Sorry I cant give you much advice.

If it's purely for asthetic purposes then its haram because Allah created the human body and we are not to change it.

If you are finding that the gap puts your teeth at increased risk of infection through food etc getting stuck there, then you are remedying a medical problem and that wouldnt be haram.

This is based on my readings of the subject and I'm sure you will need a non-kuffar to confirm it. call your sheikh in the morning, you cant get it changed tonight anyway eh? so no reason to worry.

Regards