Domain names are important for any business because it is how people find you online and remember your website. Some end in .com, .net or .org. But now recently, an extension of .xxx has been created for the adult entertainment industry.
How does this affect your practice? Well, they can use ANY domain name they like, including yours! Imagine waking up one morning to find your domain name with .xxx at the end that leads to a pornographic website. But you can take action.
Read more about it here: http://www.page1solutions.com/page-1-blog/xxx-domains-and-how-they-affect-your-dental-medical-and-legal-practice.html