Many patients have slightly crowded or overlapping anterior teeth. There is no doubt that the best way to treat the anterior crowding in the upper and in the lower arches requires the bonding of brackets to the teeth. However this is not satisfactory for the adult patients. If a patient is unable to accept comprehensive orthodontic procedures, the practitioner must determine whether the patient can be treated with minor tooth movement, restorations (bonding, laminate or crowning), reconturing/striping, extraction or a combination of these procedures. A thorough evaluation of the patient needs and expectations will establish the correct approach for the potential treatment options. Using a 0,018 inch NiTi wire as a flexible lingual retainer to solve the relapse of the lower anterior teeth was for the first time an application of ERIC and his Co-workers. The aim of this case presentation is to explain these different clinical application, especially the application procedures of a 0,014 NiTi at lingual/ palatine arches used to solve the crowding case. The 0.014 preformed NiTi wire must be cut longer then the intercanine length regarding the degree of crowding. The lingual/palatine surfaces of the teeth are cleaned, etched and bonded as a normal retainer. The wire is tightly tied to fit each tooth using a inter dental floss and after that the retainer was bonded. The result achieved is a good tooth alignment in a short period of time ( 6-8 months) and with very good aesthetic in such simple ways.