A centering tool for transverse centering between an upper vertebra and a lower vertebra is disclosed. The centering tool comprises a support portion having a proximal end and a distal end, two handles, and two pin placement guides, each guide having a hollow cylinder shape for the placement of a drill or pin on each of the upper and lower vertebrae. The two handles each have a proximal end and a distal end, wherein the proximal end of each handle is connected to the proximal end of the support portion, and the distal end of each handle ultimately contact the uncular joint of one of the vertebrae when centering is achieved. Preferably, each handle has a spring that biases the handle in a closed position so that the distal portions of both handles abut each other in a resting or closed position.