How can you correct a “sunken smile” with a protruding chin after braces & extractions?

It appears that you have a prominent chin when viewed form the profile view. This problem is likely due to the bony growth but requires the correction of the soft tissue pad of the chin as well. The bony chin can be reduced and the soft tissue pad reduced along with some chin and jawline liposuction. The procedures can all be accomplished simultaneously with intravenous sedation and will not affect your smile or teeth. 

You are quite perceptive. The dental extractions 'contract' the dental arches, change the smile and affect the soft tissue support of the upper and lower lips. In fact, they accentuate the chin since the lower lip 'falls back'. Females also look fullness in the upper lip as aging occurs. One can reinstitute orthodontics to somewhat 'reverse' the change; or augment the area alongside the lip and under the nose; alter the width of the chin (not too much though); but the actual 'width' of the smile wont' change. More completely, one can advance both the upper and lower jaws with surgery alongside Invisalign.