Sweden's Medical Products Agency is investigating a complaint from a man who says the mouthguard given to him by his dentist caused erectile dysfunction and shrank his genitals.
The unidentified man was prescribed the mouthguard in 2015 to prevent him from grinding his teeth while he slept, according to The Local. He reportedly used the device for 10 months, during which time he says his penis gradually shrank.
Suspecting that it was due to the plastic in the mouthguard, he stopped using it. Within a week, he says his penis returned to its normal size.
He took the mouthguard back to his dentist, who reported the case to the Medical Products Agency. There is no word on whether the regulatory body has been able to corroborate the man's theory.
Teeth grinding, known clinically as bruxism, is a condition in which the person unconsciously grinds his or her teeth, according to Mayo Clinic. The grinding can occur either throughout the day or while asleep at night.
The causes of bruxism are not completely understood, although emotions like anxiety, stress, frustration and anger are significant risk factors. If left untreated, bruxism can result in damage to teeth, headaches and facial pain.