I don't think its a matter of whether its suitable but the purpose of doing the HIFU and whether pain tolerance is an issue.
I think anyone with laxity of skin can do HIFU - but I have found that high energy settings lead to significant volume loss, and in an already skinny face, it would be counterproductive.
The solution is to do more shots, but with a lower energy setting.
The Ultherapy's initial white paper showed that more shots is beneficial compared to fewer shots with high energy. That is the approach I take if I want to solve laxity, as it is less painful and also less likely to lead to volume loss.
