Abstract: Objective To evaluate the clinical application effect of modified retaining appliance in the treatment of ectopic eruption of first permanent molar. Methods The subjects consisted of 25 children aged from 7 to 9 with ectopic eruption of the first maxillary permanent molar, 10 of which were bilateral and 15 of which are unilateral. By welding the distal extension hook via traditional Nance arch and bonding the lingual button on the first permanent molar, the first permanent molar was moved distally to the normal position using chain rubber band. Results All the children completed the treatment and acquired good curative effect that the first permanent molar with ectopic eruption was moved to the normal position. Conclusion The modified retaining appliance can be utilized as a simple and more effective way of correcting ectopic eruption of first permanent molar.

Key words: modified retaining appliance, first permanent molar, ectopic eruption