What was it??? I remember that that Klingon scientist said he would be interested in "cranial reconstruction. " Was that the solution, or was it genetic manipulation???
Maybe they discovered injecting augment blood directly into their veins cured all illness immediately, thus, like alcohol, it became both the solution to, and cause of, their problems
I believe the solution was that Phlox injected an altered form of the Klingon's version of the Augments genetic manipulation. This version created only the physical appearance augment and halted before it got to the added aggression portion of the augmentation. So, to be cured those infected would lose their cranial ridges and look more human in appearance. After being cured and losing his cranial ridges the Klingon scientists said he should perhaps change his line of work to cranial reconstruction, since there would be so many Klingons that would now lack the ridges.
...Of course, if the cure makes cranial ridges disappear in a matter of minutes, odds are that it would also make any reconstructions of cranial ridges disappear! So the only cosmetic solution would be to wear falsies, things immune to the biological effect. Perhaps this would be beneath a warrior's honor, explaining the prominence of smooth foreheads a century later still. Only 24th century medicine would find a way to truly cope. Or then a cure never was found, but becoming Dahar Master grants you immunity for wearing falsies? Timo Saloniemi