Do I need surgery for my facial asymmetry? (Photo)

85% of the population is asymmetric in the face, therefor your asymmetry does not have a "cause".  It is likely secondary to normal development.  There are many options to improve your asymmetry.  They include:1)  Non surgical options   a)  Fillers to widened and add volume to your smaller left side2)  Surgical options   a)  Fat injections to widened and add volume to your smaller left side   b)  Rhinoplasty to straighten your noseI hope this helps.  

No human face is perfectly symmetric, but if it's bothering you and/or has progressed, you should enlist the services of a professional to be sure there is no ongoing pathology (tumor, hemifacial atrophy, etc.). If all is OK and you want improved symmetry, it becomes a cosmetic issue.  Individual asymmetric features can be addressed electively.

It appears from the photo that you have a mild form of left sided hemifacial microsomia.  If your teeth occlusion is normal, then only the left lower face soft tissues need to be treated.  The asymmetry can be corrected with fat grafting, which is a more permanent solution or with facial fillers, such as Sculptra, which lasts one to two years. However, I would only do this if you are being treated by a Craniofacial fellowship trained plastic surgeon, board certified by the American Board of Plastic Surgery.  Good luck.