The two main reasons for a dismissal is abandonment (claimant did not appear at the hearing) and withdrawal (claimant withdrew the hearing request).
A denial is a judgement made by the ALJ after a hearing takes place where he/she does not approve you receiving SS disability benefits.
[OOPS! I originally posted a url to a Social Security Administration web page. My apologies to the moderators. Please PM me if you are interested in the source of this info].
I hope you aren’t dwelling too much on a judge's approval ratings.
Rather, I suggest you concentrate your energies on making sure you and your lawyer have built up a strong case. Take care and wishing you the best!