Determination of the comfort zone for intergingival height and its practical application to treatment planning: A survey.

Background: The concept of the 'comfort zone' for intergingival height is a simple guideline to help establish the correct vertical dimension necessary for occlusal harmony in any individual. It can be used as a guide for identifying individuals at relatively greater risk of developing temporomandibular dysfunction and also when rebuilding the occlusion in the treatment of patients with temporomandibular dysfunction. The intergingival height varies according to the patient's age and stage of development, as well as with the height of the incisor crowns. In orthodontics this parameter can be used to track the progress of a patient being treated with functional appliances. This parameter has not been studied in detail and hence this survey was designed and conducted to gain information regarding its significance. Objectives: The objectives of this survey were to estimate the value of 'comfort zone' for intergingival height in the region of the central incisor and to establish the norm for the comfort zone in males and females. Materials and Methods: The intergingival height was measured in the region of the right central incisor using a vernier caliper. The intergingival height was measured as the vertical distance from the midpoint of the free gingival margin of the right maxillary central incisor to a similar point on the right mandibular central incisor, with the teeth in occlusion. Results: According to the results of this, the range for the comfort zone for intergingival height in all subjects was 15.96-16.55 mm. The range for female subjects was 14.86-15.32 mm and the range for male subjects was 17.12-17.67 mm. Conclusion: The comfort zone of intergingival height should become a part of our vocabulary and should be routinely utilized as a guideline for consistently achieving the correct vertical dimension at the end of treatment. The areas of utilization of this measurement are many and it should be used to assist in achieving better and more stable clinical results.

Efecto de la temperatura y la humedad relativa en los parámetros productivos y la transferencia de calor en pollos de engorde / Effect of temperature and relative humidity on the productive behaviour and the transfer of heat in broilers

Para lograr máximos rendimientos productivos en las explotaciones de pollo de engorde, es imprescindible manejar un entorno adecuado que les proporcione a las aves las condiciones ambientales óptimas. En este trabajo se evaluó el efecto de la temperatura y la humedad relativa en la respuesta productiva y transferencia de calor en pollos de engorde, con el propósito de establecer la zona termo-neutral en el microclima de la hacienda Vegas de la Clara (nordeste antioqueño, Colombia), para optimizar los modelos de producción. En la primera parte del trabajo, se determinó, mediante un análisis estadístico descriptivo exploratorio el comportamiento térmico de los pollos de la línea Ross en la etapa de cría, midiendo los cambios de temperatura corporal desde el nacimiento (heterotermos con temperatura corporal de 39.741 ± 0.44 ºC), hasta que alcanzaron la condición de endotermos (temperatura corporal: 40.37 ± 0.221 ºC); al finalizar ésta etapa fue determinada la homogeneidad del lote, en cuanto a pesos corporales, con el propósito de obtener uniformidad en las unidades experimentales (pollos) para llevar a cabo la fase experimental correspondiente a la etapa final del periodo productivo. En la fase experimental, se evaluó los efectos de tres diferentes temperaturas (19, 25, y 31 ºC) a una humedad relativa del 75% en la transferencia de calor y en el rendimiento productivo, por medio de consumo de alimento, peso corporal, conversión alimenticia y morbi – mortalidad. Mediante la aplicación de la técnica de MANOVA con contrastes canónicos y un diseño de estructuras completamente aleatorizado se determinó que el mejor comportamiento productivo para el peso corporal y la conversión alimenticia se obtuvo a una temperatura de 19 ºC (p<0.05) con respecto a los demás tratamientos. Las pérdidas de calor representadas mediante la graficación en la carta Sicrométrica, indicaron mayores pérdidas de calor sensible en el tratamiento a 19 ºC, seguido del tratamiento a 31 ºC y luego del tratamiento a 25 ºC (p<0.05). En cuanto a las pérdidas de calor latente no se encontraron diferencias estadísticamente significativas (p>0.05).

To achieve maximum productive yields in broiler production, it is indispensable to manage an appropriate environment that provides to the birds the good environmental conditions. In this work the effect of temperature and relative humidity in the productive performance and transfer of heat in broilers was evaluated, with the purpose of establishing the thermal comfort zone in the microclimate of Vegas de la Clara farm (Nordeste antioqueño, Colombia), to optimize the production models. In the first part of the work, the behaviour of breed Ross chickens in the breeding stage was determined by means of an exploratory descriptive statistical analysis, measuring changes of corporal temperature from birth (heterothermos with (corporal temperature of 39.741 ± 0.44 ºC), until the chickens reached the endothermos condition (corporal temperature of 40.37 ± 0.221 ºC); when concluding this stage the homogeneity of the lot was determined, concerning body weight, with the purpose of obtaining uniformity in the experimental units (chickens) to carry out the experimental phase corresponding to the final stage of the productive period. In the experimental phase, the influence of three different temperatures (19, 25 and 31 ºC) with a constant relative humidity of 75% on heat transfer and broiler productive yield as measured by food consumption, body weight, nutritional conversion and morbi–mortality, was evaluated. The results were evaluated by MANOVA with canonical contrasts and a totally randomized design of structures. The best productive behaviour to body weight and nutritional conversion was obtained at a temperature of 19 ºC when compared to the other treatments (p<0.05). Heat losses were represented in a psychrometric cart, which indicated that treatment at 19 ºC, followed by treatments at 31 ºC and 25 ºC (p<0.05), represented the greatest losses of sensible heat, respectively. Regarding latent heat losses statistically significant differences were no found (p>0.05).