The author examined a group of 20 children who attended his department because of retention of an upper incisor caused by an injury of a primary tooth. In the investigated group the most frequent type of injury of the deciduous tooth was intrusion. The mean age at the time of injury was 2.8 years, girls were affected more frequently. The most frequent type of malformation which led to retention of the tooth was dilaceration of the dental crown. The teeth most frequently affected were the permanent upper central incisors.

        Key words: injury of deciduous tooth – retention of permanent tooth