Keep trying the orthadontists in your area - sometimes different ones will have different opinions on your teeth. If need be, sound really upset about how your teeth make you look and mention any pains you have in your mouth - if you are suffering pain or are really upset about how you look they may be more lenient...
However, they do have guidelines to follow - such as a certain amount of overbite, a certain amount of overlaping on your teeth, need to be under 18, etc. - if you know you have a slight overbite you could emphasising it in your checkup by pulling your jaw back a little...