Trainer is an excellent choice for initial adjustment before orthodontic treatment, for children with mixed dentition. The appliance sets the "crooked teeth" in the correct position. Stops the tongue, lips and cheeks pressure. Corrects the incorrect position of tongue and thus removes the cause of malocclusion. Trainer helps to replace incorrect mouth breathing into healthy nose breathing. The appliance is available in one size but in two designs. In the first phase one uses highly flexible silicone trainer, while in the second phase a trainer from a stiffer material (polyurethane), little bit harder but still flexible.