Advice wanted concerning students who have had run ins with the law. I am a first year grad student with an expunged felony in the state of Arkansas. I am looking for advice on if and how I should communicate this with my adviser. The felony is due to a drug crime and took place ~decade ago. I ask this because through out my academic career I may need to go to conferences in other countries and this may affect my ability to get through customs and enter those countries hosting the conference. 

I am looking for other students who were in the same boat, professors who have dealt with similar situations, and in general opinions from advisers on how they would like to be approached in situations such as this. 

Thanks for the communities knowledge in advance.
You don't need to explain the details.  Here is the most I would do.  If the situation comes up (e.g., your advisor suggests you attend a conference that would require international travel you are not comfortable with), tell your advisor how this will affect your professional work: e.g., you would prefer to publish in domestic conferences, you are not comfortable travelling internationally, or whatever the implication is.  Your advisor doesn't need to know the details of why (e.g., that you had a felony).

Of course, you can always explain these details if you feel comfortable doing so.  That will depend upon the nature of your relationship with your advisor.  But you shouldn't feel like it is mandatory to explain this aspect of your personal history.  This is a professional relationship, and in professional relationships, you only need to provide enough information to allow you to meet your professional obligations and goals.

Basically, think of it this way.  Why does your advisor need to know?  What will the implications be, in terms of how it will affect his advice to you?  Then think about how to convey the implications without the unnecessary details, and whether there is even any need or value in conveying any information at all.  That might help guide you figure out what to explain.  You might find you never need to explain anything related to this to your advisor.