While I was sculpting a model I noticed a vertex has gone way out of whack and gone inside the model and will not move back to where it should be by using brushes.
It is a vertex generated by the multi-resolution modifier, below is the vertex in question:
Base mesh without modifier:
It did not happen immediately and I am not exactly sure when, it was after 5 or so hours of sculpting I noticed it and it wouldn't have gone unnoticed for a too long. I believe it may have occurred when I was using the Crease brush if this helps.
If anybody knows how to fix this it would be much appreciated, I don't understand how this has happened to one side and not the other also, as it should be mirrored.
Many thanks!