To provide a chin dislocation device for easily executing operation by facilitating visual recognition at the time of operation.

In basic structure, at least two straightening bands are provided for each side of a dentition bow to be treated, these straightening bands are formed to be suited to a prescribed tooth element and fixed to corresponding main bodies 5 and 6, two parallel guide rods 7 are extended by penetrating these main bodies on both sides of developing screws 2, the developing screw drives the main bodies 5 and 6 to separate in order to extend-develop the straightening bands, and a driving part is additionally formed at the screw 2 so that a treating person can rotate it to extend-develop the straightening bands as above by this rotation. Then the driving part of the screw 2 is arranged at a head part in parallel with the rods 7 and faces a patient's mouth to engage a driving tool with.