What is the ruling on uncovering the ear or part of the head for a necessary medical examination in this case? What is the ruling on removing the hijab or uncovering the neck for massage in mixed-gender places? And what is the Sharia ruling on remaining silent in the face of mockery in such a situation?

It is permissible for female students to uncover their heads or what needs to be uncovered, such as the ears, in the laboratory. The presence of a glass portion in the door does not prevent this. As for male teachers, it is not permissible for female students to allow them to touch their bodies, or to remove their hijab in front of them, or to joke with them. These reprehensible acts should be denounced, unless harm is feared from denouncing them, in which case the obligation to denounce falls away. Among the conditions for denouncing are: that it does not lead to a greater harm, that the denouncer is safe in regards to themselves and their property, and that the desired outcome of the denunciation is likely to be achieved.