I have saggy skin after massetter and jaw botox. What can I do? (Photo)

Especially given your age and your skin elasticity, it is unlikely that Botox for masseter reduction caused you to have more skin laxity or skin "sagginess".  Also, when the effects of the Botox wear off you should return to your pre-treatment state, just 3-4 months older.  

Thank you for your question and images. I do not see significant amounts of excess skin from your images and given your age with time you may see some retraction of the skin. Like everything in life there are positives and negatives to all procedures. Theoretically, if you reduce the volume of deep structures in the face (masseter muscles) you could produce some redundancy in the overlying skin. More commonly this is associated with bony reduction rather than soft tissue but can potentially occur with either. Your options include replacing the lost volume with fillers or utilising some skin tightening techniques. I would encourage you to try non surgical forms of skin tightening such as ulthera. good luck.RegardsDr Guy Watts

Probably the best course would be to wait and let the effects wear off and see if things return to normal, which I believe they should.  If there is still an issue then consider an injectable filler treatment along the jawline for better definition or a procedure such as Ulthera or Exilis Ultra which help tighten the skin.