If, after your case has been assessed, you are offered more than one possible treatment option, the most important thing is to weigh up the pros and cons of each. If you do not have enough information, it is a good idea to talk the situation through with your orthodontist.
For example, a patient with a moderate lack of space for her teeth, a correct bite and slightly protruding teeth has to choose between two options – stripping (interproximal reduction, IPR) or having four premolars taken out.
With the first option, the space needed to align the teeth is created by slightly widening the dental arch and carrying out the maximum permissible amount of stripping. The drawbacks of this approach are that it removes some enamel and that it does not allow the teeth to be moved back, because the space created is only enough to align them. The advantage is that all the teeth are kept and treatment time is shorter.
The second option involves taking out four premolars, which provides enough space not only to align the teeth but also to move them back. The drawbacks are that healthy teeth are removed and treatment takes longer.
The choice between the two plans depends on the patient's personal preferences and the end result they are hoping for.
This answer is for general information. Your own case needs an examination by an orthodontist.