RESUMO

Diverse mechanosensory neurons detect different mechanical forces that can impact animal behavior. Yet our understanding of the anatomical and physiological diversity of these neurons and the behaviors that they influence is limited. We previously discovered that grooming of the Drosophila melanogaster antennae is elicited by an antennal mechanosensory chordotonal organ, the Johnston's organ (JO) (Hampel et al., 2015). Here, we describe anatomically and physiologically distinct JO mechanosensory neuron subpopulations that each elicit antennal grooming. We show that the subpopulations project to different, discrete zones in the brain and differ in their responses to mechanical stimulation of the antennae. Although activation of each subpopulation elicits antennal grooming, distinct subpopulations also elicit the additional behaviors of wing flapping or backward locomotion. Our results provide a comprehensive description of the diversity of mechanosensory neurons in the JO, and reveal that distinct JO subpopulations can elicit both common and distinct behavioral responses.

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Objetivo: Determinar la exactitud del Índice de Tanaka-Johnston e Índice de Moyers mediante el análisis de modelos de estudio iniciales con dentición definitiva de pacientes chilenos del Postgrado de Ortodoncia de la Universidad Andrés Bello sede Santiago. Materiales y métodos: Se seleccionaron por conveniencia 100 pares de modelos según los criterios de inclusión y exclusión establecidos, correspondientes 50 al género femenino y 50 al masculino, y se realizó medición directa con un pie de metro manual, de la suma incisiva inferior y suma de segmentos canino-premolar. La medición fue realizada por dos examinadores previamente calibrados. Se determinó la exactitud de cada uno de los métodos y presencia de diferencias estadísticas significativas. Resultados: Para mujeres, Moyers 65% en maxilar superior y Moyers 50% en maxilar inferior presentan mayor exactitud en predicción de tamaño mesiodistal de caninos y premolares permanentes no erupcionados; en cambio, para hombres, Moyers 75% en maxilar superior y Moyers 65% en maxilar inferior son más exactos. El método de Tanaka-Johnston a pesar que solo presenta diferencias estadísticamente significativas en maxilar inferior en el género femenino (p<0,05), es menos exacto tendiendo a sobrestimar valores reales en mujeres, y a subestimar en hombres. Conclusión: Método de Moyers es más exacto en la predicción del espacio necesario en pacientes chilenos, su nivel de confianza varía según género y maxilar. Diferencias son explicadas por dimorfismo sexual y variaciones étnicas con respecto a la población de origen de métodos de predicción.

Objetive: Determine the accuracy of Tanaka-Johnston and Moyers indexes through the initial analysis of study models with permanent teeth of Chilean patients of the Graduate School Orthodontics of University Andres Bello in Santiago. Materials and Methods: 100 pairs of models were selected by convenience as the inclusion and exclusion criteria established, corresponding to 50 female and 50 male. Direct measurement was performed with a manual caliper gauge by two examiners previously calibrated. The sum of permanent mandibular incisors and sum of segments canine-premolar were measured. The accuracy of each of the present methods and statistical differences were determined. Results: In females, the prediction of width of unerupted canines and premolars is more accurate on maxilla with Moyers 65% and mandible with Moyers 50%. For males, Moyers 75% on maxilla and Moyers 65% in mandible are more accurate. Tanaka-Johnston method although only presented statistically significant differences in mandible of female gender (p <0.05), is less accurate tending to overestimate actual values in women as in men underestimated. Conclusion: Moyers method is more accurate in predicting space required in Chilean patients, the confidence level varies according to gender and jaw. Differences are explained by sexual dimorphism and ethnic variations from the source population of prediction methods.

RESUMO

El análisis de Tanaka-Johnston, mundialmente empleado para la predicción del espacio de caninos y premolares no brotados, ha sido muy cuestionado por la variabilidad en el tamaño dentario entre las diferentes poblaciones, y por haber sido realizado en un grupo étnico no aplicable a todos. Se realizó un estudio descriptivo transversal, con el objetivo de determinar el ancho mesiodistal de incisivos, caninos y premolares mandibulares, así como de caninos y premolares maxilares, y comparar la suma real de estos dientes con los estimados por Tanaka-Johnston, según el sexo y la arcada. El universo de esta investigación estuvo constituido por 50 estudiantes de la Facultad de Estomatología de La Habana, 25 del sexo femenino y 25 del sexo masculino, con oclusión normal, sin antecedentes de tratamiento ortodóncico; todos descendientes de cubanos. En los resultados se observó que los anchos mesiodistales de los incisivos, caninos y primeros premolares inferiores y de caninos y segundo premolar izquierdo superiores fueron significativamente mayores en el sexo masculino que en el femenino. La suma real de caninos y premolares superiores e inferiores fue mayor en el sexo masculino que en el femenino. Cuando se comparó la suma real de caninos y premolares, con lo estimado según la ecuación de Tanaka-Johnston, se halló que la esta sobrestimó los valores de caninos y premolares, ya que los resultados fueron significativamente menores(AU)

The Tanaka-Johnston analysis used at worldwide to predict the space of non-erupted canines and premolars has been questioned due to the variability in the teeth size among different populations and also to be carried out in non-applicable whole ethnic group. A cross-sectional and descriptive study was conducted to determine the mesiodistal width of mandibular incisives, canines and premolars, as well as of danines and premolar-maxillary and to compare the real sum of these theeth with the estimates by Tanaka-Johnston, according to sex and the arcade. Universe of this research included 50 students of Stomatology Faculty of havana (25 males and 25 females) presenting with normal occlusion, without a history of Orthodontics treatment all of them descendants of Cubans. In results it was noted that the mesiodistal widths of incisives, canines and first lower premolars and of canines and second left premolars upper are greater in male sex than in the female one. The real sum of upper and lower canines and premolars was greter in male sex than in the female one. Comparing the real sum of canines and premolars with that estimated according Tanaka-Johnston, it was noted that it overestimated the values of canines and premolar since the results were significantly lower(AU)

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El anàlisis del espacio requiere una comparación entre el espacio disponible y el espacio necesario para la alineación de los dientes. El ampliamente usado análisis del espacio de Tanaka-Johnston es cuestionado cuando es aplicado a diferentes poblaciones. Por tanto el propósito de este estudio fue determinar el ancho mesiodistal de incisivos, caninos y premolares mandibulares y caninos y premolares maxilares, para validar el anàlisis de Tanaka-Johnston según el sexo en 100 estudiantes yemenitas comprendidos entre las edades de 12 a 16 años. Se encontró diferencias estadísticamente significativas en el ancho mesiodistal de caninos y premolares según el sexo, excepto para el segundo premolar maxilar. La ecuación de Tanaka-Johnston sobreestima el ancho mesiodistal de los segmentos bucales en esta población(AU)

In space-analysis it is necessary a comparison between the available space and the necessary space in teeth alignement. The well-used Tanaka-Jhonston space analysis is questioned when it is applied in different populations; thus, the aim of present study was to determine the mesiodistal width of mandibular incisives, canines and premolar and of maxillary canines and premolar to validate the Tanaka-Johnston analysis according to sex in 100 Yemeni students aged from 12 to 16. There were statistically significant differences in mesiodistal width of canines and premolars according sex, except for the second maxillary premolar. The Tanaka-Johnston equation overrates the mesiodistal width of oral segments in this population(AU)

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Entre as estratégias de comunicação utilizadas por animais o som é uma das mais importantes. Nos Hymenoptera destacam-se como órgãos auditivos o órgão subgenual, localizado na porção proximal da tíbia, e o órgão de Johnston, localizado no segundo segmento da antena. O objetivo do presente trabalho foi analisar morfologicamente tais estruturas em Agelaia pallipes (Olivier), Polybia paulista (Ihering) and Mischocyttarus cassununga (Ihering). As tíbias e antenas das três espécies foram retiradas e fixadas em glutaraldeído a 2 por cento em tampão cocodilato de sódio 0,2 M, pH 7,4 durante 2h a 4ºC. Uma pós-fixação seguiu-se em tetróxido de ósmio a 2 por cento no mesmo tampão. Nas espécies estudadas observaram-se semelhanças quanto à forma, localização e tamanho do órgão subgenual (OSG) e órgão de Johnston (OJ). O OSG apresentou a forma de um cone constituído por células nervosas presas à parede interna da tíbia em pontos laterais e opostos. Tal estrutura e sua localização parecem estratégias para a percepção de estímulos vibratórios decorrentes do substrato. No pedicelo das antenas das três espécies observaram-se células sensoriais do OJ, dispostas radialmente e terminando na conexão cuticular entre pedicelo e flagelo antenal. Esse arranjo permite ao OJ detectar estímulos vibratórios. Neste trabalho não foi analisada a possível relação entre a morfologia das estruturas sensoriais e o desenvolvimento da audição nas diferentes espécies estudadas.

Among the communication strategies used by the animals, the sound is one of the most important. Hymenoptera have as auditory organs, the subgenual organ (SGO) located in the tibia proximal portion, and the Johnston organ (JO) located in the second antenna segment. The subject of this work was to analyze the morphology of these structures in Agelaia pallipes (Olivier), Polybia paulista (Ihering) and Mischocyttarus cassununga (Ihering). The tibiae and antennae of the three species were dissected and fixed in 2 percent glutaraldhyde in 0, 2 M sodium cacodylate buffer, pH 7.4, during 2h, at 4ºC. Afterward, they were postfixed in 2 percent osmium tetroxide in the same buffer. We observed similarity in the shape, location and size of both, SGO and JO, among the studied species. SGO presented a conical shape formed by nervous cells fixed to the internal wall of the tibia on lateral and opposite points. Such structure and its location seem to constitute strategies to perceive vibratory stimulations originated from the substratum. In the pedicellum of the three species antenna, we observed JO sensorial cells, disposed in a radial form, ending in the cuticular connection between the pedicellum and the antennal flagella. This arrangement allows the JO to detect vibratory stimuli. In this work, a possible relation between morphology of the sensorial structures and the development of hearing in the different species was not analyzed.

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