Dr. Pierpont in my houston interview said that they do not send rejection letters until the first day of dental school starts, because it is possible to get in the day before if someone drops out. Although, I would assume that hearing nothing by this time means you are not at the top of the list....
I also assume all three texas schools operate in this same fashion because they all communicate with each other as to who has been accepted and where and where people are going and so on and so forth.
hope this helps
GEAUX TIGERS