Please check if I qualify for salivary gland Botox.

I was worried because the area under my ears and chin was always swollen and looked thick as if I had gained weight, and I was told that this might not just be simple fat but could be due to salivary gland enlargement.

I looked it up online and found that Botox is effective for reducing salivary gland muscles, but I would like to know exactly what symptoms qualify someone for this treatment. Can people who experience stiffness or swelling around their jaw when eating also see improvement through this procedure? I am also curious if the injection site or mechanism is significantly different from jaw Botox.

I am under a lot of stress because my face looks wide every time I look in the mirror, so I am seeking expert advice on whether I can expect my face to become smaller if I receive this Botox treatment.