Well, not celebrities but TV shows and game shows where they appear.
Edit: I’m sorry to any Brits that feel offended. It’s not a criticism of British dental care. I think you are maybe taking a shower thought a bit too serious. Also I’m not American but Scandinavian design though my teeth must be empire.
It’s a relatively interesting difference between our two countries, in the 1940s the USA was being introduced to movie stars who had the “Hollywood smile” which led to a lot of people turning to cosmetic dentistry.
In the UK in 1948 dentistry became available for free on the NHS, with a focus on health rather than cosmetics. Sadly in 2006 they changed the deal for dentists so they had to perform hundreds of procedures before they could claim any money, rather than the pay-per-procedure they had been on before. In the last 20 years it’s become almost impossible to find an NHS dentist because they have all quit, and the UK has got too used to getting it for free so it’s not considered something you need to pay for.