Abstract: PURPOSE: Cone-beam CT（CBCT）was used to analyze the related characteristics of supernumerary teeth and provide more reference for clinical diagnosis and treatment. METHODS: A total of 234 multiple teeth diagnosed by CBCT from the Department of Stomatology, Affiliated Hospital of Inner Mongolia Medical University from January 2019 to December 2020 were selected as the research subjects. The growth and development characteristics and secondary effects of supernumerary teeth were analyzed with SPSS 25.0 software package. RESULTS: The average age of patients was 11.16±7.61 years old, with the largest number of patients in the age group of 7-12 years old. The male to female ratio was 1.6∶1. Han nationality accounted for 85.0%. The supernumerary teeth were mainly unilateral. The quantity was mostly one. Maxillary supernumerary teeth mainly occurred in the incisor area, while mandibular supernumerary mainly occurred in the premolar area. Maxillary supernumerary teeth in the incisor area was more common in the age group of 7-12 years old, while those in the canine and premolar area were more common in the age group of 13-18 years old, those in the molar area were more common in the age group over 19 years old. Supernumerary teeth in the incisor area was more likely to occur in males, and mainly conical; the remaining of the growth areas were more likely to occur in females and mainly nodular. The differences were statistically significant(P<0.05). Development status in the age group over 19 years old was better than the other three groups; the molar area was better than other areas; the maxilla was better than the mandible; the differences were statistically significant (P<0.05). The supernumerary teeth located between the roots of the two permanent teeth were better than the other three groups, the difference was not statistically significant(P>0.05). The eruption situation was that partial root formation and fully formed supernumerary teeth were higher than crown formation, positive growth was higher than other directions, supernumerary teeth located between the roots of two permanent teeth were higher than the other groups. The differences were statistically significant(P<0.05). The secondary effects were that supernumerary teeth located in each growth area and located on the labial side, the apex of the permanent teeth and between the roots of the two permanent teeth mainly affect the adjacent permanent teeth, and most of the supernumerary teeth located on the palatal side of the permanent teeth have no secondary effects. The differences were statistically significant(P<0.05). CONCLUSIONS: CBCT can accurately analyze the clinical characteristics of supernumerary teeth, which is beneficial to formulate and improve the diagnosis and treatment plan and improve the treatment effect.

Key words: Supernumerary teeth, Cone-beam CT, Clinical characteristics, Secondary impact