It is very difficult to predict the extent of facial changes due to extraction-type braces treatment. Even for patients who have jaw surgery done, the true extent of their facial changes as a result of the treatment cannot be predicted with 100% accuracy.
The changes that we tend to see with extraction of 4 premolars is reduction in the protrusion of your lips and softening of the nasolabial folds. It is rare that the chin point will change much in an adult.
I am not sure if the hollowing out of your cheeks is due to extraction of the premolars. This usually does not occur to such a great extent with Asian patients due to the thicker underlying dermis layer that supports the skin on top. Weight loss due to a change in diet after starting your braces treatment could also account for this change.
If you wish to not retract the front teeth further to fully close the extraction spaces, you need to let your orthodontist know. There may be residual gaps between your remaining front teeth that need to be consolidated and the root positions need to be parallel BEFORE implants are placed.
After the implants go into the bone, further movement of the adjacent teeth WILL NOT BE POSSIBLE. The person placing the implants needs to work closely with your orthodontist to manage the spaces and the root positions.
Hope this helps!
