Do I have a weak chin?

Your chin is indeed short. But the dimensions of its shortness is very important to understand as it is both horizontally and vertically short. Thus a standard chin implant will not produce a good result. You can use either a special vertical lengthening chin implant or a sliding bony genioplasty to bring the chin forward and down. Computer imaging will demonstrate the value of this type of can augmentation.

An osseous sliding genioplasty allows one to move the chin point in 3 dimensions. This may be a good option for you. It allows more versatility  in movement and position than with a chin implant procedure. Your upper and lower jaw position (occlusion) is also important when evaluating the best procedure for you. From your pictures, it appears you have a shorter lower third of your facial profile. An osseous genioplasty could serve to lengthen the lower third of your face and help you achieve the balance you desire. A preoperative 3-D Vectra analysis may also be helpful during your consultation in order to define your exact aesthetic goals Seek consultation with a board certified plastic surgeon or maxillofacial surgeon experienced with jaw surgery. Good luck!