Objective To discuss the correlation between the extraction timing of mesiodens and the orthodontic treatment duration of its eruption-related complications in children to provide a reference for the clinic. Methods The mesiodentes of 187 children were classified as eruption type (typeⅠ), dental crown impacted type (type Ⅱ), interdental impacted type (type Ⅲ), and dental root impacted type (type Ⅳ). According to the timing of extraction, mesiodentes in typeⅠ, type Ⅲ, and type Ⅳ were divided into Groups A: before the eruption of the adjacent central incisor and B: after the eruption of the adjacent central incisor. Mesiodentes in type Ⅱ were divided into Group A: before the eruption of the contralateral central incisor and B: after the eruption of the contralateral central incisor. Eruption-related complications and orthodontic treatment durations caused by mesiodens were statistically analyzed. Results There were 106 cases of displacement, 28 cases of failed eruption, 27 cases of tooth rotation, and 26 cases of individual cross-bite among the eruption-related complications caused by mesiodens. The mean orthodontic treatment cycle in Group A of type Ⅰ (7.07 ± 2.45 month), Group A of type Ⅱ (6.57 ± 1.12 month), and Group A of type Ⅲ (6.95 ± 2.52 month) were lower than that in Group B of type Ⅰ (9.67 ± 3.04 month), Group B of type Ⅱ (10.25 ± 1.29 month), and Group B of type Ⅲ (9.33 ± 3.26 month), and the differences were statistically significant (P0.05). Conclusion In most cases, the mesiodens are removed before the eruption of the adjacent central incisor, which can reduce the duration of orthodontic treatment for eruption-related complications in children.