What you want and what you need may be two different things.

When you visit the dental office for the first time (or even when your situation changes at your existing dentist), It's important to communicate your wants to your dental team.  You may say "I want a check-up and cleaning" because that's what you know to say, but what do you really want? Whiter teeth? Healthy teeth and gums? Able to chew better and be more comfortable? Get past your fear of dental treatment?
The more information you can give your dental team, the better they can help you. Sometimes though, what you need doesn't match what you want. For example, you may want straighter teeth but what you really need is treatment of your gum disease and that's why your teeth have drifted. Or you want tooth whitening, but you really need cavities fixed first.
Your dental team will be able to diagnose your needs and with proper communication can help you get what you want.