Luckily now there are so many options available for adults who want to straighten their teeth, from traditional metal fixed braces, to clear aligners like Invisalign and fast braces like the Inman Aligner. You can even have fixed braces on the back of your teeth where no-one can see them. What's more treatment times can be halved by the use of a device called Acceledent which when worn for an hour a day uses gentle vibrations to help the teeth move more quickly. As more and more people have these treatments and are thrilled with the results, word is spreading. I expect the demand for straight teeth to increase for many years to come. I also expect more new ways to become available to help people achieve great results as quickly, and comfortably as possible.
Of course what is even better is to prevent this age related dental crowding in the first place. I am now starting to suggest to young patients with straight teeth that they have some retainers made to wear occasionally at night. That way if they feel the retainers are tight going in they will know their teeth are trying to move and can wear them a little more often and keep their teeth straight for life.
A hundred years ago women sometimes had all their teeth extracted and full dentures made as a wedding present. Now it's becoming common for women to have their teeth straightened and whitened in time for their wedding. I know which I'd prefer!