Let $ACE = x$ and $EBF = y$.
So, $y^2-x^2 = (x+y)(y-x) = TBBB(y-x) = 1000(MCM-DD)$.
It's very tempting to let $B = 0$ already, but let's see why the other numbers don't work. It's clear that if $B = 1,3,7,9$ then $1000$ won't share any factors with $TBBB$, so $TBBB$ would have to divide $MCM-DD$ but the latter is a smaller positive number. If $B = 5$, then $y-x$ is even whereas $TBBB$ is odd. Yet $y-x$ and $x+y$ must share the same parity. If $B = 2,4,6,8$, we know that $y-x$ contains all of the factors of 5, as well as share the same parity as $x+y$ (that is, even). So $y-x$ is divisible by 10. However, this means that $ACE \equiv EBF \bmod 10$, that is, $E \equiv F \bmod 10$, contradicting our distinct digits condition earlier.
Great, so $B = 0$. Therefore, $C = 9$ as $ACE+E0F = T000$. Oh right, $ACE+EBF \leq 1998$, so $T = 1$. We have $E0F^2 = MCMA09$. This means that $F = 3$, and therefore $E = 7$ and therefore $A = 2$. So $ACE = 297$ and $EBF = 703$. We can now square these numbers to get the other digits: $297^2 = (300-3)^2 = 90000-1800+9 = 88209$, and $703^2 = (700+3)^2 = 490000+4200+9 = 494209$, so $M = 4$ and $D = 8$.
Therefore, the digits we want are: $\boxed{A,B,C,D,E,F,M,T = 2,0,9,8,7,3,4,1}$