MOVING PRO TRUCK TO READY LINE AT CRUSHER. LIGHT BULB HAD FALLEN OUT FROM UNDER DASH. HAVING HEAD BENT OVER UNDER STEERING COLUMN TRYING TO FIND LIGHT BULB. MOVED HEAD BACK HELLMUT STRUCK STEERING COLUMN CAUSING HIS MOUTH TO HIT BOX ON HEATER VENT SYSTEM RESULTING IN CHIPPED TOOTH WHICH REQUIRED REPAIR