M.D. 8 years old. He had cross-bite of the upper left central incisor, which wedged between the lower central and lateral incisor. This bite was traumatic for the three teeth and the problem had to be fixed as soon as possible. The patient held early treatment with a trainer. For nine months the upper left central incisor was taken out from the cross-bite. Orthodontic practice, Dr. Gergana Doshkova.