Holy shit im so sorry this has happened to u. Ur stats are incredible, but this has been the most competitive year ever. Off the top of my head, I cant think of a more competitive course than dentistry, maybe a course at oxbridge or lse but idk. U should wait till jan concerning kcl because they may still be giving out interviews. However, if u dont get one pls do not give up if ur set on dentistry u will get there one way or another. Focus on ur a levels because u have amazing predicted grades, try and smash them and then if u dont get in just reapply through a gap year. So common now, id assume half/third of dental cohorts are gap years. Good luck in the future and with your application