Success rates of zygomatic implants for the rehabilitation of severely atrophic maxilla: a systematic review

Zygomatic implants are a treatment solution for patients with severe maxillary atrophy. This treatment option allows delivering immediate fixed teeth within 24 h. Numerous peer-reviewed publications have reported different success rates, resulting in a disagreement on the topic. Therefore, the overall efficacy and predictability of this rehabilitation is still a matter of discussion. With this study, we aimed to identify the published literature on the use of zygomatic implants for the reconstruction of the severely atrophic maxilla and report the cumulative success rate (CSR) as a function of follow-up time. A systematic review of the literature on zygomatic implant for the treatment of severe maxillary atrophy was performed and 196 publications were included in the study. The cumulative success rate of zygomatic implants for the treatment of severe maxillary atrophy was 98.5% at less than 1 year, 97.5% between 1 and 3 years, 96.8% between 3 and 5 years and 96.1% after more than 5 years. The most commonly reported complications were soft tissue dehiscence, rhinosinusitis and prosthetic failures. The treatment of severe lack of bone in the upper maxilla with zygomatic implants is a safe procedure, reaching a cumulative success rate of 96.1% after more than 5 years

Estrogen Promotes Mandibular Condylar Fibrocartilage Chondrogenesis and Inhibits Degeneration via Estrogen Receptor Alpha in Female Mice

Temporomandibular joint degenerative disease (TMJ-DD) is a chronic form of TMJ disorder that specifically afflicts people over the age of 40 and targets women at a higher rate than men. Prevalence of TMJ-DD in this population suggests that estrogen loss plays a role in the disease pathogenesis. Thus, the goal of the present study was to determine the role of estrogen on chondrogenesis and homeostasis via estrogen receptor alpha (ERα) during growth and maturity of the joint. Young and mature WT and ERαKO female mice were subjected to ovariectomy procedures and then given placebo or estradiol treatment. The effect of estrogen via ERα on fibrocartilage morphology, matrix production, and protease activity was assessed. In the young mice, estrogen via ERα promoted mandibular condylar fibrocartilage chondrogenesis partly by inhibiting the canonical Wnt signaling pathway through upregulation of sclerostin (Sost). In the mature mice, protease activity was partly inhibited with estrogen treatment via the upregulation and activity of protease inhibitor 15 (Pi15) and alpha-2- macroglobulin (A2m). The results from this work provide a mechanistic understanding of estradiol on TMJ growth and homeostasis and can be utilized for development of therapeutic targets to promote regeneration and inhibit degeneration of the mandibular condylar fibrocartilage.National Institute of Dental & Craniofacial Research of the National Institutes of Health under Award Numbers R56DE020097 (SW) and F32DE026366 (JR

The effect of boundary conditions on Rayleigh-Taylor instability

Laser experiments are widely used to investigate excitation of Rayleigh-Taylor modes, which are of great importance for astrophysical applications. Measured growth rates are normally compared with either the sharp interface or the smooth gradient model. In the present paper an analytical solution is obtained that is valid for arbitrary density gradient scale L. It is a further development of the Mikaelian & Lindl model. New explicit presentation omega(k) is found which describes all discrete modes at all transverse wavenumbers k with one parametric expression. A critical value of kL is shown to exist when two independent solutions for the fastest growing main mode become degenerate, in this case the growth rate is calculated exactly. The focus is on astrophysical applications when boundary conditions are at infinity. The case of rigid walls is also considered to study the interrelation with the Chandrasekhar model. Results are supposed to be used for nonlinear RT treatment to analyze mixing in supernovae and other RT-driven objects

High-voltage space tether for enhanced particle scattering in Van Allen belts

New applications of space tethers (High-Voltage Tethered Satellite System project) are discussed in relation with ideal of an active experiment in the Earth's radiation belts. Two conducting strings are supposed to be tethered between the main satellite and two small subsatellites flying through the ERB. A large potential difference similar to 1MV is applied between the tethers by means of a generator carried on the main satellite. The tethers effectively scatter the high energy particles into loss cone of magnetic trap, providing a control of particle life time in ERB. The rigorous theory of the sheath layer formed by relatively cold plasma is developed, yielding the electric field profile,which is then used for the treatment of scattering problem. With the help of Fokker-Planck equation the average rate of particle losses, normalized per 1 km of the tether's length is found to be: (2.5 divided by 14) . 10(16) s(-1) km(-1) for electron belts and 1.8 . 10(14)divided by 2.5 . 10(20) s(-1) km(-1) for proton belts. New active experiments in space become possible under the joint realization of HVTSS and HAARP projects

Radial motion of highly conducting sphere in magnetic field

Radial motion of a highly conducting sphere in external magnetic field is considered. It both perturbs the external magnetic field and generates an electric field. Exact analytic solution has been obtained previously for a uniformly expanding sphere. In the present paper a new exact solution is derived which is valid not only for expansion but for contraction as well. It allows us to calculate analytically the total electromagnetic energy irradiated by the sphere involved in periodical radial motion with arbitrary velocity. (C) 2000 American Institute of Physics. [S0022- 2488(00)04805-2]

Modeling of the expansion of ultra-short-pulse laser-produced plasmas in magnetic fields

The study of hot plasma expansion in a uniform magnetic field is of interest for many astrophysical applications. In order to observe this process in laboratory, an experiment is proposed in which an ultrashort laser pulse produces a high-temperature plasma by irradiation of a jet of atomic clusters. The very high laser light absorption exhibited in such a gas of clusters facilitates the creation of a hot (> 5 keV), dense (10(19)-10(20) cm(-3)) plasma with a sharp boundary. The small scale of the plasma ( 1T). Pump-probe techniques can then be used to diagnose the density and magnetic field with high spatial and temporal resolution (<50fs). In the present work the expansion rate of the plasma and deceleration caused by the magnetic field are examined analytically. Electrodynamical aspects related to the radiation and transformation of energy are considered as well. The results obtained can be used in treating experimental data, studying magnetic R-T instabilities and other phenomena of astrophysical significance

Current trends and status of continuing professional development in implant dentistry in Europe

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