Forensic Dentists Play Key Role in Air Crash Victim ID in Ahmedabad

Forensic odontology, also known as forensic dentistry, is a branch of dentistry that helps identify people using their dental records.

It plays a key role in solving crimes, identifying victims in disasters, and supporting investigations where bodies are badly damaged or unrecognizable. Forensic dentists (odontologists) examine teeth, jaws, and bite marks to assist legal cases and identify victims in disasters.

Why Is Forensic Odontology Important?

Unlike other forensic techniques like fingerprinting or DNA analysis, forensic odontology focuses on the oral cavity and teeth. Teeth are strong and often survive even in extreme conditions, making them very useful for:

• Identifying Victims: If a body cannot be identified using fingerprints or DNA, dental records can help confirm identity.

• Mass Disaster Victim Identification: In events like plane crashes, earthquakes, or fires, forensic dentists compare dental remains with existing dental records to identify victims.

• Bite Mark Analysis: Bite marks found on a victim can be examined and compared to a suspect’s teeth to help solve criminal cases, such as assault or abuse.

• Estimating Age: Dentists can estimate a person’s age by studying tooth development and wear, which is useful in both criminal investigations and identifying unknown remains.

Common Techniques Used

• Dental Records Comparison: Dentists keep detailed records for each patient, including X-rays and treatment history. These can be matched with the dental remains of unknown bodies.

• Post-Mortem Dental Exams: After someone passes away, a dental examination is done to record things like missing teeth, fillings, or unique dental features, which can help with identification.

• Age Estimation: By looking at the bone structure, tooth growth and eruption patterns, dentists can estimate the gender and how old a person was at the time of death.

• DNA Sampling: By examining the dental remains and then analyzing them to extract DNA, which is compared with reference samples obtained from personal items (like toothbrushes or hairbrushes), or from close biological relatives.⁽¹⁾

How Dentists Are Helping After the Ahmedabad Air India Crash

Tragedy struck when an Air India flight from Ahmedabad to London crashed shortly after takeoff, causing a huge fire from over 1.25 lakh litres of jet fuel. Many passengers died, and their bodies were severely burned, making identification difficult.

Dr. Jayasankar P. Pillai and his team of MDS students at B.J. Medical College and Civil Hospital in Ahmedabad are working tirelessly to help. They are using teeth to extract DNA and identify the victims so families can claim their loved ones quickly.

Dr. Pillai is an experienced forensic dentist who has handled over 500 legal cases. He has also served as an expert witness in child abuse and age verification cases.

Dr. Pillai spoke to The Week about the role of dentists in identifying the victims and the situation.

A special DNA collection room has been set up at the hospital, where families are coming in to provide samples. The DNA results are expected within 72 hours. The Forensic Science Laboratory and the National Forensic Sciences University are leading the testing process.

Recovering DNA: A Vital Tool in Forensic Identification

Even after exposure to high heat, human teeth can still serve as a reliable source of DNA for forensic analysis. This is particularly true for mitochondrial DNA (mtDNA), which tends to survive better than nuclear DNA under extreme conditions. Here's a simplified and clearer breakdown of how DNA is extracted from charred teeth:

Preparing the Sample

• Cleaning: To start, the tooth is carefully cleaned to remove any surface debris, soot, or external contaminants that might interfere with the DNA extraction process.

• Pulverization: Once cleaned, the tooth is crushed into a fine powder, often using cryogenic methods like liquid nitrogen and a mortar and pestle, or with a mechanical bead-beating device. This step exposes the internal structures rich in DNA.

Extracting the DNA

• Lysis: The powdered sample is treated with a lysis buffer, which helps break open the cells and release their DNA content.

• Separation: A chemical solution, usually a mixture of phenol, chloroform, and isoamyl alcohol is then used to separate DNA from proteins, fats, and other cellular materials.

• Purification: The DNA is further purified to remove any residual impurities. Techniques such as spin columns or alcohol precipitation are commonly used for this purpose.

DNA Quantification and Genetic Analysis

• Measuring DNA Concentration: The purified DNA is quantified using devices like fluorometers or spectrophotometers to determine how much DNA was successfully recovered.

• Amplification: Specific DNA regions, particularly short tandem repeats (STRs) are then copied many times using Polymerase Chain Reaction (PCR) to generate enough material for analysis.

• Identification: Finally, the amplified DNA is examined using capillary electrophoresis and specialized software to develop a genetic profile that can be used for identification. ⁽²⁾

Final Thoughts

Forensic odontology is a vital tool in modern investigations, especially when other methods fail. Whether it’s identifying victims in disasters or helping solve crimes, the work of forensic dentists is critical. As technology advances, this field continues to grow more accurate and dependable, making it a key part of forensic science for years to come.

References:

1. Maryanne Ferree, “Beneath the Surface: The Indispensable Science of Forensic Odontology”, Maxill, Last modified on August 2,2024. https://www.maxill.com/ca/blog/post/beneath-the-surface-the-indispensable-science-of-forensic-odontology

2. Devaraju, Rama Raju; Gantala, Ramlal; Ambati, Madhavi; Vemula, Arjun; Kubbi, Jitender Reddy; Gotoor, Srikanth Goud. “DNA detection in tooth exposed to different temperatures: An in vitro study”. Journal of Indian Academy of Oral Medicine and Radiology 26(4):p 393-397, Oct–Dec 2014. DOI: 10.4103/0972-1363.155681

(Rehash/Dr. Hansini Bhaskaran/MSM)