Due to not having middle teeth on the upper left side, my left cheek has become sunken and noticably asymetric. can it be corrected in a 22-year old by implanting teeth?

Implant: Is a good choice. It is much stronger compared to a bridge or denture, and will preserve the integrity of the neighboring and opposing teeth.

Possibly: Depends of your problem is caused by a bony defect or from the teeth which are missing. You did not say whether you were born without the teeth or if they were extracted. Consult with a local dentist who can place wax or acrylic in the defect. In this way you will be able to visualize if filling the space will change your appearance. All the best..

Options are: Missing teeth can be replaced in many ways. Implants, if there is enough bone mass for ideal placement, would be the best solution both functionally and esthetically. There are other options, both removable and fixed to replace missing teeth and probably correct any facial asymmetry, if the missing teeth was the cause of that problem. See a dentist to discuss your options and what is best for you.

Implants: Yes, implants can fix the problem, but you also may be able to do the same with a bridge or partial, depending on the number of missing teeth. You should consult your dentist for more information.

Yes, with bone graft: The absence of teeth will cause the jaws to atrophy leading to that sunken appearance. Your first step is the have a ct scan of the area to evaluate your upper jaw and the sinus. From this point a prosthodontist and periodontist or oral surgeon can help develop the best treatment plan for you.

Replacing teeth: You will need to have a consultation with your dentist where you can have x-ray and be evaluated for placing implants.

Yes: Missing posterior teeth can definitely cause a change in appearance. Replacing with well placed implants and crowns is a great way to restore your cheek fullness.