Complex sentence: He also served as Director of Pain Services at TTUHSC from 1977 to 2006, and became Co-Director when Mark Boswell joined the department as Interim Department Chairman and Director of the new Messer-Racz Pain Center.
Split into simpler sentences: He also served as Director of Pain Services at TTUHSC from 1977 to 2006. His title was changed to Co-Director when Mark Boswell joined the department as Interim Department Chairman and Director of the new Messer-Racz Pain Center.