How can I get a stronger jawline and chin, square face? (Photo)

A chin implant will give you a stronger profile that is still in harmony with your natural beauty. The implant will balance your face better and may obviate the need for further work on your jawline. I hope this helps.

From the profile photo of yourself that you posted, it does appear that you would be a good candidate for chin augmentation with an implant.  This procedure should help to strengthen your chin and balance your face better.  There are many different styles and sizes of chin implants and you could discuss the possible options at the time of your consultation.  I would recommend seeing a facial plastic surgeon or plastic surgeon.  

Yes, you are a candidate for chin implant.  If you place your finger from your lips straight down, your chin should almost touch your finger.  Yours is behind.  Having a chin implant will project the chin forward to better balance the lower half of your face.   When your chin is weak, it will make your nose appear larger.  The other difference between you and the other models are your cheeks.  Your cheek area is flatter than theirs.  Having cheek implants or fillers will give you a soft, round appearance to your face so it is not so long.  

The jawline you admire is composed not only of the chin/front section, but the 'angle' near the ear. The models have a more defined, more vertical and fuller 'angle' of the jaw, with a lower 'slope' to the jawline than you possess at present. The chin prominence should be balanced with this 'angle' area both  frontally as well as in profile. You can obtain these features given your present structure. (see website). The magnitude of the change has to be considered with respect to the middle part of the face/cheekbones, as well.