Mar 2005 (UTC) 

 :::::::I think you're showing some bias again.  Not all gunshot wounds are intentional (including in warfare), and not all vehicular crashes are accidental (especially in warfare). 

 :::::::Most healing is the result of the human body's ability to patch things together without very large amounts of regeneration.  If you break a bone, for instance, the bone can knit, but if a bone, or part of one, is totally removed, it won't grow back.  Stitches, casts, and sometimes screws and metal plates, are all artificial means of holding parts together so they can heal.  While I'm not a doctor, I would guess that very large holes in muscle can be closed using dissolving sutures inside the wound.  And some clever methods of suturing at the surface can close up large holes. 

 :::::::As an example, I recently had a very large cyst surgically removed from my back, which left about a 2 or 3 cubic centimeter empty space.  The doctor used a suturing technique to create a "tensionless" closure, by very tightly binding the skin so that it stuck up in a ~5mm tall ridge, closing up the empty space.  It's "tensionless" in that there is a very large contact area between the skin edges, so it heals together still in a ridge shape; then tension on the skin from just moving around gradually causes it to flatten, and since all tension is on the tissues which have joined together below the surface, visible scarring is reduced.  At least in theory.  The scar left by the procedure looks pretty big to me.   21:46, 25