This is a potential problem first pointed out to me by my friends at TNT Dental:
Your domain name is a business asset
It has value. It is as much a part of your business as the name, the logo, and the client list. You should always be in control of your domain name. Never let anyone else register it for you. If you ever decide to sell the business, the domain name is a part of the assets included with the business.
The problem arises when a dentist (or any small business owner) contracts with a web designer to create a business web page and the web company registers the domain in their name not in the name of the dentist. There are several well known web site companies in dentistry who do this routinely. The linked article explains it all well.
To find out who owns your domain you can look it up using an online data base called Whois. Just follow the link, type in your domain (that is your web site address such as drjones.com) and submit. Look for Registrant.