Evaluación de la anatomía mandibular relacionada con la osteotomía sagital de la rama / Evaluation of mandibular anatomy related to sagittal split ramus osteotomy

La osteotomía sagital de la rama mandibular (SSRO) es una de las técnicas quirúrgicas más frecuentes para corregir las deformidades de la mandíbula. Con el fin de prevenir problemas anatómicos y quirúrgicos, los cirujanos requieren una mayor investigación sobre las estructuras anatómicas relacionadas con la SSRO. El objetivo de este estudio fue investigar las posiciones de la antilingula (AL), la entrada al nervio alveolar inferior (NAI) en la mandíbula y otros puntos de referencia anatómicos en relación con la língula mandibular (L). Fueron estudiadas 70 hemimandíbulas secas. La AL y los demás puntos de referencia y, la posición correspondiente de la L se marcaron en la cara medial y lateral de la rama mandibular respectivamente. Fueron medidas las distancias de la AL, NAI y L en los planos anterior-posterior y superior-inferior con un caliper, y se estableció su relación geométrica. Los resultados mostraron que la AL era perceptible en el 100 por ciento de las caras laterales mandibulares. La mayoría de las ALs se encuentran anterior a la L, con una distancia media de 0,66+/-2,43mm y 0,92+/-2,56 mm y, 4,23+/-2,97 mm y 3,62 +/- 3,14 mm superior a ella (lados derecho-izquierdo respectivamente) (ambos con un valor de p <0,001). Valores similares se observaron en relación con el NAI. No se encontraron diferencias significativas entre los lados derecho e izquierdo, para la mayoría de los parámetros. Los parámetros estudiados pueden asistir a los cirujanos maxilofaciales a determinar la proximidad anatómica del NAI, y reducir al mínimo el riesgo de dañar el nervio y vasos sanguíneos. No recomendamos el uso de la AL como única referencia anatómica cuando se realiza un procedimiento de SSRO.

Sagittal split ramus osteotomy (SSRO) of the mandible is one of the most common surgical techniques to correct mandibular deformities. In order to prevent many surgical anatomical problems, surgeons have found that further investigation of the anatomical structures related to SSRO is needed. This study aims to investigate positions of the antilingula (AL), inferior alveolar nerve (IAN) and other anatomic landmarks in relation to the lingula of dried mandibles. 70 Chilean dried hemimandibles were studied. The AL, others landmarks and the corresponding position of the L were marked on the internal and external aspect of the mandibular ramus respectively. The distances from the AL, IAN and L were measured in the anterior­posterior and the superior­inferior planes using a digital caliper and geometric relationship was established. The results showed the AL was discernible in 100 percent of lateral mandibular rami studied. The most of the AL was found anteriorly to the L with a mean distance of 0.66+/-2.43mm and 0.92+/-2.56mm, and 4.23 +/- 2.97mm and 3.62+/-3.14mm superiorly (right-left sides respectively) (both with p value <0.001). Similar values were seen in relation with IAN. No significant differences were found between the right and left sides, for the majority of parameters. The studied parameters will assist clinicians to determine the anatomical proximity to the IAN, and, minimize the risk of damaging nerver and vessels. We do not recommend the use of antilingula as only anatomical landmark when performing a SSRO procedure.

Estudo longitudinal comparativo cefalométrico das mudanças dento-esqueléticas observadas no tratamento e pós-tratamento (Herbst e aparelho ortodôntico fixo pré-ajustado) de adolescentes com má oclusão de Classe II, divisão 1ª e retrognatismo mandibular / Longitudinal comparative chephalometric study of dento-skeletal changes observed during and after the treatment (Herbst and pre-adjusted fixed appliance) in adolescents with Class II, division 1 malocclusion and mandibular retrognathism

O Objetivo neste estudo prospectivo foi avaliar as mudanças dento-esqueléticas decorrentes do tratamento da má oclusão de Classe II e retrognatismo mandibular, realizado em duas fases de tratamento (ortopédica com aparelho de Herbst e ortodôntica com aparelho fixo pré-ajustado). As telerradiografias em norma lateral, de 17 adolescentes brasileiros consecutivos, foram obtidas no início (T1), final da FASE ORTOPÉDICA (T2), primeiros 13 meses da FASE ORTODÔNTICA (T3) e término da FASE ORTODÔNTICA (T4). As diferenças entre as variáveis cefalométricas (análise de Pancherz) foram analisadas estatisticamente. Os resultados mostraram que de T1 a T4, do total da projeção para anterior da maxila, 42% aconteceram de T1 a T2, 40,3% de T2 a T3 e 17,7% de T3 a T4. 48,2% do crescimento mandibular expressaram-se de T1 a T2 e 51,8% de T2 a T4, no entanto com desaceleração do crescimento de T2 a T3, para logo retomar um crescimento significativo, expressando os 36,7% até T4. A relação molar de classe II e o aumento da sobressaliência que apresentavam os pacientes no início do tratamento foram corrigidos idealmente. Em T4, todos exibiam oclusão normal estável, com boa relação molar e sobressaliência adequada, atingindo os objetivos do tratamento. O plano oclusal que de T1 a T2 sofreu rotação horária, de T2 a T3 retornou às características iniciais, que se mantiveram estáveis até T4. A inclinação do plano mandibular, que descreve o tipo facial, não sofreu alterações em nenhum tempo de observação. Com base nestes resultados pode-se concluir que as mudanças caracterizaram diferencialmente as duas fases de tratamento, sendo que na fase I houve um maior incremento do crescimento mandibular e mudanças dentárias que sobrecorrigiram a má oclusão. A recidiva parcial das mudanças dentárias observada na fase II, não comprometeu as metas ideais do tratamento. O tipo facial foi preservado.

The aim of this prospective study was to assess the dento-skeletal changes in the treatment of Angle Class II, division 1 malocclusion with mandibular retrognathism, realized in two phases (Phase I: Herbst appliance, Phase II: pre-adjusted fixed appliance). Lateral cephalograms of 17 consecutively adolescents were taken at the beginning (T1), at the end of the ORTHOPEDIC FASE (T2), first thirteen months of the ORTHODONTIC FASE (T3) and at end of the ORTHODONTIC FASE (T4). Differences among the cephalometric variables (Pancherz analysis) were statistically analyzed. The results exhibited that from T1 to T4 from the overall maxillary forward growth, 42% happened from T1 to T2, 40,3% from T2 to T3 and 17,7% from T3 to T4. From the overall mandibular forward movement, 48,2% happened from T1 to T2 and 51,8% from T2 to T4, meanwhile with growth slowdown from T2 to T3. The molar Class II relation and the excessive overjet were ideally corrected. At T4, all patients showed stable normal occlusion reaching the objectives of the treatment. The oclusal plane, that from T1 to T2 rotated clock-wise, from T2 to T3 returned to the initial position and remain stable until T4. Mandibular plane inclination, that caracterizes facial type, did not change at any time during the treatment. Based on these results it can be concluded that the changes characterized differently each phase of the treatment: during Phase I there were larger increase of mandibular growth and dental changes that overcorrected the malocclusion. The partial relapse observed in Phase II of treatment did not jeopardize the ideal goals of the treatment. The facial type was preserved.

Método combinado L.S. 78 / The L.S. 78 combined method

El síndrome de clase II división 1 es considerado como un cuadro clínico integrado por varios signos, síntomas morfológicos y funcionales; en la mayoría de los casos se produce por alteraciones funcionales del aparato estomatognático, que conducen a la aparición de un retrognatismo mandibular. Para la solución de este problema, se hace necesario el uso de un aparato de ortopedia funcional, que sea capaz de reestablecer las funciones y transmitir estímulos propioceptivos adecuados a la musculatura y los dientes, logrando así una relación adecuada de los maxilares, tanto en sentido vertical como sagital. Con el objetivo de brindar información a estudiantes y especialistas, se realiza la descripción de un aparato de ortopedia funcional de los maxilares: el método combinado L.S. 78 diseñado por el profesor uruguayo Indalecio Buño Loureiro, el cual combina la utilización de la placa activa y el activador universal, y que está indicado específicamente para el tratamiento de la clase II división 1 o clase I con características de la anterior(AU)

The syndrome of class II division I is considered as a clinical picture composed of various signs, morphological and functional syndromes. In most of the cases, it is caused by functional alterations of the stomatognathic apparatus leading to the appearance of mandibular retrognathia. To solve this problem, it is necessary the use of a functional orthopedic apparatus capable of restoring the functions and of transmitting adequate propioceptive stimuli to the muscles and tooth to attain an appropriate relation of the maxillae in vertical and sagittal sense. In order to give information to students and specialists, it is described an apparatus of functional orthopedics of the maxillae: the combined method L.S. 78 designed by the Uruguayan professor Indalecio Buño Loureiro, who combines the use of the active plaque and the universal activator. It is specifically indicated for the treatment of class II division I or class I with characteristics of the above(AU)

Retrognathic changes during mandibular growth in impaired breathing individuals

Mandibular retrognathism was evaluated in 32 impaired breathing adult subjects, as diagnose by an otolaryngologist, and also evaluated in an equal number of controls. The lateral cephalogram revealed that a significant retrognathism of the mandible in the breathing impaired sample occurred as result in a backward rotation in both tempromandibular joint, which affect mandibular spatial position and gonial angle that direct mandibular growth. It seems to be these changes overcomed the non-significant protrusive changes in the articular angle. The investigation also defined the changes in the gonial angle a confined to the lower and anterior divisions only; since the body of mandible significantly rotated downward and backward rather than backward rotation of the ramus part

Interpretaçäo esquemática das maloclusöes segundo cefalograma de Steiner e Wylie / Maloclusions interpretation trough Steiner and Wylie

O autor mostra várias nuances de interpretaçäo cefalométrica com aspectos dentários e esqueletais, visando mostrar as variáveis ou näo variáveis segundo compensaçöes anatômicas e funcionais