Design Characteristics of A31. Firm polyurethane construction - provides excellent retention.2. Hollow tongue tag; tongue guard and elevators – train the tongue to sit in final correct position.3. Extended lip bumper and high sides – discourage strong, overactive lips and facial musclesHow The A3 WorksA3 is a three-stage appliance system designed specifically to correct poor oral habits while treating upper and lower jaw development problems. The A3 provides final alignment and retention. Its firm polyurethane construction provides excellent tooth alignment and retention. The hollow tongue tag finalises tongue position and improves habit correction. The A3 is available in regular and large. MRC has pioneered the use of appliances to correct myofunctional habits in growing children and has proven success in orthodontic correction without braces. This treatment can also lead to better facial development in growing children. The key to this treatment is correcting the position and function of the tongue, obtaining correct nose breathing and retraining the oral muscles to function correctly. Although these corrections are more difficult in adult patients, the treatment principles are the same to obtain optimum results.Patient SelectionThe A3 is made of hard polyurethane and is intended to be used as the final appliance in the Myobrace for Adults™ system. It is suitable for mild malocclusion, and final stages of alignment and retention.Directions for useThe A3 must be worn for one to two hours each day and overnight while sleeping and always remember to follow these few simple steps: • Lips together at all times except when speaking or eating. • Breathe through the nose, to assist the development of the upper and lower jaws, and to achieve the correct bite. • No lip activity when swallowing, which allows the front teeth to develop correctly. • Improved dental alignment. • Improved facial development.Cleaning the Myobrace A3The A3 should be cleaned under warm running water every time the patient removes it from their mouth.