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.

Frecuencia de maloclusiones sagitales y transversales en estudiantes de 12 a 18 años de Asunción / Frequency of sagittal and transverse malocclusions in students from 12 to 18 years of age in Asunción

La maloclusión es uno de los trastornos bucodentales más comunes. Reconocer su importancia lleva a la necesidad de realizar estudios epidemiológicos cuyos resultados orienten el desarrollo de programas para su prevención, intercepción y tratamiento. El objetivo de la presente investigación fue determinar la frecuencia de maloclusión en sentido sagital y transversal en estudiantes de nivel secundario de la ciudad de Asunción. Se realizó un estudio descriptivo de corte transversal. La población de estudio estuvo conformada por los alumnos de 12 a 18 años inscriptos en colegios públicos y privados de la ciudad de Asunción durante el 2017. Los datos recabados de la inspección bucodental fueron anotados en fichas clínicas yanalizadas con el programa Epi-Info TM. El número de participantes fue de 1047 estudiantes que cumplieron con los criterios de inclusión. El 52% de los participantes fueron de sexo femenino y el 48% del sexo masculino. La frecuencia de maloclusión en sentido sagital fue del 98%, y en sentido transversal del 27,6%.Entre las maloclusiones en sentido sagital la más frecuente fue la Clase I (53%). La frecuencia de mordida cruzada fue del 23%, de los cuales, el 43% presentó mordida cruzada anterior y el 57% mordida cruzada posterior. De los que presentaron mordida cruzada posterior, el 61% fue unilateral y el 39% bilateral. Se observa una importante frecuencia de maloclusiones en la población de estudio indicativa de la necesidad de establecer acciones para su diagnóstico y tratamiento oportunos

Malocclusion is one of the most common oral disorders. Recognizing its importance leads to the need for epidemiological studies whose results guide the development of programs for its prevention, interception and treatment. The objective of the present investigation was to determine the frequency of malocclusion in the sagittal and transverse direction in secondary school students from the city of Asunción. A descriptive cross-sectional study was carried out. The study population was made up of students from 12 to 18 years old enrolled in public and private schools in the city of Asunción during 2017. The data collected from the oral inspection was recorded in clinical records and analyzed with the Epi-Info program. TM. The number of participants was 1047 students who met the inclusion criteria. Fifty two percent of the participants were female and 48% male. The frequency of malocclusion in the sagittal direction was 98%, and in the transverse direction it was 27.6%.Among sagittal malocclusions, the most frequent was Class I (53%). The frequency of crossbite was 23%, of which 43% presented an anterior crossbite and 57% a posterior crossbite. Of those who presented posterior crossbite, 61% were unilateral and 39% bilateral. An important frequency of malocclusions is observed in the study population indicative of the need of establishing actions for its timely diagnosis and treatment

2X4 Appliance: Effective Treatment Modality for Anterior Crossbite

The 2x4 appliance consists of bands on the first permanent maxillary molars, bonded brackets on the maxillary incisors, and a continuous archwire inserted into buccal tubes of the molar bands. It provides total control of anterior tooth position, allows precise and rapid positioning of the teeth, does not require any adjustment and is very well accepted by the patient, and. This case report presents correction of anterior crossbite at early mixed dentition stage with the help of 2x4 appliances. The results achieved, satisfied the esthetic demands of the patients as well as parents.

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.

Use of digital scan data for evaluation of edentulous ridge relationship: A case report for removable prosthesis with unilateral cross bite / 대한치과보철학회지

After the teeth were extracted, maxillary and mandibular alveolar ridges show the opposite resorption pattern and as a result, the mandibular arch is enlarged than maxillary arch relatively. In this situation, we should evaluate both alveolar ridge relationship and arrange the artificial teeth properly for stability of removable prosthesis. This case is a 77 years old male patient who wishes to make removable prosthesis and has atrophic alveolar ridge. By use of model scanner and CAD software, the angle between interalveolar crest line and occlusal plane was easily measured. Depending on the measurement, the artificial teeth are arranged in unilateral cross bite and after completion, patient was satisfied with the denture which showed proper stability, retention, support.

Interalveolar ridge crest relation analysis and rehabilitation of edentulous patient using dental CAD software: A case report / 대한치과보철학회지

As the number of elderly population increases, the proportion of edentulous patients is increasing, and the demand for traditional dentures will also increase. Arranging the artificial teeth according to the relationship and shape of the upper and lower alveolar ridge is an important factor increasing the stability of the denture. This case is a 79 year old female patient who wishes to make denture covered by national health insurance for psychological and economical reasons. With the alveolar bone severely atrophic, the dental CAD software was used for accurate diagnosis and the posterior teeth were arranged in a cross bite according to the interalveolar crest line angle by the program. After completion, the denture showed adequate stability and maintenance in periodic examinations and treatment, and the patient also expressed high satisfaction.

Prosthetic treatment for Down's syndrome patient with dental cross bite problem using maxillary double crown denture / 대한치과보철학회지

Patients with Down's syndrome have several dental complications such as small teeth caused by underdevelopment of dentin and enamel, periodontitis, agenesis of teeth, prolonged retention of primary teeth and malocclusion due to narrow palate. Removable denture with maxillary double crowns would be a good treatment option to solve the problems of the patient with Down's syndrome. Double crowns compensate the insufficient support and retention of denture and easily solve the cross bite problem. Double crowns also allow easy repair of denture in case of abutment teeth extraction. In this case, 26-year-old female patient with Down's syndrome and dental phobia had small number of teeth with enamel hypoplasia, prolonged retention of primary teeth and dental cross bite. Prosthetic treatment was done using removable denture with double crowns in the maxilla. In the mandible, teeth preparation was done on enamel margin without anesthesia. Anterior laminate and posterior complete zirconia crown restorations were performed. As a result, the cross bite was effectively corrected by denture with double crowns. Pronunciation and appearance were also improved without extraction of teeth and dental anesthesia.

Mordida cruzada anterior y recesión periodontal: Tratamiento con el MUH Shield. Reporte de caso / Anterior cross bite and periodontal recession: Treatment with the MUH Shield. Case report

Fundamento: Según el Programa Nacional de Atención Estomatológica Integral, se observa una disminución de la prevalencia de caries dental en la población infantil y adolescente, mientras que las periodontopatías ocupan el segundo lugar en la jerarquización de las enfermedades bucales, y la Organización Mundial de la Salud las considera entre las afecciones más comunes del género humano. Entre los factores causantes de recesión periodontal se encuentran la malposición dentaria, las inserciones frénicas anormales y los defectos de la oclusión. Objetivo: Descruzar la mordida anterior simple, asimismo mejorar el estado periodontal del paciente con el aparato tipo MUH Shield. Reporte del caso: Paciente masculino de raza negra, ocho años de edad, con antecedentes de retención dentaria temporal, que acudió a consulta por maloclusión, con trastorno mucogingival asociado a una mordida cruzada anterior simple, sobrepase de 2 mm, resalte de 1 mm. Conclusiones: Se logró descruzar la mordida anterior a las nueve semanas de tratamiento con el aparato tipo MUH Shield y se mejoró el estado periodontal del paciente.

ABSTRACT Background: According to the National Program of Integral Stomatological Care, there is a decrease in the prevalence of dental cavities in children and adolescents, while periodonthopathies rank second in the hierarchy of oral diseases, and the World Organization of Health considers them among the most common conditions of mankind. Among the factors causing periodontal recession are dental miss position, abnormal phrenic insertions, and defects of occlusio. Objective: To uncross the simple anterior bite, as well as to improve the periodontal status of the patient with the MUH Shield type device Case report: An eight years old white male patient, with a history of temporary dental retention, who came to the clinic due to malocclusion, with a bucogingival disorder associated with a simple anterior cross bite, exceeding 2 mm, and a 1 mm margin Conclusions: The anterior bite was uncrossed after nine weeks of treatment with the MUH Shield type device and the patient's periodontal status was improved.

Sistemas de autoligado. Caso clínico

En la actualidad, la ortodoncia desempeña un papel muy importante en la vida de los pacientes. Han salido muchos sistemas ortodónticos al mercado tratando de que el tratamiento de ortodoncia sea más rápido, cómodo y eficaz. Sin duda alguna, el sistema de autoligado viene a revolucionar la ortodoncia, debido a que es un sistema pensado en la comodidad del paciente, así como reducir el tiempo disminuyendo la fricción. El lapso de tratamiento es un factor clave, ya que se puede dar estabilidad postretención, aun cuando este haya sido corto. Se presenta una paciente de 21 años, con clase II esquelético, hiperdivergente, clase I molar bilateral, clase I canina bilateral, mordida abierta anterior, mordida cruzada del segundo premolar superior derecho, caninos fuera de arco, apiñamiento moderado superior y leve inferior, líneas medias dentales desviadas superior de 1 mm a la derecha, e inferior de 0,5 mm a la izquierda hipoplasia generalizada del esmalte. Terceros molares ausentes. Se le realizó el tratamiento de alineación, nivelación, suavizado interproximal, detallado y retención.

Today, orthodontics plays a very important role in the lives of patients. There is many orthodontic systems market trying to orthodontic treatment faster, convenient and effective. The self-ligating system will revolutionize orthodontics because it is a thought system patient comfort and reduce time reducing friction. The treatment time is a key factor, because it can provide stability post retention, even when there has been short. A 21 years old female patient is presented with a skeletal class II, hyperdivergent, molar and canine bilateral class I, anterior open bite, second right premolar in crossbite, canines outside arc, moderated upper crowding and light lower crowding. Deviated lower midline 0.5 mm to left, widespread enamel hipoplasia. Third molars absent. She underwent in alighment, leveling, stripping, detailing and retention treatment. Keywords: Class II, cross bite, moderated crowding. Trainer.

Prevalence of Posterior Cross Bite in 3-5-Year-Old Children from Vitória, Brazil

To evaluate the prevalence of posterior cross bite and the possible association with deleterious oral habits in 3-5-year-old children from Vitória, Espírito Santo,Brazil.Material and Methods:This retrospective observational study with a longitudinal design used as parameters for sample calculation prevalence of 35%, confidence level of 95% and error of 5%. The final random sample included 903 children, proportionally distributed according to the number of children enrolled per school. Thus, the representative sample of 9,829 children enrolled in public schools of Vitória was guaranteed. A questionnaire with six open and eighteen closed items was used to collect data on socioeconomic status, age, sex and deleterious habits. Clinical exams were carried out by trained examiners (Kappa 0.86) for posterior cross bite diagnosis. The association between variables was verified by the Chi-Square Test and Fisher Exact Test. Odds Ratio evaluated the association strength. This research was approved by the UFES Ethics Research Committee.Results:The prevalence of cross bite was of 16.2% and children that used pacifier were two times more likely to develop posterior cross bite (OR = 1.775; CI 95% = 1.242; 2.537).Conclusion:The prevalence of posterior cross bite was expressive, and thumb sucking and pacifier use were considered risk factors. Association was verified with the habit of using pacifier, increasing twice the likelihood of presenting malocclusion and posterior cross bite...

Repid Bite Raiser For Anterior Crossbite' (RBRAC) Appliance For Rapid Correction of Anterior Crossbite - A New Appliance Design.

Correction of anterior cross bite by jumping over the bite is challenging to an orthodontist. This new technique describes a rapid bite raiser for intrusion of anterior teeth in crossbite.

Comparison of tongue postures at rest position between anterior cross-bite and normal bite / 中华医学美学美容杂志

ObjectiveTo compare tongue positions at rest between normal occlusion people and patients with anterior cross-bite malocclusions,and to explore whether there is any abnormality in the tongue position of the anterior cross-bite malocclusions.Methods Twenty adults of normal bite (8 males and 12 females,with an average age of 23.8 years) and 20 adults of anterior cross-bite (1 1males and 9 females,with an average age of 24.6 years) were involved in this study.The position habits of tongue were investigated by a questionnaire.The tongue positions,which were enhanced by applying barium to tongue and palatal surface,were compared by cephalometric roentgenogram.Two groups were compared by t-test to determine the variation of anterior cross-bite. Results In normal occlusion group,the dorsum of tongues was sealed with all palatal surfaces except uvula site.In anterior cross bite group,tongues were far from palate,and were difficult to lift.The profile of tongue showed standing upright forward and up in normal occlusion group,while inclining back and low in anterior cross-bite group.The tops of tongue dorsum sites were at the border of soft and hard palate in normal occlusion group.While in anterior cross bite group,the tops of tongue dorsum sites were at the border of uvula and soft palate.In anterior cross-bite group,the tongue-to palate distance was bigger than that of normal occlusion group (P＜0.01).However,both length and height of the tongue had no significant differences between two groups (P＞0.05).ConclusionsIn anterior cross-bite patients,tongue positions were lower than that of normal occlusion people.

Resorte de Coffin: estudio de 2 diferentes tipos de ligas metálicas / Coffin appliance: study of 2 different types of metal alloys

La aparición de los alambres con una baja cantidad de níquel son un gran avance en ortodoncia, supliendo la necesidad de ortodoncia para pacientes que pueden tener hipersensibilidad de este ión, pero no se conoce mucho acerca de las propiedades mecánicas de estos alambres. El objetivo de este estudio fue probar la hipótesis de que no hay diferencia en el desempeño mecánico de los alambres de acero inoxidable y alambres de acero inoxidable con bajo contenido de níquel, evaluando la fuerza, resistencia y módulo de elasticidad producida por el resorte de Coffin hecho con alambre de 0,032 y 0,036 pulgadas. Se construyeron 60 unidades de Coffin, 30 para cada tipo de aleación, siendo 15confeccionadas con alambre de 0,032 pulgadas y 15 con alambre de 0,036 pulgadas. Todos los arcos fueron sometidos a la prueba mecánica de compresión en la máquina EMIC DL-10000, simulando 4, 6, 9 y 12 mm de activación. El análisis de varianza y comparación múltiple (ANOVA) y la prueba de Tukey (p <0,05) fueron utilizados para evaluar la fuerza, resistencia y módulo de elasticidad. Los grupos que utilizaron alambre de 0,036 pulgadas presentaron estadísticamente (p <0,05) mayores niveles de fuerza, resistencia y módulo de elasticidad en comparación con dispositivos con 0,032 pulgadas de alambre para ambas aleaciones. Para el mismo espesor, no hubieron diferencias estadísticamente significativas entre los 2 tipos de aleaciones, con excepción de los dispositivos con activación de 9 mm y espesor de 0,036 pulgadas que mostraron una diferencia estadística (p <0,05). Los resortes de Coffin evaluados para ambas aleaciones metálicas produjeron fuerzas adecuadas para el tratamiento ortodontico, por lo que debe ser correctamente planificada su aplicación clínica.

The emergence of stainless steel wire made of low-nickel content was a major breakthrough in the orthodontic, supplying the need for orthodontics patients who may have hypersensitivity by this ion, but do not know much about the mechanical properties of these wires. The objective of this study is to test the hypothesis that there is no difference between stainless steel wires and low-nickel stainless steel ones regarding their mechanical behaviour. Force, resilience, and elasticity modulus produced by Coffin appliances made of 0.032-inch and 0.036-inch wires were evaluated. Sixty appliances Coffin were made, thirty for each type of alloy being fifteen for each wire thickness. All the arches were submitted to mechanical compression test by using an EMIC DL-10000 machine simulating activations of 4, 6, 9, and 12 mm. Analysis of variance (ANOVA) with multiple comparisons and Tukey’s test were employed (p< 0.05) for assessing force, resilience, and elasticity modulus. The groups using the 0.036 inch presented statistically (p<0.05) higher levels of force, resiliency and elasticity modulus when compared to the arches using the 0.032 inch wire for both alloys. The Coffin appliances for both alloys evaluated can produce adequate forces for orthodontic treatment as long as their clinical application is correctly planned.

The anterior dental cross-bite: the paradigm of interception in orthodontics / A mordida cruzada anterior: o paradigma da interceptação em ortodontia

OBJECTIVES: To present specific clinical interception procedures instituted to reduce malocclusionseverity on developmental stage. Anterior tooth cross-bite, involving one or two permanent teeth, is acommon form of malocclusion diagnosed in children about 6 years of age. RESULTS ANDDISCUSSION: Various devices can be suggested for single tooth cases, like removable cantilevereddouble-helix apparatus with digital springs, which is one of the most efficient to intercept malocclusion.In the other hand, fixed appliance does not depend on patient’s cooperation and have greater actionpower and liberates more continuous forces. CONCLUSION: Dental anterior cross-bite, involvingone tooth, can be corrected by means of the multi-loop arch wire with a double-helix, even in caseswhere adequate space for alignment is lacking.

OBJETIVOS: Apresentar procedimento de interceptação clínica específica para reduzir aseveridade da má oclusão no estágio de desenvolvimento. O cruzamento anterior, comprometendoum ou dois dentes permanentes, é forma comum de má-oclusão, diagnosticada em crianças emtorno de seis anos de idade. RESULTADOS E DISCUSSÃO: Vários dispositivos podem ser utilizados para casos de cruzamento de um dente apenas, como os aparelhos de duplo hélice emextremo livre, com molas digitais, um dos mais eficientes para interceptar más-oclusões. Poroutro lado, os aparelhos fixos não dependem da colaboração do paciente, tendo maior poder deação e de liberação de forças contínuas. CONCLUSÃO: Os cruzamentos anteriorescomprometendo um dente podem ser corrigidos por meio de arco com dobras múltiplas, comhélice dupla, mesmo em casos onde há deficiência de espaço para o alinhamento.

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.

Avaliação in vitro da citotoxicidade de parafusos expansores palatinos / In vitro evaluation of the cytotoxicity of palatal expanders

Objetivo: Avaliar a citotoxicidade de parafusos expansores confeccionados com aço inoxidável ou compósito. Métodos: Foram avaliados 6 parafusos expansores divididos em 2 grupos de acordo com o material: expansor metálico e expansor de compósito. Três grupos controle foram utilizados: controle positivo (cilindro de amálgama), controle negativo (bastão de vidro) e controle de célula (células não expostas). Os expansores esterilizados foram imersos em meio mínimo essencial de Eagle por 24 h, onde se procedeu a remoção do sobrenadante e contato com fibroblastos L929. Após contato com o meio as células foram incubadas por 24 h, sendo adicionados 100 μL do corante vermelho neutro a 0,01%, seguido por incubação por 3 h e fixação das células. A citotoxicidade foi analisada em 4 períodos: 24, 48, 72 e 168 h. A contagem de células viáveis foi realizada com espectrofotômetro (λ = 492 nm) e os dados foram analisados por ANOVA. Resultados: Os grupos controle positivo (amálgama) foram estatisticamente diferentes dos demais grupos. Não houve diferença estatística na comparação entre os demais grupos e períodos. Conclusões: Os resultados sugerem que os parafusos expansores testados não apresentam citotoxicidade significativa conforme o desenho experimental utilizado.

Objective: To evaluate the cytotoxicity of two palatal expanders made of stainless steel or composite. Methods: Six expanders were divided into two experimental groups: metallic expander and composite expander. Three control groups also were assessed: positive control (amalgam), negative control (glass stick), and control cell (cells not exposed to any material). The sterilized expanders were immersed into Eagle's minimum essential medium for 24 h, and the contact assay was performed using L929 fibroblasts. The cells were incubated for 24 h, and 100 μL of 0.01% neutral-red staining solution were added followed by incubation for 3 h and cell fixation. Cytotoxicity was evaluated at four different periods of time: 24, 48, 72, and 168 h. Counting of viable cells was performed by using a spectrophotometer at a wavelength of 492 nm, and data were analyzed by ANOVA. Results: The positive control groups (amalgam) were statistically different from the other groups. No difference of cytotoxicity was found among the groups and periods of time. Conclusions: The tested metallic and composite expanders showed no significant cytotoxicity within this experimental design.

Quantitative electromyographic assessment of facial muscles in cross-bite female children / Avaliação eletromiográfica quantitativa de músculos faciais em crianças do sexo feminino com mordida cruzada

The electromyography has been widely used as a diagnostic method for facial muscle conditions. The aim of this study was to determine the RMS (Root Mean Square) value of the electromyographic signal of facial muscles in children with normal occlusion or cross-bite as well as to verify a possible clinical application of this parameter. “Normal group” was composed of female children with normal occlusion and “cross-bite group” was composed of female children with cross-bite. We performed quantitative electromyographic analysis of masseter and temporal muscles at rest and with maximum biting force. Our results showed that the occlusion modifications affect normal masticatory muscle function, and that the quantitative electromyography is an important tool to help diagnosing the malocclusion in female children. Considering the analysis of the results, we verified that the electromyographic rest activity of the masseter or temporal muscles in cross-bite female children is higher in relation to the rest activity of normal occlusion female children. We concluded that the RMS value of the masseteric and temporal electromyographic signal has a diagnostic value to discriminate female children with cross-bite from those with normal occlusion.

A eletromiografia tem sido amplamente utilizada como método diagnóstico de disfunções de músculos da face. O objetivo deste estudo foi determinar a tensão RMS do sinal eletromiográfico de músculos da face de crianças do sexo feminino com oclusão normal ou com mordida cruzada, visando avaliar uma possível aplicação clínica deste parâmetro. O “grupo normal” foi composto por crianças do sexo feminino com oclusão normal e o “grupo mordida cruzada”por crianças do sexo feminino com diagnóstico de mordida cruzada. Foram realizadas análises eletromiográficas quantitativas dos músculos masseter e temporal nas condições de repouso e em máxima contração voluntária isométrica (MCV). Considerando a relação da tensão RMS do sinal eletromiográfico no repouso e em MCV, nossos resultados mostraram que variações de oclusão influenciam a função muscular mastigatória normal e que a eletromiografia quantitativa é uma ferramenta útil para auxiliar o diagnóstico de alterações oclusais em crianças do sexo feminino. Encontrou-se maior atividade eletromiográfica em repouso dos músculos masseter e temporal em crianças do sexo feminino com mordida cruzada em relação às com oclusão normal. Concluímos que a tensão RMS do sinal eletromiográfico massetérico e temporal tem valor diagnóstico para discriminar crianças do sexo feminino com mordida cruzada em relação às com oclusão normal.

Prevalencia y factores de riesgo de mordida cruzada posterior en niños de 4-9 años de edad en ciudad Nezahualcóyotl

Introducción. La mordida cruzada posterior es una maloclusión con una prevalencia reportada entre 5 y 27% de los individuos, dependiendo de la edad y características de la población estudiada. Debido a la información existente hasta este momento, donde los factores de riesgo no son específicos; el propósito de este estudio fue conocer la prevalencia de mordida cruzada posterior y los factores de riesgo potenciales que dan lugar a su aparición (erupción ectópica, respiración bucal, succión digital, interferencias oclusales y grupo edad). Material y métodos. Se llevó a cabo un estudio transversal en una población de 1 000 niños de 4 a 9 años de edad en ciudad Nezahualcóyotl, a los cuales se les hizo una exploración intrabucal, valorando la oclusión y análisis funcional. Se efectuó un análisis univariado y de regresión logística con el paquete estadístico SPSS versión 10.0. Resultados. La prevalencia de mordida cruzada posterior fue de 11.3%; dividido en 5.4% con mordida cruzada unilateral; 1.5% mordida cruzada bilateral, 4.8% abarcando un solo diente; por sexo se observó con mayor frecuencia en los niños. Los factores de riesgo que mostraron significancia estadística fueron: erupción ectópica, interferencia oclusal y edad. Con el análisis multivariado se observó que la erupción ectópica y la interferencia oclusal permanecen como los factores de riesgo más importante (P <0.001). Conclusión. La prevalencia de mordida cruzada posterior es alta y la mayor dependencia está dada por erupción ectópica e interferencias oclusales; por lo que es necesario la detección y corrección temprana de cualquier anormalidad en la oclusión dentaria lo que permitirá corregir defectos en el crecimiento dento facial.

Introduction. Posterior cross bite is a malocclusion with a prevalence reported from 5 till 27% of individuals, depending on age and the features of the population studied, due to the existing information at the moment which the risk factors are not specific, the purpose of the present study was to know the prevalence of posterior cross bite and the potential factors of risk which may cause its appearance (ectopic dental eruption, mouth breathing, finger sucking, occlusal disturbances, and age). Material and methods. It was carried out a cross-section study in a population of 1 000 children from 4 till 9 years old in Ciudad Nezahualcoyotl (a suburb of Mexico City), which were undergone to intraoral examination assessing occlusion and functional analysis. Univariate and logistic regression analyses were executed with the statistical software SPSS version 10.0. Results. The prevalence of posterior cross bite was 11.3%, with the following breakdown: 5.4% having unilateral cross bite; 1.5% having bilateral cross bite; 4.8% being affected one tooth only; in the sex structure more prevalence in boys was observed. The factors of risk, which showed statistical significance, were: ectopic eruption, occlusal interference, and group age. Using multivariate analysis, it was observed that ectopic eruption and occlusal interference are the more important risk factors (P < 0.001). Conclusion. Prevalence of posterior cross bite is high and the greatest dependency is produced by ectopic eruption and occlusal interferences, being necessary the early detection and correction of any abnormalities in the tooth occlusion, which would allow correcting disturbances in the dent facial growth.

Morphological differences between functional and skeletal anterior cross-bite patients / 대한치과교정학회지

The purpose of this study was to compare the dento-skeletal characteristics between functional and skeletal anterior cross-bite patients. Twenty-eight functional anterior cross-bite patients and thirty-one skeletal anterior cross-bite patients were selected as a test and a control group. Mean ages of the test and the control group were 9.6+/-1.8 and 9.8+/-1.9, respectively. Lateral cephalograms were taken. Forty-nine cephalometric variables were measured and statistical analysis was performed to find the morphological differences between the groups. Statistically significant differences were found in the cephalometric variables of cranial deflection, maxillary depth, ANB, convexity, NPo-AB, APDI, Mx 1-SN, Mx 1-NA angle, Mx 1-NA, Md 1-NB angle and Md 1-NB. The test group showed more Class III growth potential, more protruded maxilla, lesser maxillo-mandibular difference, more uprighted and retruded maxillary central incisor, more labially tipped and protruded mandibular central incisor.