You can lie through your teeth but your teeth don't lie. Persephone Lewin knows that. She's written a book that enters the kind of world featured in fictional dramas like Silent Witness.

You can lie through your teeth but your teeth don't lie. Persephone Lewin knows that. She's written a book that enters the kind of world featured in fictional dramas like Silent Witness. Steven Russell learns about this branch of forensic science

THEY say that behind every great man there's a great woman - and being prepared to store a human head in your freezer must surely warrant such a tribute.

When you're married to a forensic odontologist, life can be . . . well . . . interesting. How many of us would be comfortable in the cells with a suspected murderer, for instance, taking a dental impression that could prove his guilt?

Investigating death and injury isn't everyone's cup of tea, but Persephone Lewin has come to embrace her husband's fascinating profession. She used to run a small manufacturing company but steadily worked more and more with her husband.

She helps in the mortuary, assisting with the comparisons of teeth with bitemarks or blunt instruments with wounds, and edits legal statements. Then while David gives expert evidence from the witness box during a court case, Persephone is often found projecting an image of the injury on to an eight-foot-wide screen and moving the outlines of the alleged weapon over the top of it. Voila! Just like Cinderella's glass slipper, it fits.

“I love the work,” she enthuses. “I even enjoy carrying the bags in court, which is a bit of exercise. So, forensic togetherness for you.”

One of her early wifely duties was storing the aforementioned head in the freezer for a couple of weeks. “It was in a box. This one was an age assessment from the teeth and David handed it back to the detective in charge of the case on the corner of London's Baker Street, outside Madame Tussaud's.”

The intriguing story of injury analysis, including technological developments along the way, is told in Persephone's engaging book: Bite to Byte. There's more than a little mortuary humour mixed in for good measure.

It tells how Essex dentist David got involved with legal work and how the analysis of bitemarks has become part of the forensic arsenal used in criminal cases.

The book draws 10 cases, from more than 200 to date, to show how the specialism works in practice: including the infamous incident where a Rottweiler belonging to maverick Conservative MP Alan Clark was alleged to have bitten a BBC cameraman.

David, she admits, didn't want the book written - but she went ahead and did it anyway! Her husband, she says, is not ambitious and does not seek publicity. “I am quite the opposite!”

He originally had a traditional practice in south Essex. “A cheerful chap - he was a slim, quick-moving dentist with large green eyes and sticking-out ears and a sailor's tan to the neck and forearms,” remembers his wife. He was “not just an unmitigated academic, but a practising wet-fingered dentist”, said to be very good with children.

Persephone, meanwhile, ran a small manufacturing company in the heart of London's East End. “We worked hard and, of a Friday night, locked up our respective businesses and headed for the coast.”

The subject of forensic work was first mentioned one afternoon in late September, 1986, when they were sitting holding hands on the beach, their boat pulled up on the shingle. With their two children having left home, and with more than 30 years' experience in general dental work under his belt, David was thinking of applying for a course on forensic dentistry.

His wife was fully in support, though she recognised many people would wonder at the choice.

“Forensic dentistry is clearly not everyone's cup of tea, as the brutally-murdered, the battered babies or distressed rape victims are obviously less cheerful prospects than little Johnny at the surgery who still has no fillings and would like the grape-flavoured fluoride gel, please. So why choose forensic dentistry?”

David's motivation was that he had earned a living from dentistry and would like to give something back. So that his dental patients didn't suffer, he started earlier at his surgery during the rest of the week, and finished later.

David soon decided on a course project: finding a way of eliminating the operator-produced distortions involved in taking a two-dimensional photograph of a three-dimensional object - a bitemark on a curved surface such as an arm, specifically.

“If you do not start with an accurate photograph in the first place, how can you state that a suspect's dentition does, or does not, match a particular bitemark?” points out Persephone.

David experimented, using graph paper wrapped round different-shaped sections of yacht masts. He took 500 photographs from every conceivable angle.

“It became the basis of a method of forensic photography that was to gain universal acceptance. It changed the face of bitemark comparison from an art into a science.”

David used to get the first train of the day to arrive at medical college at 6.30am. This gave him time to do all his developing, printing and enlarging in the darkroom before lectures began at 9am or so.

During the five decades before he qualified, there had been a trickle of forensic odontology cases, says Persephone - mainly in this country, America and Scandinavia. Nowadays, in the UK, cases crop up weekly.

She points out that odontology can be highly effective. U.S. serial killer Ted Bundy was trapped by his bitemark on one of his young victims, for example.

“Teeth are man's oldest weapon . . . With a bitemark, only one person could have wielded the teeth. For here is the perpetrator's trademark, a unique visiting card, which, like a fingerprint, is capable of distinguishing the biter from other suspects; of proving an inseparable connection between assailant and victim.”

The first recorded case of a bitemark leading to a conviction came in 1906, the book explains, when dental models of a Cumberland burglar matched patterns left in a bitten hunk of cheese left at the scene.

It can work both ways: when odontology ruled out a criminal aspect to an investigation it saved the taxpayer a five-figure sum on an unnecessary murder inquiry.

Nowadays, as a freelance, David's principal employers are the police and Crown Prosecution Service, though a fair number of assignments come from defence lawyers. There are only a handful of such specialists in the UK.

The march of technology helps in the pursuit of justice. David, points out his wife, pioneered the application of digital imaging for forensic use.

Persephone ran her manufacturing company for many years before giving it to her son-in-law in order to write and help her husband with the forensic work.

“Occasionally people ask me how I cope working in the mortuary with murder victims, especially children and with live victims,” she says. “Also in the police cells, helping take dental impressions of the perpetrators of such horrific crimes.

“I have to say I love the work. I don't get nightmares. The cases don't upset us, with the exception of just two cases throughout all that time. One was a miscarriage of justice. The other was a case where we were engaged privately by the parents of a convicted killer to check the evidence.

“You could say our work is macabre but fascinating. Usually our side of things is more apropos to solving the case than the other forensic specialities - it's like living in a detective novel, occasionally even finding the weapon that caused the injury. And fact is so much stranger than fiction.

“Although it is also essential work, for me a non-criminal case of, say, an identification of a drowned person just doesn't have the same appeal.”

She suggests, contentedly: “Forensic odontology would appear to be the most glamorous of the medical forensic specialties. In many instances it points the finger; solves the crime.”

* Chapter and verse

The key details: Bite to Byte is launched on February 23, Parrel Press, £14.99. ISBN: 0-9550420-0-3

What's it about: Forensic dentist David Lewin and his wife Persephone. She wrote the book. Cases on which he has worked include the Victoria Climbie trial - the girl was abused and murdered by her aunt and the aunt's boyfriend.

Where do they live? Colchester area

Trivia about David: Keepsakes on top of his computer include a hare's skull and wind-up plastic dentures

Trivia about Persephone: Her mother is Greek; hence the name. Bite to Byte is her first book, though she has had articles in magazine such as Practical Boat Owner. Her first fictional book, Once Bitten, is due in about nine months

You'll never believe it, but: Persephone also has a comedy act as Madame Fifi, involving a trumpet, lifejacket and toy penguin - Peregrine. Her first proper set was at Colchester Arts Centre in April, 2003. She now performs mainly on the London circuit. “Last set was about a month ago at a large pub in Finsbury Park. Danced the cancan with another penguin strapped to my knee - my penguin's auntie . . .”

ONE of the cases highlighted in Persephone Lewin's book Bite to Byte is a sad incident from Suffolk: the disappearance of loner Steven Burt.

It was around Christmas-time in 1998 that a dog-walker found mummified remains in brambles at Woodbridge's Fen Meadow. The body was wrapped in a sleeping bag and the remains clothed in a flying jacket.

Media appeals brought forward a woman who had last seen her son in 1994. He had been living with his father, former accountant Tony Burt, in Woodbridge.

Neighbours had long complained about smells and rats around Mr Burt's home. Environmental health officers had visited in the past and found six-inch-high piles of food debris mixed with cats' excreta.

Mr Burt was about to move to an old people's home, with his bungalow due to be knocked down, and had been giving away some of his possessions prior to leaving. Detectives, says Persephone Lewin in her book, halted the demolition.

Inside, the bungalow was in a dreadful state. Officers sifting through the detritus found a piece of foam filling from a sofa cushion that had a stain in the shape of a pair of human legs.

Back at the mortuary, forensic odontologist David Lewin placed the remains of the legs on white paper, in the same pose as the leg-shaped stains - or as near as he could manage. These were photographed. Later, he scanned the photographs onto a computer and reduced the legs to an outline, making a comparison with the shapes and dimensions of the stains.

“The left foot and leg was such a good match it was incredible,” says Persephone.

Tony Burt was initially charged with the murder of his son, though this was later dropped. There was no way of pinpointing the cause of death. “His family thought that, possibly, Stephen had caught an infection and become ill and died.”

Tony Burt, 63, was found guilty of failing to give his son a Christian burial and of causing a public nuisance by dumping his remains. In the summer of 2000 he was sentenced to six months in jail, suspended for 12 months. The judge said Burt had been suffering from dementia.