Normally you would say "upper right" or "upper left". The hyphen (-) could be used to imply a more direct relationship between the two words. That is, in this case ("upper right/left" with no hyphen) the "corner" is "upper", and the "corner" is "left" (or "right"). However, you could use the hyphen ("upper-right/left") to indicate that the "corner" is "left" (or "right") and the "left" is "upper". The hyphen is rarely used, but can be used if the words are of the same kind and level. For example: "The pink-blue car..." "The high-low combination..." "The cat-dog toy...." More common is to use the hyphen to link a word to another that it would not normally describe. For example, "blue" and "sexy". "The sexy-blue car..." "Sexy" describes "blue", not the "car".

They're all the same!