injured mature male

hi.
First time poster on the site so I hope someone can help. I have 2 adult males - one paired off and hopefully about to mate. During quite strong sparring, the non-paired one seems to have got a mouth injury- it looks like his mouth is permanently fixed open or "dislocated jaw". He seems to be otherwise in great health, assuming he's able to feed Anyone have any idea whether this is a common occurrence with male fights and if it can easily be remedied ? I'd welcome any advice.Thanks. PS I've got jpeg of it but don't know how to upload

Basically he has a dislocated jaw, I have seen fish spontaneously recover from it; I've also heard of people trying to gently manipulate it back into place. Personally I'm too ham-fisted to try anything like that. I'm also not sure of the legal position on doing so, I suspect (but don't quote me on this) that to do so, would be considered an operation on a vertebrate animal and as such should only be preformed by a suitably qualified person ie a vet.

Thanks for the advice. Will keep an eye on him and if he's feeding ok then I guess there's no need to intervene.