Booklets are uniquely identified by a serial number and the patients phone number. Each booklet will be pre-randomized and assignment to either the gum group or the control group. The group assignment and serial number are indicated on the booklet cover. After instructions are given, the booklet cover is removed and kept in a closed container. The group assignment is only initially known to the investigator who administers the instructions. The remaining pages of the booklet will only be identified by the serial number of the participant with no mention of the group assignment. This way the group assignment is kept secret from both the operators who place the appliances, and the measurement investigator who will later measure the patients' responses. The booklet will contain space for participants to indicate if they have taken any non-study related medication (e.g. an analgesic). A copy of the booklet is included will this document.