Unsupportive family? Sure! S.O., dad, mom, grandparents, bff, relative(s), you name it!
To be honest, I put off surgery for a few years because I felt like no one around me was supportive about it. In the end, I realize it's MY decision and I don't need everyone's approval. I did have a long discussion with my immediate family so they understand my reasoning for going through with the surgery, and they eventually somewhat came to terms with it. When I was getting nervous about my surgery date, my dad would make comments like "well just call the surgery off!" or "why are the doctors taking so many impressions, maybe they don't know what they're doing". I immediately told him he's being very hurtful, and described the long, painful orthodontic journey I went through in preparation of the surgery, and then he stopped.
My grandma even asked me to call off the surgery once she found out about it. I also have a relative who's an orthodontist, and who initially recommended against it as he doesn't think my case is "clinically severe" enough. Generally, your friends and family who are "unsupportive" just love you for who you are (and not what you look like), and probably think you're beautiful already. So don't be too upset about having unsupportive family members. In the end, if you're going through with this, you're the one who should be making the decision. You're also the one who has to live with the end results.
