TUESDAY, Nov. 27 (HealthDay News) -- In a development that could dramatically cut the time needed to identify victims of mass disasters, Japanese researchers have developed an automated identification system that uses X-rays and image-correcting software to produce fast, accurate matches of dental records.
The researchers say the speed and reliability of the computerized approach significantly improves on current dental identification methods, which rely on painstakingly slow body-by-body forensic work.
And the new approach should enable public health workers to better respond to the aftermaths of earthquakes, tsunamis, plane crashes or acts of terrorism, the researchers said.
"In the event that a person's body is damaged beyond recognition -- facial features, clothing, personal possessions -- then often a person's teeth are our last chance to identify the victim," explained study lead author Dr. Eiko Kosuge, a dentist, radiologist and lecturer with the department of oral and maxillofacial radiology at Kanagawa Dental College in Japan. "Teeth are very hearty in nature and tend to keep their features even when the body is severely damaged."
"Manual dental identification works fine when the number of victims are few," she said. "For example, a house fire or single auto accident." However, as the number of victims increases, the time required to identify the bodies increases exponentially, and the risk of identification error increases sharply as well, she added.
Kosuge pointed to the 2004 Southeast Asian tsunami disaster and the crash of Japan Air Lines flight 123 in 1985 as two examples of the identification challenges posed by mass disasters. She noted that after the JAL crash, 325 of the 520 victims had to be identified by dental X-rays. In that case, "more than 2,800 doctors, dentists and forensic scientists worked for over three months to identify all of the bodies," she said.
"Our system will cut the workload of forensic scientists by 95 percent [and] will drastically reduce the chance of error," Kosuge said.
Kosuge and her team are to present their findings Tuesday at the Radiological Society of North America's annual meeting, in Chicago.
To develop the new dental identification system, the researchers relied on "Phase-Only Correlation" (POC) technology. This image-matching software automatically adjusts and corrects the kind of distortions that commonly appear in dental X-rays.
Kosuge and her colleagues tested the viability of POC software while analyzing the dental X-rays of 60 Japanese patients both before and after dental treatment. Following POC image corrections, the computerized system generated a list of the three closest identification matches for each set of X-rays. Total computation time needed to generate the match list was just 3.6 seconds per pair, on average.
Next, a group of forensic experts evaluated each of the three matches to arrive at a final identification decision. They found that 87 percent of the patients were correctly "recognized" by the POC method's first match. The success rate rose to 98 percent by the second match. A perfect 100 percent identification match rate was achieved by the third go-round.
Kosuge and her colleagues estimated that by accurately zeroing in on just three X-ray-to-patient matches from among all possible combinations, their computerized approach would effectively reduce the forensic workload by 95 percent.