An affliction of the upper-spine and/or neck, similar to scoliosis, resulting in a permanent bend in the neck titling the head to either the left or right. Caused by constantly straining to reach the upper rack of the fridge to get dad "another cold one" as a child.
Cletus the hoosier's dirty-ass head can be seen leaning to the right while he's driving around in his shitty old truck. The poor guy is afflicted by mulletosis, for which science has not found a cure. (Probably because medicaid doesn't cover it)