Criminal Law misdemeanors and citizenship

[peri]

I have been a permanent resident since 1987 and my green card does not have an expiration. I have not applied for citizenship because I am afraid of the consequences of the 2 misdemeanors (for shoplifting) I have on my record, both of which were less than $50. One was in 1989 and the other was in 1991. Needless to say, I completely regret this every day of my life. The misdemeanors have been expunged and I don't have anything on my record since 1991. I would like to become a citizen but I am afraid that if I apply, I will get deported. I would really appreciate your help on what I should do, specifically what the concequences can be if I do appy for the citizenship. Thanks.