Abstract: PURPOSE: To explore the traumatic characteristics of primary and permanent teeth in children and the influencing factors of pulp necrosis after treatment. METHODS: A total of 110 children with dental trauma(169 teeth involved) who received treatment at Dental Clinic, Shaoxing Stomatological Hospital from June 2021 to June 2022 were selected. The age, gender distribution, composition of permanent and deciduous teeth injuries, location and number of affected teeth were statistically analyzed. The children were divided into pulp necrosis group and pulp survival group according to whether pulp necrosis occurred. The basic characteristics of the two groups were compared, and the risk factors of pulp necrosis after dental trauma were analyzed by univariate and multivariate factor models. SPSS 21.0 software package was used for data analysis. RESULTS: Among the 110 children with dental trauma, there were 57 male and 53 female patients. The age group with the highest incidence of dental trauma in male patients was 5 years old (21.05%) and 6 years old (19.30%), while the age group with the highest incidence in female patients was 5 years old (15.09%). The 4-year-old group, 6-year-old group, and 7-year-old group all had a rate of 13.21%. A total of 169 teeth were injured in the 110 children with dental trauma, of which 102 teeth were fractured (60.36%) and 67 teeth were avulsed (39.64%). Among the injured teeth, 73 were permanent teeth (66.36%) and 37 were deciduous teeth (33.64%). The most common location of injured teeth was the central incisors (92 teeth, 54.44%). Among the 110 children with dental trauma, 37 had pulp necrosis (59 teeth), while 73 had pulp survival(110 teeth). There was no significant difference in the average age, type of injured teeth, type of trauma, and location of injured teeth between the pulp necrosis group and the pulp survival group(P>0.05). The proportion of male patients, the proportion of type Ⅲ-Ⅳ fractures, the proportion of grade 3 avulsion, the proportion of patients with a visit time of ≥24 hours, and the proportion of patients with bone injury were all significantly higher in the pulp necrosis group than in the pulp vitality group (P<0.05). The results of the logistic regression model showed that male children, type Ⅲ-Ⅳ of crown fracture, grade 3 of protrusion type, and combined alveolar bone injury were independent risk factors for dental pulp necrosis in children with dental trauma after treatment(P<0.05). CONCLUSIONS: The most common age of primary and permanent teeth trauma in children is 5-6 years old, with permanent and incisor injuries being the main cause. Male children, those with type Ⅲ-Ⅳ coronal fractures, those with grade 3 protrusions, and those with combined alveolar bone injuries can increase the risk of dental pulp necrosis.

Key words: Children, Deciduous teeth, Permanent teeth, Trauma, Pulp necrosis, Influence factor