Adjusting horse's head carriage?

A martingale would be good if you know how to properly utilize it. Probably a running martingale. It keeps your horse's head down and in place. If your horse isn't used to gizmos such as martingales I suggest letting them sit in a stall with it for a day (Not the whole day, just half an hour or so... until they are calm), and then lunging and proceeding to ride so that your horse becomes accustom to the gadget... Hope this helps!!