It does appear that the orthodontic movements have altered the support of the lips, which changes the 'relative' position of the chin and the nose too. You have to be careful with a 'chin reduction' since the lower incisors determine the position of the lower lip; and if the chin is reduced, one can get a 'tall' looking/flat appearance to the chin. It is best to have a look at the 'side xray/cephalometric xray' from your orthodontists to see the relative positions/shape of the chin/front teeth angles - before determining the plan.
In this type of structure, smiling 'increases' the 'relative' prominence of the chin due to muscle pull.
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Your chin is prominent and reducing it would improve your appearance. Cheek augmentation might help also along with careful submalar grafting. Consult a board-certified Facial Plastic surgeon. Your best plan would be determined with computerized imaging. This would help decide if a more aggressive jaw surgery is needed. Best wishes.