CHICAGO – In the ongoing battle over the use of bite-mark evidence, two Chicago-area dentists have opened a new legal front, suing a colleague for alleged defamation because he used a Lake County, Ill., rape case they worked on as an example of the oft-criticized discipline gone awry.

Dentists Russell Schneider, of Waukegan, and Carl Hagstrom filed their lawsuit against Michael Bowers, a dentist in California who is a frequent critic of his fellow forensic odontologists for work that has led to numerous wrongful convictions.

The two dentists allege in their lawsuit that Bowers spoke at a conference of forensic dentists in Chicago this year and included a case they worked on in a list of 10 wrongful convictions caused by bite-mark evidence. That, the two allege, was wrong and subjected them to ridicule and a loss of business.

Bowers declined to comment, as did his attorney.

Bite-mark testimony has been criticized by courts for its lack of a scientific foundation, essentially leaving dentists to compare by visual examination bite marks on a victim’s skin with X-rays or molds of a suspect’s teeth and trying to determine if they match. Even some of the forensic discipline’s leading practitioners, stung by reversals linked to DNA evidence, now argue that bite marks are best used to exclude suspects, not identify them.

Schneider and Hagstrom filed the lawsuit in Cook County Circuit Court in November. They asked for an unspecified sum in damages.

Schneider and Hagstrom examined evidence for Lake County prosecutors in the case against Bennie Starks, who was convicted in 1986 of pulling a 69-year-old Waukegan woman into a ravine and beating and raping her. Schneider and Hagstrom testified at trial that they compared Starks’ teeth to a bite mark on the woman’s shoulder and that there was a match.

Starks was convicted and was sentenced to 60 years in prison. He has maintained his innocence.

In 2006, after Starks had served nearly 20 years, the Illinois Appellate Court granted him a new trial because DNA tests excluded him as the source of semen on the victim’s underwear; that evidence, the court said, showed that a crime-lab analyst had presented false evidence at trial.

The appeals court did not rule on the bite-mark evidence. Examinations of Schneider and Hagstrom’s work by two dentists retained by Starks’ attorneys concluded that their work was flawed. Those two dentists said Schneider and Hagstrom mistook the upper jaw for the lower and the lower for the upper.

Although Starks was awarded a new trial nearly six years ago, Lake County prosecutors still have not retried him.