Beloved actor Dick Van Dyke, 87, has finally figured out what’s been causing his mysterious mental health issues – his titanium dental implants.

Last month, Van Dyke had to cancel an appearance at the 92nd Street Y’s annual awards event in New York City because of “symptoms of a yet-to-be diagnosed neurological disorder,” his rep told ET News.

The actor – who is best known for his role as a jolly chimney sweep in Mary Poppins – was set to receive the Lifetime Achievement Award for Bettering Humanity through Comedy.

Van Dyke tweeted about his mysterious ailment, writing: “My head bangs every time I lay down. I’ve had every test come back that I’m perfectly healthy. Anybody got any ideas?”

The actor underwent extensive medical testing – including a CAT scan, MRI, and spinal tap – but still no clues.

Until yesterday, when Van Dyke took to Twitter again to share some progress.

“It seems that my titanium dental implants are the cause of my head pounding. Has anyone else experienced this? Thanks for all your replies,” he tweeted.

According to a report by the BBC, this diagnosis is plausible. It appears that 1% of dental implants – which are artificial tooth roots used to hold a replacement tooth in place – can cause nerve damage as well as issues with speech and eating.

Van Dyke is currently laying low at his home in Malibu, California and, on doctor’s orders, is refraining from any air travel.