乳猪肢体牙痕损伤的形态学研究

Research of morphology for the toothmark in pocket limb

目的观察乳猪肢体牙痕形态变化,深入了解咬痕的发生发展规律。方法用万能试验机和自制上颌中切牙压头在乳猪肢体上形成牙痕损伤模型。利用数码细目拍照、计算机图像分析和激光光学三维测量观察24h内不同生存状态下牙痕淤斑及凹痕变化。结果生存组乳猪肢体牙痕形态变化快于死亡组;24h内牙痕淤斑变化不明显;牙痕深度和面积在形成初期迅速下降,而后变化缓慢。结论乳猪肢体牙凹痕变化迅速,提示在实际案件中应及早尽快地搜集咬痕证据。

Objective The purpose of this study was to observe the morphological changes of toothmarks in pocket limbs and to explore the durative development of bitemarks. Methods Firstly a toothmark model was established by using a universal testing machine and a self-made incisor nod which was pressed particularly on pocket limbs. The changes of toothmarks were observed on alive and dead animals with time elapsing. The scopes of bruise and inden were analyzed by soft on digital photos. The depth data of inden were collected by three dimensional laser measurement. Results The changes in the alive group were faster than that in dead group. There was no obvious fadeaway of bruise during 24 h. The scopes of inden were decreased remarkably in 1 h, while the decrease slowed down in the following hours. Conclusion The changes of indent are fast in pocket limb. It implies that bitemark evidence should be collected as fast as possible in cases.