Early loss of deciduous teeth in the lateral portions of an early mixed dentition usually causes shortening of the supporting zone. Secondary cramming of the teeth develops and there is not enough space for the permanent canines and premolars. In case of early losses of deciduous teeth prosthesis rehabilitation is indicated. The authors examined a group of 212 children (--111 boys and 101 girls)--from the 1st-5th form of a primary school in Prague 2. The age varied between 6 and 10 years. In 19 children early losses of deciduous teeth in the lateral portions of the dentition were found. Early losses in the lower jaw predominated. Multiple losses of deciduous teeth were recorded more frequently in both the upper and lower jaw.