פירוש על עבודה זרה 56:8

All agree that it is permitted to “restore the ear into its proper position” which means to fix a dislocated jaw. However, they disagree with regard to whether it is better to do so with medicine or with the hand. Those who prefer the hand would say that taking medicine is a rabbinic prohibition and therefore should be avoided. Those who prefer the medicine would say that resetting the jaw by hand might cause injury, and it is prohibited by the Torah to cause injury.