Abstract: Abstract Objective To analysis the clinical application effect of fixed space maintainer in the Affiliated Stomatological Hospital of Nanjing Medical University. Methods A retrospective analysis of the clinical data of 482 children with fixed space management due to premature loss of deciduous teeth in the Department of Pediatric Dentistry of our hospital in the past 3 years was conducted, and the short-term prognosis was studied. Results The 3 and 6-month retention rates of 482 cases of space maintainers were 77.73% and 54.99%, respectively. In 71 cases of fixed space maintainers with the first permanent molar as the abutment, there was no statistical difference in the 3-month retention rate at different developmental stages (P>0.05)..The 6-month retention rate was the highest when the root development reached 1/2 to 2/3 of the root length and there was a statistical difference (P=0.027). There was no significant difference in the retention rate of the upper and lower jaw with band loop maintainer at 3 months and 6 months (P>0.05). Conclusion The retention rate of the band loop space maintainer based on the early eruption of the first permanent molar as the abutment is higher. Clinically, the space maintainer has repeatedly fallen off and is damaged, and it needs to be improved.

Key words: space maintainer, premature loss of deciduous molar, root development of the first permanent molars, retrospective study