Question 1: Confirmatory test of blood stain:
- A. Kastle-Meyer test
- B. Benzidine test
- C. Spectroscopic test (Correct Answer)
- D. Orthotoluidine test
Explanation: ***Spectroscopic test***
- The **spectroscopic test** is considered a **confirmatory test** for bloodstains due to its ability to identify the characteristic **absorption spectrum of hemoglobin**.
- It specifically detects the presence of **hemoglobin derivatives**, unequivocally confirming the presence of blood.
*Kastle-Meyer test*
- This is a **presumptive test** for blood, relying on the **peroxidase activity** of hemoglobin.
- While sensitive, it can yield **false positives** due to other peroxidase-like substances (e.g., plant material, rust).
*Benzidine test*
- The **benzidine test** is also a **presumptive test** for blood based on peroxidase activity.
- It is **highly sensitive** but has been largely replaced by other tests due to the **carcinogenic nature** of benzidine.
*Orthotoluidine test*
- Similar to the Kastle-Meyer and benzidine tests, the **orthotoluidine test** is a **presumptive test** that detects the peroxidase activity of hemoglobin.
- It can also produce **false positive results** from various oxidizing agents or plant peroxidases.
Question 2: The most reliable criterion in Gustafson's criteria is:
- A. Attrition
- B. Root resorption
- C. Transparency of root (Correct Answer)
- D. Periodontosis
Explanation: ***Transparency of root***
- This criterion, specifically **dentinal translucency**, is considered the most reliable age indicator in **Gustafson's criteria** due to its continuous and predictable increase with age.
- The **translucency** results from the deposition of **secondary dentin** and obliteration of dentinal tubules, progressing from the apex towards the crown.
*Attrition*
- **Attrition** refers to the wear of tooth surfaces, which is highly variable and depends on diet, habits, and dental health, making it an unreliable age indicator.
- While it generally increases with age, its rate is subject to many confounding factors.
*Root resorption*
- **Root resorption** is the progressive loss of tooth structure from the root and can be caused by various factors like trauma, infection, or orthodontic treatment, not solely age.
- It is an unpredictable process and not a consistent age-related change.
*Periodontosis*
- **Periodontosis**, or **periodontal disease**, is inflammation and infection of the supporting structures around the teeth, influenced by oral hygiene and genetics.
- While its prevalence may increase with age, it's not a direct and reliable physiological age marker for individuals.