My chin pokes out when I smile. What can be done to correct it? (Photos)

Dynamic changes such as smiling are difficult to treat. Sometimes botox injections are used to improve unwanted dynamic changes. In your case, the photos appear to show a prominent chin and a short lower facial height. Without the benefit of seeing your complete photo, you would likely benefit from a reduction genioplasty in the horizontal plane and a simultaneous vertical lengthening. A prominent chin is considered a masculine characteristic and is generally less accepted in females.