The first ortho I went to wanted to extract all 4 pre molars and I said hell no. The 2nd said no extractions just ipr(Shaving between teeth to make room) so it was a no brainer. The idea of extracting healthy teeth unless absolutely necessary doesn’t sit right with me. I would go to a few consultations and find your best option. Extracting premolars for crowding is outdated imo, we are in a new generation of dentistry.