Pradeep L, Kokila Ganganna, Gopinathan Pillai Arun, Guruswamy Shwetha, Nazir Salroo Humaira, Chatterjee Ananjan
Department of Dentistry, Sapthagiri Institute of Medical Sciences and Research Centre, Bangalore, Karnataka, India.
Department of Oral Pathology and Microbiology, Sri Siddhartha Dental College, Sri Siddhartha Academy of Higher Education, Tumkur, Karnataka, India.
J Microsc Ultrastruct. 2021 Jan 22;9(2):55-60. doi: 10.4103/JMAU.JMAU_3_20. eCollection 2021 Apr-Jun.
In forensic science, the determination of age plays a vital role in the identification of bodies and persons associated with crimes. Teeth are frequently better conserved than any other human remains, so their use for identifying age at death is vital. The root portion of the teeth is covered by a thin calcified layer called cementum, the annulations of which is considered to be helpful in age estimation. The objective of the study was to ascertain and compare the accuracy and efficiency of age estimation between light, polarized, and phase-contrast microscopy in the ground and decalcified sections of the tooth stained with hematoxylin and eosin by light microscopy and picrosirius red (PSR) by polarized microscopy.
Fifty extracted teeth were collected and stored in a solution of 10% formalin. The middle one-third portion of the root was used, later sectioned into two halves using carborundum disc. One-half of it was used to prepare ground sections, which was studied with light, polarized, and phase-contrast microscopy. The other half was decalcified with 10% formic acid, processed, and two sections of 5 -μm thickness were prepared. One was stained with PSR stain and the second section was stained with hematoxylin and eosin (H and E) stain, One was stained with PSR stain and the second section was stained with hematoxylin and eosin (H and E) stain. Statistical analysis was performed using -test and Karl Pearson's correlation coefficient.
No statistically significant difference was observed between actual and calculated age in the ground sections, while there was a statistically significant difference observed between actual and calculated age in decalcified sections stained with H and E and PSR. A strong positive correlation was observed between actual and calculated age by Karl Pearson correlation coefficient test.
Cemental annulation and phase contrast microscopy can be reliably utilized in forensic science to establishing age, especially among young and middle age group individuals.
在法医学中，年龄的确定在尸体和与犯罪相关人员的身份识别中起着至关重要的作用。牙齿通常比其他人体遗骸保存得更好，因此利用牙齿来确定死亡年龄至关重要。牙齿的根部被一层称为牙骨质的薄钙化层覆盖，其年轮被认为有助于年龄估计。本研究的目的是确定并比较光学显微镜、偏光显微镜和相差显微镜在苏木精和伊红染色的牙齿磨片及脱钙切片以及偏光显微镜下的天狼星红（PSR）染色切片中年龄估计的准确性和效率。
收集50颗拔除的牙齿并保存在10%的福尔马林溶液中。使用牙根的中三分之一部分，随后用碳化硅盘将其切成两半。其中一半用于制备磨片，用光学显微镜、偏光显微镜和相差显微镜进行观察。另一半用l0%的甲酸脱钙、处理，并制备两片5μm厚的切片。一片用PSR染色，另一片用苏木精和伊红（H&E）染色。使用t检验和卡尔·皮尔逊相关系数进行统计分析。
在磨片中，实际年龄与计算年龄之间未观察到统计学上的显著差异，而在H&E染色和PSR染色脱钙切片中，实际年龄与计算年龄之间观察到统计学上的显著差异。通过卡尔·皮尔逊相关系数检验，实际年龄与计算年龄之间观察到强正相关。
牙骨质年轮和相差显微镜可在法医学中可靠地用于确定年龄，尤其是在青年和中年人群体中。
