RESUMEN
Background and Objectives: There is still considerable controversy regarding the possibility of submitting replanted teeth to orthodontic movement (OM). The purpose of the present study was to evaluate the tissue response after orthodontic movement on replanted teeth. Materials and Methods: Sixty Wistar rats were randomly assigned to four groups (n = 15): G1, replantation without OM after 30 days; G2, replantation with OM after 30 days; G3, replantation without OM after 60 days, and G4, replantation with OM after 60 days. The maxillary left central incisors were extracted and the teeth were stored in milk media. After 30 min, the teeth were replanted and fixed with non-rigid immobilization. All specimens were observed after 30 and 60 days of replantation and then subdivided into two subgroups (with OM or without OM). The animals were euthanized after seven days of the OM started, and the maxillary bone blocks were processed for histological evaluation. Results: The histological results showed periodontal ligament repair in both periods studied without OM; however, ankylosis and root resorption was seen in all orthodontically moved teeth. Conclusions: The orthodontic movement did not favor tissue response in all replanted teeth, regardless of the experimental periods.
Asunto(s)
Incisivo/patología , Incisivo/cirugía , Ligamento Periodontal/patología , Resorción Radicular/patología , Técnicas de Movimiento Dental/efectos adversos , Reimplante Dental , Animales , Incisivo/fisiopatología , Modelos Animales , Fotomicrografía , Complicaciones Posoperatorias/patología , Distribución Aleatoria , Ratas , Ratas Wistar , Resorción Radicular/etiología , Avulsión de Diente/cirugía , Raíz del Diente/patologíaRESUMEN
OBJECTIVE: To evaluate the effect of bite positions characterizing different splint treatments (anterior repositioning and stabilization splints) on the disc-condyle relation in patients with TMJ disc displacement with reduction (DDwR), using magnetic resonance imaging (MRI). MATERIAL AND METHODS: 37 patients, with a mean age of 18.8±4.3 years (7 male and 30 females) and diagnosed with DDwR based on the RDC/TMD, were recruited. MRI metrical analysis of the spatial changes of the disc/condyle, as well as their relationships, was done in three positions: maximum intercuspation (Position 1), anterior repositioning splint position (Position 2), and stabilization splint position (Position 3). Disc/condyle coordinate measurements and disc condyle angles were determined and compared. RESULTS: In Position 1, the average disc-condyle angle was 53.4° in the 60 joints with DDwR, while it was -13.3° with Position 2 and 30.1° with Position 3. The frequency of successful "disc recapture" with Position 2 was significantly higher (58/60, 96.7%) than Position 3 (20/60, 33.3%). In Positions 2 and 3, the condyle moved forward and downward while the disc moved backward. The movements were, however, more remarkable with Position 2. CONCLUSIONS: Anterior repositioning of the mandible improves the spatial relationship between the disc and condyle in patients with DDwR. In addition to anterior and inferior movement of the condyle, transitory posterior movement of the disc also occurred.
Asunto(s)
Luxaciones Articulares/fisiopatología , Luxaciones Articulares/terapia , Cóndilo Mandibular/lesiones , Ferulas Oclusales , Disco de la Articulación Temporomandibular/lesiones , Adolescente , Adulto , Análisis de Varianza , Niño , Diseño de Equipo , Femenino , Humanos , Incisivo/fisiopatología , Luxaciones Articulares/diagnóstico por imagen , Imagen por Resonancia Magnética , Masculino , Cóndilo Mandibular/diagnóstico por imagen , Cóndilo Mandibular/patología , Cóndilo Mandibular/fisiopatología , Variaciones Dependientes del Observador , Valores de Referencia , Reproducibilidad de los Resultados , Disco de la Articulación Temporomandibular/diagnóstico por imagen , Disco de la Articulación Temporomandibular/fisiopatología , Resultado del Tratamiento , Adulto JovenRESUMEN
Abstract Objective: To evaluate the effect of bite positions characterizing different splint treatments (anterior repositioning and stabilization splints) on the disc-condyle relation in patients with TMJ disc displacement with reduction (DDwR), using magnetic resonance imaging (MRI). Material and Methods: 37 patients, with a mean age of 18.8±4.3 years (7 male and 30 females) and diagnosed with DDwR based on the RDC/TMD, were recruited. MRI metrical analysis of the spatial changes of the disc/condyle, as well as their relationships, was done in three positions: maximum intercuspation (Position 1), anterior repositioning splint position (Position 2), and stabilization splint position (Position 3). Disc/condyle coordinate measurements and disc condyle angles were determined and compared. Results: In Position 1, the average disc-condyle angle was 53.4° in the 60 joints with DDwR, while it was −13.3° with Position 2 and 30.1° with Position 3. The frequency of successful "disc recapture" with Position 2 was significantly higher (58/60, 96.7%) than Position 3 (20/60, 33.3%). In Positions 2 and 3, the condyle moved forward and downward while the disc moved backward. The movements were, however, more remarkable with Position 2. Conclusions: Anterior repositioning of the mandible improves the spatial relationship between the disc and condyle in patients with DDwR. In addition to anterior and inferior movement of the condyle, transitory posterior movement of the disc also occurred.
Asunto(s)
Humanos , Masculino , Femenino , Niño , Adolescente , Adulto , Adulto Joven , Ferulas Oclusales , Disco de la Articulación Temporomandibular/lesiones , Luxaciones Articulares/fisiopatología , Luxaciones Articulares/terapia , Cóndilo Mandibular/lesiones , Valores de Referencia , Imagen por Resonancia Magnética , Variaciones Dependientes del Observador , Reproducibilidad de los Resultados , Análisis de Varianza , Resultado del Tratamiento , Disco de la Articulación Temporomandibular/fisiopatología , Disco de la Articulación Temporomandibular/diagnóstico por imagen , Luxaciones Articulares/diagnóstico por imagen , Diseño de Equipo , Incisivo/fisiopatología , Cóndilo Mandibular/fisiopatología , Cóndilo Mandibular/patología , Cóndilo Mandibular/diagnóstico por imagenRESUMEN
INTRODUCTION: In order to understand the mechanical behavior of a weakened incisor, this study aimed to evaluate the stress distribution caused by different alveolar bone heights and cement layer thickness. METHODS: A finite element analysis was conducted for this investigation. An intact maxillary central incisor was initially modeled, and the bone of the models was modified in order to simulate 4 levels of bone height: BL0 (no bone loss), BL1 (1/3 bone loss), BL2 (1/2 bone loss), and BL3 (2/3 bone loss). These teeth models were remodeled with a fiber post at 2 different cement thicknesses and restored with a ceramic crown; "A" refers to the well-adapted fiber post (0.3 mm) and "B" to the nonadapted fiber post (1 mm), resulting in 12 models. RelyX ARC (3M ESPE, St Paul, MN) cement was simulated for the cementation of the crowns and fiber posts for all groups. Numeric models received a load of 100 N on the lingual surface. All materials and structures were considered linear elastic, homogeneous, and isotropic. Numeric models were plotted and meshed with isoparametric elements, and results were expressed in maximum principal stress. RESULTS: For fiberglass posts, cement, and dentin, the highest stress concentration occurred in the groups with increased bone loss. For cortical bone, the highest values were for the groups with 1/3 bone loss. A greater thickness of cement layer concentrates more stress. CONCLUSIONS: More bone loss and greater CLT were the influential factors in concentrating the stress.
Asunto(s)
Pérdida de Hueso Alveolar/cirugía , Cementos Dentales/uso terapéutico , Incisivo/cirugía , Diente no Vital/fisiopatología , Pérdida de Hueso Alveolar/fisiopatología , Fenómenos Biomecánicos , Fuerza Compresiva , Cementos Dentales/efectos adversos , Análisis del Estrés Dental , Análisis de Elementos Finitos , Humanos , Imagenología Tridimensional , Incisivo/fisiopatología , Maxilar , Resistencia a la TracciónRESUMEN
El tamaño de los dientes permite establecer un diagnóstico precoz de la falta de espacio para su ubicación futura en el arco dentario y practicar tratamientos interceptivos tempranos. El propósito de este trabajo fue determinar el diámetro mesiodistal de incisivos y caninos superior e inferior, y los índices incisivos superior e inferior, con la finalidad de establecer valores propios de esta población, que contribuyan a elevar la calidad del diagnóstico en Ortodoncia. Fue realizado un estudio descriptivo y transversal en sujetos con oclusión normal, en una muestra de 362 estudiantes: 174 del sexo femenino y 188 del masculino, distribuidos en 143 de doce, 106 de trece y 113 de catorce años, respectivamente, seleccionados en las escuelas secundarias básicas de la ciudad de Matanzas. Las mediciones fueron realizadas por un solo observador, directamente en la boca desde el punto de contacto mesial hasta distal a nivel de su mayor diámetro con el empleo de un pie de rey. Las variables empleadas fueron edad, sexo y diámetro mesiodistal de los dientes. Se determinaron los diámetros mesodistales en los dientes de la arcada superior e inferior con similares tamaños entre ambos lados derechos e izquierdos y los índices incisivos superior (31,20 mm) e inferior (22,70 mm). Se determinó dimorfismo sexual, sustentado en mayor tamaño de los incisivos laterales (P= 0,008), y caninos derechos superiores (P= 0,000) en los varones, así como también en los incisivos laterales derechos (P= 0,001) y caninos derechos (P= 0,000) inferiores en este mismo sexo(AU)
Teeth size allows arriving to a precocious diagnosis of the lack of space for their future location in the dental arch and practicing early interceptive treatments. The aim of this work was finding out the mesiodistal diameter of upper and low incisors and canines, and the upper and low incisal indexes, with the objective of establishing this population own values contributing to the diagnosis quality improvement in Orthodontics. We carried out a cross-sectional descriptive study in people with normal occlusion, in a sample of 362 students: 174 females and 188 males, 143 aged 12 years, 106 aged 13 years and 133 aged 14 years, selected in the secondary schools of the city of Matanzas. Measures were taken by only one person, directly in the mouth, from the mesial contact point to the distal one, at the level of the higher diameter using a Vernier caliper. The used variables were age, gender, and teeth mesial-distal diameter. We determined mesial-distal diameters of the upper and lower arches with similar sizes in both right and left sides, and upper (31,20 mm)and lower (22,70 mm) incisal indexes. We found sexual dimorphism, based on the males´ higher size of the lateral incisors (P= 0,008), and upper right canines (P= 0,000), and also of the right lateral incisors (P= 0,001) and low right canines (P= 0,000)(AU)
Asunto(s)
Humanos , Masculino , Femenino , Adolescente , Ortodoncia , Caracteres Sexuales , Incisivo/fisiopatología , Diente Canino/fisiopatología , Epidemiología Descriptiva , Estudios TransversalesRESUMEN
PURPOSE: This study investigated stress distribution in maxillas that underwent surgically assisted palatal expansion (SARPE). MATERIALS AND METHODS: Five maxillary models were built: no osteotomy (M1), Le Fort I osteotomy with a step in the zygomaticomaxillary buttress (M2), Le Fort I osteotomy with a step in the zygomaticomaxillary buttress and the pterygomaxillary disjunction (M3), Le Fort I osteotomy without a step (M4), and Le Fort I osteotomy with pterygomaxillary disjunction and no step (M5). Displacement coherence and maximum stress (MS) analyses were used for all models. RESULTS: Areas of tension spread to the maxilla and the region between the alveolar ridge and the palate and a critical point in the median suture for M2, M3, M4, and M5. In M2 and M4, MS spread farther toward and over the pterygoid process, contrary to what was found in M3 and M5. M3 had a better performance than the other models, and the tensile stress was interrupted by the posterior osteotomy, thus avoiding possible damage to the sphenoid bone or difficulties in expanding the posterior region of the maxilla. CONCLUSIONS: The steps in the zygomaticomaxillary buttress and the pterygomaxillary disjunction seem to be important to decrease the harmful dissipation of tensions during SARPE.
Asunto(s)
Análisis de Elementos Finitos , Maxilar/cirugía , Osteotomía Le Fort/métodos , Técnica de Expansión Palatina , Proceso Alveolar/fisiopatología , Diente Premolar/fisiopatología , Fenómenos Biomecánicos , Simulación por Computador , Suturas Craneales/fisiopatología , Humanos , Incisivo/fisiopatología , Maxilar/fisiopatología , Modelos Anatómicos , Modelos Biológicos , Diente Molar/fisiopatología , Hueso Paladar/fisiopatología , Hueso Esfenoides/fisiopatología , Hueso Esfenoides/cirugía , Estrés Mecánico , Cigoma/fisiopatología , Cigoma/cirugíaRESUMEN
STATEMENT OF PROBLEM: It is unclear how the amount of remaining coronal dentin and the type of post and core rehabilitation affect the strain, stress distribution, and fracture resistance of endodontically treated teeth. PURPOSE: The purpose of this study was to evaluate the effects of the type of post, type of crown, and the amount of remaining coronal dentin on the biomechanical behavior of endodontically treated teeth. MATERIAL AND METHODS: The investigation was conducted by using 3-dimensional finite element analysis and laboratory tests. Three-dimensional models of a maxillary central incisor were generated: without remaining coronal dentin, with 1.0 mm of remaining coronal dentin, with 2.0 mm of remaining coronal dentin, and restored with a glass-fiber post or a cast post and core in combination with a metal crown or an alumina-reinforced ceramic crown. The results were evaluated by using the von Mises criterion and Maximum Principal Stress. One hundred twenty bovine incisors were selected and divided into 12 treatment groups (n=10). Specimens were loaded at a 135-degree angle to perform strain measurements and were then loaded until fracture. The strain and fracture resistance results were analyzed with 3-way analysis of variance and the Tukey honestly significant difference test (α=.05). RESULTS: The alumina-reinforced ceramic crowns and metal crowns associated with a glass-fiber post showed a homogeneous stress distribution within the root. The cast post and core concentrated higher stresses at the post-dentin interface. Significant differences were found among the mean fracture resistance values for all groups (P<.05). The presence of 2.0 mm of coronal remnants resulted in lower strains and higher fracture resistance for both the metal and ceramic crowns. Roots restored with glass-fiber posts exhibited more favorable fractures. CONCLUSIONS: The presence of 2 mm of remaining coronal dentin improved the mechanical behavior of the endodontically treated maxillary incisors. Teeth restored with glass-fiber posts and composite resin cores showed a homogeneous stress distribution within the root dentin.
Asunto(s)
Coronas/clasificación , Dentina/patología , Incisivo/fisiopatología , Técnica de Perno Muñón/instrumentación , Diente no Vital/rehabilitación , Óxido de Aluminio/química , Animales , Fenómenos Biomecánicos , Bovinos , Cerámica/química , Simulación por Computador , Diseño Asistido por Computadora , Aleaciones Dentales/química , Diseño de Prótesis Dental , Cavidad Pulpar/fisiopatología , Módulo de Elasticidad , Análisis de Elementos Finitos , Vidrio/química , Humanos , Imagenología Tridimensional/métodos , Incisivo/patología , Modelos Anatómicos , Modelos Biológicos , Estrés Mecánico , Fracturas de los Dientes/fisiopatología , Raíz del Diente/fisiopatología , Diente no Vital/fisiopatologíaRESUMEN
OBJECTIVE: The objective of this study was to evaluate dentoskeletal effects in the treatment of Class II malocclusion performed with the Herbst appliance in patients at post-peak stage of growth. METHODS: The sample consisted of 16 patients with Class II malocclusion and average initial and final ages of 14.04 (ranging from 11.50 to 35.66) and 17.14 (ranging from 13.68 to 38.64) years, respectively, who were treated for an mean time of 2.52 years. Lateral cephalograms were obtained at treatment onset (T1) and completion (T2) to evaluate the effects of therapy. Initial dental casts were also used to evaluate the overjet and the anteroposterior severity of molar relationship at treatment onset. The cephalometric changes between initial and final stages were compared by means of the non-parametric Wilcoxon test. RESULTS: The results showed that the Herbst appliance did not promote significant changes in the maxillary component and the effective length of the mandible significantly increased without improving the maxillomandibular relationship. Changes in the maxillary and mandibular dentoalveolar components revealed that the maxillary incisors exhibited retrusion and lingual tipping, while the mandibular incisors presented increased protrusion and buccal tipping. The dental relationships exhibited significant improvements with the treatment. CONCLUSION: Based on the present results, it was concluded that the effects of treatment performed with the Herbst appliance in patients at post-peak stage of growth are predominantly of dentoalveolar nature.
Asunto(s)
Maloclusión Clase II de Angle/terapia , Desarrollo Maxilofacial , Aparatos Ortodóncicos Funcionales , Ortodoncia Correctiva/instrumentación , Adolescente , Adulto , Factores de Edad , Cefalometría , Niño , Humanos , Incisivo/fisiopatología , Mandíbula/crecimiento & desarrollo , Maxilar/crecimiento & desarrollo , Sobremordida/terapia , Estadísticas no Paramétricas , Adulto JovenRESUMEN
OBJECTIVE: This retrospective study aimed to conduct a cephalometric evaluation of the skeletal, dental and soft tissue effects resulting from treatment of adult patients presenting Class II malocclusion, performed with a Mandibular Protraction Appliance (MPA) combined with a fixed orthodontic appliance. METHODS: The sample consisted of teleradiographs obtained before and after treatment of 9 adult patients (initial mean age of 22.48 years) with bilateral Class II, division 1, malocclusion. Paired t test (p < 0.05) was applied to compare initial and final values. RESULTS: t test revealed an increase in anteroinferior facial height and posterior facial height. The dental changes include: extrusion of upper incisors, buccal inclination, protrusion of lower incisors, mesialization and extrusion of mandibular molars. Regarding the soft tissue component, there was an increase in nasolabial angle in addition to upper lip retrusion. CONCLUSIONS: The effects of treating Class II malocclusion adult patients, by means of using Mandibular Protraction Appliance (MPA) combined with a fixed appliance were mostly observed in the mandibular arch, and consisted of buccal inclination, protrusion and intrusion of incisors, and mesialization and extrusion of the molars.
Asunto(s)
Maloclusión Clase II de Angle/terapia , Avance Mandibular/instrumentación , Aparatos Ortodóncicos Funcionales , Adulto , Cefalometría , Vértebras Cervicales/diagnóstico por imagen , Vértebras Cervicales/crecimiento & desarrollo , Femenino , Humanos , Incisivo/fisiopatología , Masculino , Desarrollo Maxilofacial , Diente Molar/fisiopatología , Extrusión Ortodóncica/instrumentación , Radiografía , Estudios Retrospectivos , Estadísticas no Paramétricas , Adulto JovenRESUMEN
OBJECTIVE: The objective of this study was to evaluate a sagittal variation on the lower incisors with the use of the lingual arch on the transition from mixed to permanent dentition. METHODS: The sample was constituted of 44 Caucasian patients (26 girls and 18 boys), divided in two groups: CG, control group, monitoring the lower arch space with no orthodontic/orthopedic treatment during the rated period (n = 14); EG, experimental group, presenting anterior inferior mild crowding and installation of the lingual arch for space maintenance (n = 30). The position of the lower incisors was analyzed on computerized cephalometric tracings performed at the beginning of the monitoring (T1) and at the end, on the permanent dentition (T2). In order to evaluate the position of the incisors it was used Tweed and Steiner measurements: IMPA, 1.NB and 1-NB. The alterations were analyzed through the "t" test for paired samples, while the differences between the groups were analyzed through the "t" test for independent samples, as for sexual dimorphism. RESULTS: The values in T2 were greater in relation to T1 for all measurements on EG (IMPA, p = 0.038; 1.NB, p = 0.007 and 1-NB, p < 0.0001). On comparing the differences (T2-T1) between CG and EG, it can be gauged differences significantly superior for measure 1.NB (p = 0.002) and 1-NB (p < 0.0001) on EG. There was no statistically significant difference between genres. CONCLUSIONS: It was concluded that the lower incisors were projected after using the lingual arch to control the space on the transition from mixed to permanent dentition, however, within acceptable standards, not having difference between genres.
Asunto(s)
Incisivo/fisiopatología , Maloclusión/terapia , Aparatos Ortodóncicos Funcionales , Mantenimiento del Espacio en Ortodoncia , Técnicas de Movimiento Dental/instrumentación , Cefalometría , Niño , Dentición Mixta , Dentición Permanente , Femenino , Humanos , Masculino , Mandíbula , Mantenimiento del Espacio en Ortodoncia/instrumentaciónRESUMEN
OBJETIVO: avaliar os efeitos dentoesqueléticos do tratamento da má oclusão de Classe II com o aparelho de Herbst em pacientes que se encontravam na fase pós-pico de crescimento. MÉTODOS: a amostra consistiu de 16 pacientes com má oclusão de Classe II com medianas das idades inicial e final de 14,04 (amplitude 11,50 - 35,66) e 17,14 anos (amplitude 13,68 - 38,64), respectivamente, que foram tratados por um período médio de 2,52 anos. Telerradiografias em norma lateral foram obtidas ao início e final do tratamento para avaliar as alterações decorrentes do tratamento. Os modelos de gesso iniciais foram utilizados para avaliar o trespasse horizontal e a severidade da relação anteroposterior existente entre os molares ao início do tratamento. As alterações cefalométricas entre as fases inicial e final foram comparadas pelo teste não-paramétrico de Wilcoxon. RESULTADOS: os resultados mostraram que o aparelho de Herbst não promoveu alterações significativas no componente maxilar, o comprimento efetivo da mandíbula aumentou significativamente, sem promover uma melhoria da relação maxilomandibular. As alterações dos componentes dentoalveolares superiores e inferiores mostraram que os incisivos superiores apresentaram uma retrusão e inclinação lingual, ao passo que os incisivos inferiores evidenciaram um aumento na protrusão e inclinação para vestibular. As relações dentárias apresentaram uma melhora significativa com o tratamento. CONCLUSÃO: com base nos resultados desse trabalho, concluiu-se que os efeitos da terapia com o aparelho de Herbst em pacientes na fase pós-pico de crescimento são de natureza predominantemente dentoalveolar.
OBJECTIVE: The objective of this study was to evaluate dentoskeletal effects in the treatment of Class II malocclusion performed with the Herbst appliance in patients at post-peak stage of growth. METHODS: The sample consisted of 16 patients with Class II malocclusion and average initial and final ages of 14.04 (ranging from 11.50 to 35.66) and 17.14 (ranging from 13.68 to 38.64) years, respectively, who were treated for an mean time of 2.52 years. Lateral cephalograms were obtained at treatment onset (T1) and completion (T2) to evaluate the effects of therapy. Initial dental casts were also used to evaluate the overjet and the anteroposterior severity of molar relationship at treatment onset. The cephalometric changes between initial and final stages were compared by means of the non-parametric Wilcoxon test. RESULTS: The results showed that the Herbst appliance did not promote significant changes in the maxillary component and the effective length of the mandible significantly increased without improving the maxillomandibular relationship. Changes in the maxillary and mandibular dentoalveolar components revealed that the maxillary incisors exhibited retrusion and lingual tipping, while the mandibular incisors presented increased protrusion and buccal tipping. The dental relationships exhibited significant improvements with the treatment. CONCLUSION: Based on the present results, it was concluded that the effects of treatment performed with the Herbst appliance in patients at post-peak stage of growth are predominantly of dentoalveolar nature.
Asunto(s)
Adolescente , Adulto , Niño , Humanos , Adulto Joven , Desarrollo Maxilofacial , Maloclusión Clase II de Angle/terapia , Aparatos Ortodóncicos Funcionales , Ortodoncia Correctiva/instrumentación , Factores de Edad , Cefalometría , Incisivo/fisiopatología , Mandíbula/crecimiento & desarrollo , Maxilar/crecimiento & desarrollo , Sobremordida/terapia , Estadísticas no ParamétricasRESUMEN
OBJECTIVE: This retrospective study aimed to conduct a cephalometric evaluation of the skeletal, dental and soft tissue effects resulting from treatment of adult patients presenting Class II malocclusion, performed with a Mandibular Protraction Appliance (MPA) combined with a fixed orthodontic appliance. METHODS: The sample consisted of teleradiographs obtained before and after treatment of 9 adult patients (initial mean age of 22.48 years) with bilateral Class II, division 1, malocclusion. Paired t test (p < 0.05) was applied to compare initial and final values. RESULTS: t test revealed an increase in anteroinferior facial height and posterior facial height. The dental changes include: extrusion of upper incisors, buccal inclination, protrusion of lower incisors, mesialization and extrusion of mandibular molars. Regarding the soft tissue component, there was an increase in nasolabial angle in addition to upper lip retrusion. CONCLUSIONS: The effects of treating Class II malocclusion adult patients, by means of using Mandibular Protraction Appliance (MPA) combined with a fixed appliance were mostly observed in the mandibular arch, and consisted of buccal inclination, protrusion and intrusion of incisors, and mesialization and extrusion of the molars.
OBJETIVO: esse estudo retrospectivo teve como objetivo avaliar, cefalometricamente, os efeitos esqueléticos, dentários e tegumentares decorrentes do tratamento com o Aparelho de Protração Mandibular em conjunto ao aparelho fixo em pacientes adultos para correção da má oclusão de Classe II. MÉTODOS: a amostra foi composta por telerradiografias pré- e pós-tratamento de nove adultos (idade inicial média de 22,48 anos), portadores de má oclusão de Classe II, divisão 1 bilateral. O teste t pareado (p < 0,05) foi empregado para comparação dos valores iniciais e finais. RESULTADOS: de acordo com o teste t, observou-se aumento da altura facial anteroinferior e da altura facial posterior. As alterações dentárias foram: extrusão dos incisivos superiores, inclinação para vestibular e protrusão dos incisivos inferiores; e mesialização e extrusão dos molares inferiores. Com relação ao componente tegumentar, houve aumento do ângulo nasolabial e retrusão do lábio superior. CONCLUSÃO: os efeitos do tratamento com o Aparelho de Protração Mandibular em conjunto com aparelho fixo em pacientes adultos para correção da má oclusão de Classe II foram direcionados, principalmente, à arcada inferior, com inclinação vestibular, protrusão e intrusão dos incisivos e mesialização e extrusão dos molares.
Asunto(s)
Adulto , Femenino , Humanos , Masculino , Adulto Joven , Maloclusión Clase II de Angle/terapia , Avance Mandibular/instrumentación , Aparatos Ortodóncicos Funcionales , Cefalometría , Vértebras Cervicales/crecimiento & desarrollo , Vértebras Cervicales , Incisivo/fisiopatología , Desarrollo Maxilofacial , Diente Molar/fisiopatología , Extrusión Ortodóncica/instrumentación , Estudios Retrospectivos , Estadísticas no ParamétricasRESUMEN
BACKGROUND: The aim of this study was to measure the effect of simulating two different loads on maxillary incisors displaying eight morphological types of non-carious cervical lesions, unrestored and restored with an adhesive restoration, by quantifying the stress distributions generated using finite element analysis. METHODS: Virtual models of maxillary incisors were generated using the CAD software (RhinoCeros). After composing virtual dental and supporting structures with and without non-carious cervical lesions, each model was meshed using a control mesh device (ANSYS Finite Element Analysis Software). All of the virtual models were subjected to two load types, oblique load and vertical load, to simulate occlusal forces of 100 N each. Comparisons were made between simulated teeth with non-carious cervical lesions, with and without composite resin restorations, and a simulated sound tooth. Data summarizing the stress distributions were obtained in MPa using von Mises criteria. RESULTS: Oblique loading on simulated non-carious cervical lesions resulted in greater stress concentration compared with vertical loading, and non-carious cervical lesions with acute angles displayed higher stress concentrations at the depth of the lesion. Restoring the lesions with an adhesive restoration, such as composite resin, appeared to overcome this stress concentration. CONCLUSIONS: Restoring NCCLs with adhesive restorative materials, such as a nanohybrid composite resin, appears to recover the biomechanical behaviour similar to sound teeth.
Asunto(s)
Fuerza de la Mordida , Análisis del Estrés Dental/métodos , Incisivo/fisiopatología , Abrasión de los Dientes/fisiopatología , Cuello del Diente , Fenómenos Biomecánicos/fisiología , Resinas Compuestas/uso terapéutico , Materiales Dentales/uso terapéutico , Análisis de Elementos Finitos , Humanos , Maxilar , Resistencia a la Tracción , Abrasión de los Dientes/patología , Abrasión de los Dientes/terapiaRESUMEN
OBJECTIVE: The objective of this study was to evaluate a sagittal variation on the lower incisors with the use of the lingual arch on the transition from mixed to permanent dentition. METHODS: The sample was constituted of 44 Caucasian patients (26 girls and 18 boys), divided in two groups: CG, control group, monitoring the lower arch space with no orthodontic/orthopedic treatment during the rated period (n = 14); EG, experimental group, presenting anterior inferior mild crowding and installation of the lingual arch for space maintenance (n = 30). The position of the lower incisors was analyzed on computerized cephalometric tracings performed at the beginning of the monitoring (T1) and at the end, on the permanent dentition (T2). In order to evaluate the position of the incisors it was used Tweed and Steiner measurements: IMPA, 1.NB and 1-NB. The alterations were analyzed through the "t" test for paired samples, while the differences between the groups were analyzed through the "t" test for independent samples, as for sexual dimorphism. RESULTS: The values in T2 were greater in relation to T1 for all measurements on EG (IMPA, p = 0.038; 1.NB, p = 0.007 and 1-NB, p < 0.0001). On comparing the differences (T2-T1) between CG and EG, it can be gauged differences significantly superior for measure 1.NB (p = 0.002) and 1-NB (p < 0.0001) on EG. There was no statisticaly significant difference between genres. CONCLUSION: It was concluded that the lower incisors were projected after using the lingual arch to control the space on the transition from mixed to permanent dentition, however, within acceptable standards, not having difference between genres.
OBJETIVO: avaliar a alteração sagital ocorrida nos incisivos inferiores com o uso do arco lingual no período de transição da dentição mista para a permanente. MÉTODOS: a amostra foi composta por 44 pacientes leucodermas (26 meninas e 18 meninos), divididos em dois grupos: (GC) grupo controle, no qual foi efetuado monitoramento do espaço da arcada inferior, sem tratamento ortodôntico/ortopédico no período avaliado (n = 14); (GE) grupo experimental, presença de suave apinhamento anteroinferior e instalação do arco lingual para manutenção do espaço (n = 30). A posição dos incisivos inferiores foi analisada em traçados cefalométricos computadorizados realizados ao início (T1) e ao final do acompanhamento, já na dentição permanente (T2). Para avaliar a posição dos incisivos foram utilizadas as medidas das análises cefalométricas de Tweed e de Steiner: IMPA, 1.NB e 1-NB. As alterações ocorridas foram analisadas pelo teste t para amostras pareadas, enquanto as diferenças entre os grupos foram avaliadas pelo teste t para amostras independentes, bem como para o dimorfismo sexual. RESULTADOS: os valores em T2 foram maiores em relação a T1 para todas as medidas no GE (IMPA, p = 0,038; 1.NB, p = 0,007; e 1-NB, p < 0,0001). Na comparação das diferenças (T2-T1) entre o GC e GE pôde-se aferir diferenças significativamente superiores para as medidas 1.NB (p = 0,002) e 1-NB (p < 0,0001) no GE. Não houve diferença significativamente estatística entre os sexos. CONCLUSÃO: concluiu-se que os incisivos inferiores foram projetados após a utilização do arco lingual para o controle do espaço no período de transição da dentição mista para a permanente, porém a projeção esteve dentro dos padrões aceitáveis, não havendo diferença entre sexos.
Asunto(s)
Niño , Femenino , Humanos , Masculino , Incisivo/fisiopatología , Maloclusión/terapia , Aparatos Ortodóncicos Funcionales , Mantenimiento del Espacio en Ortodoncia , Técnicas de Movimiento Dental/instrumentación , Cefalometría , Dentición Mixta , Dentición Permanente , Mandíbula , Mantenimiento del Espacio en Ortodoncia/instrumentaciónRESUMEN
BACKGROUND: Orthodontic force application to the teeth is responsible for a series of biological responses in the bone and dentin, which lead to some alterations of the mineral density of the tissues. Our objective was determine, through cone-beam computed tomography (CBCT), the mineral density of the apical third of the roots of the upper central incisors and of the periapical bone portion surrounding these teeth, in patients submitted to orthodontic treated and untreated individuals. MATERIAL/METHODS: 30 untreated individuals and 15 treated ones (treatment cessation at least 1 year before the study) underwent CBCT. Mineral density was assessed in the apical third of the root of the upper central incisors and in the alveolar bone in the periapical region of these teeth. In order to reduce CBCT-related mineral density variability, we standardized the cone-beam tomography device, the image-acquisition settings and the field of view positioning and size. Student's t test was used for the analyses. RESULTS: bone mineral density (BMD) and root mineral density (RMD), in Hounsfield Units, were 674.84 and 1282.26 for the untreated group and 630.28 and 1370.29 for the treated group, respectively. The differences between the group means were statistically significant for RMD (p<0.05). CONCLUSIONS: untreated individuals had a significant lower mean RMD in comparison with those submitted to orthodontic treatment.
Asunto(s)
Densidad Ósea/fisiología , Ortodoncia/métodos , Técnicas de Movimiento Dental , Raíz del Diente/fisiopatología , Adulto , Tomografía Computarizada de Haz Cónico , Femenino , Humanos , Incisivo/diagnóstico por imagen , Incisivo/fisiopatología , Masculino , Valores de Referencia , Raíz del Diente/diagnóstico por imagen , Adulto JovenRESUMEN
In crowded dental arches, the permanent lateral incisors often erupt and resorb the mesial portion of the root of deciduous canines, causing their premature loss. Therefore, knowledge on clinical aspects related to etiologic factors is necessary to pediatric orthodontists and clinical dentists for diagnosis and treatment with regard to incisor crowding and adjustment. The aim of the present study was to describe a clinical case characterized by the unilateral loss of a lower deciduous canine, offering clinical considerations on this issue and discussing the various procedures implemented to prevent potential problems. A patient, 8 years of age, had the lower right deciduous canine prematurely lost, resulting in a deviation from the midline to the same side of the loss caused by the migration of the permanent incisors. The antimeric canine was removed and a fixed apparatus was attached to the lower arch associated to a spring to correct the midline. Next, a lip bumper device was employed to promote the vestibular conduction of the lower incisors to accommodate the permanent canines in the arch. Although early loss of deciduous canines occurs frequently, treatment possibilities are controversial and further studies on the subject are necessary Orthodontic evaluation should be always considered to minimize the need to extract permanent teeth and/or future orthodontic treatment.
Asunto(s)
Diente Canino/patología , Incisivo/fisiopatología , Ortodoncia Correctiva/métodos , Pérdida de Diente/complicaciones , Migración del Diente/etiología , Migración del Diente/terapia , Niño , Diente Canino/cirugía , Asimetría Facial/etiología , Femenino , Humanos , Maloclusión/terapia , Ortodoncia Correctiva/instrumentación , Resorción Radicular/etiología , Exfoliación Dental , Extracción Dental , Diente PrimarioRESUMEN
Multiloop Edgewise Archwire Technique es una técnica desarrollada en los años 60 por Young H. Kim, la cual ha tenido un fuerte desarrollo en los países de Asia, especialmente Japón y Corea, por el Prof. Sadao Sato de la Universidad de Kanagawa, Japón. En la experiencia de la filosofía MEAW se ha dado particular importancia al tratamiento no quirúrgico de clases III y mordidas abiertas esqueletales. La discrepancia posterior (CP), concepto nuevo para la ortodoncia occidental, es considerada para determinar la remoción temprana de los terceros molares debido a su importancia como factor coadyuvante en la recidiva de los tratamientos de ortodoncia, especialmente el apiñamiento incisivo y en particular en la orientación del Dr. Sato, debido a su importancia en el desarrollo de la DP, que como se ha mencionado, es un factor etiopatogénico en el desarrollo de las maloclusiones esqueletales y mordidas abiertas antes, durante y postratamiento de ortodoncia.
Asunto(s)
Humanos , Mordida Abierta/etiología , Mordida Abierta/terapia , Ortodoncia Correctiva/métodos , Tercer Molar/fisiopatología , Facultades de Odontología , Incisivo/fisiopatología , Alambres para Ortodoncia , Recurrencia/prevención & controlRESUMEN
Multiloop Edgewise Archwire Technique es una técnica desarrollada en los años 60 por Young H. Kim, la cual ha tenido un fuerte desarrollo en los países de Asia, especialmente Japón y Corea, por el Prof. Sadao Sato de la Universidad de Kanagawa, Japón. En la experiencia de la filosofía MEAW se ha dado particular importancia al tratamiento no quirúrgico de clases III y mordidas abiertas esqueletales. La discrepancia posterior (CP), concepto nuevo para la ortodoncia occidental, es considerada para determinar la remoción temprana de los terceros molares debido a su importancia como factor coadyuvante en la recidiva de los tratamientos de ortodoncia, especialmente el apiñamiento incisivo y en particular en la orientación del Dr. Sato, debido a su importancia en el desarrollo de la DP, que como se ha mencionado, es un factor etiopatogénico en el desarrollo de las maloclusiones esqueletales y mordidas abiertas antes, durante y postratamiento de ortodoncia.(AU)
Asunto(s)
Humanos , Mordida Abierta/etiología , Mordida Abierta/terapia , Ortodoncia Correctiva/métodos , Tercer Molar/fisiopatología , Recurrencia/prevención & control , Facultades de Odontología , Incisivo/fisiopatología , Alambres para OrtodonciaRESUMEN
The purpose of this article is to report the orthodontic treatment of a patient with extremely delayed development of the maxillary lateral incisors. At 7 years of age, the boy's permanent maxillary lateral incisors had not erupted. A radiograph showed no tooth germs in place, although well-defined radiolucent areas were evident. Removal of the radiolucent areas was contemplated, but it was rejected in favor of a conservative approach. At age 13, peg-shaped maxillary lateral incisors erupted; they were positioned during orthodontic treatment and reshaped with composite restorations, providing good esthetics and function.
Asunto(s)
Restauración Dental Permanente , Incisivo/fisiopatología , Anomalías Dentarias/fisiopatología , Erupción Dental , Diente Primario/anomalías , Cefalometría/estadística & datos numéricos , Niño , Restauración Dental Permanente/métodos , Dientes Fusionados , Humanos , Incisivo/anomalías , Frenillo Labial/anomalías , Frenillo Labial/cirugía , Masculino , Técnica de Expansión Palatina , Anomalías Dentarias/rehabilitación , Diente no Erupcionado/fisiopatologíaRESUMEN
AIM: To investigate ex vivo the influence of the post system on fracture resistance and failure mode of root filled incisor, canine, premolar and molar teeth. METHODOLOGY: Eighty human teeth were divided into eight groups (n = 10) resulting from the interaction between the two study factors: post system (glass fibre post; cast Ni-Cr alloy post and core) and type of tooth (maxillary incisors, maxillary canines, maxillary premolars and mandibular molars). All roots were prepared with a 2-mm ferrule and restored with metal crown. Fracture resistance (N) was assessed in a mechanical testing device, and the data were analysed by two-way anova (4 × 2) followed by Tukey's test (α = 0.05). The failure mode was evaluated using an optical stereomicroscope and classified according to the location of the failure. Failure mode data were analysed by two-factor anova and Student-Newman-Keuls (SNK) tests (α = 0.05). Correlation between fracture resistance and failure mode was analysed by linear regression. RESULTS: Glass fibre and cast posts and cores had similar fracture resistance, regardless of the type of tooth. Canines and molars had significantly higher fracture resistance (P < 0.001) than premolars. Incisors teeth had significantly lower fracture resistance (P < 0.001) than premolars. The fracture mode for incisors, premolars and molars was more amenable to restoration when the teeth were restored with glass fibre posts. Fracture resistance had no correlation with fracture mode, regardless of the post system and type of tooth analysed. CONCLUSIONS: Post system had no significant effect on fracture resistance, regardless of the type of tooth. The mode of fracture was more restorable with glass fibre posts.