1949 Canadian penny.. what does "a off denticle" or "a to denticle" mean?

i have a 1949 Canadian penny and from what i can see they are very valuable. could anyone tell me what off denticle or to denticle means? its something to do with the french saying on the back "georgivs vi dei gratia rex" it is the last a in the word gratia... but i still am unsure what on or off means. it is a valuable penny, of that i'm sure... but could anyone help me?