Which is the best treatment for square jaw/recessed chin: sliding osteotomy at mandible angle or shaving of angle only? (Photo)

When you have a very short chin and square jaw angles (fairly flat mandibular plane angle), the best treatment is going to be a sliding genioplasty and jaw angle shaving. This is particularly true in a female where large chin implants can make the chin very wide and their position on the 45 degree slant of the recessed chin often creates a vertically longer chin as well.

 A chin implant can be inserted in the chin to give the added augmentation from both a profile and frontal view. Chin implants are manufactured in a variety of sizes and shapes, are composed of Silastic, and can be custom carved according to the patient's deires. Chin implants are performed under local anesthesia as an outpatient surgical procedure.  A sliding genioplasty is performed  under general anesthesia as an inpatient procedure at a hospital with at least one night stay. A sliding genioplasty is performed by an oral surgeon to make sure that the occlusion of the teeth is in proper alignment. Sometimes the upper jaw and the lower jaw have to be realigned.

If the jaw is small, I recommend orthodontics and jaw advancement. X-rays would be helpful in diagnosis. 

Consider the entire facial look/balance when you make a decision. Aging accentuates the lower face and it appears 'heavier'. The facelift you have had, could have accentuated the cheekpad area more so that the 'weight' of the face is 'higher' and then the face appears more oval. You could alter the contour of the angles slightly but also use 'filler' (given the previous facelift/.surgery approach) to accentuate the cheekbones. The Chin with the filler is emphasizing the lower face - so careful at your age with too much emphasis. Talk to a surgeon who understands facial balance.