5 letter words:
oobit7,
topoi7,
4 letter words:
bito6,
boot6,
obit6,
poot6,
topi6,
topo6,
3 letter words:
bop7,
bio5,
bit5,
boi5,
boo5,
bot5,
obi5,
obo5,
oop5,
opt5,
pit5,
poi5,
poo5,
pot5,
tip5,
top5,
oot3,
too3,
2 letter words:
bi4,
bo4,
ob4,
op4,
pi4,
po4,
io2,
it2,
oi2,
oo2,
ti2,
to2,