Twin Block Appliances

Functional Appliances: Twin Block Appliances

Dr. William Clark, an Orthodontist, developed an uncomplicated technique that incorporates the use of upper and lower bite blocks to reposition the mandible forward for skeletal Class II correction. The Twin Block technique is easy to use and very patient friendly. The design utilizes two separate appliances that fit the maxilla and mandible. The unique design allows for more patient comfort and increased patient cooperation. The Twin Block design also allows for independent development of the upper and lower arches with the addition of transverse and/or sagittal screws.

Standard Twin Block	Twin Block to Close	Sagittal Twin Block
	McNamara Twin Block Dr. James McNamara designed Twin Block includes two upper expansion screws for maxillary arch development. To enhance retention of the lower portion of the appliance a labial bow with acrylic is added to the design. In addition, the lower flanges of acrylic are extended to the molars.

Functional Appliances: Twin Block Stage II

Once “three-point” contact has been achieved a fixed or removable incline bite plane is used to support Class II correction. The Stage II appliance is used until the bicuspids have erupted into occlusion and the posterior open bite has been closed.

“Stage II”

Rick-A-Nator

Rick-A-Nator II

How To Send A Case
All Functional Appliance designs require accurate working models. A construction bite should be provided to indicate the amount of mandibular advancement. Acrylic designs require a posterior opening of 2mm to 3mm to allow for proper appliance fabrication.