RESUMO
Objective: This study was conducted to investigate the relationship between dental development and cervical vertebral maturation stages in a group of Yemeni children and adolescents. Materials an Methods: The study included digital panoramic radiographs and lateral skull cephalograms obtained from 207 Yemeni subjects122 females and 85 males aged between 8 to 18 years. Dental maturity was evaluated according to the method of Demirijian et al., calcification stages of the left mandibular canines, first and second premolars and second molars were assessed. Skeletal maturity was assessed by the cervical vertebral maturation (CVM) stages according to the method of Baccetti et al. Correlation between CVM and dental maturation was evaluated by Spearman rank-order correlation coefficient (SROCC). Results: CVM and dental calcification stages were highly correlated (p<0.001) in both genders, ranging from 0.686 to 0.873 for females and 0.787 to 0.871 for males. Calcification stages of the second molars showed the strongest correlation with CVM. Conclusion: Calcification stages of the second molar may be used as a reliable maturation indicator. Dental maturation may be applied to determine the skeletal maturity status of Yemeni children and adolescents.
Objetivo: Este estudio se realizó para investigar la relación entre el desarrollo dental y las etapas de maduración vertebral cervical en un grupo de niños y adolescentes yemeníes. Material y Métodos: El estudio incluyó radiografías panorámicas digitales y cefalogramas laterales del cráneo obtenidos de 207 sujetos yemeníes: 122 mujeres y 85 hombres de entre 8 y 18 años. La madurez dental se evaluó de acuerdo con el método de Demirijian et al. Se evaluaron las etapas de calcificación de los caninos mandibulares izquierdos, primer y segundo premolares y segundos molares. La madurez esquelética se evaluó mediante las etapas de maduración vertebral cervical (CVM) de acuerdo con el método de Baccetti et al. La correlación entre la CVM y la maduración dental se evaluó mediante el coeficiente de correlación de orden de rango de Spearman (SROCC). Resultado: Las etapas de CVM y calcificación dental estuvieron altamente correlacionadas (p<0.001) en ambos sexos, con un rango de 0.686 a 0.873 para las mujeres y 0.787 a 0.871 para los hombres. Las etapas de calcificación de los segundos molares mostraron la correlación más fuerte con CVM. Conclusión: las etapas de calcificación del segundo molar pueden usarse como un indicador de maduración confiable. La maduración dental puede aplicarse para determinar el estado de madurez esquelética de los niños y adolescentes yemeníes.
Assuntos
Humanos , Masculino , Feminino , Criança , Adolescente , Calcificação de Dente/fisiologia , Vértebras Cervicais/crescimento & desenvolvimento , Iêmen , Dente Pré-Molar/fisiologia , Desenvolvimento Ósseo , Radiografia Panorâmica , Cefalometria , Epidemiologia Descritiva , Estudos Transversais , Dente Canino/fisiologia , Incisivo/fisiologia , Dente Molar/fisiologiaRESUMO
Sexual selection favours traits that increase reproductive success via increased competitive ability, attractiveness, or both. Male rhesus macaque (Macaca mulatta) morphological traits are likely to reflect the effects of multiple sexual selection pressures. Here, we use a quantitative genetic approach to investigate the production and maintenance of variation in male rhesus macaque morphometric traits which may be subject to sexual selection. We collected measurements of body size, canine length, and fat, from 125 male and 21 female free-ranging rhesus macaques on Cayo Santiago. We also collected testis volumes from males. We used a genetic pedigree to calculate trait heritability, to investigate potential trait trade-offs, and to estimate selection gradients. We found that variation in most male morphometric traits was heritable, but found no evidence of trait trade-offs nor that traits predicted reproductive success. Our results suggest that male rhesus macaque morphometric traits are either not under selection, or are under mechanisms of sexual selection that we could not test (e.g. balancing selection). In species subject to complex interacting mechanisms of selection, measures of body size, weaponry, and testis volume may not increase reproductive success via easily-testable mechanisms such as linear directional selection.
Assuntos
Macaca mulatta/fisiologia , Reprodução/genética , Caracteres Sexuais , Animais , Tamanho Corporal , Dente Canino/fisiologia , Feminino , Masculino , Linhagem , Fenótipo , Porto Rico , Seleção Genética , Comportamento Sexual , Testículo/fisiologiaRESUMO
OBJECTIVES: To analyze the stress distribution on the PDL of the maxillary first molar in a mixed dentition Class III malocclusion, using a Hyrax-type appliance and maxillary protraction. SETTING AND SAMPLE POPULATION: A Class III malocclusion in the mixed dentition was reconstructed based on CBCT images. MATERIAL AND METHODS: The 3D FEM comprised the maxilla, alveolar bone, right first permanent molar teeth, and PDL and consisted of 1 133 497 nodes and 573 726 elements. Maxillary protraction force was applied to a hook positioned close to the deciduous canines with 600 g and at 15°, 30°, and 45° downward angles to the maxillary occlusal plane. RESULTS: Analysis was carried out from the top and buccal view of the sagittal plane. The magnitude of the stresses at 15°, 30°, and 45° of protraction angulation resulted in the highest stress magnitude being in the region between the distobuccal and palatal roots, as well as on the distal surface of the mesial root. The vector direction in this area showed traction and mesial movement. With 30° and 45° protraction angulations, the stress was located only between the distobuccal and palatal roots, and the vector direction was more extrusive at 15°. CONCLUSIONS: The suggested orthodontic movement is in the mesial direction with a small amount of extrusion with 15° angulation and greater extrusion with 30° and 45°.
Assuntos
Dentição Mista , Análise de Elementos Finitos , Má Oclusão Classe III de Angle/terapia , Maxila/fisiologia , Dente Molar/fisiologia , Ligamento Periodontal/fisiologia , Técnicas de Movimentação Dentária/métodos , Processo Alveolar/fisiologia , Fenômenos Biomecânicos , Criança , Tomografia Computadorizada de Feixe Cônico/métodos , Dente Canino/fisiologia , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Desenho de Aparelho Ortodôntico , Técnica de Expansão Palatina/instrumentação , Estresse Mecânico , Raiz Dentária/fisiologia , Dente Decíduo/fisiologiaRESUMO
La finalidad del presente trabajo fue comparar los resultados de la medición de la altura de la cortical vestibular de caninos, por tomografía lineal (TL) y tomografía computada de haz cónico,3D Accuitomo (CBCT, cone beam computed tomography) antes y después de alinear ortodóncicamente las arcadas dentarias. Se realizaron TL y CBCT pre y post alineación ortodóncica de 12 caninos, correspondientes a tres pacientesen tratamiento ortodóncico y se midió en mm la altura de las corticales óseas vestibulares de los caninos. Las medidasfueron tomadas por dos operadores a doble ciego. La variación de la altura promedio de la cortical vestibular con el tratamiento ortodóncico utilizando CBCT fue de -0,33 mm ± 0.233 de error standard y con TL de -0,08mm ± 0.55 de error standard. Se realizó Análisis de varianza (ANOVA) comparando las técnicas, los pacientes y los caninos superiores e inferiores, sin encontrarse diferencia estadísticamente significativa en ninguno de los casos. La evaluación de la cortical de la cresta vestibular de caninos utilizando TL es un método comparable en eficiencia a la CBCT. La medida de la altura en milímetroses menor en la TL debido a que la resolución de las imágenes es menor y no es apreciable por este método cuando ésta es extremadamente delgada...
Assuntos
Humanos , Masculino , Adolescente , Adulto , Feminino , Adulto Jovem , Dente Canino/fisiologia , Dente Canino , Ortodontia Corretiva , Processo Alveolar , Tomografia Computadorizada de Feixe Cônico/métodos , Tomografia Computadorizada por Raios X/métodos , Análise de Variância , Imageamento Tridimensional , Braquetes Ortodônticos , Odontometria/métodos , Interpretação Estatística de DadosAssuntos
Anodontia/terapia , Dente Pré-Molar/anormalidades , Dente Molar/cirurgia , Dente Decíduo/cirurgia , Criança , Dente Canino/fisiologia , Seguimentos , Humanos , Masculino , Planejamento de Assistência ao Paciente , Mantenedor de Espaço em Ortodontia/instrumentação , Mantenedor de Espaço em Ortodontia/métodos , Erupção Dentária/fisiologia , Extração Dentária , Técnicas de Movimentação Dentária/métodosRESUMO
This study aims at revising the biomechanical principles of the segmented archwire technique as well as describing the clinical conditions in which the rational use of scientific biomechanics is essential to optimize orthodontic treatment and reduce the side effects produced by the straight wire technique.
Assuntos
Desenho de Aparelho Ortodôntico , Fios Ortodônticos , Técnicas de Movimentação Dentária/instrumentação , Fenômenos Biomecânicos , Dente Canino/fisiologia , Elasticidade , Humanos , Incisivo/fisiologia , Dente Molar/fisiologia , Extrusão Ortodôntica/instrumentação , Sobremordida/terapia , Planejamento de Assistência ao Paciente , Rotação , Estresse Mecânico , Coroa do Dente/fisiologia , Técnicas de Movimentação Dentária/métodos , Raiz Dentária/fisiologia , TorqueRESUMO
This study aims at revising the biomechanical principles of the segmented archwire technique as well as describing the clinical conditions in which the rational use of scientific biomechanics is essential to optimize orthodontic treatment and reduce the side effects produced by the straight wire technique.
O objetivo desse trabalho é revisar os princípios biomecânicos da técnica do arco segmentado, bem como descrever situações clínicas onde o uso racional da biomecânica científica é fundamental na otimização do tratamento ortodôntico e eliminação dos efeitos colaterais da abordagem com arco contínuo.
Assuntos
Humanos , Desenho de Aparelho Ortodôntico , Fios Ortodônticos , Técnicas de Movimentação Dentária/instrumentação , Fenômenos Biomecânicos , Dente Canino/fisiologia , Elasticidade , Incisivo/fisiologia , Dente Molar/fisiologia , Extrusão Ortodôntica/instrumentação , Sobremordida/terapia , Planejamento de Assistência ao Paciente , Rotação , Estresse Mecânico , Torque , Coroa do Dente/fisiologia , Técnicas de Movimentação Dentária/métodos , Raiz Dentária/fisiologiaRESUMO
INTRODUCTION: Secondary bone grafting consists in a routine procedure on the treatment of patients with alveolar cleft. Usually, it is performed by the end of the mixed dentition, when the permanent canine is erupting, with autogenous cancellous bone from the iliac crest. OBJECTIVE: The present article discusses the alternative of autogenous bone grafting with allogeneic bone, obtained from human bone bank, illustrating the result with the report of a clinical case of left unilateral alveolar cleft.
Assuntos
Aloenxertos/transplante , Enxerto de Osso Alveolar/métodos , Transplante Ósseo/métodos , Processo Alveolar/diagnóstico por imagem , Dente Canino/fisiologia , Seguimentos , Humanos , Masculino , Radiografia Panorâmica , Procedimentos de Cirurgia Plástica/métodos , Erupção Dentária/fisiologiaRESUMO
INTRODUCTION: Secondary bone grafting consists in a routine procedure on the treatment of patients with alveolar cleft. Usually, it is performed by the end of the mixed dentition, when the permanent canine is erupting, with autogenous cancellous bone from the iliac crest. OBJECTIVE: The present article discusses the alternative of autogenous bone grafting with allogeneic bone, obtained from human bone bank, illustrating the result with the presentation of a clinical case of left unilateral alveolar cleft.
INTRODUÇÃO: o enxerto ósseo secundário consiste em um procedimento rotineiro no tratamento de pacientes com fissura alveolar. Via de regra, é realizado no final da dentadura mista, na época de erupção do canino permanente, com osso medular autógeno retirado da crista ilíaca. OBJETIVO: o presente artigo discorre sobre a alternativa de enxerto ósseo autógeno realizado com osso alógeno, obtido de banco de ossos humanos, ilustrando o resultado com a apresentação de um caso clínico de fissura alveolar unilateral do lado esquerdo.
Assuntos
Humanos , Masculino , Aloenxertos/transplante , Enxerto de Osso Alveolar/métodos , Transplante Ósseo/métodos , Processo Alveolar , Dente Canino/fisiologia , Seguimentos , Radiografia Panorâmica , Procedimentos de Cirurgia Plástica/métodos , Erupção Dentária/fisiologiaRESUMO
PROPOSAL: Evaluate pulp vitality of mandibular teeth after chin bone harvesting. MATERIALS AND METHODS: Thirty patients underwent chin bone harvesting and accompanied for 12 months, being submitted to testing for pulp vitality with Endo Ice refrigerant spray to produce a local temperature of -50 °C. The statistical analysis was executed with McNemar test with P value < 0.05. RESULTS: Results show that canine teeth are most susceptible to alterations; 68.82% (181) of the teeth tested showed no loss of pulp sensitivity to cold 30 days after surgery (P < 0.05), and at the end of the study, that figure had risen to 100% (263) of all teeth included in the sample. CONCLUSIONS: Pulp vitality testing showed that 31.18% (82) of teeth experienced some loss of sensitivity, but by 12 months after surgery, all teeth had recuperated their pulp sensitivity to cold unaided.
Assuntos
Queixo/cirurgia , Teste da Polpa Dentária/métodos , Polpa Dentária/fisiologia , Coleta de Tecidos e Órgãos/métodos , Adulto , Idoso , Aumento do Rebordo Alveolar/métodos , Dente Pré-Molar/fisiologia , Transplante Ósseo/métodos , Temperatura Baixa , Dente Canino/fisiologia , Arco Dental/cirurgia , Feminino , Seguimentos , Humanos , Incisivo/fisiologia , Masculino , Nervo Mandibular/fisiologia , Pessoa de Meia-Idade , Osteotomia/métodos , Estudos Prospectivos , Radiografia Interproximal , Recuperação de Função Fisiológica/fisiologia , Raiz Dentária/fisiologia , Sítio Doador de Transplante/cirurgia , Adulto JovemRESUMO
OBJECTIVES: To evaluate the influence of resin cements on cuspal deflection, fracture load and failure mode of endodontically-treated teeth restored with composite resin inlays. MATERIALS AND METHODS: Forty maxillary premolars were randomly divided into four groups: G1 (sound teeth, control), G2 (RelyX ARC), G3 (RelyX Unicem) and G4 (Maxcem Elite). The teeth from groups 2, 3 and 4 received mesial-occlusal-distal preparations and endodontic treatments. Impressions were taken with vinyl polysiloxane and poured using type IV die stone. Inlays with Z250 composite resin were built over each cast and luted with the resin cements. A 200-N load was applied on the occlusal surface and the cuspal deflection was measured using a micrometer. The specimens were then subjected to an axial load until failure occurred. The resulting failure mode was analyzed. RESULTS: The means for cuspal deflection (µm) and fracture load (N) followed by the same letter represent no statistically significant difference based on ANOVA and Tukey's test (p < 0.05). Cuspal deflection: G1 = 4.7 (± 1.7)(a), G2 = 12.0 (± 8.9)(a), G3 = 39.0 (± 27.0)(b) and G4 = 56.8 (± 18.2)(b). Fracture load: G1 = 1982 (± 893)(a), G2 = 690.9 (± 225.5)(b), G3 = 679 (± 193.6)(b) and G4 = 465.5 (± 121.6)(b). G1 presented cusp fractures only at the cement-enamel junction (CEJ). There was a high frequency of cusp fractures below the CEJ in G2, G3 and G4. CONCLUSIONS: Composite resin inlays luted with resin cements do not recover the strength of sound teeth. However, teeth restored with composite resin inlays and luted with RelyX ARC can withstand mechanical fatigue longer before failure occurs than those luted with RelyX Unicem and Maxcem Elite.
Assuntos
Dente Canino/fisiologia , Análise do Estresse Dentário , Endodontia , Cimentos de Resina , Análise de Variância , HumanosRESUMO
OBJECTIVE: To measure space closure during the retraction of upper permanent canines with self-ligating and conventional brackets. MATERIALS AND METHODS: Fifteen patients who required maxillary canine retraction into first premolar extraction sites as part of their orthodontic treatment completed this study. In a random split-mouth design, the retraction of upper canines was performed using an elastomeric chain with 150 g of force. The evaluations were performed in dental casts (T0, initial; T1, 4 weeks; T2, 8 weeks; T3, 12 weeks). The amount of movement and the rotation of the canines as well as anchorage loss of the upper first molars were evaluated. RESULTS: There was no difference between self-ligating and conventional brackets regarding the distal movement of upper canines and mesial movement of first molars (P > .05). Rotation of the upper canines was minimized with self-ligating brackets (P < .05). CONCLUSION: Distal movement of the upper canines and anchorage loss of the first molars were similar with both conventional and self-ligating brackets. Rotation of the upper canines during sliding mechanics was minimized with self-ligating brackets.
Assuntos
Desenho de Aparelho Ortodôntico , Braquetes Ortodônticos , Fechamento de Espaço Ortodôntico/instrumentação , Técnicas de Movimentação Dentária/instrumentação , Adolescente , Adulto , Criança , Dente Canino/fisiologia , Feminino , Humanos , Masculino , Maxila , Dente Molar/fisiologia , Estatísticas não Paramétricas , Adulto JovemRESUMO
A dentigerous cyst is the most common developmental odontogenic cyst. It is a benign and asymptomatic intraosseous lesion that affects the bones of the maxillofacial complex, interfering with tooth eruption. This article reports the spontaneous eruption of a canine after marsupialization of an infected dentigerous cyst and extraction of the deciduous teeth. A radiograph showed a large cyst with a radiolucent area involving the mandibular left deciduous canine and first molar, and the permanent canine and first premolar. Although enucleation is the treatment of choice, marsupialization is the best option for large cysts involving an unerupted permanent tooth, as in this case. The patient was followed for 1 year, and eruption of the permanent canine and first premolar and gradual reduction of the radiolucent area were observed.
Assuntos
Dente Canino/fisiologia , Cisto Dentígero/cirurgia , Doenças Mandibulares/cirurgia , Erupção Dentária/fisiologia , Dente Pré-Molar/fisiologia , Criança , Líquido Cístico , Seguimentos , Humanos , Masculino , Dente Molar/cirurgia , Extração Dentária , Dente Decíduo/cirurgia , Dente não Erupcionado/fisiopatologiaRESUMO
The aim of this study was to determine the effect of tooth clenching and grinding on anterior temporalis electromyographic (EMG) activity. The sample included 30 healthy subjects with natural dentition and bilateral molar support, 15 with bilateral canine guidance and 15 with bilateral group function. An inclusion criterion was that subjects have to be free of signs and symptoms of any dysfunction of the masticatory system. Bipolar surface electrodes were located on the left and right anterior temporalis muscles. EMG activity was recorded during the following conditions: A. eccentric grinding from intercuspal position to the right lateral edge-to-edge contact position; B. clenching in right edge-to-edge lateral contact position; and C. concentric grinding from right lateral edge-to-edge contact position to intercuspal position. On the working side, EMG activity was not significantly different between conditions in both occlusal schemes. On the nonworking side, EMG activity was significantly higher during condition C than condition B in both occlusal schemes (mixed model with unstructured covariance matrix). When comparing by side, EMG activity was significantly higher during conditions A and B on the working side than on the nonworking side. However, there was no significant difference during condition C. EMG activity was significantly lower with canine guidance than group function on the working side (in all conditions) as well as during concentric grinding on the nonworking side. These results could explain muscular symptoms in the anterior temporalis muscles if the subject is experiencing parafunctional habits either while awake and/or sleep that exceed the individual's adaptation capability.
Assuntos
Bruxismo/fisiopatologia , Eletromiografia , Contração Muscular/fisiologia , Músculo Temporal/fisiologia , Adolescente , Adulto , Dente Canino/fisiologia , Oclusão Dentária , Eletrodos , Eletromiografia/instrumentação , Feminino , Humanos , Incisivo/fisiologia , Contração Isométrica/fisiologia , Masculino , Processamento de Sinais Assistido por Computador , Adulto JovemRESUMO
This study was designed to determine the effect of the occlusal scheme on masseter EMG activity at different jaw posture tasks. The sample included 30 healthy subjects with natural dentition and bilateral molar support, 15 with bilateral canine guidance, and 15 with bilateral group function. An inclusion criterion was that subjects had to be free of signs and symptoms of any dysfunction of the masticatory system. Bipolar surface electrodes were located on the left and right masseter muscles. EMG activity was recorded during the following jaw posture tasks: A. maximal clenching in the intercuspal position; B. grinding from intercuspal position to edge-to-edge lateral contact position; C. maximal clenching in the edge-to-edge lateral contact position; D. grinding from edge-to-edge lateral contact position to intercuspal position. EMG activity in tasks B, C, and D was lower than in task A (mixed model with unstructured covariance matrix). EMG activity was not significantly different with canine guidance or group function. EMG activity recorded on the nonworking side was higher than the working side during task C, and no different between tasks B or D. On the nonworking side, EMG activity in task B was significantly lower than C and D, and similar between task C and D. On the working side, EMG activity was significantly higher in task D than C and B, and in task B significantly higher than task C. The EMG patterns observed could be of clinical importance in the presence of parafunctional habits, i.e., clenching and/or grinding.
Assuntos
Bruxismo/fisiopatologia , Oclusão Dentária , Eletromiografia , Músculo Masseter/fisiologia , Contração Muscular/fisiologia , Adolescente , Adulto , Índice de Massa Corporal , Dente Canino/fisiologia , Oclusão Dentária Central , Feminino , Humanos , Contração Isométrica/fisiologia , Masculino , Dente Molar/fisiologia , Fatores Sexuais , Dimensão Vertical , Adulto JovemRESUMO
Este artículo presenta la distribución mundial del rasgo Metaconulo en los primeros molares superiores humanos. Su conocimiento poblacional nos ayuda a tener una visión más completa de la morfología dental humana y nos permite tener un referente geográfico y temporal de este rasgo.
This article shows the world wide distribution of Metaconule trait on first human upper molars. The populational record of this trait can help us to know better the human dental morphology, its geographic and microevolution of this dental trait.
Assuntos
Dente Canino , Dente Molar , Dentição , Dente Canino/fisiologiaRESUMO
Los caninos son piezas dentales de sumo valor en la arquitectura craneana; pero muchas veces sufren desviaciones en el trayecto eruptivo, dando lugar a retenciones y/o impactaciones. Este trabajo pretende iformar acerca de las causas que intervienen en esta anomalía y cómo se puede interferir en el proceso de dicha patología.(AU)
Assuntos
Humanos , Adolescente , Criança , Feminino , Dente Impactado/diagnóstico , Dente Impactado/etiologia , Dente Impactado/diagnóstico por imagem , Erupção Ectópica de Dente , Dente Canino/fisiologia , Dente Decíduo , Dentição Permanente , Maxila , Mandíbula , Aparelhos Ortodônticos , Braquetes Ortodônticos , Dente Canino/diagnóstico por imagem , Radiografia PanorâmicaRESUMO
The objective of this study is to determine if there is an association between HIV infection in children and alterations in the chronological development of permanent dentition detectable by radiographic examination. The sample comprised two groups of children: (1) 50 children infected with HIV by vertical transmission and (2) 50 healthy children. The groups were paired according to age, sex, race, and socioeconomic level. After obtaining a panoramic radiograph, the stages of tooth calcification and the frequency of subjects showing alveolar eruption of the first and second mandibular permanent molars were determined. There was no significant difference in stages of tooth calcification and frequency of subjects showing alveolar eruption of the permanent molars between the groups (P > 0.05). Children infected with HIV by the vertical route showed upon radiographic examination stages of tooth calcification and alveolar eruption compatible with normal patterns. There is no association between HIV infection and alterations in the chronological development of the permanent teeth, detectable radiographically, in children infected by vertical transmission.