Abstract: Objective To explore the clinical characteristics of immature permanent teeth trauma in school-age children, to better maintain oral health. Methods The database was based on 353 children aged 5-12 who had treatments in Department of pediatric dentistry, Affiliated Hospital of Stomatology, Nanjing Medical University during the whole year 2015. Data collection included patient’s age, gender, waiting time for a consultation after injury, position of trauma tooth and type of trauma. All the data were retrospectively analyzed. Results Male and female ratio was 2.33:1.The majority of the injury occurred in December and most frequently happened between age 7 and 9. Waiting time for the the consultation after injury was from 2 to 24 hours. Among all types of permanent teeth trauma, maxillary lateral incisor high frequently happened, and dentin fracture and subluxation most commonly occurred. Nolla 9 was the most common stage of hard tissue injury. Conclusion Immature permanent teeth trauma has its unique characteristics. The prevention and health care propaganda of dental trauma should be strengthened, and the public awareness of treatment should be improved.

Key words: immature permanent teeth, dental trauma