RESUMO
The aim of this study was to determine the effect of the increase in the occlusal vertical dimension by means of an orthodontic appliance on craniocervical relationships and position of the cervical spine. Thirty children presenting malocclusion were divided into two groups of 15 (a study and a control group). Those in the study group wore an orthodontic appliance to correct cross-bite. The children in the control group had no treatment during the experimental period. Two lateral craniocervical radiographs were taken for each child. The first one was taken in the intercuspal position in both groups. The second radiograph was taken of the study group after four months of wearing the appliance and also of the control group after four months. Cephalometric analysis in the study group showed a significant forward cervical spine position. There were no significant changes in the control group. The changes found in the study group suggest that when there are signs and symptoms of cervical dysfunction in children undergoing long-term orthodontic treatment, it is necessary to make an evaluation of the cervical column position after the insertion of any orthodontic appliance which increases the occlusal vertical dimension.
Assuntos
Vértebras Cervicais/fisiopatologia , Cabeça , Aparelhos Ortodônticos Removíveis/efeitos adversos , Postura , Curvaturas da Coluna Vertebral/etiologia , Dimensão Vertical , Estudos de Casos e Controles , Cefalometria , Vértebras Cervicais/diagnóstico por imagem , Criança , Feminino , Humanos , Modelos Lineares , Masculino , Má Oclusão/terapia , Pescoço/fisiopatologia , Placas Oclusais/efeitos adversos , Radiografia , Análise de Regressão , Estatísticas não ParamétricasRESUMO
The evidences of spontaneous oxidation of Mn(II) by the dissolved oxygen in azide buffer medium, which is dependent on the N (-)(3)HN (3) concentration, suggested a formation of stable Mn(III) complexes due to marked colour changes. Spectrophotometric studies combined with coulometric generation of Mn(III), in presence of large excess of Mn(II), showed a maximum absorbance peak at 432 nm. The molar absorptivity increases with azide concentration (0.44-3.9 mol 1(-1)) from 3100 to 6300 mol(-1) 1 cm(-1), showing a stepwise complex formation. Potential measurements of the Mn(III) Mn(II) system in several azide aqueous buffers solutions: 1.0 x 10(-2) mol 1(-1) HN(3), (0.50-2.0 mol 1(-1)) N(-)(3) and 5.0 x 10(-2) mol 1(-1) Mn(II) and constant ionic strength 2.0 mol 1(-1), kept with sodium perchlorate, leads to the conditional potential, E(0')x, in several azide concentrations at 25.0 +/- 0.1 degrees C. Considering the overall formation constants of Mn(II) N (-)(3), from former studies, and the potential, E(0')s = 1.063 V versus SCE, for Mn(III) Mn(II) system in non-complexing media, it was possible to calculate the Fronaeus function, F(0)(L), and the following overall formation constants: beta(1) = 1.2 x 10(5) M(-1), beta(2) = 6.0 x 10(8) M(-2), beta(3) = (2.4 +/- 0.7) x 10(11) M(-3), beta(4) = (1.5 +/- 0.5) x 10(11) M(-4) and beta(5) = (9.6 +/- 0.8) x 10(11) M(-5) for the Mn(III) N (-)(3) complexes. These data give important support to understand the importance of Mn(II) and Mn(III) synergistic effect on the analytical method of S(IV) determination based on the Co(II) autoxidation.
RESUMO
This study was conducted in order to determine the effects of body position on electromyographic (EMG) activity of sternocleidomastoid and masseter muscles, in 15 patients with myogenic cranio-cervical-mandibular dysfunction undergoing occlusal splint therapy. EMG activity was recorded by placing surface electrodes on the sternocleidomastoid and masseter muscles (contralateral to the habitual sleeping side of each patient). EMG activity at rest and during swallowing of saliva and maximal voluntary clenching was recorded in the following body positions: standing, supine and lateral decubitus. In the sternocleidomastoid muscle significant higher EMG activities at rest and during swallowing were recorded in the lateral decubitus position, whereas during maximal voluntary clenching EMG activity did not change. In the masseter muscle significant higher EMG activity during maximal voluntary clenching in a standing position was observed, whereas EMG activity at rest and during swallowing did not change. The opposite pattern of EMG activity supports the idea that there may exist a differential modulation of the motor neuron pools of the sternocleidomastoid and masseter muscles, of peripheral and/or central origin. This suggests that the presence of parafunctional habits and body position could be closely correlated with the clinical symptomatology in these muscles in patients with myogenic craniomandibular dysfunction.
Assuntos
Músculo Masseter/fisiopatologia , Músculos do Pescoço/fisiopatologia , Placas Oclusais , Postura/fisiologia , Adulto , Transtornos Craniomandibulares/fisiopatologia , Transtornos Craniomandibulares/terapia , Deglutição/fisiologia , Eletromiografia/métodos , Eletromiografia/estatística & dados numéricos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Contração Muscular/fisiologiaRESUMO
The complex formation between Mn(II) cations and N(3)(-) anions was studied in aqueous medium at 25 degrees C and ionic strength 2.0 M (NaClO(4)). Data of average ligand number, n (Bjerrum's function), were obtained from pH measurements on the Mn(II)/N(3)(-)/HN(3) system followed by integration to obtain Leden's function, F(0)(L). Graphical treatment of data and a matrix solution of simultaneous equations have given the following overall formation constants of mononuclear stepwise complexes: beta(1)=4.15+/-0.02 M(-1), beta(2)=6.61+/-0.04 M(-2), beta(3)=3.33+/-0.02 M(-3), beta(4)=0.63+/-0.01 M(-4). A linear plot of log K(n) vs. (n-1) shows no change in the configuration during complex formation. Slow spontaneous oxidation of solutions to Mn(III) occurs when the N(3)(-) concentration is greater than 1.0 M.
RESUMO
HLA-A and -B antigens incidence were investigated in 100 cases of Seronegative Spondyloarthropathies and in 303 control individuals of a Venezuelan Mestizo population. Significative increased incidence of B27 was found among 69% of patients with ankylosing spondylitis and 68% with Reiter syndrome being the incidence in the control group of 2.9%. The B27 negative patients showed 40.4% positivity for Bw35, with spondylitic lesion in 12 out of 17 cases. Our results question the applicability of B27 as diagnostic criteria in the Mestizo patients bearers of a Seronegative Spondyloarthropathy and suggest the need to investigate further the role of antigens of the B locus in the pathophysiology of these clinical entities.
Assuntos
Artrite Reativa/imunologia , Artrite/imunologia , Antígenos HLA/genética , Indígenas Sul-Americanos , Espondilite Anquilosante/imunologia , Frequência do Gene , Humanos , Venezuela/etnologiaAssuntos
Amputação Cirúrgica/métodos , Neoplasias Ósseas/cirurgia , Úmero , Osteossarcoma/cirurgia , Criança , Seguimentos , Humanos , Úmero/cirurgia , MasculinoRESUMO
Se presenta el caso de un paciente de 12 anos de edad tratado por un osteosarcoma osteogenico de humero izquierdo con amputacion de extremidad superior del tipo interescapulotoracica segun la tecnica de Litlewood y quimioterapia durante 2 anos, con una sobrevida de 5 anos y medio. Se analiza las ventajas y las indicaciones de esta tecnica quirurgica