Piercings may harm teeth and gums.

Lip or tongue pierced? Do not be shocked if your dentist is upset.

"Our research discovered that many persons with oral piercings had significant pockets and gaps around their teeth, and receding and bleeding gums,"

Walter and his colleagues reviewed 8 trials with 408 lip and tongue piercings.

One-fifth had more than one oral piercing. Most individuals had metal jewellery in their piercings and had them for 1 to 19 years.

3 out of 5 studies revealed larger pockets surrounding teeth close to tongue piercings and greater gaps between teeth

The research evaluation was presented Wednesday at an EFP conference in Copenhagen