How common is internal scar tissue formation after Asian rhinoplasty? Or any primary rhinoplasty procedure for that matter?

Thanks for your question.  Scar formation after surgery is predetermined by your genetics.  The darker our skin is, the more likely we can form thicker scars such as hypertrophic scars and keloids, which can greatly impact your rhinoplasty results.  Improved Asian rhinoplasty results can be enhanced by using cartilage tip and dorsal grafts and sometimes thinning the skin for best results

It has been my experience that scar tissue is usually related to unresolved bleeding more than any other factor.  Achieving good homeostasis (control all bleeding)--best achieved with open technique rather than closed in my hands, delicate handling of the tissues, spraying the tissue field with a fibrin sealant (platelet rich plasma) and careful application of tape and splints has eliminated a lot of the rind-like scar layer that I witnessed early in my career.