Abstract: Objective To establish an animal model for orthodontic extrusion of anterior residual roots in dogs. Methods： Three healthy adult hybrid dogs were selected for this study. Two maxillary lateral incisors from each dog were used, one for orthodontic traction, the other for control randomly. The models for residual roots were established, and orthodontic traction devices were installed. The stability of the devices was observed every day, and periodontal indicators were recorded at 0 and 30 days. Results The survival rate of the orthodontic devices was 100%. There was no significant difference between the experimental group and control group in periodontal status. The residual roots were pulled out by （1.22±0.12）mm at average, while the control group moved （0.15±0.06）mm at average. Conclusions The present animal model for orthodontic extrusion of anterior residual roots is stable, efficient, and easy to operate. Also, it hardly influences the periodontal status.

Key words: animal model, orthodontic traction, residual roots, extrusion