颌面部高速投射物伤致牙髓间接损伤的实验研究

An experimental study on indirect injury of dental pulp caused by high speed missile projectile in maxillofacial region

目的:研究颌面部高速投射物伤导致的牙髓间接损伤的特点。方法:18只实验犬随机分为6组,以直径6.0mm、质量0.88g的高速投射物(不锈钢珠)致伤犬右下颌骨体部第四前磨牙根尖下方区域,但不直接伤及牙齿;分别于伤后6h、24h、3d、7d、2周和4周处死实验犬,观察右下颌第四前磨牙、第二前磨牙及左下颌第二前磨牙牙髓的组织病理学表现。结果:右下颌第四前磨牙牙髓损伤严重,发生不可逆性坏死改变;右下颌第二前磨牙牙髓损伤相对较轻,且为可逆性改变;左下颌第二前磨牙牙髓仅有轻微一过性损伤。结论:犬下颌骨高速投射物伤导致的牙髓间接损伤具有损伤范围较广,损伤程度随着距离的增加而迅速递减,牙髓出血多发生在成牙本质细胞层下的无细胞层等特点。

AIM： To investigate the characteristics of indirect injury of dental pulp caused by high speed missile projectile in maxillofacial region. METHODS： Eighteen dogs were divided into six groups with random allocation, then a high speed projectile （stainless steel bead,φ 6.0mm, 0.88g） was shot into the body of right mandible （the region below the fourth premolar） of each dog, but the teeth were not injured directly. The experimental dogs were killed 6h, 24h, 3d, 7d, 2wk and 4wk later; then the histopathologic changes of dental pulp of the fourth premolar of right mandible, the second premolar of right mandible and the second premolar of left mandible were observed. RESULTS ： In the wounded side, the dental pulp of the fourth premolar of right mandible was injured seriously, irreversibly; yet the dental pulp of the second premolar of right mandible was injured less seriously, reversibly ; in the opposite side, the dental pulp of the second premolar of left mandible was injured slightly and temporarily. CONCLUSION ： The characteristics of indirect injury of dental pulp caused by high speed missile projectile in maxillofacial region are as follows： the injured area is extensive ; the effect of the trauma decreases progressively and sharply as the distance to the wound increases; hemorrhage in dental pulp usually appears in the zone of Weil, etc.