sure the surgeon can fix it, now a day. you can choose either jaw shaving reduction surgery or botox injection to the muscles of the jaw.
Botox injection helps to reduce the muscles and last about 6 months and sometimes stays perminant. as well as it might perilyze the muscle(very rare case). (excuse my grammar)
Jaw reduction, it all depends on how severve your face is, is it really uneven on both sides? is 1 side longer & shorter than the other?
well, my suggestion I think that if it's not that noticable and u want to get it fix, then get the jaw reduction without implants. But if it's really uneven then get both jaw reduction & implant. you don't have to get both done at the same time.
Jaw reduction takes 6-8 weeks to recover and like other surgery it will take a few months(6 & up) to heal. for the next few weeks u have to eat liquid food, so get a blender,ehehe...
The surgeon will start from the back of the jaw, underneth the ear, under the gum, and starts shaving it. It's best for u to google it & do some research. I've seen some before & after pictures, they look very interesting.
There are many causes, such as; -unhealthy oral hygiene, missing teeth, too much sugar when you were young, ate a lot of chewing food, chewed on 1 side, genetics, uneven teeth, and mainly sleeping on one side of the face for many years.
How would I know about all these stuff? well, it happened to me & I did some research.
when I was young, i had a cavity in the back of my mouth n never got it checked, that area became erupted and never came back to normal. and I had a lot of sweets & missing teeth, my teeth were crooked n i had servere cross bit, plus I slept on 1 side of my face for many years. (Facial bone kinda stops developing by the age of 25)
The best solution before any surgery is to get braces, I had it done N love it!
Everyone should get braces but poeple with uneven jaw needs it the most, because they have more problems than others.like; cross bite, teeth don't align with each other, crooked teeth equals crooked face, n so on.
i just got my braces taken off, it cost $4,800, if u can't afford it then u can pay monthly plus u get to claim it back from income tax, i got almost half back. the braces will take about 2-3 yrs, I'm telling u that it's worth the wait!
my teeth became straighter and my face look more normal then before. but my jaw has grown to it's shape

, so i'm planning to get jaw reduction surgery with implants. I spoke to the surgeon, it will cost $5,000 to get 1 side shaved, N $8,000 thousand for both sides.
is your face similar to this: -1 side wider N jaw bone exeeds far back. -other side smaller N longer?
I would suggest: -shave the angle of wider side.
-longside; shave the length of the longer side & add implant to the angle/jaw.
-n get chin implant if it's uneven.
the best way to examine yourself would be looking at the mirror front n sides view, 3 way mirrors. lay down flat on your back, face facing the ceiling, havong a mirror facing down on u you, open n close your mouths. imagine n use both hands on each side of the face n measure from the back of your ear to the front.
-go to a plastic surgeon N have a consultation
-have an x-ray
-best way is to use a digital camera n take photos on different angles, bottom agles are the best (face facing upward n take a picture below the jaw.
-video your face
anyhow good luck