Históricamente es bien sabido que la mordida abierta anterior, conocida como la falta de contactos de los dientes anteriores superiores e inferiores es uno de los tipos de maloclusión que, aunque prevenible, afecta a gran parte de la población. La mayoría de los casos está asociada con la presencia de hábitos orales como la deglución atípica, la succión digital y la respiración bucal; así como, en menor proporción, con trastornos hereditarios y congénitos. El odontólogo especialista en ortodoncia es el profesional que tiene la tarea de aplicar el tratamiento correctivo adecuado una vez instalada la mordida abierta anterior ya que la misma afecta no sólo la cavidad bucal, sino también el aspecto facial del paciente, dependiendo de la severidad. Este podrá variar desde tratamientos ortopédicos, tratamientos ortodónticos, inclusive con extracción de premolares hasta cirugía ortognática. Afortunadamente este trastorno se puede prevenir y es el médico pediatra quien conjuntamente con el odontopediatra tiene el mayor peso en este sentido, a través del diagnóstico oportuno de los hábitos parafuncionales mediante una simple evaluación intra y extra oral del paciente. El trabajo preventivo del médico pediatra ayudaría a disminuir notoriamente la morbilidad de la mordida abierta anterior.

It is well known that the anterior open bite, previously known as lack of contact of upper and lower anterior teeth is one of the types of malocclusions that, although preventable, affects a large part of the population. Most cases are associated with the presence of oral habits such as atypical swallowing, thumb sucking and mouth breathing as well as hereditary and congenital disorders in a lesser extent. The dental specialist in orthodontics is the professional who has the task of applying the appropriate treatment after the anterior open bite is installed. According to its severity it not only affects the oral cavity but also the patient's facial appearance. Treatment may range from orthopedic treatments, including orthodontic treatment with premolar mutilation to orthognathic surgery. Fortunately this condition is preventable and it is the pediatrician together with the pediatric dentist who has the greatest importance in regard to the early diagnosis of parafunctional habits through a simple intra and extra oral assessment. The preventive approach of the pediatrician would help reduce the morbidity due to the anterior open bite.

OBJECTIVE: This study compared the load-deflection ratios between 0.019 x 0.025-in rectangular orthodontic wires using 5 conventional preformed nickel-titanium (NiTi) and 5 heat-activated NiTi archwires from four different manufacturers (Abzil, Morelli, 3M Unitek and Ormco), totaling 40 archwires. The archwires were placed in typodonts without tooth # 11 and tested using a universal testing machine connected to a computer. RESULTS: The comparisons of mean load-deflection values of conventional NiTi wires revealed that the lowest mean-deflection ratio was found for 3M Unitek, followed by Ormco, Morelli and Abzil. Regarding the heat-activated wires, the lowest load-deflection ratio was found for Ormco, followed by 3M Unitek, Abzil, and Morelli. CONCLUSION: The comparison of mean load-deflection ratios revealed that the heat-activated wires had lowest mean load-deflection ratios, and this trend was seen during all the study. However, at 2-mm deflection, mean load-deflection ratios for heat-activated Morelli and conventional 3M Unitek wires were very similar, and this difference was not statistically significant.