First systematic assessment of dental growth and development in an archaic hominin (genus, Homo) from East Asia.

Several human dental traits typical of modern humans appear to be associated with the prolonged period of development that is a key human attribute. Understanding when, and in which early hominins, these dental traits first appeared is thus of strong interest. Using x-ray multiresolution synchrotron phase-contrast microtomography, we quantify dental growth and development in an archaic Homo juvenile from the Xujiayao site in northern China dating to 161,000-224,000 years or 104,000-125,000 years before present. Despite the archaic morphology of Xujiayao hominins, most aspects of dental development of this juvenile fall within modern human ranges (e.g., prolonged crown formation time and delayed first molar eruption). For its estimated age-at-death (6.5 years), its state of dental development is comparable to that of equivalently aged modern children. These findings suggest that several facets of modern human dental growth and development evolved in East Asia before the appearance of fully modern human morphology.

Assessment of second (I2M) and third (I3M) molar indices for establishing 14 and 16 legal ages and validation of the Cameriere's I3M cut-off for 18 years old in Chilean population.

This retrospective cross-sectional study has two-fold aims: the first is to assess new cut-offs at the legal age thresholds (LATs) of 14 and 16 years old and the second is to validate the cut-off of third molar index I3M=0.08 for 18 years of age in Chilean people. Orthopantomographs from 822 Chilean children aged from 11 to 22 (472 girls and 350 boys) were analysed. For LAT of 14 years, cut-offs were found using the ROC curves singly for boys and girls. The cut-offs for boys were I2M=0.16 and I3M=0.73 while for girls we obtained I2M=0.10 and I3M=0.77. For LAT of 16 years we obtained the same cut-offs regardless of gender, which were 0.06 and 0.36 for I2M and I3M respectively. Concerning the validity of I3M cut-off for 18 years old in Chilean population, the proportion of correctly classified individuals was 83% and estimated post-test probability, PPV, was 93.2%, with a 95% confidence interval equals to 91.3%, 94.6%. Hence, the probability that a subject positive on the test was 18 years of age or older was 93.2%, confirming the validation of the I3M cut-off for Chilean population.

Influencia de los determinantes sociales en la salud del primer molar permanente / Influence of the social determinants in the first permanent molar health

Introducción: el proceso salud enfermedad depende de múltiples y complejas condiciones y no se rige solamente por las leyes conocidas de las ciencias naturales, sino que abarca también influencias psicológicas, socioeconómicas y ambientales. Estas son consideradas determinantes sociales de salud. Los factores causales que clínicamente producen la caries están bien identificados, pero no los determinantes socialesos a su prevalencia y menos asociados al primer molar permanente, considerado por diferentes autores como llave de la oclusión. Objetivo: determinar la salud del primer molar permanente, relacionado con algunos determinantes sociales de la salud en escolares de 11 a 16 años de edad. Materiales y métodos: para ello se decidió realizar una investigación observacional descriptiva prospectiva y transversal con el objetivo de determinar la salud del primer molar permanente, relacionado con algunos determinantes sociales de la salud en escolares de 11 a 16 años de la Escuela Secundaria Básica “Fermín y Yolanda” del municipio Unión de Reyes de septiembre 2014 de a abril de 2015. Resultados: se encontró que la mayoría de los adolescentes eran del sexo femenino, y tenían entre 13 y 14 años de edad. La mayoría de las familias de los adolescentes eran disfuncionales. De las barreras para conductas saludables estudiadas, la que más incidió fue la ingestión de alimentos que expenden alrededor de la escuela con el 95,3%. Conclusiones: a pesar de estos resultados el 60,7% de los molares permanentes eran saludables(AU).

Introduction: the health-disease process depends on multiple and complex conditions and it is not only ruled by the acknowledged laws of the natural sciences. It also includes psychological, socioeconomic and environmental influences. These are considered health social determinants. The causal factors clinically producing caries are well identified, but the social determinants related with its prevalence are not, less those associated to the first permanent molar considered by several authors as the key of the occlusion. Aim: to determine first permanent molar health related with several health social determinants in students aged 11-16 years. Materials and methods: a cross-sectional, prospective, descriptive and observational research was carry out with the aim of determining the health of the first permanent molar that is related with several health social determinants in students aged 11-16 years of the Basic Secondary School (Junior High School in the United States) “Fermin y Yolanda”, of the municipality Unión de Reyes from September 2014 to April 2015. Outcomes: most of the teenagers were females ones, aged 13-14 years. Most of their families were dysfunctional. From the studied barriers for healthy behaviour, the one with more incidences was the intake of food sold near the school with 95.3 %. Conclusions: in spite of these results, 60.7 % of the permanent molars were healthy (AU).

Influencia del tutor en la educación en el trabajo / Tutor's influence in education at work

El método de tutoría actúa de forma flexible y se acomoda a cada uno de los estudiantes, de acuerdo con su personalidad, intereses, conocimientos, capacidades, nivel de dificultades y avances. Actúa dentro de un sistema de enseñanza aprendizaje colectivo. En este proceso juegan un papel importante los factores que influyen en la formación de la personalidad, y dentro de ellos la escuela; que como institución está llamada a cumplir el rol de mayor responsabilidad en la formación de las nuevas generaciones, pero para cumplir con este papel, requiere de un trabajo conjunto con el tutor del área práctica, ya que este resulta un eje fundamental para el desempeño del futuro profesional. En Cuba, en las condiciones de la formación profesionallos tutoresson docentes en ejercicio. Dada la importancia que tiene el tutor y el papel que debe jugar en la práctica profesional, para una correcta contribución a la preparación y formación de los futuros tecnólogos, este artículo se propuso fundamentar el valor que tiene este durante la educación en el trabajo. Se abordan aspectos de gran interés para su desempeño, relacionados con su labor desde el área práctica, incluyendo la formación en valores (AU).

The tutoring method works in a flexible way and is able to accommodate to every of the students according to their personality, interests, knowledge, capacity, difficulties level and advances. It functions as a part of a collective teaching-learning process. The factors influencing in personality's formation play an important role in this process, especially the school. As an institution, the school should play a role of higher importance in forming new generations, but to play this role a combined work with the tutor of the practical area is needed because the tutor is a main piece in the performance of the future professional. In Cuba, in the conditions of the professional training, tutors are pedagogues in exercise of their profession. Due to the importance of the tutor and the role he/she should play in the professional practice for a correct contribution to the training of future health technologists, this article had the purpose of explaining the importance they have in the education at work. Several aspects are approached that are of great interest for the sake of tutors´ performance, related with their practical work including values formation (AU).

Tooth mineralization stages as a diagnostic tool for assessment of skeletal maturity.

INTRODUCTION: The objective of this study was to determine whether dental calcification can be used as a first-level diagnostic tool for assessment of skeletal maturity. METHODS: A total of 150 healthy subjects (79 boys, 71 girls; mean age, 12.19 ± 2.03 years; range, 8-16 years) were enrolled in the study. Dental maturity was assessed through the calcification stages from panoramic radiographs of the mandibular canine, the first and second premolars, and the second molar. Determination of skeletal maturity was according to the modified middle phalanx of third finger (MP3) stages method on digital radiographs. RESULTS: Diagnostic ability was evaluated according to the dental maturation stages for each tooth for identification of the MP3 stages and the growth phases (prepubertal, pubertal, postpubertal) using positive likelihood ratios. Dental maturation stage E of the first premolars and the combination of canine stage F, first premolar stage E, second premolar stage E, and second molar stage D (FEED) gave the highest values for identification of the prepubertal growth phase, and stage H of the second molar had the highest value for identification of the postpubertal growth phase. CONCLUSIONS: Dental maturation assessment is only useful for diagnosis of the prepubertal and postpubertal growth phases.

Assessment of skeletal maturation using mandibular second molar maturation stages.

OBJECTIVES: To investigate the relationship between cervical vertebrae maturation and mandibular second molar calcification stages. STUDY DESIGN: The study was designed as a retrospective, descriptive and crosssectional research project. Pre-treatment lateral cephalograms and panoramic radiographs of 99 males and 110 females in the age range of 7 to 18 years 7 months were evaluated with Demirjian Index (DI) and cervical vertebrae maturation indicators (CVMI) of Hassel and Farman. A null hypothesis was proposed that there is no relation between CVMI and DI. RESULTS: A highly significant association (Pearson's contingency coefficient 0.713 for males and 0.863 for females) was found between DI and CVMI. In males, the DI stage E corresponded to stage 2 of CVMI (pre-peak of pubertal growth spurt) and DI stages F and G corresponded to stages 3 and 4 of CVMI (peak of pubertal growth spurt). DI stage H was associated with stages 5 and 6 of CVMI (end of pubertal growth spurt). In females, the DI stages C, D corresponded to CVMI stages 1, 2; DI stages E, F with CVMI stages 3, 4; DI stages G, H with CVMI stages 5, 6. CONCLUSION: Mandibular second molar calcification stages can be used as indicators for assessment of skeletal maturity.

Molecular and structural assessment of alveolar bone during tooth eruption and function in the miniature pig, sus scrofa.

The development of alveolar bone adjacent to the tooth root during tooth eruption is not well understood. This study tested the hypothesis that predominantly woven bone forms adjacent to tooth roots during tooth eruption, but that this immature structure transitions to lamellar bone when the tooth comes into function. Additionally, bone resorption was predicted to play a key role in transitioning immature bone to more mature, load-bearing tissue. Miniature pigs were compared at two occlusal stages, 13 weeks (n = 3), corresponding with the mucosal penetration stage of M(1) tooth eruption, and 23 weeks (n = 3), corresponding with early occlusion of M(1) /M(1) . Bone samples for RNA extraction and qRT-PCR analysis were harvested from the diastema and adjacent to M(1) roots on one side. Following euthanasia, bone samples for haematoxylin and eosin and TRAP staining were harvested from these regions on the other side. In contrast to expectations, both erupting and functioning molars had reticular fibrolamellar structure in alveolar bone adjacent to M(1) . However, the woven bone matrix in older pigs was thicker and had denser primary osteons. Gene expression data and osteoclast cell counts showed a tendency for more bone resorptive activity near the molars than at distant sites, but no differences between eruptive stages. Thus, although resorption does occur, it is not a primary mechanism in the transition in alveolar bone from eruption to function. Incremental growth of existing woven bone and filling in of primary osteons within the mineralized scaffold generated the fortification necessary to support an erupted and functioning tooth.

Longitudinal assessment of vertical and sagittal control in the mandibular arch by the mandibular fixed lingual arch.

The purpose of this investigation was to determine and quantify vertical changes in the position of the mandibular molars while maintaining arch perimeter with a fixed lingual arch. Twenty-three patients with a mean age of 10.4 +/- 0.6 years were selected to receive fixed lingual arch treatment as the only appliance in the mandibular arch. Average treatment time was 18.3 +/-+/- 0.6 months. Longitudinal records for 12 and 24 months of 24 individuals matched by ethnic origin, age, gender, and mandibular plane inclination were used as controls. Pretreatment and posttreatment cephalograms were used to determine positional changes. Statistically significant differences between the fixed lingual arch and control groups were found. The results of this investigation indicated that the mandibular fixed lingual arch is a useful tool to control the vertical development of the mandibular molars.

Perfil de la oclusión del niño en edad preescolar. Factores de beneficio y riesgo / Occlusal profile of the preschool child. Benefit and risk factors

Se realizó un estudio transversal para identificar condiciones de beneficio y riesgo para el establecimiento de una oclusión normal, en una muestra representativa de preescolares ubicados en Unidades Educactivas Públicas y Privadas del Municipio Maracaibo, Estado Zulia, Venezuela. Se seleccionaron mediante muestreo bietápico estratificado, 443 niños en edades comprendidas entre los tres y seis años, a los cuales se les realizó examen clínico para el riesgo de aspectos antropométricos, relaciones de oclusión, características del proceso de erupción dentaria, periodo de desarrollo oclusal y los factores que puediesen afectar el recambio dentario. Asimismo, se realizó encuesta socioeconómica al padre o representante para establecer algunas características relacionadas con la calidad de vida del niño y su grupo familiar. Los resultados obtenidos permiten identificar un poder adquisitivo "bajo" en más del 50 por ciento de los padres, condición vinculada a la alta prevalencia de caries detectada en este grupo y el acceso mayoritario de este grupo a los servicios públicos de salud, donde reciben preferentemente atención odontológica de tipo mutiladora (exodoncias). Según los indicadores antropométricos considerados en el estudio (talla, peso, circunferencia cefálica) los individuos categorizados como "poder adquisitivo alto", presentaron una talla 2 cm. mayor y un peso promedio de 1 kg. más con respecto a las otras categorías. En cuanto a las condiciones clínicas estudiadas, los resultodos evidencian en forma global, características en su mayoría beneficiosas para el establecimiento de una oclusión normal. Más del 60 por ciento no presentaron evidencia de caries dental, presencia en ambas arcadas de espacios de crecimiento y primates, relación de segundos molares primarios en posición bilateral plano recto y escalón mesial. Se detectaron algunas condiciones de riesgo: bruxismo, succión digital, deglución atípica, respiración bucal y malposiciones individuales. El análisis comparativo, permite establecer diferencias en el perfil de oclusión de los niños dependiendo de sus características bioindividuales y sociales.

Timing of emergence of individual primary teeth. A prospective longitudinal study of Pakistani children.

Primary tooth emergence in Pakistani children was investigated as a part of a prospective interdisciplinary study of growth and development. The average order of emergence of the primary teeth was in agreement with previous studies from other countries. There was no sex difference in emergence of individual primary teeth. The emergence of the primary incisors and mandibular first molars in both sexes, and the canines in boys were significantly delayed compared to Swedish standards (Hägg & Taranger 1986).

Aplicación de la tabla de vida a la evaluación de la salud de los primeros molares permanentes / Use of life table for the evaluation of the health of first permanent molar teeth

Se aplica la tabla de vida a los primeros molares permanentes para obtener indicadores positivos que permitan evaluar la salud de los mismos. La obtención de las funciones de la tabla de vida se realiza en 2 etapas, una primera en la que se estimaron los porcentajes de mortalidad dentaria por grupos quinquenales de edades en pacientes de 15 a 79 años, con historias clínicas confeccionadas durante el año 1980 y primer semestre de 1981 en 4 clínicas estomatológicas del municipio 10 de Octubre, y una segunda etapa, en la que se obtienen las funciones de la tabla de vida. Se alcanzan los siguientes resultados: los primeros molares que muestran mayor esperanza de vida al brote son los superiores y dentro de éstos, los derechos, y los de menor esperanza de vida al brote son los inferiores y dentro de éstos los izquierdos. Los primeros molares del lado derecho presentan mayor esperanza de vida al brote que los izquierdos. La mayor pérdida de estos molares se manifiesta entre los 0-9 años (de edad del diente). Se recomienda extender la aplicación de este método a todos los dientes, realizar estudios epidemiológicos sobre pérdida dentaria que serán de apoyo a la aplicación de la tabla de vida dentaria, y su aplicación como un procedimiento para obtener indicadores, que permitan comparar la situación de salud bucal en épocas distintas