While a minor degree of facial asymmetry is not uncommon, there are many people who do have significant facial asymmetry, where either one side of the face overgrows, or more commonly, one side of the face is small. This is a spectrum from the very mild to the very severe. Management of this is best done in the setting of a multidisciplinary team such as a craniofacial unit, involving specialists from a number of different areas including plastic surgery, dentistry, orthodontics, otolaryngology etc. There is no quick fix and management requires treatment through to completion of growth. This may include orthodontics and jaw surgery to straighten the teeth and subsequent soft tissue surgery to improve the symmetry of the soft tissues. In severe cases, the orbits may also need to be repositioned.
So in answer to your question, facial asymmetry can be managed and certainly be improved, it requires a comprehensive team approach to give you the best possible outcome