No, actually. It was all 277. Even in "Far Beyond the Stars" he still appears in Klingon make-up as well.
I must have misunderstood you, then. Dorn played four different characters - Worf, Colonel Worf, Regent Worf and Willie Hawkins. In his time on TNG and DS9 he only missed six episodes - "Code of Honor", "Haven", "Rocks and Shoals", "The Magnificent Ferengi", "Chrysalsis" and "Prodigal Daughter".
We watched First Contact on UniversalHD Thursday night and Majel's voice did not go unnoticed It occurs to me how prevalent she has been in my day to day life after so many of her "computer" sound-bytes I use on my PC, laptop, and phones for so many years. And there, I can assure you, they will always remain.
A mod after my own head Problem is that now she won't be able to do the recordings when we get to the next generation of BBS-software… Etc.