Question
We have recently lost 3 kittens, at different times,seemly dissapear over night/ They are 3-4 minths old. At about the same time we have 2 orphan coons (young) and a young possum that started coming to our yard. Would either of those have gotten the kittens? We find no hair or remains.  

Answer
I have a number of questions concerning your comments. First, were kittens left outdoors over night? Second, how do you know the raccoons were orphaned? Juveniles, especially males will be searching for their own territories this time of year. I would suspect the same for the opossum.
Third, what was attracting these animals to your yard? Was food or water being left out?
Fourth, do coyotes live nearby? Coyote populations are expanding in urban areas.

You cannot rule out aerial predators such as hawks and owls.
It is possible that a juvenile raccoon took the cats provided the size difference was great enough. Opossum is less likely but still in the realm of possibility.

Without physical evidence though, it is impossible to determine what species took the kittens if in fact it was a wild animal in the first place. Sorry.
The best thing you can do for the cats and the environment is to keep the cats up to date with their shots and keep them indoors. This will not only protect the cats from harm, but also protect the environment. Keeping the cats indoors also reduces risks of the cats bringing infections to the humans. Free-ranging cats are a major environmental menace. For more information visit http://icwdm.org to learn why.