A GROSS AND MICROSCOPIC STUDY OF CEREBRAL INJURIES ACCOMPANYING MAXILLOFACIAL HIGH-VELOCITY PROJECTILE WOUNDING IN DOGS

Purpose: This study investigated the pathologic characteristics and so me related factors of cerebral damage associated with maxillofacial hi gh-velocity missile wounds. Materials and Methods: Sixty dogs, divided into two groups, were wounded randomly by steel spheres weighting 1.0 3 g at impact velocities of 1,400 m/s (46 dogs) and 800 m/s (14 dogs). Six dogs served as controls. The maxillofacial wounds and cerebral in juries were examined grossly. The distance between the center of wound and the base of skull and the largest diameter of the wound were meas ured, and the incidence of the brain injury in the two groups was comp ared. The cerebral specimens, dissected at 1 and 6 hours after trauma, were observed by light and electron microscopy. Results: Cerebral hyp eremia, contusion, spotty hemorrhage, and intracerebral hematoma were found in some of the dogs. In the 1,400 m/s velocity missile wound gro up, the incidence of the brain injury was 71.7% (33 of 46), and in the 800 m/s group it was 7.1% (1 of 14) on macroscopic examination. Micro scopic observation showed intracerebral microhemotomas and degeneratio n and necrosis of the nervous cells. Conclusion: High-velocity project ile maxillofacial wounds can induce associated brain injury.