https://dentistry.uic.edu/news-stories/the-surprising-connections-between-oral-health-and-well-being/
https://www.deardoctor.com/articles/replacing-all-teeth-but-not-all-at-once/
http://www.webmd.com/oral-health/teeth-gums-age#1
https://www.youtube.com/watch?v=H2NrqWJkui8