It is an ailment whose name is as strange as the syndrome: its main symptom is self-mutilation.

Lesch-Nyhan syndrome is a disease related to genetic abnormality to metabolize the enzymes of uric acid.

Japanese researchers tell the story of a male patient diagnosed with severe case of Lesch-Nyhan syndrome.

The good news is that the injuries caused by self-mutilation behavior decreased after the continuous use of a mouth guard over several years.

The behavior had been observed since the patient was six months old. The behavior of biting his hands and lips worsened just before he was brought as a four-year-old to the Hiroshima University Hospital.

“Multiple self-mutilation wounds were observed on his hands and lips as well as attrition on the teeth,” says Dr. Yuki Oda of the Department of Special Care Dentistry, Hiroshima University Hospital.

“His mother brought him to our clinic to receive mouth-guard treatment for prevention of self-mutilation behavior,” Dr. Oda, the lead researcher, writes in a case report.

With colleagues at the Hiroshima University Hospital, he made a soft-type mouth guard which subsequently prevented self-mutilation. However, at the age of seven years, a large wound caused by self-mutilation was observed on the lower lip.

The mouth guard has become incompatible because his teeth were undergoing replacement with permanent teeth. A new mouth guard significantly reduced self-mutilation, a process repeated every one or two months until the age of 12 years.

By then, a serious wound was found. Dr. Oda and his colleagues considered the pros and cons of extracting the teeth that could cause serious wounds. Several reports, however, observe that self-mutilation behavior is reduced as age increases in patients with Lesch-Nyhan syndrome.

“We decided to avoid tooth extraction and produced a new mouth guard,” Dr. Oda says. “The mouth guard was a hard type, because permanent dentition was completed, and the soft-type mouth guards were soon broken due to severe self-mutilation behavior.”

A replacement hard-type mouth guard was also broken when the patient was 13 years old and he again wore a soft-type one. However, his mother noticed that a gagging reflex gradually worsened at the age of 15 years, and it made it impossible for him to keep wearing any type of mouth guard.

When the patient reached 16 years of age, the severe self-mutilation behavior has not been observed, says Dr. Oda./WDJ