OBJECTIVES:Access to the pterygopalatine fossa is very difficult due to its complex anatomy. Therefore, an open approach is traditionally used, but morbidity is unavoidable. To overcome this problem, an endoscopic endonasal approach was developed as a minimally invasive procedure. The surgical aim of the present study was to evaluate the utility of the endoscopic endonasal approach for the management of both benign and malignant tumors of the pterygopalatine fossa.METHOD:We report our experience with the endoscopic endonasal approach for the management of both benign and malignant tumors and summarize recent recommendations. A total of 13 patients underwent surgery via the endoscopic endonasal approach for pterygopalatine fossa masses from 2014 to 2016. This case group consisted of 12 benign tumors (10 juvenile nasopharyngeal angiofibromas and two schwannomas) and one malignant tumor.RESULTS:No recurrent tumor developed during the follow-up period. One residual tumor (juvenile nasopharyngeal angiofibroma) that remained in the cavernous sinus was stable. There were no significant complications. Typical sequelae included hypesthesia of the maxillary nerve, trismus, and dry eye syndrome.CONCLUSION:The low frequency of complications together with the high efficacy of resection support the use of the endoscopic endonasal approach as a feasible, safe, and beneficial technique for the management of masses in the pterygopalatine fossa.

To improve the mechanical properties of steel materials such as Vanadis 4extra, Vanadis 10, Vancron 40, and Böhler S600, the isothermal heat treatment procedure using salt bath was used. Samples of the steels were processed at different time of austempering at various temperatures and compared to the samples processed by heat treatment (i.e. quenching in air or quenching in oil and tempering in air) which is most widely used in practice. Hardness properties are determined by the steel microstructure, the size and number of carbide particles in this microstructure. The suitability of heat treatment for improving mechanical properties of different steel materials is assessed. steel, hardering, tempering, salts, bainite, martensite

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