If you think that 224 out of 4329 (5.17%) is impressive so be it. While there may be some ambiguity about the numbers with 4 years (sine a bacc), there is no escaping the fact that ~92% were in the other 5 categories. Conviction is part of the equation, but there are other parameters (maturity, personality, etc,) that need to be entered into consideration. "Not young" is very relative, but if you are in your late 20' s you may have a bone of contention. In addition, you may have unique qualifications that will make your application stand out. In any case, your acceptance to dental school has little to do with generalizations made regarding acceptance sine completion of a bacc. degree and the challenge for those with only 2 or 3 years of college is reflected in the low admission stats.