The US is the home of the perfect Hollywood smile, but in one of the world’s richest countries tens of millions of people struggle to pay for a dentist. Natalia Guerrero goes on a dental voyage of discovery across America to investigate the relationship between cavities and cash. In the Appalachian Mountains she encounters the 82-year-old British adventurer who sets up temporary dental hospitals to provide free treatment to the dentally poor.

And in Beverly Hills she meets the celebrity dentist who created the world’s most expensive dental jewellery for pop star Katy Perry.

Photo: Dental work being administered at a temporary dental hospital in Virginia, US Credit: BBC Show less