Comportamiento de la maloclusión funcional e interferencias oclusales en niños con dentición mixta

Introducción: las interferencias oclusales no controladas precozmente pueden producir desviación de la mandíbula en sentido anteroposterior o transversal. El manejo de las mordidas cruzadas se debe iniciar en el momento del diagnóstico, preferiblemente en edades tempranas, con el fin de tratarlas en el nivel primario de prevención. Objetivo: determinar el comportamiento de la maloclusión funcional causada por interferencias oclusales en niños con dentición mixta de la Escuela Primaria Mártires del Corynthia, entre octubre de 2019 y junio de 2021. Materiales y métodos: se realizó un estudio observacional descriptivo de corte transversal en la Escuela Primaria Mártires del Corynthia, del Área de Salud José Jacinto Milanés, del municipio de Matanzas, entre octubre de 2019 y junio de 2021. El universo estuvo conformado por 66 niños. Se utilizó una planilla de recolección de datos y se solicitó el consentimiento informado a los tutores de los niños. Resultados: las edades donde los niños presentaron mayor afectación fueron de 6 a 7 años y de 8 a 9 años, ambos rangos con un 10,6 %. El 27,3 % presentó interferencias oclusales y mordida cruzada posterior unilateral. El 48,5 % fue del sexo femenino y el 30,3 % tenían edades de 6 a 7 años. El 71,2 % eran simétricos y presentaron mordida cruzada posterior unilateral. Los simétricos y con línea media coincidente representaron un 36,4 %. Conclusiones: la maloclusión funcional más frecuente en niños con dentición mixta fue la mordida cruzada posterior unilateral, que se relacionó de manera directa con las interferencias oclusales. Las asimetrías faciales y la línea media desviada estuvieron asociadas a dicha maloclusión.

Introduction: early uncontrolled occlusal interferences can produce anterior-posterior jaw deflection. Management of cross-bites should be initiated at the time of diagnosis, preferably at early ages, in order to treat them at the primary level of prevention. Objective: to determine the behavior of functional malocclusion caused by occlusal interferences in children with mixed dentition from the Martires del Corynthia primary school between October 2019 and June 2021. Materials and methods: a cross-sectional, observational, descriptive study was carried out at the Martires del Corynthia Primary School, of the Jose Jacinto Milanes Health Area, Matanzas municipality, between October 2019 and June 2021. The universe consisted of 66 children. A data collection form was used and informed consent was requested from the children's guardians. Results: the ages where the children presented more affectation were from 6 to 7 years and from 8 to 9 years, both ranges with 10.6%. 27.3% presented occlusal interferences and posterior unilateral cross-bite. 48.5% were female and 30.3% were 6 to 7 years old. 71.2% were symmetrical and presented unilateral posterior cross-bite. Symmetric patients and with a coincident midline represented 36.4%. Conclusions: the most frequent functional malocclusion in children with mixed dentition was the unilateral posterior cross-bite, which was related to occlusal interferences in a direct way. Facial asymmetries and a deviated midline were associated with the before mentioned malocclusion.

Root resorption pattern in panoramic radiographs of pediatric patients with unilateral posterior crossbite: a cross-sectional and retrospective study / Patrón de reabsorción radicular en radiografías panorámicas de pacientes pediátricos con mordida cruzada posterior unilateral: estudio transversal y retrospectivo

SUMMARY: temporary mandibular molars in panoramic radiographs of pediatric patients with unilateral posterior crossbite (UPCB). This cross-sectional and retrospective study analyzed 114 orthopantomograms of patients between 6 - 9 years of age with unilateral posterior crossbite diagnosis. The first and second mandibular molars were analyzed. Their root resorption stage was typified, and the root lengths were measured; to later compare the data obtained depending on the malocclusion side. 86.4 % of molars showed a linear resorption pattern, and atypical resorption prevalence in patients with UPCB was 13.5 %. The total length average of the first molars on the side of the malocclusion was 8.20 mm, while the contralateral exhibited a mean of 9.29 mm. Lastly, the second molars had a mean length of 11.12 mm in crossbite side and 12.30 mm in the normal occlusion side. UPCB could affect physiological resorption by observing a resorption alteration in those mandibular molars located on the malocclusion side.

RESUMEN: El trabajo de este estudio se realizó en molares mandibulares temporales en radiografías panorámicas de pacientes pediátricos con mordida cruzada posterior unilateral (MCPU). Este estudio transversal y retrospectivo analizó 114 ortopantomografías de pacientes entre 6 - 9 años de edad con diagnóstico de mordida cruzada posterior unilateral. Se analizaron los primeros y segundos molares mandibulares. Se tipificó su estado de reabsorción radicular y se midió la longitud de las raíces; para luego comparar los datos obtenidos según el lado de la maloclusión. El 86,4 % de los molares mostró un patrón de reabsorción lineal y la prevalencia de reabsorción atípica en pacientes con MCPU fue del 13,5 %. El promedio de longitud total de los primeros molares del lado de la maloclusión fue de 8,20 mm, mientras que el contralateral exhibió una media de 9,29 mm. Por último, los segundos molares tenían una longitud media de 11,12 mm en el lado de mordida cruzada y de 12,30 mm en el lado de oclusión normal. La MCPU podría afectar la reabsorción fisiológica al observar una alteración de la reabsorción en aquellos molares mandibulares ubicados en el lado de la maloclusión.

Discrepancia negativa transversal del maxilar y diferencias cefalométricas laterales según el ancho de la arcada superior / Negative maxillary transverse discrepancy and cephalometric lateral differences according to the width of upper arch

Introduction: Negative maxillary transverse discrepancy is not exclusive to narrow upper arch. The transverse discrepancy due to maxillary deficiency is well described, but this is not the case when the maxilla displays adequate dimensions and the origin of the problem is an excess of mandibular width. Objective: To describe the cephalometric characteristics of negative maxillary transverse discrepancy present in narrow upper arches with those of normal or increased width. Methods: An observational and cross-sectional study was carried out in records of patients with negative maxillary transverse discrepancy. The cases referred to the maxillofacial surgery department at Hospital Clínico Quirúrgico "Hermanos Ameijeiras" between January 2016 and January 2020 were selected. The initial study models were measured and two groups were formed: those with a distance between central fossae of 16 to 26, less than 47 mm and the other with equal or greater values. Lateral cephalometric analysis of Ricketts, McNamara, Björk & Jarabak, Burstone and soft profile were performed on the initial teleradiographs. Using the Mann Whitney U test of independent samples, measurements with statistically significant differences between both groups were selected. (p <0.05). Results: Significant differences were found regarding the cranial-mandibular relationship, mandibular anatomy, maxillo-mandibular relationship and occlusal relationship. The most important differences observed in each group were respectively: S-Ar / Ar-Go ratio (p = 0.033), mandibular body length (p = 0.01), mandibular-maxillary difference (p = 0.003) and overjet (p = 0.043). Conclusions: In the studied patients, negative maxillary transverse discrepancy has the same probability of presenting a wide or in norm upper arch, as well as a narrow arch. In the first case, it is more likely to find jaws with increased body length, a skeletal class III pattern and a concave profile; in the second case, the tendency is to present small jaws with increased articular angle and dental overjet(AU)

Introducción: La discrepancia negativa transversal del maxilar no es exclusiva de una arcada superior angosta. La discrepancia transversal por deficiencia maxilar está bien descrita, pero no ocurre así cuando el maxilar se presenta con dimensiones adecuadas y el origen del problema es un exceso del ancho mandibular. Objetivo: Describir las diferencias cefalométricas de la discrepancia negativa transversal del maxilar que presentan arcadas superiores estrechas con aquellas de ancho normal o incrementado. Métodos: Se realizó un estudio observacional, de corte transversal, en expedientes de pacientes con discrepancia negativa transversal del maxilar. Se seleccionaron los casos que acudieron entre enero del 2016 y enero del 2020 a la consulta de cirugía maxilofacial del Hospital Clínico Quirúrgico "Hermanos Ameijeiras". Se midieron los modelos de estudio iniciales y se conformaron dos grupos: aquellos con distancia entre fosas centrales de 16-26, menor de 47 mm y el otro con valores iguales o superiores. Se realizaron análisis cefalométricos laterales en las telerradiografías iniciales de Ricketts, McNamara, Björk & Jarabak, Burstone y perfil blando. Por medio de la prueba U de Mann Whitney de muestras independientes, se seleccionaron las mediciones con diferencias estadísticas significativas entre ambos grupos (p < 0.05). Resultados: Se encontraron diferencias significativas concernientes a la relación cráneo mandibular, anatomía mandibular, relación máxilo mandibular y relación oclusal. Las diferencias observadas más importantes de cada grupo fueron respectivamente: relación S-Ar/Ar-Go (p = 0,033), longitud del cuerpo mandibular (p = 0,01), diferencia mandibular-maxilar (p = 0,003) y resalte (p = 0,043). Conclusiones: En los pacientes estudiados, las discrepancias negativas transversales tienen la misma probabilidad de presentarse con la arcada superior ancha o en norma, que angosta. En los primeros es más probable encontrar mandíbulas con longitud del cuerpo incrementada, patrón de clase III esquelética y perfil cóncavo; en los segundos, la tendencia es a presentar mandíbulas pequeñas con ángulo articular y resalte dentario aumentados(AU)

El quad-hélix, un aparato versátil / The quad-hélix, a versatile appliance

El quad-hélix (QH) es un aparato de expansión maxilar, fabricado con alambre de acero inoxidable soldado a bandas en molares, que dispone de espirales o hélices que aumentan la longitud de alambre del aparato, lo que lo hace muy elástico y aligera la magnitud de la fuerza sobre los dientes, es ampliamente usado tanto en dentición mixta como en permanente temprana, fácil de fabricar, higiénico y bien tolerado por los pacientes. Su principal acción es mover hacia vestibular los procesos dentoalveolares de la arcada maxilar, influyendo secundariamente en la expansión de la sutura palatina media en pacientes con dentición mixta o permanente temprana. El QH es muy práctico y tiene muchos usos y adaptaciones y se puede utilizar como auxiliar en el tratamiento de problemas de hábito de dedo o lengua, para abrir mordida, rotar y dar torque a molares permanentes o para mover sólo un diente en particular. En este artículo describimos una nueva aplicación del QH que consiste en la tracción, de dientes anteriores superiores permanentes retenidos, después del abordaje quirúrgico para localizarlos. También revisaremos las indicaciones, contraindicaciones, ventajas y desventajas del aparato QH soldado a bandas en molares así como su elaboración, variantes y forma de activación (AU)

The quad-helix (QH) is a maxillary expansion appliance, manufactured with stainless steel wire welded to bands in molars, which has spirals or helix to increase the length of wire of the device, which makes it very elastic and lightens the magnitude of the force on the teeth, is widely used both in mixed and in early permanent dentition, is easy to manufacture, hygienic and well tolerated by patients. Its major action is to move towards the dentoalveolar process of the maxillary arcade, secondarily influencing the expansion of the middle palatal suture in young patients with mixed or permanent early dentition. The QH is very practical and has many uses and adaptations as an aid in the treatment of problem of thumb sucking or tongue habit, to open bite, to rotate and torque permanent molars or to move only one particular tooth. In this article we describe a new application of the QH that consist of the traction or retained permanent upper teeth, after surgical approach to locate them. We will also review the indications, contraindications, advantages and disadvantages of the QH welded to molar bands, as well as its construction, variants and activation form (AU)

Non-surgical treatment of transverse deficiency in adults using Microimplant-assisted Rapid Palatal Expansion (MARPE)

ABSTRACT Introduction: Maxillary transverse deficiency is a highly prevalent malocclusion present in all age groups, from primary to permanent dentition. If not treated on time, it can aggravate and evolve to a more complex malocclusion, hindering facial growth and development. Aside from the occlusal consequences, the deficiency can bring about serious respiratory problems as well, due to the consequent nasal constriction usually associated. In growing patients, this condition can be easily handled with a conventional rapid palatal expansion. However, mature patients are frequently subjected to a more invasive procedure, the surgically-assisted rapid palatal expansion (SARPE). More recently, researches have demonstrated that it is possible to expand the maxilla in grown patients without performing osteotomies, but using microimplants anchorage instead. This novel technique is called microimplant-assisted rapid palatal expansion (MARPE). Objective: The aim of the present article was to demonstrate and discuss a MARPE technique developed by Dr. Won Moon and colleagues at University of California - Los Angeles (UCLA). Methods: All laboratory and clinical steps needed for its correct execution are thoroughly described. For better comprehension, a mature patient case is reported, detailing all the treatment progress and results obtained. Conclusion: It was concluded that the demonstrated technique could be an interesting alternative to SARPE in the majority of non-growing patients with maxillary transverse deficiency. The present patient showed important occlusal and respiratory benefits following the procedure, without requiring any surgical intervention.

RESUMO Introdução: a deficiência transversa da maxila é uma má oclusão com alta prevalência em todas as faixas etárias, da dentição decídua à permanente. Se não for corrigida, pode agravar-se com o passar do tempo, prejudicando o crescimento e desenvolvimento facial. Além dos prejuízos oclusais, essa deficiência pode trazer problemas respiratórios também severos, devido à consequente constrição da cavidade nasal. Em pacientes em crescimento, a sua resolução é relativamente simples, por meio da expansão rápida convencional da maxila. Porém, os pacientes já maduros geralmente são encaminhados para um procedimento mais invasivo, a expansão rápida de maxila assistida cirurgicamente (SARPE). Mais recentemente, pesquisadores têm demonstrado que é possível executar a expansão palatal esquelética em pacientes adultos sem auxílio de osteotomias, mas sim com auxílio de mini-implantes. Essa técnica é denominada Microimplant-Assisted Rapid Palatal Expansion, ou MARPE. Objetivo: o objetivo do presente artigo é demonstrar e discutir uma das técnicas disponíveis de MARPE, desenvolvida por Won Moon e colaboradores, na University of California, Los Angeles (UCLA). Métodos: a técnica encontra-se detalhadamente descrita, com as etapas laboratoriais e clínicas que devem ser seguidas para sua correta execução. Para descrevê-la, é apresentado o caso clínico de uma paciente adulta, detalhando toda a sequência do tratamento e os resultados obtidos. Conclusão: a técnica apresentada pode ser uma alternativa não invasiva à SARPE na resolução da deficiência transversa de maxila, podendo ser empregada na maioria dos pacientes com crescimento facial finalizado. A paciente apresentada demonstrou benefícios significativos nos aspectos oclusal e respiratório, sem a necessidade de intervenção cirúrgica.

Orthodontic retreatment of a Class III patient with significant midline asymmetry and bilateral posterior crossbite

Posterior crossbite might cause serious long-term functional problems if not early treated. Nevertheless, in older patients, treatment might include palatal expansion in order to correct such malocclusion. In view of the above, this article aims at reporting late correction of bilateral posterior crossbite associated with Angle Class III malocclusion, right subdivision, with consequent midline shift (good skeletal pattern). The case was presented to the Brazilian Board of Orthodontics and Dentofacial Orthopedics (BBO), with DI equal to or greater than 10, as a requirement for the title of certified by the BBO.

A mordida cruzada posterior pode causar sérios problemas funcionais em longo prazo, se não tratada precocemente. Porém, em alguns pacientes com idade mais avançada, ainda é possível realizar a disjunção palatina para corrigir essa condição. Assim sendo, o objetivo do presente caso é relatar a correção tardia de uma mordida cruzada posterior bilateral, associada a uma má oclusão de Classe III de Angle, subdivisão direita, com consequente desvios de linhas médias dentárias (bom padrão esquelético). Esse caso foi apresentado à Diretoria do Board Brasileiro de Ortodontia e Ortopedia Facial (BBO), se enquadrando na categoria IGC igual ou superior a 10, como requisito para revalidação do título de Diplomado.

Tratamento ortodôntico e ortopédico da mordida cruzada posterior / Orthodontic and orthopedic treatment of posterior crossbite

O presente estudo teve como objetivo revisar os trabalhos no que se diz respeito ao tratamento da mordida cruzada posterior e apresentar um caso clínico de uma paciente com mordida cruzada posterior e anterior tratada com disjuntor de Haas e máscara facial. Com uma estimativa de 8% a 23,5%, a mordida cruzada posterior é a má oclusão de maior frequência na clínica, sendo que estes números são similares tanto na dentição decídua quanto na permanente. Os fatores etiológicos podem ser hábitos viciosos, problemas respiratórios, interferências oclusais, más formações congênitas, entre outros, podendo agir isolados ou em conjunto. O tratamento deste tipo de má oclusão exige, além de um conhecimento do profissional para definir qual a melhor terapêutica de acordo com a idade do paciente, um diagnóstico minucioso por diversos meios preconizados como análise clínica, modelos de estudo, telerradiografias em norma lateral e frontal, auxiliando o clínico na elaboração de um plano de tratamento adequado e, como consequência, levando a um prognóstico mais favorável desta má oclusão. A expansão rápida da maxila ou disjunção, além de corrigir a deficiência transversa da maxila, proporciona diversas mudanças na oclusão como expansão indireta do arco inferior, melhora na estética do sorriso e auxílio no tratamento de Classe II. O tratamento deve ser realizado, preferencialmente, na dentadura decídua...

This study aimed to perform a literature review on the treatment of posterior crossbite and present the clinical case of a patient with posterior and anterior crossbite treated with breaker Haas and facemask. The posterior crossbite is the most frequent malocclusion, an estimative of 8% and 23.5%, in both deciduous and permanent dentitions. The etiological factors may include vicious habits, respiratory problems, occlusal interference, and congenital malformations, among others. These factors may act alone as well as combined. Beside a proper knowledge of the professional that will determine the best approach based on the age of the patient, the treatment of this malocclusion also requires an accurate diagnosis obtained through clinical analysis, study models, frontal and lateral teleradiographs. Thereby, a detailed diagnosis may assist the clinician on the development of a treatment plan that may lead to a more favorable prognosis. The fast maxillary expansion, or disjunction, in addition to correct the transverse maxillary deficiency also provides several changes in the occlusion such as indirect expansion of the lower arch, improvement of dental aesthetics, and assistance on the treatment of Class II. This kind of treatment should be conducted in patients with deciduous dentition...

Functional evaluation of orthopedic and orthodontic treatment in a patient with unilateral posterior crossbite and facial asymmetry / 대한치과교정학회지

An 8-years old boy with facial asymmetry and unilateral posterior crossbite on the left side received orthopedic and orthodontic treatment. During the first phase of treatment, the narrow maxillary arch was expanded using an acrylic plate. Then, the acrylic plate was used as a bite block with occlusal indentations from the construction bite that was obtained with the incisors in a coincident dental midline. After the position of the mandible was stabilized, the second phase of orthodontic treatment was initiated using fixed appliances for detailing of the occlusion. Skeletal symmetry, ideal occlusion, and coincident dental midlines were thus achieved. Functionally, occlusal force balance and masticatory muscle activity were improved, and the chewing patterns were normalized.

Mordida cruzada posterior, corrección y consideraciones: caso clínico con 7 años de seguimiento / Posterior crossbite correction and considerations: case report with 7 years of follow-

El tratamiento precoz de la mordida cruzada posterior unilateral funcional durante la dentición mixta es extremadamente importante para la Ortodoncia contemporánea porque provee un correcto posicionamiento de las bases óseas, dientes y de la articulación temporomandibular cuando el sistema estomatognático está en pleno crecimiento y desarrollo. Estos resultados generalmente producen una adecuada relación Craneofacial, reduciendo la necesidad de tratamientos cada vez más complejos en la dentición permanente. El propósito de este artículo fue presentar el caso de un niño que a los 8 años de edad fue diagnosticado, mordida cruzada posterior unilateral funcional, tratado por medio de un expansor fijo tipo Quad-helix donde enfatizamos la estabilidad a largo plazo. La maloclusión fue corregida en tres meses de uso activo del Quad-helix, tres meses de contención y fue realizado un seguimiento post tratamiento por siete años. La estabilidad a largo plazo del tratamiento de la mordida cruzada posterior unilateral funcional está íntimamente relacionada con el diagnostico precoz, la eliminación del factor etiológico asociado con la correcta aparatología y la mecánica de tratamiento

Early treatment of functional unilateral posterior crossbite during the mixed dentition is extremely important for contemporary Orthodontics, provides the correct positioning of osseous bases, teeth and temporomadibular joint when the stomatognathic system is in growth and development. These results generally develop into an adequate craniofacial relationship, reducing the necessity for more complex treatments at permanent dentition. The subject of this paper was to report patient 8 years old, diagnosed with functional unilateral posterior crossbite, and was treated by an expander appliance type Quad-helix emphasizing the long-term stability. The malocclusion was corrected in 3 months of active use of the appliance, 3 months for retention purposes and followed up during 7 years post-treatment. The stability in long term of functional unilateral posterior crossbite treated is closely related with early diagnostic, the elimination of the etiological factor associated with a correct appliance and the mechanic of treatment

Quad-helix vs placa removible con tornillo de expansión / Quad-helix vs removable screw plate expansion

La variedad de aparatología para el tratamiento de la mordida cruzada posterior hace con que el Ortodoncista evalúe algunos criterios para su selección y éxito en el tratamiento. El objetivo de este artículo es comparar dos métodos de tratamiento de mordida cruzada posterior en dos casos clínicos tratados con Quad-helix y Placa removible con tornillo de expansión. Podemos concluir que el Quad-helix es el método de tratamiento de primera elección en relación a la placa removible por el corto tiempo de tratamiento, las pocas visitas al ortodoncista, su bajo costo y por la poca colaboración que se necesita del paciente

The different kind of appliances for the treatment of posterior crossbite make that the orthodontist assess some criterions for their selection and success for the treatment. The aim of this paper was to compare two methods of treatment of the posterior crossbite by two case reports treated with Quad-helix and removable plate. Concluding that the Quad-helix is the appliance of first choice in relation of the removable plate for the short time of active treatment, the less visits and chair time, the fewer cost of treatment and the smaller cooperation of the patient

Avaliação do crescimento condilar através de cintilografia óssea em pacientes com mordida cruzada posterior funcional / Assessment of condylar growth by skeletal scintigraphy in patients with posterior functional crossbite

OBJETIVOS: avaliar a atividade de crescimento condilar em 10 pacientes com mordida cruzada posterior funcional antes e após a correção, usando a cintilografia óssea mandibular. MÉTODOS: os pacientes receberam injeção endovenosa de contraste radioativo (Technesium-99m, difosfato de metileno de sódio). Após duas horas, imagens cintilográficas planares foram realizadas por meio de uma câmera Gama. Imagens laterais da boca fechada, mostrando os côndilos direito e esquerdo, foram usadas. Uma imagem da quarta vértebra lombar também foi usada como referência. RESULTADOS: diferenças estatisticamente significativas não foram encontradas nos valores da taxa de absorção, em ambos os lados, quando os períodos de pré-tratamento e pós-tratamento foram analisados separadamente e também quando os períodos de pré-tratamento e pós-tratamento foram analisados no mesmo lado. Não foram encontradas diferenças na atividade de crescimento condilar em pacientes com mordida cruzada posterior funcional.

OBJECTIVES: This study evaluates the condylar growth activity in 10 patients with functional posterior crossbite before and after correction, using the mandibular bone skeletal scintigraphy. METHODS: Patients received endovenous injection of radioactive contrast (Technesium-99m labeling, sodium methylene diphosphate). After two hours, planar scintigraphic images were taken by means of a Gamma camera. Lateral images of the closed mouth, showing the right and left condyles, were used. An image of the 4th lumbar vertebra was also used as reference. RESULTS: Statistically significant differences were not found in the uptake rate values, on both sides when pre-treatment and post-treatment periods were analyzed separately and also when pre-treatment and post-treatment periods were analyzed in the same side. No differences were found in the condylar growth activity, in patients with functional posterior crossbite.

Avaliação por tomografia computadorizada helicoidal dos efeitos da expansão rápida da maxila no posicionamento condilar em pacientes com mordida cruzada posterior funcional / Evaluation with helicoidal computed tomography of rapid maxillary expansion effects in the condylar position of patients with functional posterior crossbite

OBJETIVO: este estudo clínico avaliou, por meio da tomografia computadorizada helicoidal, os efeitos da expansão rápida da maxila no posicionamento condilar de pacientes com mordida cruzada posterior funcional na fase da dentadura mista. MÉTODOS: dez pacientes com faixa etária entre os 7 anos e 2 meses e os 11 anos e 2 meses - apresentando mordida cruzada posterior funcional, com desvio da linha média de pelo menos 2,5mm para o lado do cruzamento - foram tratados com expansão rápida da maxila. Após a obtenção de cortes tomográficos sagitais da articulação temporomandibular, as medidas dos espaços articulares anterior, posterior e superior foram realizadas e o posicionamento relativo do côndilo foi calculado. Utilizando-se cortes tomográficos axiais, avaliou-se o posicionamento anteroposterior e transversal dos côndilos em relação às estruturas da base craniana. RESULTADOS: foram identificadas diferenças significativas, antes do tratamento, entre os espaços articulares posteriores, na posição relativa do côndilo e um posicionamento mais anterior e mais próximo ao plano sagital mediano do côndilo do lado não-cruzado. Após o tratamento, não foram evidenciadas diferenças significativas nessas medidas. CONCLUSÕES: após a expansão rápida da maxila, um posicionamento mais centralizado dos côndilos nas fossas articulares foi observado, além de uma maior simetria anteroposterior e transversal entre os mesmos.

AIM: This clinical study evaluated, through helicoidal computed tomography (CT), the effects of rapid maxillary expansion in the condylar position of patients with functional posterior crossbite in mixed dentition stage. METHODS: Ten patients aged between 7 years and 2 months and 11 years and 2 months were selected. This patients which presented functional unilateral posterior crossbite with mandibular midline deviation of at least 2.5mm to the crossbite side were submitted to rapid maxillary expansion. After obtaining sagittal CT slices of the temporomandibular joints, measurements of the anterior, posterior and superior joint spaces were carried out and the relative positioning of the condyle was calculated. Axial slices of the temporomandibular joint were also used to evaluate the anteroposterior and transversal position of the condyles in relation to the cranial base structures. RESULTS: Before treatment, significant differences were observed in the posterior joint spaces, in the relative positioning of the condyle and with the non-crossbite side condyle displaced more anteriorly and medially in relation to midsagittal line. After treatment there was no statistically significant difference. CONCLUSION: After the rapid maxillary expansion, a more centralized position of the condyles in the joint cavities was observed, and a greater anteroposterior and transverse symmetry between them.

Enfoque temprano de las maloclusiones transversales, diagnóstico y tratamiento: revisión de la literatura / Early approach of the transversal malocclusions, diagnosis and treatment: literature review

El tema de las mal oclusiones transversales, ha sido ampliamente estudiado e investigado desde muchos puntos de vista: esquelético, muscular, dental y funcional, por muchos autores alrededor del mundo y los correspondientes informes, además de describir las diferentes etiologías, complicaciones y compromisos, ha llevado a un consenso general según el cual, entre más pronto sea corregida, menores serán sus consecuencias y secuelas negativas en el crecimiento y desarrollo y se pueden alcanzar muy buenos resultados y gran estabilidad a largo plazo. Por ello el objetivo de este artículo es identificar a través de una revisión de la literatura, las herramientas necesarias que permitan la detección, diagnóstico y tratamiento de estas mal oclusiones de manera temprana y preventiva para evitar así asimetrías esqueléticas mayores.

The issue of transversal malocclusions has been widely studied by many authors around the world and researched from many perspectives: skeletal, muscular, dental and functional. Reports describe the different etiologies, complications and compromises of malocclusion, leading to a general consensus that, the sooner it is corrected, the less their consequences and negative effects on growth and development will be, and good results can be achieved with great long-term stability. Therefore the aim of this paper is to identify through a literature review, the necessary tools that allow the detection, diagnosis and treatment of these malocclusions at an early stage and to prevent severe skeletal asymmetries.

Mordida cruzada posterior: uma classificação mais didática / Posterior crossbite: a more didactic classification

O objetivo deste trabalho é apresentar uma nova classificação de mordida cruzada posterior, sendo esta mais didática e de fácil entendimento, diferindo das demais em sua nomenclatura, preservando, no entanto, os princípios fundamentais que regem a Ortodontia. Essa classificação torna o processo de diagnóstico da mordida cruzada posterior sistematizado, tornando-o mais preciso, auxiliando o clínico na elaboração de um plano de tratamento adequado e, como conseqüência, levando a um prognóstico mais favorável dessa má oclusão.

The aim of this work is to present a new posterior crossbite classification, being this more didactic and of easy understanding, differing from the others in your nomenclature, preserving, however, the basic principles that govern the Orthodontics. This new classification makes the posterior crossbite diagnosis process systematized and accurate, assisting the clinician in the elaboration of a suitable treatment plan and as consequence, leading to more favorable prognostic of this malocclusion.

A posteroanterior cephalometric study on the change of maxilla by rapid palatal expansion / 대한치과교정학회지

The purpose of this study was to evaluate whether the basal bone of maxilla was expanded transversely by rapid palatal expansion through the posteroanterior cephalometric analysis. Thirty patients with the maxillary deficiency were utilized in this study, The posteranterior cephlometric X-ray film taken twice, before and after rapid palatal expansion. The obtained results were as follows : 1. There was a significant increase of the maixllary width by rapid palatal expansion in male and female.(p<0.001) 2. there was no significant difference between the male and female in the expansion of the maxillary width by rapid palatal expansion. 3. There was a significant increase of the mixillary by rapid palatal expansion in th both of before and after the puberty. 4. There was no significant difference between before and after the puberty in the expansion of the maxillary width by rapid palatal expansion.

Analysis of masticatory muscles electromyography of the patients with unilateral posterior crossbite / 实用口腔医学杂志

Objective:To study the effects of unilateral posterior crossbite on masticatory muscle functions pattern by using electromyography(EMG).Methods:20 subjects(11 males and 9 females)with unilateral posterior crossbite were selected.Subjects were instructed to stay mandibular postural position and to make maximum bite in intercuspal position(ICP)and bilateral chewing.EMG data of the left and right masseter and anterior temporalis muscles were recorded.Asymmetry index of masseter muscles(ASMM) and asymmetry index of temporalis muscles(ASTA)were calculated and compared.20 subjects with individual normal occlusion were used as control.Results:Compared to control group,masseter and temporal muscle activities in unilateral posterior crossbite group were lower in maximum bite and bilateral chewing;The activities of two muscles at crossbite side were lower than that at noncrossbite side.Under maximum bite and bilateral chewing,ASMM and ASTA in unilateral posterior crossbite group were significantly higher than those in control group;ASMM and ASTA in Subjects with one posterior tooth crossbite is lower than subjects with several teeth crossbite.Conclusion:It can be suggested that unilateral posterior crossbite may damage the function of mastication muscle.

Study of the tracings of the condylar movements during opening/closing of the unilateral posterior crossbite / 西安交通大学学报(医学版)

Objective To discuss the influence of dental occlusion on mandibular movements. The characteristic tracings of mandibular movements at the condyle of unilateral posterior crossbite patients were investigated using a computerized axiography. The differences between patients with normal occlusion and unilateral posterior crossbite were compared by some recordings of condylar movements in three dimensions. Methods Seven unilateral posterior crossbite patients (at least two posterior teeth were crossbite) were chosen as experiment group, and five with normal occlusion without signs or symptoms of temporomandibular disorders (TMD) were chosen as controls. By computer-aided axiography (CADIAX) and gamma dental software for windows 2.3.2.22 (GDSW) from Grbh company (Germany), the tracings of condylar movements in right and left parasagittal planes during opening/closing were recorded, and the data were input into the computer and analyzed using GDSW software. The drifts in X, Y and Z coordinated with condylar movements, respectively, and the transverse condylar inclination from the orbital axis line and the horizontal condylar inclination were calculated, respectively. Results The lengths of the axiographical in opening/closing movement were significantly shorter in the experiment group than that in normal occlusion group; the bilateral condylar tracing of opening/closing movement was symmetric in younger cases but asymmetric in older cases; the lateral deviation of opening/closing movement was significantly larger in unilateral posterior crossbite than that in control group. Conclusion The condylar tracings of envelope of movement in unilateral posterior crossbite patients are significantly different in the patients with normal occlusion. With age increasing, tracings of the affected side and contralateral side vary from symmetry to asymmetry. The results suggest that the functional opening movements are limited in the patients with the unilateral posterior crossbite.