- Austria / Österreich
- Bosnia and Herzegovina / Босна и Херцеговина
- Bulgaria / България
- Croatia / Hrvatska
- Czech Republic & Slovakia / Česká republika & Slovensko
- France / France
- Germany / Deutschland
- Greece / ΕΛΛΑΔΑ
- Italy / Italia
- Netherlands / Nederland
- Nordic / Nordic
- Poland / Polska
- Portugal / Portugal
- Romania & Moldova / România & Moldova
- Slovenia / Slovenija
- Serbia & Montenegro / Србија и Црна Гора
- Spain / España
- Switzerland / Schweiz
- Turkey / Türkiye
- UK & Ireland / UK & Ireland
Following his dental degrees as an orthodontist, Dr. Earl Bergersen went on to become an assistant professor at Northwestern University. For 25 years, Dr. Bergersen taught on the subject of orthodontic growth and development, cephalometric radiography and cephalometric analysis. He is inventor of a number of orthodontic techniques available from Ortho-Tain.