Jacko, recruitment ought to be a regular (ie open at least once a year) thing now that the system has caught up with itself. Waiting until you're at university will make you a better candidate and make it more likely to get through. Since the RAF is recruiting fewer Pilots than it has done previously, why give it anything less than your best shot? When I went through IOT just 3 years ago Pilots were already ~75% graduate entry, and that other ~25% was made up of re-entrants and direct entrants. By not going in with a degree you're giving yourself; nothing to fall back on should you for whatever reason fail training, worse pay and promotion prospects once in, a shot at a far smaller proportion of entrants.
Why make it harder for yourself? Go to university, join the UAS, get the experience, use the UAS to get a bursary, learn how to fly with them, get a degree and then join up. And oh, btw, your teeth will be fixed by then too.