One of the basic objectives of Islam is to alleviate people’s physical and psychological suffering by guiding them to the best way through which they can lead a happy and honorable life. Easiness and flexibility are the basic characteristics of Islam in this regard; whenever man faces hardship in his life, the Islamic Law is usually relaxed. Allah Almighty refers to this in the Glorious Qur’an when He says, [He hath chosen you and hath not laid upon you in religion any hardship] (Al-Hajj 22:78).
Dr. Maher Hathout, chairman of the Islamic Center of Southern California, Los Angeles, states the following: As for the first issue, if the patient is diagnosed as brain-dead by specialists and this is confirmed by a flat wave on the EEG (Electroencephalogram), this means that this person is considered to be dead. If that person, during his or her lifetime and while in a state of awareness, decided to donate his or her organs after death to save or improve the life of others, this is—and Allah knows best—an act of charity.
Regarding whether there is a special ruling for the face or not, I do not think that the face is more important than the heart, the kidney, the liver, or the cornea of the eyes, whose transplantation was allowed by scholars. If the issue is a mere concern about the similarity in complexion and features, I would say that this similarity will not be completely identical; besides the medical technology now can make the transplanted face look as close as possible to the features of the patient before injury.
As to whether we should resort to this kind of surgery regardless of the severity of the injury, in my judgment this should be restricted to cases of necessity or extreme need because, as we know, the Shari`ah of Islam classifies matters into necessities, needs, and conveniences. So this technique should be used in cases of necessities or extreme needs.