Estado actual de los diferentes sistemas de escaneado para CAD/CAM / Current status of different scanning systems for CAD/CAM

OBJETIVO: El objetivo del trabajo es presentar y debatir los principales sistemas de escaneado de restauraciones mediante la tecnología CAD/CAM, destacando los más relevantes, así como las nuevas apariciones en el mercado. Mencionándolos de mayor a menor antigüedad y de un modo comparativo. MATERIAL Y MÉTODO: La documentación fue recopilada de la información facilitada por las casas comerciales así como también de los artículos sobre el tema, publicados en los últimos años. CONCLUSIONES: 1. Los sistemas CAD/CAM han ido evolucionando de un procedimiento mecánico a uno óptico. 2. Todos los sistemas descritos anteriormente se encuentran dentro del rango de las 120μ. dato clínicamente aceptado en cuanto al ajuste marginal se refiere. 3. La utilización de los sistemas CAD/CAM en el momento actual resulta una alternativa más para su empleo en restauraciones protésicas, siempre que se elija el caso clínico adecuadamente y se utilicen los materiales apropiados (AU)

PURPOSE:The aim of this paper is to present and debate the main systems of restoring scans with CAD/CAM technology, remarking the most relevant as well as the new arrivals in the market. In a comparative mode, they will be mentioned in from oldest to newest. MATERIAL AND METHODS: The documentation was gathered from the information provided by the commercial brands as well as papers written and published on this subject. RESULTS: 1. CAD/CAM systems have been evolving from a mechanical procedure into an optic one. 2. All the previously described systems are located within the 120μ range. This data has been clinically accepted when referring to the marginal adjustment. 3. At the present time, the use of CAD/CAM systems is a great alternative for it´s use in prosthetics restaurations. However, it is necessary to choose the correct case and the appropiate materials for that (AU)

Desórdenes temporomandibulares y acúfenos / Temporomandibular joint disorders and tinnitus

Ensayos clínicos recientes han demostrado la mayor prevalencia de acúfenos en pacientes diagnosticados de desórdenes temporomandibulares. A día de hoy el mecanismo fisiopatológico del acúfeno aún no se ha confirmado y las distintas teorías planteadas para relacionar ambas entidades tampoco se han podido demostrar en su totalidad. El objetivo de este trabajo es realizar una revisión bibliográfica del tema, exponiendo aquellas hipótesis que se consideran más relevantes en la actualidad (AU)

Recent clinical trials have demonstrated the greater prevalence of tinnitus in patients diagnosed with temporomandibular disorders. To date the physiopathological mechanism of the tinnitus has not yet been confirmed and it has not been possible to demonstrate completely the different theories proposed to relate the two entities. The objective of this work is to perform a bibliographical review of the subject, setting out the hypotheses that are considered more relevant at present (AU)

Projections from the inferior colliculus to the tectal longitudinal column in the rat.

We have used the anterograde tracer Phaseolus vulgaris-leucoagglutinin (PHA-L) to study with albino rats the projections from the inferior colliculus (IC) to the tectal longitudinal column (TLC), a newly discovered nucleus that spans the midbrain tectum longitudinally, on each side of the midbrain, immediately above the periaqueductal gray matter. We studied the projections of the medial IC, which includes the classical central nucleus (CNIC) and the dorsal cortex (DCIC), and those of the lateral IC, equivalent to the classical external cortex (ECIC). Following unilateral injections of PHA-L into the medial IC, numerous terminal fibers are labeled bilaterally in the TLC. The ipsilateral projection is denser and targets the entire nucleus, whereas the contralateral projection targets significantly only the caudal half or two-thirds of the TLC. Fibers from the medial IC reach the TLC by two routes: as collaterals of axons that travel in the commissure of the IC and as collaterals of thick ipsilateral colliculogeniculate axons; the latter travel through the deep superior colliculus on their way to the TLC. Within the TLC, individual IC fibers tend to run longitudinally. The injection of PHA-L into the lateral IC indicates that this subdivision sends a weak, bilateral projection to the TLC whose trajectory, morphology and distribution are similar to those of the projection from the medial IC. These results demonstrate that all subdivisions of the IC send projections to the TLC, suggesting that the IC may be one of the main sources of auditory input to this tectal nucleus.

Implanted reuptake-deficient or wild-type dopaminergic neurons improve ON L-dopa dyskinesias without OFF-dyskinesias in a rat model of Parkinson's disease.

OFF-L-dopa dyskinesias have been a surprising side-effect of intrastriatal foetal ventral mesencephalic transplantation in patients with Parkinson's disease. It has been proposed that excessive and unregulated dopaminergic stimulation of host post-synaptic striatal neurons by the grafts could be responsible for these dyskinesias. To address this issue we transplanted foetal dopaminergic neurons from mice lacking the dopamine transporter (DATKO) or from wild-type mice, into a rat model of Parkinson's disease and L-dopa-induced dyskinesias. Both wild-type and DATKO grafts reinnervated the host striatum to a similar extent, but DATKO grafts produced a greater and more diffuse increase in extra-cellular striatal dopamine levels. Interestingly, grafts containing wild-type dopaminergic neurons improved parkinsonian signs to a similar extent as DATKO grafts, but provided a more complete reduction of L-dopa induced dyskinesias. Neither DATKO nor wild-type grafts induced OFF-L-dopa dyskinesias. Behavioural and receptor autoradiography analyses demonstrated that DATKO grafts induced a greater normalization of striatal dopaminergic receptor supersensitivity than wild-type grafts. Both graft types induced a similar downregulation and normalization of PEnk and fosb/Deltafosb in striatal neurons. In summary, DATKO grafts causing high and diffuse extra-cellular dompamine levels do not per se alter graft-induced recovery or produce OFF-L-dopa dyskinesias. Wild-type dopaminergic neurons appear to be the most effective neuronal type to restore function and reduce L-dopa-induced dyskinesias.

Influence of cell preparation and target location on the behavioral recovery after striatal transplantation of fetal dopaminergic neurons in a primate model of Parkinson's disease.

Surgeries involving transplantation of fetal dopamine (DA) neurons into the caudate-putamen of patients with Parkinson's disease (PD) have been performed in various clinical trials to examine a potential restoration of motor function. The absence of studies in non-human primates to define the best transplantation protocols have lead to the use of a broad variety of techniques that potentially could have a major impact on the clinical outcome. The effects of using different cell and tissue preparation, and surgical targets, remain unknown. For this purpose, 20 St. Kitts African Green Monkeys (AFG) rendered parkinsonian by i.m. injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) were balanced into 4 groups and unilaterally grafted in the (a) caudate or (b) putamen with fetal ventral mesencephalic (VM) tissue as (c) solid pieces or as a (d) cell suspension. By 9 months post-transplantation all animals showed significant and similar behavioral improvement as determined by a UPDRS based PD scale. Postmortem analyses showed that VM transplants survived in all animals. They were located in both surgical target sites, producing a broad DA reinnervation of the targeted nuclei that could also extend to the non-grafted nucleus on the ipsilateral side. Although no differences between groups were found in survival of DA neurons or degree of DA reinnervation, there was a significant correlation between striatal reinnervation and behavioral recovery only in animals transplanted in the putamen surgical target. Additionally, there was in general a stronger glial reaction to solid grafts than to cell suspensions. These studies provide data for the optimal time course, cell preparation and surgical targets for systematic examinations of both potential benefits and side effects of dopamine neuron cell transplantation in primate models of PD.

Coronas implantosoportadas: ¿individualizar o ferulizar? / Implant-supported crowns: Individualized or splinting?

Existen diferentes formas de rehabilitación de coronas sobre implantes adyacentes en un tramo edéntulo. Las opciones que pueden encontrarse son la de restaurar con varias coronas unitarias, o bien unir esas coronas en una sola prótesis. Material y Método: Se llevó a cabo una búsqueda bibliográfica a través de bases de datos en revistas especializadas de Odontología. Resultados: En la bibliografía revisada se observa que existen defensores y detractores de cada una de las técnicas, basándose cada autor en distintos estudios y argumentos. Discusión: Se encontraron ventajas e inconvenientes en ambas opciones prostodóncicas, valorando en base a éstos cuándo utilizar cada una de las técnicas propuestas. Conclusiones: Cuando las condiciones son idóneas, se considera adecuada la restauración con coronas individuales; por otro lado cuando existan condiciones adversas (implantes cortos, hueso de mala calidad, carga inmediata o factores oclusales no adecuados), en las que el reparto de fuerzas pueda comprometer el pronóstico de la restauración, la ferulización será el tratamiento de elección (AU)

There are different methods of crown rehabilitation refering to implants adjacent in edentulous sites. The options can be: rehabilitation with several single crowns or the splinting of the crowns in the prostheses. Material and method: A bibliographical research through the data base of the U.C.M. library and a review of clinical files of patients treated under the title implant-prostheses has been carried out. Results: There are supporters and non-supporters of each technique, based on different arguments and studies. Discussion: Advantages and inconvenients have been found in each method, taking these into consideration when it comes to using the appropriate restoration. Conclusions: When conditions are suitable, the implants can be restored by using single crowns. On the other hand, when there are no ideal factors (short implants, low bone quality, early loading, adverse oclussal factors) the use of splinting crowns will be more appropriate (AU)

GABAA receptor subunit immunoreactivity in primate visual cortex: distribution in macaques and humans and regulation by visual input in adulthood.

Subunit proteins that make up functional GABAA receptors were localized immunocytochemistry in the primary visual cortex (area 17) of adult monkeys and humans. Immunoreactivity for the alpha 1, beta 2/3, and gamma 2 subunits is greatest in layers (II-III, IVA and IVC) of monkey area 17 that contain the highest density of GABA neurons and terminals. Immunostaining for each subunit is unevenly distributed in layers II and III, where patches of immunoreactivity correspond to regions of intense cytochrome oxidase (CO) staining, and in layer IVA, where intense immunoreactivity forms a honeycomb pattern identical to the CO staining pattern. Immunoreactivity for the subunits is localized principally within the neuropil, which, by simultaneous comparison with the distribution of microtubule-associated protein immunostaining, was found to include bundles of thin dendrites and zones of numerous dendritic segments. In addition, gamma 2 immunostaining surrounds the somata of a subpopulation of GABAergic neurons, immunoreactive for the calcium-binding protein parvalbumin. All three subunits are present in the somata and processes of neurons that occupy the white matter subjacent to monkey area 17. In human visual cortex, the alpha 1, beta 2/3, and gamma 2 subunits are distributed in a manner similar to that found in monkeys, with relatively intense immunostaining in layers IVC and IVA. In layer IVC, vertical stripes of intense receptor immunostaining (20-30 microns wide) alternate with wider stripes of pale immunostaining (30-60 microns wide). In the upper and lower halves of IVC beta, these stripes form lattices similar to those in layers IVC and IVA of monkeys. Following monocular deprivation by intravitreal injections of TTX in adult monkeys, immunoreactivity for each subunit in layer IVC consists of alternating intensely and lightly stained stripes. Comparison with the pattern of CO staining indicates that intense immunostaining for alpha 1, beta 2/3, and gamma 2 occurs in normal-eye stripes while abnormally light immunostaining is present in deprived-eye stripes. For all three subunits, immunoreactivity in deprived-eye stripes is reduced within 5 d of monocular deprivation and remains abnormally low for deprivations that extend to at least 30 d. These findings indicate that each of several GABAA receptor subunits adopt similar laminar and compartmental distributions in monkey and human area 17 and are likely to be expressed by the same neurons. The deprivation-dependent reduction in immunoreactivity for alpha 1, beta 2/3, and gamma 2 subunits suggests that all are regulated by visually driven activity.(ABSTRACT TRUNCATED AT 400 WORDS)

Distorted distribution of nicotinamide-adenine dinucleotide phosphate-diaphorase neurons in temporal lobe of schizophrenics implies anomalous cortical development.

The distribution of neurons expressing the enzyme nicotinamide-adenine dinucleotide phosphate-diaphorase (NADPH-d) in the lateral and medial temporal lobes of schizophrenic and matched control brains was investigated in a systematic blind analysis. Schizophrenics had significantly lower numbers of NADPH-d neurons in the hippocampal formation and in the neocortex of the lateral temporal lobe but significantly greater numbers of NADPH-d neurons in the white matter of the lateral temporal lobe and a tendency toward greater numbers in parts of the parahippocampal white matter. The distorted distribution of NADPH-d neurons in the lateral temporal lobe, which may be explained by developmental disturbances, such as impaired neuronal migration or an alteration in the death cycle of transitory subcortical neurons, is similar to that found in the prefrontal cortex of schizophrenics. Alterations of cortical ontogenesis, as reflected in the distribution of NADPH-d neurons, appear to be widespread among neocortical association fields in schizophrenics and may provide a clue to the cause of the disease.

Calbindin and parvalbumin cells in monkey VPL thalamic nucleus: distribution, laminar cortical projections, and relations to spinothalamic terminations.

The ventral posterior lateral nucleus (VPL) of the monkey thalamus was investigated by histochemical staining for cytochrome oxidase (CO) activity and by immunocytochemical staining for the calcium-binding proteins parvalbumin and 28 kDa calbindin. Anterograde and retrograde tracing experiments were used to correlate patterns of differential distribution of CO activity and of parvalbumin and calbindin cells with the terminations of spinothalamic tract fibers and with the types of cells projecting differentially to superficial and deeper layers of primary somatosensory cortex (SI). VPL is composed of CO-rich and CO-weak compartments. Cells are generally smaller in the CO-weak compartment. Parvalbumin-immunoreactive cells and parvalbumin-immunoreactive medial lemniscal fiber terminations are confined to the CO-rich compartment. Calbindin-immunoreactive cells are found in both the CO-rich and CO-weak compartments. The CO-weak compartment, containing only calbindin cells, forms isolated zones throughout VPL and expands as a cap covering the posterior surface of the ventral posterior medial nucleus (VPM). Spinothalamic tract terminations tend to be concentrated in the CO-weak compartment, especially in the posterior cap. Other CO-weak, parvalbumin-negative, calbindin-positive nuclei, including the posterior, ventral posterior inferior, and anterior pulvinar and the small-celled matrix of VPM are also associated with concentrations of spinothalamic and caudal trigeminothalamic terminations. Parvalbumin cells are consistently larger than calbindin cells and are retrogradely labeled only after injections of tracers in middle and deep layers of SI. The smaller calbindin cells are the only cells retrogradely labeled after placement of retrograde tracers that primarily involve layer I of SI. The compartmental organization of VPL is similar to but less rigid than that previously reported in VPM. VPL and VPM relay cells projecting to different layers of SI cortex can be distinguished by differential immunoreactivity for the two calcium-binding proteins. The small-celled, CO-weak, calbindin-positive zones of VPL and VPM appear to form part of a wider system of smaller thalamic neurons unconstrained by traditional nuclear boundaries that are preferentially the targets of spinothalamic and caudal trigeminal inputs, and that may have preferential access to layer I of SI.

Hemangioendothelioma of bone. A case report with massive tissular necrosis.

Hemangioendothelioma or histiocytoid hemangioma of bone is a low grade tumor, which may be a quite indolent and controlable lesion, even in the rare case it develops distant metastasis. Our case presents features of such lesion by light microscopy and with a peroxidase-antiperoxidase technique for Factor VIII related antigen, but it exhibits an unusual extensive tissular necrosis. Necrosis does not seems to make worse the usual course, after six years and ten months of conservative surgical treatment and radiation therapy.

Oxyuris granulomas of pelvic peritoneum and appendicular wall.

Infestation with Enterobius (Oxyuris) vermicularis is very common but seldom produces lesions and even more rarely causes granulomas. Two cases of oxyuris granulomas/nodules), one in the serosa of ovaries and left fallopian tube in a female of 32-years and the other in the submucosa of the appendix in a 10-year old girl are identified by the presence of true necrotizing granulomas containing the parasite. The pathogenesis and differential diagnosis of abdominal granulomas is discussed.

[Juvenile xanthogranuloma]. / Xantogranuloma juvenil.

The clinical and histopathological picture of a case of Juvenile Xanthogranuloma present in a new-born, in which all the investigations and analytic results were normal, is commented upon. The patient presents a case of exclusive skin affectation.