Longevity of a nose job? Doe cartilage grafts ever resorb/lose structure during the lifetime after having a nose job?

Depending on the cartage that is used for grafting and the type of grafts used, cartilage grafts tend to stay where they are put.  There is no real reason a cartilage graft should absorb, BUT if the place they are used and for the purpose they are used, the cartage might not be supported to live on.  An example of this is in secondary or tertiary rhinoplasty where the wound bed is mostly scar tissue.  However, in primary rhinoplasty, the wound bed is generally good so the grafts should take and stay over time.

There is certainly some absorption over time but the scar around the cartilage also creates support and strength. The primary area where there should be concern is absorption of dorsal onlay grafts or grafts used to make a nose bigger. The grafts in primary rhinoplasty are almost always support and structural grafts and there are rarely ever any issues with absorption there.