Sadly, being self-centered is part of growing up and realizing you are an individual. Showing your teen that the world is bigger than themselves could potentially help, but i recommend a longer lasting remedy. The best thing that you can do is be a role model. Try to get them involved, as a family activity, in volunteering and helping others. Seeing the impact they can make in another's life will make them want to be "other centered" and it will empower them as an individual, in knowing they can make a difference.