CHENNAI: It takes three weeks for a dead body to fully decompose; one would think that would be the end of a person’s identity. But that is absolutely untrue, as the only thing that does not decompose is the enamel of the tooth. “Even if there is no enamel, a tiny part of the root of the tooth is enough to determine the sex, age, type of food intake, occupation, cultural behaviour, socio-economic status and even whether the dead person was a left or right hander! All this is possible through dental forensics, which can revolutionise how we solve crimes but is currently finding no takers in the country,” said noted dental researcher, anthropologist and forensic expert Parul Khera Sinha, who spoke to City Express during a visit to Sri Ramachandra University recently.
While prusuing a degree in dentistry, Sinha had decided that she wanted to specialise in forensics, but there wasn’t any scope in India. “For Masters in Dental Surgery (MDS), I published a paper on how DNA extraction from human skin, after a bite, can help identify a killer. It was the first-of-its-kind and I was invited to give lectures on it. So, after deciding I wanted to pursue it more, I went to Belgium to study,” she said.
Sinha works as an assistant professor at Jiao Tong University, Shanghai, China, but frequently visits her home country in the hope that this kind of research would be promoted by involving both the judiciary and police as well. “Dental forensics could act as a saviour in situations where the body is partially or fully decomposed and nothing but the teeth remain,” said Sinha.
She explained that the sex of the person is easy to determine by the shape of the jaw and size of the teeth. “Besides the visible physical differences, evidence of ornaments or other dental accessories could also determine the sex.”
Explaining how age can be determined through a tooth, Sinha said it was similar to how the age of a tree was determined, because every year a new line forms around the tooth. “In places like Uttar Pradesh, parents kill their girl child soon after birth and then claim that the child was stillborn. In such instances, you can find the truth by looking for the line around the tooth because it only makes a mark after birth,” the doctor said.
She also explained that the difference in people’s teeth structures — such as how their molars are places and incisors are shaped — can say a lot about what regions they come from and their socio-economic conditions. “It’s simple…if the teeth are badly maintained or decayed, we can be sure that they are from a poor family, but if they have gold fillings and maintained well, then they come from a rich family,” she explained. Sinha also gave examples of cases of child abuse cases when the suspect was caught, simply by doing a dental forensic. “In rape or child abuse cases, there are usually bite marks on the body. The mark can be used as evidence, but the saliva left on the body because of the bite can also be used.”
She however rued the fact that in India nobody is interested in this field, though it has revolutionised the forensics field in just 15 years. There is only one dental forensics lab in the country — Delhi, but Sinha added that they weren’t doing much in the field. “Delhi should be the first to take steps because it has become a crime city already,” she said.