Abstract: Objective　①To investigate the animal model establishment of maxillofacial gunshot wound and blast injury; ②To study the early treatment strategies of maxillofacial gunshot wound and blast injury. Methods Eight dogs (6 Chinese garden dogs and 2 Beagle dogs, 6 months old, male) were randomly divided into two groups: gunshot wound (A) group and blast injury (B) group. Before the injuries were performed, the protective devices for chest and abdomen and craniocerebral were made. Besides, CT scanning and 3D reconstruction were also conducted. Group A: Debridement or/and fracture external fixation treatment was performed according to the occlusal relationship changes resulted from gunshot; Group B: Multiple penetrating wounds in the maxillofacial soft tissue and a large amount of foreign body residual resulted from blast injury, and debridement treatment was performed. These wounds caused by gunshot were 5.8mm and 7.62mm high-precision sniper rifles, and the injury distance was 50 meters. The source of blast injury was a standard 200-gram TNT drug block containing 241g thin nails, the injury distance was 3 meters and 1 meter, respectively. According to injury conditions, the tracheal intubation and debridement and fracture external fixation treatments were performed immediately after the injury, at the same time, antibiotics were given to prevent infection. CT scanning and 3D reconstruction were also performed again 12 hours after operation. Results These models could stably simulate canine maxillofacial gunshot wound and blast injury. When the shooting distance was 50 meters, with the increase of the high-precision sniper rifle caliber (5.8mm to 7.62mm), the maxillofacial trauma was also changed from the comminuted fracture of the lower mandible with normal occlusion to a comminuted fracture of the upper and lower jaw with occlusal dislocation and soft tissue laceration. When the source of blast injury was kept to a 200-gram TNT drug block containing 241g thin nails, the jaw wounds of the experimental animals became more serious while the injury distance was narrowed from 3 meters to 1 meter. After the injury, the two groups of experimental animals were treated well as we previously planned. One dog with one-meter injury distance was dead 20 hours after the blast injury, but the rest were in good condition, which had good spirit, could move freely and eat and drink a little. And the surviving experimental animals were continued to be kept alive for four weeks. Conclusion The experimental injury model can achieve normal or disorganized occlusal relationship gunshot injury model and varying degrees of injury models for blast injury. After the injury, appropriate rescue measures, such as tracheal intubation, debridement, fracture external fixation, intravenous rehydration and anti-infection, should be taken immediately to maintain the normal shape and chewing function of the canine and keep the canine alive. Among them, early treatment plays a vital role in maintaining animals’ functions and lives.

Key words: Canine, Maxillofacial, Gunshot wound, Blast injury, Early treatment