It is much easier to correct the position of a tooth during eruption than at any later time.This is certainly an old truth, but modern orthodontics often seems to ignore it.The same principle holds for skeletal deviations where functional appliances allow the correction of symptoms like severe overjet and deep bite.To start an orthodontic treatment early enough so that eruption guidance is possible appears logical.However, we are facing the problem which kind of appliance to use in a period where the dental arches undergo rapid changes.One solution might be the prefabricated appliance that is presented in the following article. Schlagwörter: Eruption guidance, Occlus-o-Guide, pre-fabricated appliance