RESUMO
In this paper a dynamic model to investigate interphalangeal coordination in the human finger is proposed. Suitable models which describe the relationship between the tendon displacement and the joint angles have been chosen and incorporated into the skeletal dynamic model. A kinematic and kinetic model for interphalangeal coordination is suggested. Digital computer simulations are carried out to study interphalangeal (IP) flexion. Moreover, the effect of two different optimization methods is contrasted. The two optimization algorithms are employed to obtain a set of feasible values for the forces in the tendons or muscles of the finger.
Assuntos
Articulações dos Dedos/fisiologia , Destreza Motora/fisiologia , Fenômenos Biomecânicos , Simulação por Computador , Humanos , Ligamentos Articulares/fisiologia , Computação Matemática , Músculos/fisiologia , Tendões/fisiologiaAssuntos
Assistência Odontológica , Odontologia , Boca/diagnóstico por imagem , Humanos , RadiografiaRESUMO
The planar motion of the human knee joint is modeled, involving the relative motion of the geometry of the contacting surface between the tibia and the femur. The pure gliding motion and the pure rolling motion are formulated including the holonomic and nonholonomic constraints that must be satisfied. A control strategy with two classes of inputs: muscle forces that stabilize and bring about the motion and the ligament forces that maintain the constraints is presented. Finally, the effectiveness of this control structure is demonstrated via digital computer simulations in the pure gliding motion and the pure rolling motion of the knee.
Assuntos
Articulação do Joelho/fisiologia , Fenômenos Biomecânicos , Computadores , Humanos , Matemática , Modelos Biológicos , MovimentoRESUMO
The authors undertook histological studies on the bone of the facial wall of the maxillary sinus from 64 out of 84 patients who had been operated on for chronic maxillary sinusitis of dental origin in the course of 16 months. Apart from mucosal changes, the specimens from 16 patients showed also osseous changes in the form of periosteal reactions of varying extent. With regard to therapy, it is concluded that patients suffering from odontogenic sinusitis should for preference be treated by surgical intervention, because the conservative treatment will not necessarily result in complete healing.
Assuntos
Seio Maxilar/patologia , Sinusite/patologia , Doença Crônica , Humanos , Periósteo/patologia , Sinusite/etiologia , Extração Dentária/efeitos adversos , Dente não ErupcionadoRESUMO
With special regard to the viewpoint of the general stomatologist, the authors deal with the problems related to the intraosseous haemangioma of the jaw and try to give a clearly arranged survey of the criteria of this extensive complex of questions, using schematic tables. They point above all to the risks of inconsiderate management and indicate the diagnostic and therapeutic possibilities which are available only in a special clinic. Finally, the authors present two personal cases, describing in detail (with reference to the preceding representations) the course of the disease in a 17-year-old female patient.