Does a chin implant or chin filler help to soften a square jaw? (Photo)

  No, chin implants are not designed to change the shape of the chin.  Chin implants are placed for patients who have a weak and recessive chin profile, and desire an augmentation.  For many examples, please see the link and the video below

 Hi, I have performed many facial shaping procedures, including Chin Augmentation with dermal fillers or silastic chin implants, for over 30 years.  A non smiling photo of your face from the side would determine whether or not your chin is weak.  A squared-shaped "weak" chin can indeed be augmented and shaped into a more rounded anatomical chin shape using either a dermal filler or a silastic chin implant. When the chin is weak, this creates an imbalance making the nose appear larger, the mid face top heavy, the lower face looks short, de-emphasizes the lips and allows early formation of a "double chin".  
 Proper placement of a silastic chin implant adds forward projection to the chin thereby creating harmony and balance to the lower face.  Using the same incision, liposuction can be performed to reduce the fat and further shape the neck.  Excess skin, from below the chin, can also be removed through the same incision.  
 I have found that placement of a silastic chin implant, through a small curved incision under the chin (also allows excess skin removal) to be very safe, quick, highly effective and far less invasive than a sliding genioplasty (requires extensive tissue dissection, bone cuts and placement of metal screws and plates to secure the cut segments of bone).  I perform chin implant surgery in 30 minutes or less, often using a local anesthetic alone.  Hope this helps.

The only 'true' solution is to alter the 'shape' of the chin by changing the bone contour - it also allows a more natural transition to the bone/jawline behind the chin and 'fits' the profile as well.