Abstract: PURPOSE: By analyzing and summarizing the clinical features of 129 mesiodens from 95 teenagers treated in recent years, the treatment outcomes were compared to provide reference for clinical management. METHODS: The distribution of age and gender of patients, numbers, shapes and locations of mesiodens from 95 teenagers with 129 mesiodens were analyzed retrospectively. Different treatments for mesiodens were adopted at different time period: the deciduous dentition period (4-6 years), the early phase of mixed dentition period (6-9 years), the advanced phase of mixed dentition period (9-12 years) and the permanent dentition period (>12 years). The outcomes 12 months after treatment (whether the incisor needs to be corrected is used as the criterion) were evaluated. The possible pathogenesis, time and methods of treatment were explored in this paper. SPSS22.0 software package was used for data analysis. RESULTS: 57.89% mesiodens were found in the early stage of mixed dentition, the incidence in males was 2.44 times as in females. 66.32% mesiodens were single, 76.74% were cone, 55.04% were vertically impacted, 37.98% were inverted impacted. There was no significant difference between female and male. Fisher's exact test indicated no significant difference at different age group 12 months after treatment. CONCLUSIONS: Removal of mesiodens at the early stage has the least impact on permanent central incisors. For those with potentials to erupt in deciduous or at the early stage of mixed dentition period, the mesiodens may be removed after observation for 3 to 6 months.

Key words: Mesiodens, Maxillary incisor, Embeded supernumerary teeth