The author gives an account on experience with treatment of a narrow upper dental arch using elastic expansive devices firmly fixed by means of orthodontic rings to the dentition. Based on his findings, he reflects on suitable indications for the use of Quad helix and Bihelix with regard to long-term stability of the therapeutic results. He presents the findings and results of a study extending over several years.

        Key words: narrow upper dental arch – elastic expansive devices – therapeutic indications