I have such a "thing" about my teeth - there's a big overbite because of my narrow upper jaw, and they've never been white
As some of you may remember, I looked into having braces a couple of years ago, but without having surgery on my jaw, there is little braces can achieve. My sister had the surgery, and although the results have been amazing she really went through it - both jaws broken surgically after a year of painful braces, having to sleep sitting up for a week, so she could breath, drinking liquid food for months.....it was awful! So not something I would contemplate!
My dentist thinks she can at least give me some improvement by whitening, and we will think about some veneers for the upper front teeth, which will give me a straighter arc, when I smile. She took moulds, so they could make silicone moulds, for the whitening gel, and I have to wear them every evening, for at least one hour, two maximum, for four weeks. I started last Sunday, and have an appointment on the 21st for a review, as they do a before and after of the colour. She said the secret of avoiding that awful "blue/white" you see with TV stars sometimes is to never go whiter than the whites of your eyes! I can already see some improvement
The worst thing so far has been having to drink tea through a straw, which has been mildly embarrassing when eating out 
It lasts a year, but as I now own the moulds I will just have to buy the gel in future........ It wasn't cheap but Mick paid as he knows how much it has bothered me
