Modified Arnold expander: an alternative for mandibular arch expansion

ABSTRACT Introduction: Due to the anatomical constraints of the mandible, mandibular dental arch usually serves as a guideline to determine the required changes in the maxillary transverse dimension. The Schwarz appliance and the Lip Bumper are the traditional orthodontic appliances for mandibular arch expansion in patients with borderline amounts of crowding, and/or transverse discrepancy. However, they often require patient cooperation, which may be a concern for orthodontists in daily practice. Objectives: This article illustrates a simple fixed orthodontic device as an alternative to achieve mandibular arch expansion in patients with moderate tooth-size/arch-length discrepancy. The four reported cases refer to 8 to 10-year-old patients in the mixed dentition, with an Angle Class I or Class II malocclusion, transverse deficiency in both arches, moderate crowding and/or posterior crossbite, combined with compromised smile aesthetics. The patients were treated with rapid maxillary expansion (RME) using Hass expander appliance and the modified Arnold expander (MAE). Conclusion: This low-cost compliance-free orthodontic appliance provided dentoalveolar decompensation by means of uprighting the posterior teeth, with minimal or no adjustments during treatment. The final results were achieved in only three to four months, and fulfilled all treatment objectives, such as an increase in the arch perimeter and width, and a better teeth alignment.

RESUMO Introdução: Devido aos limites anatômicos da mandíbula, a arcada dentária inferior geralmente serve como guia para determinar as alterações necessárias na dimensão transversal da maxila. O aparelho de Schwarz e o Lip Bumper são os aparelhos usados tradicionalmente para expansão da arcada inferior em pacientes com quantidades limítrofes de apinhamento e/ou discrepância transversal. No entanto, eles requerem a cooperação do paciente, o que pode ser uma preocupação para os ortodontistas na prática diária. Objetivos: O presente artigo ilustra uma alternativa diferente de aparelho fixo para se obter a expansão da arcada inferior em pacientes com discrepância moderada de tamanho dentário e/ou comprimento da arcada. Os quatro casos relatados referem-se a pacientes com 8 a 10 anos de idade, na dentição mista, com má oclusão de Classe I ou II de Angle, deficiência transversal em ambas as arcadas, apinhamento moderado e/ou mordida cruzada posterior, apresentando comprometimento da estética do sorriso. Os pacientes foram tratados com expansão rápida da maxila (ERM), usando aparelho expansor de Hass, e expansor Arnold modificado (EAM). Conclusão: O EAM, que é um aparelho de baixo custo e não depende da colaboração do paciente, promoveu uma descompensação dentoalveolar por meio da verticalização dos dentes posteriores, necessitando de mínimo ou nenhum ajuste durante o tratamento. Os resultados pretendidos foram alcançados em três a quatro meses e cumpriram todos os objetivos do tratamento, como aumento do perímetro e largura da arcada, assim como o melhor alinhamento dos dentes.

Alternative of timely treatment of unilateral posterior cross-bite in primary and mixed early dentition. Case series / Tratamiento de la mordida cruzada posterior unilateral en dentición primaria y mixta temprana: Serie de casos

Introduction Unilateral posterior cross bites (UPCB) are one of the most frequent types of malocclusions found in both primary and early mixed dentitions. Due to its multifactorial origin, its treatment is focused not only on the correction of malocclusion, but also on long-term functional and occlusal stability that reduces alterations in the growth and development of the stomatognathic system at an early age. The objective of this series of cases is to present two alternatives of timely treatment for this malocclusion. Description of the cases The first case is an 8-year-old patient with left UPCB who receives controlled palatal expansion treatment with a Hyrax screw with acrylic splint, in which favorable results are obtained in a short time and with long-term stability. The second case, a 4-year-old patient with a right UPCB is presented with Planas' direct tracks, achieving a desired mandibular postural change. Discussion The treatment alternatives presented, several authors have reported a series of benefits obtained from the type of intervention that not only achieve the correction of malocclusion, but also achieve the improvement of structures that make up the craniofacial complex, within which highlights the desired long-term stability. These benefits are obtained through the selected treatment alternative, according to the diagnosis and clinical characteristics presented in each patient and justifies the decision to perform an early intervention especially in this type of malocclusion. Conclusion The early treatment of the unilateral posterior crossbite should be selected according to the type of dentition and the patient's need, which favors the proper growth and development of the stomatognathic system.

Introducción: Las mordidas cruzadas posteriores unilaterales (MCPU) constituyen uno de los tipos de maloclusiones más frecuentes encontrados tanto en dentición primaria como en dentición mixta temprana. Debido a su origen multifactorial su tratamiento se encuentra enfocado no solo en la corrección de la maloclusión, sino en obtener una estabilidad oclusal y funcional a largo plazo que disminuya las alteraciones en el crecimiento y desarrollo del sistema estomatognático en edades tempranas. El objetivo de esta serie de casos es presentar dos alternativas de tratamiento oportuno para esta maloclusión. Descripción de los casos: El primer caso es un paciente de 8 años de edad con MCPU izquierda quien recibe tratamiento de expansión palatina controlada con un tornillo tipo Hyrax con férula acrílica, en el cual se obtienen resultados favorables en corto tiempo y con estabilidad a largo plazo. El segundo caso es una paciente de 4 años de edad con MCPU derecha a la cual se le realizan Pistas Directas Planas logrando un cambio postural mandibular deseado. Discusión: En las alternativas de tratamiento presentadas, varios autores han reportado una serie de beneficios obtenidos a partir del tipo de intervención que no solo logran la corrección de la maloclusión, sino que a su vez alcanzan la mejoría de estructuras que componen el complejo craneofacial, dentro de los cuales se destaca la estabilidad a largo plazo deseada. Estos beneficios se obtienen a través de la alternativa de tratamiento seleccionada, según el diagnóstico y las características clínicas presentadas en cada paciente y justifica la decisión de realizar una intervención temprana especialmente en este tipo de maloclusión. Conclusión: El tratamiento temprano de la mordida cruzada posterior unilateral debe ser seleccionado según el tipo de dentición y necesidad del paciente, lo que favorece el adecuado crecimiento y desarrollo del sistema estomatognático.

The clinical application of the canine distalization first approach during the treatment of patients with anterior moderate & severe crowding malocclusions / 实用口腔医学杂志

1 1 patients with moderate or severe crowding in the anterior arch were treated with 4 premolar extraction.After canine distaliza-tion first approach,the teeth were aligned and leveled.The results of the study suggest that,with strict implementation of indication,this method may be a viable treatment for the moderate or severe crowding anterior.

Desgaste interproximal: relato de caso / Interproximal stripping: case report

Alguns pacientes encontram-se na categoria de casos limítrofes no que diz respeito à discrepância entre bases ósseas e o tamanho dentário, podendo ser tratados com ou sem extrações dentárias. Nesses casos, a redução de esmalte interproximal pode apresentar-se como uma boa alternativa de tratamento. Essa terapia pode ser aplicada para a resolução de discrepâncias negativas suaves a moderada do arco dentário e quando não se deseja alterar o perfil facial. O objetivo deste trabalho é realizar uma revisão da literatura sobre os desgastes interproximais do esmalte como uma alternativa de tratamento ortodôntico para pacientes considerados limítrofes e exemplificar a técnica a partir de um caso clínico. Aspectos como a respeito da técnica, indicações e contraindicações serão discutidos. Foi possível concluir que esta é uma abordagem de tratamento válida, desde que aspectos fundamentais sejam considerados.

Some borderline patients can be treated both with and without dental extractions. In such cases, the reduction of interproximal enamel can present itself as a good alternative treatment. This therapy can be applied to solve mild to moderate negative discrepancies of the dental arch and when no facial profile change is expected. The aim of this paper was to review the literature about enamel interproximal reduction as an alternative of orthodontic treatment for borderline patients and illustrate the technique with a clinical case. Aspects such as technique, indications and contraindications were discussed. It was concluded that this is a valid treatment approach, since fundamental aspects have been considered.

Interproximal space recovery using an orthodontic elastic separator before prosthetic restoration: a case report

The presence of a dental contact point is essential to maintain normal occlusion and to preserve the health of periodontal structures. Occasionally dental caries could compromise the interproximal contact point, leading to migration of the adjacent teeth with consequent retention of food, gingival inflammation, pocket formation, bone loss and dental mobility. In order to achieve an adequate restorative treatment, reestablishment of interproximal space is necessary. This report describes the interproximal space recovery between the maxillary first and second molars of a 45-year-old female patient before tooth reconstruction. In this case, an orthodontic elastic separator was indicated as an alternative to fixed orthodontic appliances in order to recover the necessary space. The technique was proven efficient, effective, economical, easy to perform and, above all, less invasive than other methods. The interproximal space was regained and a ceramic onlay was cemented for restoring the maxillary second molar. Periodical clinical and radiographic follow-up should be maintained to ensure long-term success.

A presença dos pontos de contato dentais é essencial para a manutenção da oclusão habitual e da saúde das estruturas periodontais. Ocasionalmente as cáries dentárias podem comprometer o ponto de contato interproximal, induzindo a migração de dentes adjacentes com conseqüente retenção de alimento, inflamação gengival, formação de bolsa periodontal, perda óssea e mobilidade dental. A fim de realizar um tratamento restaurador adequado, o restabelecimento do espaço interproximal é necessário. O presente relato descreve a recuperação do espaço interproximal entre molares de uma paciente de 45 anos de idade antes da reconstrução dentária. Neste caso, um elástico ortodôntico separador foi indicado como alternativa aos dispositivos ortodônticos fixos no restabelecimento do espaço necessário. A técnica utilizada provou ser eficiente, efetiva e econômica, e principalmente menos invasiva e fácil de ser realizada. Contudo para que o sucesso clínico se estabeleça ao longo do tempo, faz-se necessário um controle clínico e radiográfico.

Estudio de la prevalencia de mordida cruzada en los pacientes preortodóncicos en são luís / Study of the prevalence of crossbite in patients preortodóncicos in Sao Luis

El objetivo de esta investigación fue describir la mordida cruzada analizando su prevalencia y aspectos relativos a sus modalidades, el genero, la edad, el factor etiológico, la raza y la clasificación de Angle. La muestra fue constituida de 623 pacientes pre - ortodóncicos de consultorios odontológicos e instituciones de enseñanza de odontología de São Luís, estado de Maranhão - Brasil, en el grupo etario de 8 a 15 años. Fue realizado un análisis descriptivo de los datos los cuales fueron sometidos a la prueba del Chi- cuadrado. Los resultados encontrados mostraron que: a) la prevalencia de mordida cruzada fue de 29,05%, la mordida cruzada anterior la más frecuente, con 12,05%; b) no hubo asociación significativa de la mordida cruzada con el raza, género, edad y local de tratamiento; c) portadores de maloclusión clase III fueron los más afectados observándose asociación significativa de la mordida cruzada con esa variable; d) el apiñamiento fue el factor etiológico más registrado. Se concluyó que la prevalencia de mordida cruzada fue elevada y la procura de tratamiento parece estar más relacionada con la cuestión estética

The purpose of this research is to study crossbites, analyzing their prevalence and aspects relative to modality, gender, age, etiologic factor, race, and Angle Classification. The sample consisted of 623 preorthodontic patients from private dental offices and dental educational institutions of São Luís, the state of Maranhão, Brazil, between the ages of 8- and 15- years-old. A descriptive analysis was carried out and the data were submitted to the chi-square test. The results showed that: a) the prevalence of crossbite was 29.05%, being anterior crossbite the most frequent type, with 12.05%; b) there was no significant association of crosssbite with race, gender, age and place of treatment; c) Class III malocclusion patients were the most affected with crossbites, demonstrating association between these variables. It was concluded that the prevalence of crossbite was elevated and the demand seems to be more related to esthetic concerns

THE INFLUENCE OF DENTAL FACTORS TO ERUPTION OF THE MANDIBULAR THIRD MOLAR / 解剖学报

An investigation of the eruption of the mandibular third molar and an analysis of the causes of their impaction and absence were made. On macroscopic and X-ray examination, the rate of the impaction and absence was 19.74％ and 28.95％. respectively.In the analysis of the causes of the impaction and the absence of mandibular third molars we found that besides the length of the region posterior to the second molar already reported, the frequency of crowded teeth in the normal and in the impacted group is higher than that in the absent group. The mediodistal diameters of the mandibular second molar and first molar, which in the normal group are bigger than those in the other groups, also influence the eruption of the mandibular molars.