Tom was not Voldemort..
Professor Quirrel was not Voldemort either..
Voldemort used Professor Quirrel, He had shared with professor Quirrel's body
(voldemort's face was at Professor Quirrels head), That's why Professor quirrel used a turban after he came back from somewhere i guess, he just made the Story that someone gave it to him.
it's not stated in the book if professor quirrel had been using the turban, but i think he already had the turban when Harry and him accidentally met at the Leaky Cauldron. Professor Quirrel was stuttering and his face was twitching, normally he can speak without stuttering and twitching. Remember at the last part of the book when Harry met the man with two faces, Quirrel wasn't Stuttering at all nor his face twitching.
Quote:
Professor Quirrel, in his absurd turban, was talking to a teacher with greasy lack hair, a hooked nose, and sallow skin. pg.126 SS
That's stated in the book, when Harry saw Quirrel at Hogwarts, just after the sorting and all the students and even the staffs were enjoying the food.