I think it's salivary gland hypertrophy.

Yes, after the square jaw surgery, the salivary glands hidden behind the skeleton may subside. I don't know if there is

I heard that it is a dangerous operation.

..... Look at the reviews of other YouTubers.

[@Brain] It's been about a month, but it came out like swelling under the neck ㅜㅜ Is that swelling that hasn't gone away yet?

You can get enlarged salivary glands after contouring. Check it carefully. Don't worry, you just need to get Botox on your salivary glands.