The MD Brush has an unusual grip that automatically angles the brush head at 45 degrees. Meredith Rizzo/NPR hide caption

toggle caption Meredith Rizzo/NPR

Build A Toothbrush, Change The World. Or Not

  • Download
  • <iframe src="https://www.npr.org/player/embed/341670779/343623240" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript