Uso de esquilos da mongólia como modelo experimental para estudo do colesteatoma de orelha média : comparacão entre as técnicas de obliteração da tuba auditiva e do conduto auditivo externo

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Anisotropic Chemical Etching of III—V Crystals Dissolution Slowness Surface and Application to GaAs

The analytical equation for the dissolution slowness surface of III–V crystals that belong to point group 4¯3 m is derived using a tensorial analysis of the anisotropic chemical dissolution. The role played by orientation functions in the generation of the dissolution slowness extrema is discussed. Four different databases composed of dissolution constants are proposed. The final shape of cross-sectional dissolution profiles etched in differently oriented GaAs surfaces is analyzed and compared with published experimental results. Finally etching shapes of micromachined membranes and mesa are derived showing that the anisotropy for the GaAs crystal is probably of type 2 rather than of type 1

Endoscopic-assisted canal wall-up tympanomastoidectomy for reduction of residual cholesteatoma

Introduction The treatment of cholesteatoma is generally surgical, and the major obstacle is the high prevalence of recidivism. The endoscopic ear surgery technique is proposed to minimize this problem. Objectives To utilize endoscopes to visualize andmanipulate cholesteatoma residues after microscopic removal Methods Cross-sectional study. Thirty-two patients with cholesteatoma underwent microscopic wall-up mastoidectomy combined with the endoscopic approach. The subjects were assessed for the presence and location of covert disease. Results Of the 32 cases, 17 (53.12%) had residual cholesteatoma in the endoscopic phase.Minimal disease was found, usually fragments of the cholesteatomamatrix. Pars tensa cholesteatomas had more covert disease than pars flaccida cholesteatomas (62.50% vs 43.75%). Posterior recesses (47.05%) and tegmen tympani (41.17%) were the locations with more covert disease (p<0.05). Conclusion Cholesteatomas of the pars tensa presented more residual disease and were significantly more common in the posterior recesses and tegmen tympani