I understand your concern about your facial profile changes.
The soft tissue response to orthodontic treatment varies in different individual due to the difference in thickness of the lip and soft tissue, etc. From scientific research, the main changes with orthodontic treatment, be it extraction or non-extraction will be the upper and lower lip moving backwards, usually in the range of 2-4mm according to a local study based on Chinese population.
The sunken cheek appearance most likely is due to slight weight loss due to difficulty in eating. This should improve with time. However, at the same time, I also notice from your photo that your orthodontist had placed a temporary filling (blue colour) on your back teeth to prevent you from biting off your braces. These bite blocks may also temporarily cause your lower face to appear longer and hence possibly the 'sunken' appearance. The appearance may improve after removable of the blocks
Do discuss with your orthodontist about your concern so that he/she can close your remaining gaps in a suitable manner with the help of microimplants, or replace the gaps with implants.
