Is it permissible to file or sharpen the teeth (for aesthetic purposes)?

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The one who files the teeth to make them sharp and attractive (Al-Washira) and the one who permits it to be done upon her (Al-Mustawshira) are subject to prohibition. A further narration indicates a curse upon the tattooer (Al-Washima) and the one tattooed (Al-Mustawshima), where tattooing involves puncturing the skin and filling the wound with kohl.