Métodos imagenológicos para la visualización de la articulación temporomandibular: revisión de literatura / Imaginologycal methods for the observation of the temporomandibular joint: lieterature review

Los trastornos temporomandibulares son problemas médicos que afectan a la articulación que une la mandíbula con el cráneo. Estos trastornos pueden provocar dolor, dificultades para masticar y otros síntomas. Debido a que su etiología y patogenia son poco conocidos, las enfermedades de la articulación temporomandibular (ATM) son difíciles de diagnosticar y tratar. En este sentido, uno de los métodos complementarios que el odontólogo tiene a su disposición son los estudios imagenológicos; por medio de los cuales se puede observar a dicha articulación. Estos estudios imagenológicos son de tipo convencional, los cuales utilizan radiografías simples que permiten determinar la posición del cóndilo en la fosa glenoidea antes del tratamiento, y aquellos de tipo no convencional que con los nuevos hallazgos en biomedicina y la evolución de tecnologías de la imagen están empezando a darnos una visión de futuras innovaciones en el diagnóstico y la terapéutica de los trastornos de la Articulación Temporomandibular. Por lo anteriormente expuesto, el objetivo de este artículo es realizar una revisión de la literatura sobre los diferentes medios imagenológicos utilizados para observar dicha articulación

Temporomandibular disorders are medical problems affecting the joint connecting the jaw to the skull. These disorders can cause pain, difficulty to chew and other symptoms. The etiology and pathogenesis are poorly understood, the disease of the temporomandibular joint (TMJ) are difficult to diagnose and treat. In this sense, one of the complementary methods that the dentist has at his disposal are the imaging studies, by which one can observe the joint. These studies are conventional imaging, which use simple radiographs for determining the position of the condyle in the glenoid fossa before treatment, and those non-conventional type with the new findings in biomedicine and the development of imaging technologies are beginning to give us a vision of future innovations in the diagnosis and treatment of temporomandibular joint disorders. For the foregoing reasons, the aim of this paper is to review the literature on the different imaging media used to see the joint

The modification of Si nanocrystallites embedded in a dielectric matrix by high energy ion irradiation.

We have followed the effects of heavy ion irradiation on the structural, electrical, and photoluminescence properties of ensembles of silicon nanocrystallites embedded in a dielectric (SiO(2)) matrix. This was done as a function of the irradiation dose and the content of the Si phase. The results obtained can be accounted for self-consistently assuming that a relatively small dose of the irradiation enhances the crystallization while for higher doses the irradiation enhances the amorphization. The corresponding processes suggest that tuning of the above properties can be achieved by swift heavy ion irradiation.

Formation of light-emitting Si nanostructures in SiO(2) by pulsed anneals.

Intense excimer laser pulses, flash lamp annealing and rapid thermal annealing were used to form Si nanocrystals in thin SiO(2) layers implanted with high doses of Si ions. The pulse durations were 20 ns, 20 ms and 1 s, respectively. Laser annealing produced light sources luminescing in the wavelength range of 400-600 nm. They were attributed to the Si clusters formed as a result of the fast segregation of Si atoms from the SiO(2) network. There were no indications of nanocrystal formation in the as-implanted layers after 20 ns laser pulses; however, nanocrystals formed when, before the laser annealing, the amorphous Si nanoprecipitates were prepared in the oxide layers. Evaluations show that the crystallization may proceed via melting. A photoluminescence band near 800 nm, typical of Si nanocrystals, was found after 20 ms and 1 s anneals. Calculations revealed that the annealing times in both cases were too short to provide the diffusion-limited crystal growth if one uses the values of stationary Si diffusivity in SiO(2). This points toward the existence of a transient rapid growth process at the very beginning of the anneals.