A randomized control trial investigating the effectiveness of three different upper jaw expansion devices in correcting narrow upper jaws in 10-16 year old children.

All patients recruited to this research will be given one of three different information brochures, (Parents; 10-12 year olds, and 12-16 year olds) with each adjusted to the relavent reading age. Each brochure has information regarding the three different possible interventions; possible side effects; participation requirements and contact information of the researchers. Prior to the intervention, patients will have photos, 3d photographic scans, study casts of their teeth, and cone beam CT taken to record as baseline values. There are three seperate intervention arms: Arm 1: Hyrax expansion group (which will act as control) Arm 2: Hybrid Hyrax expansion group, Arm3: Keles expansion group. These will all be performed at the Sydney Dental Hospital by three different training Orthodontic registrars under the supervision of one professor and two senior lectures who have a minimum of 15 years experience in Orthodontics. Once recruited, each patient is randomized into one of three arms. The key difference in the interventions is described below Arm 1 Hyrax: to use a conventional expansion device which is attached only to the first upper premolars and upper first molars Arm 2 Hybrid Hyrax: to use a conventional expansion device which is attached to the first upper molars but also to two mini implants that are placed in the palate Arm 3 Keles Expansion: A novel expansion device which is similar to the conventional expansion device in action and attached to the upper first premolars and molars, with the only difference being that the device has a built in operating arm, whereas the conventional expansion device requires an external key. In all three groups, the participants will be instructed to turn the expansion device twice a day, resulting in 0.5mm of expansion a day. The use of the device will be demonstrated to the patient and their guardians, as well as an instructional video given for home viewing. Interventional adherence will be monitored by using a calendar and patients reviewed on a weekly basis. They will be continued to be monitored weekly at Sydney Dental hospital until it is determined that an adequate amount of expansion has been achieved and then instructed to stop turning. This will be determined by the orthodontic registar and defined as when there is no longer a posterior crossbite between the upper and lower dentition. The expansion device will then be locked so that no further turning can occur. Patients will then have 6 months of the devices in situ to stabilize the expansion. After 6 months the devices will be removed and new records taken. Fixed orthodontic appliances will then be placed to correct any further orthodontic issues.