EE WAS IN THE PROCESS OF REMOVING THE FRONT BELLY PAN ON 739 DOZER TO REPAIR A COOLANT LEAK. THE BELLY PAN JACK WAS HANGING UP AND NOT COMING DOWN. EE TRIED USING A PRYBAR TO ASSIST. THE BAR S LIPPED & HIS FORWARD MOMENTUM CAUSED HIM TO STRIKE HIS MOUTH ON THE BLADE STABILIZER BAR.