficient space for the developing teeth buds. During the eruption of deciduous dentition, the mandible took on various morphologies, which was likely based on the child's sex and diet. Therefore, we assume that this mandibular morphogenesis is induced by the functional strains affecting the mandible during deciduous teeth development.

The deciduous dentition of Homo naledi: A comparative study.

In 2013, 2014 new hominin remains were uncovered in the Dinaledi chamber of the Rising Star cave system in South Africa. In 2015 Berger and colleagues identified these remains as belonging to a new species Homo naledi (Berger et al., 2015). Subsequent comparative studies of the skull, postcrania and permanent dentition have supported this taxonomic affiliation (Harcourt-Smith et al., 2015; Kivell et al., 2015; Irish et al., 2018). The deciduous teeth can offer unique insights into hominin evolution. Due to their early onset and rapid development their morphology is thought to be under stronger genetic control and less influenced by environment than are the permanent teeth. In this study we compared the H. naledi deciduous teeth from the 2013-2014 excavations to samples representing much of the hominin clade including Australopithecus afarensis, Australopithecus africanus, Paranthropus boisei, Paranthropus robustus, early Homo, Homo antecessor, Homo erectus s.l., Homo floresiensis, Middle Pleistocene Homo, Homo neanderthalensis, early Homo sapiens and recent H. sapiens from Sub-Saharan Africa. By making such a broad morphological comparison, we aimed to contextualize the Dinaledi hominins and to further assess the validity of their taxonomic assignment. Our analysis of the deciduous teeth revealed a unique combination of features that mirror (but also expand) that found in the permanent teeth. This mosaic includes an asymmetrical lower canine with a distal tubercle, an upper first molar with a large hypocone and epicrista associated with a mesial cuspule, a molarized lower first molar resembling Paranthropus, and upper and lower second molars that resemble later Homo in their lack of accessory cusps. The unique combination of deciduous dental characters supports previous studies assigning H. naledi to a new species, although its phylogenetic position vis-à-vis other Homo species remains ambiguous.

Low birth weight and the delay on the eruption of deciduous teething in children / Baixo peso ao nascer e atraso na erupção de dentes decíduos em crianças

Abstract Objectives: To analyze the association between low birth weight (LBW) and the occurrence of the delay on the eruption of deciduous teething (DEDT) in children from 04 to 30 months, living in Salvador, Bahia. Methods: A cross-sectional study involved 520 children at four to thirty months of age, from public, private and philanthropic daycares from two districts in Salvador. A descriptive analysis and unconditional logistic regression were done to estimate the odds ratios (ORs), using the Confidence Interval of 95% as a criterion for accepting associations. Poisson regression was used as an analytical strategy to obtain the prevalence ratio. Results: the prevalence of the delay on the eruption was 10.29%. There was a positive association between LBW and occurrence of DEDT among children with less than 24 months, both in the unadjusted model (PR=2.07, 95%CI= 0.96 4.44) as in the adjusted (adjusted PR=2, 27, 95%CI= 1.02 5.07). Conclusions: the variables of development and nutritional at birth and during the early life may be important predictors of the chronology of eruption. Further investigations should be carried out towards the adequate evaluation of the LBW role in the occurrence of the delay on the eruption.

Resumo Objetivos: analisar a associação entre o Baixo Peso ao Nascer (BPN) e a ocorrência de atraso na erupção da dentição decídua (AED) em crianças de 04 a 30 meses, residentes em Salvador-BA. Métodos: estudo transversal envolvendo 520 crianças que frequentavam creches públicas, privadas e filantrópicas de dois Distritos Sanitários de Salvador-Ba. Procedeu-se a análise descritiva e regressão logística não-condicional para estimação da oddsratios (ORs), empregando-se o Intervalo de Confiança a 95% como critério para aceitar as associações. A regressão de Poisson foi utilizada como estratégia analítica para obtenção da Razão de Prevalência. Resultados: a prevalência de atraso na erupção foi de 10,29%. Verificou-se uma associa-ção positiva entre BPN e ocorrência de AED entre as crianças com menos de 24 meses no modelo bruto (RP=2,07, IC95%= 0,96 4,44) e ajustado (RP ajustada=2,27, IC95%= 1,02 5,07). Conclusões: variáveis de desenvolvimento e nutricionais ao nascimento e durante a vida precoce podem ser importantes preditores do tempo de erupção, sendo necessárias outras investigações para uma adequada avaliação desta associação.

Enamel neonatal line thickness in deciduous teeth of Australian children from known maternal health and pregnancy conditions.

BACKGROUND: Physiological disruptions to early human development have implications for health and disease in later life. Limited research has explored how prenatal factors influence dental development in children of mothers with known pregnancy conditions. Enamel in human deciduous teeth begins forming in utero and is highly susceptible to physiological upsets experienced perinatally. The moment of birth itself is marked in deciduous enamel by the Neonatal Line (NNL) as a baby transitions from the uterine to external environment. This study evaluates the effect of maternal health factors that include stress and alcohol consumption on NNL in teeth from Australian children. STUDY DESIGN AND SUBJECTS: Mothers (n = 53) were interviewed about their health during pregnancy and experience of birth. Sixty-five deciduous teeth (incisors, molars, one canine) from their children were donated for histological examination. Neonatal line thickness was measured from thin sections and evaluated against maternal and neonatal factors using statistical analyses, controlling for tooth type and birth number. RESULTS AND CONCLUSIONS: The only maternal factor of a statistically significant effect on NNL thickness was alcohol consumption. Children of mothers who drank occasionally during pregnancy had a thicker NNL when compared to children of mothers who abstained. These results suggest that maternal lifestyle factors influence NNL formation possibly due to physiological changes that disrupt calcium homeostasis during enamel deposition. We highlight large intra-specific variation in human NNL expression. The potential of dental sampling in identifying children with prenatal exposure to alcohol is suggested.

Dependence of Deciduous Tooth Eruption Terms and Tooth Growth Rate on the Weight-Height Index at Birth in Macrosomic Children over the First Year of Life.

The aim of this research is to study the effect of body overweight at birth (fetal macrosomia) on the processes of tooth eruption and tooth growth during the first year of life in children in the Kharkiv City (Ukraine) population. One of the research tasks is to examine the features of deciduous teeth eruption in children who were born with macrosomia with different values of the weight-height index at birth. Materials and methods. The medical records of the children born between 1977 and 2013 have been analyzed. The database has been collected in one of the Kharkiv City clinic. The Main Group is comprised of the medical records of the children (separately for boys and girls) born with fetal macrosomia. All the medical records of the Main Group have been divided into subgroups taking into account the gender and the harmonious (well-balanced) development coefficient. The Comparison Group is comprised of the medical records of the children also born within the normal term range, but with weight and height that correspond to the gestation age (fetal normosomia). To determine the average time of the first tooth eruption, as well as the deciduous teeth growth rate for each of the groups under the study, we have used the hypothesis about a linear dependence between the number of erupted teeth and the age of the child. The statistical data processing and verification of the consistency of this hypothesis is performed using the multiple linear regression analysis with the STATISTICA 6.0 software package (Multiple Regression module). The number of delayed eruption and premature eruption cases observed is calculated along with the corresponding confidence intervals for the significance level, p, of less than 0.05, taking into account the binomial distribution of the random variable. The results of the study indicate a slowed growth rate of deciduous teeth in children born with macrosomia, as well as an increased number of cases (by a factor of 2 to 4 times) of deviations in the timing of teeth eruption compared to regional norms. The smallest growth rate of deciduous teeth and the smallest number of teeth at the age of one year are registered in macrosomic boys and macrosomic girls with a long body and a relatively reduced birth weight, as well as in macrosomic girls with intrauterine obesity. The macrosomic girls with intrauterine acceleration with obesity at the background have the largest average tooth growth rate and the largest percentage of premature eruption cases among all subgroups. Conclusions. The somatometric features of fetal macrosomia suggest the influence on the number of teeth that erupt by a certain age. The data on the deviation from the generally accepted terms of teeth eruption in children born with macrosomia, can be the basis for developing new and improving existing prevention programs aimed at preserving dental health.

Measurement of Early Childhood Oral Health for Research Purposes: Dental Caries Experience and Developmental Defects of the Enamel in the Primary Dentition.

Epidemiological investigations of early childhood oral health rely upon the collection of high-quality clinical measures of health and disease. However, ascertainment of valid and accurate clinical measures presents unique challenges among young, preschool-age children. The paper presents a clinical research protocol for the conduct of oral epidemiological examinations among children, implemented in ZOE 2.0, a large-scale population-based genetic epidemiologic study of early childhood caries (ECC). The protocol has been developed for the collection of information on tooth surface-level dental caries experience and tooth-level developmental defects of the enamel in the primary dentition. Dental caries experience is recorded using visual criteria modified from the International Caries Detection and Assessment System (ICDAS), and measurement of developmental defects is based upon the modified Clarkson and O'Mullane Developmental Defects of the Enamel Index. After a dental prophylaxis (toothbrushing among all children and flossing as needed), children's teeth are examined by trained and calibrated examiners in community locations, using portable dental equipment, compressed air, and uniform artificial light and magnification conditions. Data are entered directly onto a computer using a custom Microsoft Access-based data entry application. The ZOE 2.0 clinical protocol has been implemented successfully for the conduct of over 6000 research examinations to date, contributing phenotype data to downstream genomics and other "omics" studies of ECC and DDE, as well as traditional clinical and epidemiologic dental research.

Root growth and dental eruption in modern human deciduous teeth with preliminary observations on great apes.

Recent studies of dental development have indicated that root growth rates are linked to the eruption of some permanent tooth types in modern humans and Pan troglodytes. Little is known about the potential links between these aspects of dental development in deciduous teeth of any primate species. This histology study calculates the rate at which roots extend in length for human deciduous maxillary teeth and a small sample of deciduous canines and premolars from P. troglodytes and Pongo pygmaeus. Links are sought between root extension rates and previously published data for deciduous tooth emergence in each of these species. Results reported here provide the first evidence that the roots of human deciduous incisors, canines, and premolars extend in length at an accelerated rate as these teeth emerge. Accelerated extension rates in a deciduous canine from Pan coincided with the age that this tooth type emerged in captive chimpanzees. High extension rates in a canine from Pongo preceded emergence age. Preliminary observations indicate that deciduous canine and premolar roots of Pan and Pongo extend in length rapidly when compared to these tooth types from modern human children. This study provides a starting point from which to investigate new links between the incremental development of deciduous roots and tooth emergence in primates.

Integrated Analysis of LncRNA-mRNA Coexpression in the Extracellular Matrix of Developing Deciduous Teeth in Miniature Pigs.

Miniature pigs, a valuable alternative model for understanding human tooth development, have deciduous teeth from all four tooth families that are replaced once by permanent molars. The extracellular matrix (ECM) supports cells and maintains the integrity of tooth germs during tooth development. However, details on the role of the ECM in tooth development are poorly understood. Here, we performed long noncoding RNA (lncRNA) and messenger RNA (mRNA) expression profiles in the ECM components of deciduous tooth germs by RNA sequencing in miniature pigs. From the early cap to the late bell stages, we identified 4,562 and 3,238 differentially expressed genes (DEGs) from E40 to E50 and E50 to E60, respectively. In addition, a total of 1,464 differentially expressed lncRNAs from E40 to E50 and 969 differentially expressed lncRNAs from E50 to E60 were obtained. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that DEGs were enriched significantly for multiple signaling pathways, especially for the ECM pathway. We then outlined the detailed dynamic gene expression profiling of ECM components during deciduous molar development. Comparison of the cap and bell stages revealed that the structure and functions of the ECM dynamically changed. The ECM-related genes, including THBS1, COL4A5, COL4A6, COL1A1, CHAD, TNR, GP1BA, and ITGA3, were significantly changed, and some were shown to enrich during the bell stage development. Finally, we outlined the coexpression of lncRNAs and ECM properties during tooth development. We showed that the interplay of key lncRNAs could change ECM processes and influence the ECM establishment of tooth patterns to accomplish full tooth formation. These results might provide information to elucidate the regulation network of the lncRNA and ECM in tooth development.

Associations of maternal, perinatal and postnatal factors with the eruption timing of the first primary tooth.

We recruited 1296 mothers in their first trimester from the Affiliated Obstetrics and Gynecology Hospital of Nanjing Medical University between May 2014 and September 2015 to investigate the associations of maternal, perinatal and postnatal factors with the eruption timing of the first primary tooth (ETFPT) in a Chinese population. We collected maternal demographic information and clinical data during the perinatal and postnatal period, and oral examinations of the infants were performed by a doctor at 6, 9 and 12 months of age. Multiple regression analysis was used to identify significant explanatory variables for ETFPT. The mean age at eruption of the first primary tooth for all the infants was 6.82 ± 1.90 months. After adjustment for confounders, higher maternal childbearing age (ß = 0.57; 95%CI = 0.13-1.02), female sex (ß = 0.26; 95%CI = 0.07-0.52), and low birth weight (ß = 0.98; 95%CI = 0.20-1.76) were significantly associated with delayed eruption of the first primary tooth, while macrosomia (ß = -0.79; 95%CI = -1.30--0.28) was significantly associated with earlier eruption of the first primary tooth. Maternal childbearing age, infant sex and infant birth weight were significant determinants of ETFPT.

A Reappraisal of Developing Deciduous Tooth Length as an Estimate of Age in Human Immature Skeletal Remains.

This study provides an update on a quantitative method for immature age estimation based on postnatal deciduous mandibular tooth length. Two known sex and age skeletal collections from Western Europe were sampled (n = 97). Linear regression models for age estimated were calculated for each individual tooth, each sex, and sex combined sample using classical calibration. Prediction errors, residuals, and percentage of individuals whose real age fell within the 95% prediction interval were calculated. The teeth which develop earlier in life, the incisors and the first molar, showed the greatest precision, while the canine showed the least. This method has greater applicability to archeological skeletons or to children in developing countries than for use in North American or European forensic contexts. The method can be applied to incomplete or poorly preserved remains of unknown sex, particularly when dental radiographs are not an option or when teeth have been removed from the alveolus or crypt.

Clinical duration of eruption of deciduous teeth in Jordanian children: A cross-sectional study.

OBJECTIVE: The aim of this study was to investigate the clinical duration of eruption (CDE) for deciduous teeth in Jordanian children, from the moment of gingival emergence until functional occlusal contact. DESIGN: This cross-sectional study included 1988 children (885 females, 1103 males) aged 1-45 months examined for deciduous tooth emergence. Through probit regression analysis (SPSS Version 16.0), the median ages of emergence (MAE) and of functional eruption (MAF) were calculated per tooth; time difference between the two events represented CDE in months. Mann Whitney U tests and two-tailed Spearman's bivariate correlation test were used to investigate sexual dimorphisms in CDE, and find relationships between MAE and CDE, respectively. Significance was set at P ≤ 0.05. RESULTS: The average CDE was (4.45 ±â€¯1.96) months; it was less in males (4.33 ±â€¯1.99) than in females (4.57 ±â€¯1.93) with no significant gender differences (P = 0.38). Longest and shortest CDE were for maxillary first molars and mandibular lateral incisors, respectively. None of the teeth showed statistically significant differences in CDEs between genders. In addition, there were insignificant positive moderate correlations between MAE and CDE (r = 0.60, 0.52, P = 0.07, 0.12 for males and females, respectively). CONCLUSIONS: This study has established the first standards for CDE in deciduous teeth for Jordanian children with an average CDE (4.5 ±â€¯2, range 1.6-8 months). Some variations in CDE can be explained by variations in age of emergence however, variations in CDE were not related to gender. The deciduous dentition in Jordanians is in active state of eruption between approximately 8.2-32 months.

Sexual dimorphism of primary dentition in Spanish children.

AIM: To analyse differences in the eruption of primary teeth between both sexes. MATERIALS AND METHODS: A cross-sectional study was performed in a sample of 1250 children aged between 3 and 42 months. The clinical emergence of teeth was taken to estimate average ages for primary teeth eruption. The t-test was used to analyse gender and arch differences. RESULTS: Eruption of primary teeth began at the same time in girls as in boys; although the eruptive process was longer in girls. It was observed that almost all deciduous teeth emerged earlier in boys, except for the first molar (upper and lower) and the maxillary central incisors. The differences were statistically significant for almost all the primary teeth except for the central incisors, both upper and lower. CONCLUSIONS: By comparing the timing of the eruption of primary teeth in both sexes, it was found that eruption of almost all primary teeth took place earlier in boys than in girls and that the eruption process was shorter for boys than for girls. Most of the deciduous teeth erupted earlier in the right side in both sexes. No differences were found in the sequence of eruption of primary teeth between genders.

Current status of nylon teeth myth in Tanzania: a cross sectional study.

BACKGROUND: Nylon teeth myth is a belief of associating infant illnesses with bulges on infants' alveolus that mark the positions of underlying developing teeth and that it is necessary to treat the condition mainly by traditional healers to prevent infant death. The traditional treatment often leads to serious complications that may lead to infant death. Although the government instituted educational campaigns against the myth in 1980s to 1990s, to date, repeated unpublished reports from different parts of the country indicate continued existence of the myth. Therefore, this study aimed to assess the current status of the nylon teeth myth in Tanzania. METHODS: The study population was obtained using the WHO Oral Health pathfinder methodology. A structured questionnaire inquired about socio-demographics as well as experiences with "nylon teeth" myth and its related practices. Odds ratios relating to knowledge and experience of the nylon teeth myth were estimated. RESULTS: A total of 1359 respondents aged 17 to 80 years participated in the study. 614 (45%) have heard of nylon teeth myth, of whom 46.1% believed that nylon teeth is a reality, and 42.7% reported existence of the myth at the time of study. Being residents in regions where nylon teeth myth was known before 1990 (OR = 8.39 (6.50-10.83), p < 0.001) and/or hospital worker (OR = 2.97 (1.99-4.42), p < 0.001) were associated with having have heard of nylon teeth myth. Proportionately more residents in regions where nylon teeth myth was not known before 1990 (p < 0.001), the educated (p < 0.001) and hospital workers (p < 0.001) believed modern medicine, whereas, proportionately more residents in regions where nylon teeth was known before 1990 (p < 0.001), less educated (p < 0.001) and non-hospital workers (p < 0.001) believed traditional medicine to be the best treatment for symptoms related to nylon teeth myth respectively. CONCLUSION: The "nylon teeth" myth still exists in Tanzania; a substantial proportion strongly believe in the myth and consider traditional medicine the best treatment of the myth related conditions.

Quantitative proteomic analysis of deciduous molars during cap to bell transition in miniature pig.

Taking advantage of genetic manipulation tools and accessibility, almost all molecular knowledge on vertebrate tooth development was obtained from rodent models that only have one dentition in their entire lives. Whether the tooth development in other vertebrates such as swine or human follows the same rules remains elusive. Rodent dentitions differ considerably from human dentitions, therefore limiting the application of knowledge from rodent tooth to human tooth. Signal-mediated communication between cells and complex gene and protein regulatory networks are key components of tooth development. By combining isobaric tandem mass tag (TMT) labeling with liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) technology, we constructed the proteomic profile of deciduous molars at embryonic days 40 and 50 in miniature pig (Sus scrofa). During the ten days of prenatal development of the miniature pig, the morphology of the lower deciduous molar moves from the early cap to the bell stage. Thus, we identified proteins that are associated with these developing stages and identified differentially regulated proteins (DRPs) that are potential or novel drivers of tooth morphogenesis. Three candidate proteins were validated via qRT-PCR, western blotting analysis, and the location of those proteins in tooth germ were observed by immunohistochemical staining. Multiple signaling pathways and protein interaction network revealed potential mechanisms of early tooth programming in a large mammal. Bioinformatic analysis also showed that cross interaction of Wnt and Sonic hedgehog pathways may play a key role in deciduous development during cap to bell transition in miniature pig. SIGNIFICANCE: We performed the most comprehensive study of the whole tooth germ proteome in mammals to date. The high-throughput proteomic analysis identifies differentially regulated proteins and pathways that will help elucidate the mechanisms of tooth development.