17 research outputs found
Influência de diferentes contenções ortodônticas superiores na fala: análise por leigos e análise acústica
No full textIntroduction: The aim of this study was to evaluate the influence of different upper retainers in speech, through Perceptual Auditory Analysis by the laypersons and acoustic analysis. Methods: Eighteen volunteers were selected to use four types of upper retainers: conventional Wrap-Around (CWA), modified horseshoe Wrap-Around (HWA), modified anterior hole Wrap-Around (AHWA) and vacuum-formed (VF). They were used for 21 days each, with intervals of 7 days without use among them. Speech evaluation was performed in vocal excerpts recordings made before installation of the retainers (T0), immediately after the installation of each retainer (T1), and 21 days after the installation (T2). The Perceptual Auditory Analysis of laypersons was performed by means of the visual analogue scale of 100 mm, while the acoustic analysis consisted of the mean diadochokinesia (DDK) rate evaluation, as well as the formant frequencies F1 and F2 of the fricative consonants. One-way ANOVA and two-way ANOVA were used. Results: In the Perceptual Auditory Analysis of laypersons, there was a worsening in the values of T0 to T1 in all the retainers, but only for CWA and VF the values were statistically lower. In T2 the values increased, but for the VF the value still remained statistically lower than T0 while for the AHWA the difference of T0 for T2 was practically null. There were no changes in DDK values. For the formant frequencies, in general way there was a difference from T0 to T1 and a little difference from T0 to T2, whereas in the comparison among the devices the CWA presented greater changes in the F1 formants of some consonants, whereas AHWA presented lower values, with the others devices showing intermediate values. Conclusions: In both types of analysis (subjective and objective), there was a change in speech after the installation of each retainer, with an improvement after 21 days of use. The laypersons considered larger speech disorders involving VF, and smaller ones involving AHWA. For the acoustic analysis, the changes were greater for CWA, whereas for AHWA there were lower changes.Introdução: O objetivo deste estudo foi avaliar a influência de diferentes contenções superiores na fala, através de análise perceptiva auditiva por leigos e análise acústica. Métodos: Dezoito voluntários foram selecionados para utilizar quatro tipos de contenções superiores, sendo elas: placa Wrap-Around convencional (WAC), Wrap- Around modificada em formato de ferradura (WAF) Wrap-Around modificada com orifício anterior (WAO) e contenção termoplástica transparente (CTT). Elas foram usadas por 21 dias cada, com intervalos de 7 dias sem utilização entre elas. A avaliação da fala foi realizada em gravações de trechos vocais realizadas antes da instalação das contenções (T0), imediatamente após a instalação de cada contenção (T1), assim como após 21 dias de uso destas (T2). A análise perceptiva auditiva dos leigos foi realizada através da escala visual analógica de 100 mm, enquanto a análise acústica consistiu na avaliação da média da taxa de diadococinesia (DDC), bem como a frequência dos formantes F1 e F2 das consoantes fricativas. Os testes ANOVA a um critério e ANOVA a dois critérios foram utilizados. Resultados: Na análise perceptiva auditiva dos leigos houve uma piora nos valores de T0 para T1 em todas as contenções, mas somente para WAC e CTT os valores foram estatisticamente menores. Em T2 os valores voltaram a aumentar, mas para CTT ainda houve um valor estatisticamente menor do que T0 enquanto para WAO a diferença de T0 para T2 foi praticamente nula. Não houve alterações nos valores da DDC. Para os formantes, de uma maneira geral houve uma diferença de T0 para T1 e pouca diferença de T0 para T2, enquanto na comparação entre os aparelhos a WAC apresentou alterações maiores nos formantes F1 de algumas consoantes, enquanto WAO apresentou valores menores, e os demais dispositivos valores intermediários. Conclusões: Nos dois tipos de análise (subjetiva e objetiva) houve alteração na fala após a instalação de cada contenção, havendo uma melhora após 21 dias de uso. Os leigos consideraram maiores as alterações da fala envolvendo a CTT, e menores envolvendo WAO. Para a análise acústica os valores foram piores para WAC, enquanto para WAO as alterações foram menores
Comparison of deflection forces of esthetic archwires combined with ceramic brackets
No full textAbstract Coated archwires and ceramic brackets have been developed to improve facial esthetics during orthodontic treatment. However, their mechanical behavior has been shown to be different from metallic archwires and brackets. Therefore, the aim of this study was to compare the deflection forces in coated nickel-titanium (NiTi) and esthetic archwires combined with ceramic brackets. Material and Methods Non-coated NiTi (NC), rhodium coated NiTi (RC), teflon coated NiTi (TC), epoxy coated NiTi (EC), fiber-reinforced polymer (FRP), and the three different conventional brackets metal-insert polycrystalline ceramic (MI-PC), polycrystalline ceramic (PC) and monocrystalline ceramic (MC) were used. The specimens were set up on a clinical simulation device and evaluated in a Universal Testing Machine (Instron). An acrylic device, representative of the right maxillary central incisor was buccolingually activated and the unloading forces generated were recorded at 3, 2, 1 and 0.5 mm. The speed of the testing machine was 2 mm/min. ANOVA and Tukey tests were used to compare the different archwires and brackets. Results The brackets presented the following decreasing force ranking: monocrystalline, polycrystalline and polycrystalline metal-insert. The decreasing force ranking of the archwires was: rhodium coated NiTi (RC), non-coated NiTi (NC), teflon coated NiTi (TC), epoxy coated NiTi (EC) and fiber-reinforced polymer (FRP). At 3 mm of unloading the FRP archwire had a plastic deformation and produced an extremely low force in 2; 1 and 0.5 mm of unloading. Conclusion Combinations of the evaluated archwires and brackets will produce a force ranking proportional to the combination of their individual force rankings
Verticalização, em duas fases, de terceiro molar inferior impactado mesialmente, usando ancoragem esquelética
No full textMolars severely inclined in mesial position cause periodontal problems and disharmony in occlusion. Sometimes, its uprighting is indicated, even in an unfavorable position, to restore periodontal health and balance the occlusion without the need of prosthetic rehabilitation. The aim of this work is to describe the uprighting of a mesial-inclined lower third molar using skeletal anchorage, in the posterior region of the right side of the mandible. The patient was previously submitted to extraction of the first mandibular molar and presented generalized external apical resorptions. The maximum anchorage was performed in two different locations and in two stages. The first step consisted in the installation of an anchorage device in the mandibular ramus, in a distal position to the impacted tooth. The second stage consisted in mini-implant insertion in the intra-radicular space between the second molar and the second premolar in the same side, and the use of a TMA cantilever. The proper planning of the anchorage made possible to upright the tooth #48 under biomechanical control of the side effects, in a simple and easy way. At the end of the treatment, the harmony returned to the occlusion and the dentoalveolar structures were preserved.Centro Universitário Ingá Departamento de OrtodontiaUniversidade Estadual Paulista Faculdade de Odontologia de AraraquaraCentro Universitário Ingá Centro de Pós-graduação em OdontologiaSistema Odontológico de Estudo e Pesquisa FACSETEUniversidade Estadual Paulista Faculdade de Odontologia de Araraquar
Evaluation of force released by deflection of orthodontic wires in conventional and self-ligating brackets
No full textABSTRACT Introduction: The aim of the study was to evaluate deflection forces of rectangular orthodontic wires in conventional (MorelliTM), active (In-Ovation RTM) and passive (Damon 3MXTM) self-ligating brackets. Material and Methods: Two brands of stainless steel and nickel-titanium (NiTi) wires (MorelliTM and GACTM), in addition to OrmcoTM copper-nickel-titanium wires were used. Specimens were assembled in a clinical simulation device especially designed for this study and tested in an Instron universal testing machine. For the testing procedures, an acrylic structure representative of the maxillary right central incisor was lingually moved in activations of 0 to 1 mm, with readings of the force released by deflection in unloading of 0.5, 0.8 and 1 mm at a constant speed of 2 mm/min. Inter-bracket forces with stainless steel, NiTi and CuNiTi were individually compared by two-way ANOVA, followed by Tukey’s tests. Results: Results showed that there were lower forces in conventional brackets, followed by active and passive self-ligating brackets. Within the brands, only for NiTi wires, the MorelliTM brand presented higher forces than GACTM wires. Conclusions: Bracket systems provide different degrees of deflection force, with self-ligating brackets showing the highest forces
Evaluation of deflection forces of orthodontic wires with different ligation types
No full textAbstract The aim of this study was to evaluate deflection forces of orthodontic wires of different alloys engaged into conventional brackets using several ligation types. Stainless steel, conventional superelastic nickel-titanium and thermally activated nickel-titanium archwires tied into conventional brackets by a ring-shaped elastomeric ligature (RSEL), a 8-shaped elastomeric ligature (8SEL) and a metal ligature (ML) were tested. A clinical simulation device was created especially for this study and forces were measured with an Instron Universal Testing Machine. For the testing procedure, the block representing the maxillary right central incisor was moved 0.5 and 1 mm bucco-lingually at a constant speed of 2 mm/min, and the forces released by the wires were recorded, in accordance with the ISO 15841 guidelines. In general, the RSEL showed lighter forces, while 8SEL and ML showed higher values. At the 0.5 mm deflection, the 8SEL presented the greatest force, but at the 1.0 mm deflection the ML had a statistically similar force. Based on our evaluations, to obtain lighter forces, the thermally activated nickel-titanium wire with the RSEL are recommended, while the steel wire with the 8SEL or the ML are recommended when larger forces are desired. The ML exhibited the highest force increase with increased deflections, compared with the elastomeric ligatures
Class iii orthodontic camouflage: case report with biofunction prescription
No full textClass III skeletal discrepancies are still challenging in orthodontics because they follow a genetic predisposition of the individual. Early intervention may in most cases avoid more invasive, costly and traumatic treatments in adulthood, especially with regard to performing surgical procedures and complex postoperative procedures. However, the patient often presents for treatment in the adult phase, opting for a compensatory solution. Among the orthodontic alterations, there are prescriptions that embed exaggerated lingual torque to the lower incisors, resulting in an unpleasant final appearance. The objective of this article is to report and discuss a case of compensatory treatment class III with the use of a biofunctional orthodontic appliance in an adultpatient who had relapsed to a previous orthodontic treatment. Due to the patient's excellent collaboration in the use of elastics, good results were obtained, maintaining the good positioning of the mandibular symphysis mandibular symphysisAs discrepâncias esqueléticas de Classe III seguem desafiadoras na ortodontia por seguirem uma predisposição genética do indivíduo. A intervenção precoce pode evitar em grande parte dos casos tratamentos mais invasivos, onerosos e traumáticos na fase adulta, especialmente no que diz respeito à realização de procedimentos cirúrgicos e pós-operatório complexo. Entretanto, muitas vezes, o paciente apresenta-se para tratamento na fase adulta, optando por uma solução compensatória. Dentre as alterativas ortodônticas, há prescrições que embutem torque lingual exagerado aos incisivos inferiores, resultando em um aspecto final desagradável. O objetivo deste artigo é relatar e discutir um caso de tratamento compensatório Classe III com o uso de um aparelho ortodôntico biofuncional em um paciente adulto que teve recidiva a um tratamento ortodôntico prévio. Devido a ótima colaboração do paciente no uso de elásticos, foram alcançados bons resultados, mantendo o bom posicionamento dos incisivos inferiores na sínfise mandibula
CAMUFLAGEM ORTODÔNTICA DA CLASSE III: RELATO DE CASO COM PRESCRIÇÃO BIOFUNCIONAL
No full textAs discrepâncias esqueléticas de Classe III seguem desafiadoras na ortodontia por seguirem uma predisposição genética do indivíduo. A intervenção precoce pode evitar em grande parte dos casos tratamentos mais invasivos, onerosos e traumáticos na fase adulta, especialmente no que diz respeito à realização de procedimentos cirúrgicos e pós-operatório complexo. Entretanto, muitas vezes, o paciente apresenta-se para tratamento na fase adulta, optando por uma solução compensatória. Dentre as alterativas ortodônticas, há prescrições que embutem torque lingual exagerado aos incisivos inferiores, resultando em um aspecto final desagradável. O objetivo deste artigo é relatar e discutir um caso de tratamento compensatório Classe III com o uso de um aparelho ortodôntico biofuncional em um paciente adulto que teve recidiva a um tratamento ortodôntico prévio. Devido a ótima colaboração do paciente no uso de elásticos, foram alcançados bons resultados, mantendo o bom posicionamento dos incisivos inferiores na sínfise mandibular
Treatment of class ii malocclusion with the twin force appliance
No full textThe mandibular protraction appliances do not depend on the patient’s compliance regarding the use of Class II elastics and correct the malocclusion in relatively shorter time, redirecting the mandible’s growth to a more favorable position. This study aimed to report the clinical case of a boy presenting Class II malocclusion and treated through Twin Force appliance associated with fixed orthodontic appliance. The result was a functional and satisfactory occlusion with the correction of the Class II malocclusion, dental midline shifting, overbite with passive lip sealing. The Twin Force appliance is of easy application, does not require a laboratorial step, and exerts constant force. The association with fixed orthodontic appliance resulted in the correction of the Class II malocclusion, as a viable alternative for the treatment of the Class II malocclusion, avoiding the extraction protocol and optimizing the treatment time lengthOs aparelhos de protração mandibular têm sido usados porque independem da colaboração do paciente no uso dos elásticos de Classe II e tratam a má oclusão em um tempo relativamente curto, redirecionando o crescimento da mandíbula para uma posição mais favorável. O objetivo deste artigo foi relatar o caso clínico de um paciente apresentando má oclusão de Classe II por meio do uso do aparelho ortodôntico fixo associado ao aparelho Twin Force Bite Corrector. O resultado atingiu uma oclusão funcional e satisfatória, com a correção da má oclusão de Classe II, do desvio da linha média dentária, da sobremordida, com selamento labial passivo. O aparelho Twin Force é de fácil aplicação, não requer laboratório, exercendo uma força constante. Sua associação com o aparelho fixo ortodôntico resultou na correção da má oclusão de Classe II, como uma alternativa viável para o tratamento de má oclusão de Classe II, evitando-se o protocolo com extrações e otimizando o tempo de tratament
Widespread distribution of a newly found point mutation in voltage-gated sodium channel in pyrethroid-resistant Aedes aegypti populations in Vietnam.
No full textBACKGROUND:Resistance of Aedes aegypti to photostable pyrethroid insecticides is a major problem for disease-vector control programs. Pyrethroids target the voltage-gated sodium channel on the insects' neurons. Single amino acid substitutions in this channel associated with pyrethroid resistance are one of the main factors that cause knockdown resistance in insects. Although kdr has been observed in several mosquito species, point mutations in the para gene have not been fully characterized in Ae. aegypti populations in Vietnam. The aim of this study was to determine the types and frequencies of mutations in the para gene in Ae. aegypti collected from used tires in Vietnam. METHODS AND FINDINGS:Several point mutations were examined that cause insensitivity of the voltage-gated sodium channel in the insect nervous system due to the replacement of the amino acids L1014F, the most commonly found point mutation in several mosquitoes; I1011M (or V) and V1016G (or I), which have been reported to be associated to knockdown resistance in Ae. aegypti located in segment 6, domain II; and a recently found amino acid replacement in F1269 in Ae. aegypti, located in segment 6, domain III. Among 756 larvae from 70 locations, no I1011M or I1011V nor L1014F mutations were found, and only two heterozygous V1016G mosquitoes were detected. However, F1269C mutations on domain III were distributed widely and with high frequency in 269 individuals among 757 larvae (53 collection sites among 70 locations surveyed). F1269C frequencies were low in the middle to north part of Vietnam but were high in the areas neighboring big cities and in the south of Vietnam, with the exception of the southern mountainous areas located at an elevation of 500-1000 m. CONCLUSIONS:The overall percentage of homozygous F1269C seems to remain low (7.4%) in the present situation. However, extensive and uncontrolled frequent use of photostable pyrethroids might be a strong selection pressure for this mutation to cause serious problems in the control of dengue fever in Vietnam
