Do I have a weak jaw and would a rhinoplasty ir nose / chin filler deliver the best results? (photo)

Heavens! You have a gorgeous, strong chin. It needs nothing. It projects forward nicely.
If the chin *looks* weak-ish to you, it might be because your nose is a bit strong in its forward projection away from your face. If the nose has strong projection, it makes the chin look weaker. Similarly if someone truly does have a weak chin, it might make a great nose look too projecting. It's a balance, get it?
Seems to me the goal on you would be to lower the little bump on the bridge of the nose, and then bring the tip and entire nose back closer to your face.
How *much* to elevate the tip, or deproject the nose, or make other changes? We figure that out with morphs, well before surgery. I'd love for you to see some excellent professionally-designed morphs of what could possibly be done with your nose. Morphs could also help you identify better just what's bothering you, and help you set a goal for the rhinoplasty that's accurate for your tastes. Profile and three-quarter views would be particularly important in morphing your nose. (Side note: in my opinion, morphs should really be done by the surgeon, or he should direct an assistant as she makes the morphs. Morphs should be made with a constant eye to what actually *can* be done in surgery, for that particular nose, and the surgeon has that information and judgment best.)

Finally, remember that rhinoplasty is an exquisitely difficult operation to get right, and you should only have surgery if you are able to make yourself very confident in your surgeon's skills. The changes that your nose needs, particularly the movement of the tip back closer to the face, require advanced techniques, and skill that most plastic surgeons don't possess with expertise. For most noses, it's much better to not have surgery than to have inexpertly-performed surgery. Read my essay on how to stay out of trouble while selecting a rhinoplasty surgeon. And it also discusses how to take photos that are best for online evaluations.

And for those who have had previous surgery, it also discusses how to tell whether your first surgeon should be performing your revision.

Based on your photo, you appear to have an overprojected nasal appearance. That means the lower 1/3 of your nose sticks out a bit too far. If you do not have severe dissatisfaction with the appearance of your nose, it may be best not to undergo rhinoplasty surgery. Your jawline may be poorly defined due to excess fatty deposits under your chin. Depending on your examination, neck liposuction may be considered for improving your jawline. A small chin implant may be considered as well. I hope this is helpful! Sincerely, Dr Joseph