Hey Jess, I also live in Australia Sydney, I had my jaw surgery a month ago to correct my underbite, where they moved my top jaw forward and my bottom jaw back.
1. After the surgery the first couple of days are pretty rough, I didn't experience any pain really. Id say a 3/10 kind of pain. its a throbbing kinda pain not a piercing pain when you stub your toe, and it was totally bearable. They gave me a morphine button never used it. The main thing is the discomfort straight after the surgery is Swelling, Eating, and definetly sleeping. but once you reach the 4th-5th day and your home it totally turns, its so much better.
2. Whether your talking about good looks it depends what you want to take from this surgery. Is it having a structural bite, where you've had difficulties eating your whole life or worrying what you look like after. Overall what Ive taken from the surgery so far, is that my teeth finally fit together in a structural benefit which will let me eat alot better for the rest of my life, even tho i havnt been able to bite down on real food since ive been on a liquid diet the past 4 weeks, but i definitely know it will be better than before where i struggled biting into food and having it rip apart etc etc. and I can clearly see a vast difference in my appearance. that my profile is far more uniform, rather than having a very prominent lower jaw and a slight deficient top jaw. I'm happy with the results because I still look like myself but my features are now balanced with the rest of my face.
3. An elongated face. Id say my face length going downwards hasn't really changed but my side profile definitely has.
4. Yes you do lose weight, but this is to be expected only being on liquids for 6 weeks after surgery, i wouldn't exactly be packing on the weight before surgery if your of a normal weight. because you'll gain the weight back once you start eating solids, because your body is designed to store reserves when food is abundant and coming back in. Ive lost 5kg, (aprox 10 Pounds) and that was mainly muscle because i can feel and see the difference.
5. Yes there is a chance that you could experience major nerve damage, but as explained by my surgeon the percentage is super low like 1-3 percent pretty sure (But dont quote me on this ask your surgeon). and if your young you should be fine. But paralysis of the face I dont know what your thinking where maybe one side of your face is drooping from paralysis i dont know anything about that kind of level since muscle control is kinda of a brain thing. I still find it hard to smile etc but thats to be granted since they moved muscles and it was stretched etc and im still numb in areas like the lower chin but ive gotten alot of feeling back, and only have little areas of less feeling than before, and it should come back within a few months or so.
6. Everyone seems to ask about swelling and bruising and when it goes away, but i guess this is a normal question. Swelling is at its worse about day 3-5 and then it goes down heaps afterwards and it becomes alot better, but you still have residual swelling which will be fairly noticeable to yourself but maybe not so much to others. At 4 weeks i still have a fair amount of residual swelling and itll go down when it goes down. Everyone is different with there genetics, Age, Sex, and general health, But you can expect to be totally swelling free after quite a few months after surgery.
7. With your top lip looking spastic and stretched out, im guessing that there moving your top jaw forward, but i cant see how there would be problems with your lips etc.
I had super swollen lips and they were shredded after they used the retractors to open my mouth to do the surgery, but your lips are super regenerative, and mine are back to normal pretty much with only a tiny bit of swelling and not having much feeling yet really, but im sure that will come back eventually, im not worried.
8. Im 100 percent happy with the surgery, even tho its only been a month since surgery, my teeth bites turned out great, and it fits together perfect. Surgeon did a great job and would do it again, The only thing thats killing me is the food hahaha, i really want real food atm after being on liquid diet haha, but i know a month or 2 of being uncomfortable with food will definetly be worth it in the long while where my bite will last the rest of my life.