Add another health risk to the list of reasons people should steer clear of tongue, lip or cheek piercing.
Researchers say they now have a documented case of substantial gum recession occurring around the lip piercing of a 26-year-old woman, and they say the case may reflect what's happening with many more of the trendy mouth ornaments.
"There's no way to know for sure, but it would seem to make sense that if you have one case there would be others where mouth jewellery pieces are causing the gum tissue to recede," says Dr Michael McGuire, president of the American Academy of Periodontology.
The case was reported when the patient noticed that her gums started to recede in the area of a piercing with an oral barbell.
Since the recession only occurred where the barbell had direct contact with the gums, the piercing was considered the direct cause of the problem.
While it's not quite as serious as some of the other health hazards that have been linked to mouth piercing, experts say gum recession can leave the tooth root more vulnerable to decay and periodontal disease.
And those other hazards? Experts say they can include nerve injury, sensitivity or allergic reaction to the metal, obstruction of the airway and, of course, accidental swallowing.
But McGuire says one of the things that scares him most about mouth piercing is potential problems with bacteria.
"I would be very concerned with the general health risk, as with the dental risk, because piercing could cause what's called bacteriemia, which is giving bacteria that live in the mouth access to the bloodstream. And that can cause problems elsewhere, especially in the heart. So that's really a big concern," he says.
Despite the hazards, mouth piercing is a fact of life. So what do dentists advise?
"First of all, don't do it," says Dr Bryan S. Michalowicz, an associate professor in the department of preventive sciences at the University of Minnesota School of Dentistry. "But for patients with existing devices, I'd advise them to temporarily remove the devices when they are eating or sleeping and to permanently remove them if there is persistent inflammation such as swelling, redness or pain."
Those planning to get pierced may also avoid some problems by taking a few other precautions, Michalowicz adds.
"Piercing that do not either impinge on or rub against the gums, or that are not positioned near the cusps of the teeth are probably the safest in terms of avoiding damage to the teeth and gums," he says.
"It is not possible to sterilize the oral cavity, so any piercing should be done in as clean an environment as possible," he adds. "Although post-operative infection, bleeding and nerve damage are all possible complications."