A disposable marking device particularly suited for marking wires used in orthodontic treatment is disclosed, comprising a shaft made of metal, plastic, paper, wood, or any other material of suitable stiffness, preferably about the size of a toothpick, coated on at least one end with a pigmented binder, preferably a wax or polymer based material, capable of marking metal wires. A method for marking an orthodontic wire is also disclosed.