Salvador García-López

Alterations in the Synthesis of IL-1β, TNF-α, IL-6, and Their Downstream Targets RANKL and OPG by Mouse Calvarial Osteoblasts In vitro: Inhibition of Bone Resorption by Cyclic Mechanical Strain

Mechanical strain is an important determinant of bone mass and architecture, and the aim of this investigation was to further understand the role of the cell–cell signaling molecules, IL-1β, TNF-α, and IL-6 in the mechanobiology of bone. Mouse calvarial osteoblasts in monolayer culture were subjected to a cyclic out-of-plane deformation of 0.69% for 6 s, every 90 s for 2–48 h, and the levels of each cytokine plus their downstream targets RANKL and OPG measured in culture supernatants by ELISAs. Mouse osteoblasts constitutively synthesized IL-1β, TNF-α, and IL-6, the production of which was significantly up-regulated in all three by cyclic mechanical strain. RANKL and OPG were also constitutively synthesized; mechanical deformation however, resulted in a down-regulation of RANKL and an up-regulation OPG synthesis. We next tested whether the immunoreactive RANKL and OPG were biologically active in an isolated osteoclast resorption pit assay – this showed that culture supernatants from mechanically deformed cells significantly inhibited osteoclast-mediated resorptive activity across the 48 h time-course. These findings are counterintuitive, because IL-1β, TNF-α, and IL-6 have well-established reputations as bone resorptive agents. Nevertheless, they are pleiotropic molecules with multiple biological activities, underlining the complexity of the biological response of osteoblasts to mechanical deformation, and the need to understand cell–cell signaling in terms of cytokine networks. It is also important to recognize that osteoblasts cultured in vitro are deprived of the mechanical stimuli to which they are exposed in vivo – in other words, the cells are in a physiological default state that in the intact skeleton leads to decreased bone strains below the critical threshold required to maintain normal bone structure.

Evaluation of the Loading, Unloading, and Permanent Deformation of Newly Available Epoxy Resin Coated Ni-Ti Wires Using Self-Ligating Brackets

Aim The purpose of this study was to evaluate the load and unload deflection and permanent deformation of round 0.016′′ and rectangular 0.016′′ × 0.022′′ regular and coated Ni-Ti wires. Materials and Methods Ni-Ti archwires produced by two manufacturers were evaluated. Both regular and coated round and rectangular Ni-Ti wire segments (n = 15) from each group were submitted to a three-point bending test. Both types of wires were evaluated for permanent deformation at the end of a recovery cycle. Results The coated round 0.016′′ Ni-Ti wires produced a significantly lower force in loading (p < 0.01) and unloading (p < 0.01) than regular wires of the same manufacturer and size. There was no significant difference in permanent deformation between coated and regular round Ni-Ti wires from the same company. For rectangular 0.016 × 0.022′′ Ni-Ti wires, there was a significant difference in the loading evaluation, but the unloading test presented no significant differences. The permanent deformation of the rectangular wires revealed no significant difference between them. Conclusion The addition of an esthetic coating to these new Ni-Ti wires produced changes in their mechanical properties, manifested as a reduction in the applied force, which should be considered in clinical management.

Aparato preortopédico con pines utilizado en el alineamiento de los segmentos maxilares en pacientes con labio y paladar unilateral fisurado

Resumen Este articulo describe un aparato ortopedico con pines utilizado en el tratamiento prequirurgico para pacientes con labio y paladar unilateral completamente fisurado antes de la reparacion del labio. Este aparato fue disenado con el fin de corregir transversalmente los segmentos palatinos en la parte posterior, alinear el segmento menor en la parte anterior hacia la linea media facial y reducir la fisura cerca del labio para mejorar la forma del piso de la base nasal y evitar compensaciones quirurgicas posteriores de los tejidos blandos.

Analysis of condylar and dental displacement by means of an interocclusal record taken prior and after the use of an occlusal splint in TMJ symptomatic patients

Abstract Objective The purpose of this study was to evaluate the displacement of the condyle and dental arches with the record of an immediate deprogramming splint one month after the use of the splint in TMJ symptomatic patients. Material and methods The records of 15 symptomatic patients who were subjected to a questionnaire and clinical evaluation for their inclusion in the study were used. Casts were mounted from three records: 1) maximum intercuspation, 2) centric relation with Roth power centric bite, and 3) centric relation a month after the daily use of the splint. Condylar position of the right and left side in horizontal and vertical was measured and compared as well as the vertical and horizontal overbite in each of the three records. Results There were no significant differences in the results obtained from the records made in centric relation with an immediate splint and in centric relation after the use of the occlusal splint. However, it was found that there is a considerable discrepancy in the condylar and dental displacement in a position of maximum intercuspation and in centric relation after the use of the splint, as well as an improvement in the patients’ symptoms with the use of that device. Conclusions Cast mounting on the articulator is recommended for diagnostic purposes, in the measurement of condylar position and the use of splint in patients with TMJ pain to identify more reliably the goals to consider during and by means of orthodontic treatment. Otherwise they could be masked and determine a different course in treatment planning.