Disproportionately short chin and wide jaw. Could dermal fillers be used to lengthen my face?

I have reviewed your photos and your face is well balanced. Your chin projection is good and the width of your jawline is normal. You have a beautiful and youthful face and I wouldn't change anything!

Thanks for the photos!You would be a great candidate for a combination of fillers and a toxin such as BOTOX Cosmetic and I would recommend using them in the following manner:BOTOX Cosmetic (to decrease the size of your masseter muscle and narrow your jawline)Voluma XC (to build out more volume in your mid face and emphasize your cheeks)Voluma XC (to lengthen your chin point and ultimately create a longer jawline)Used together, this combination approach would give you a more V-shaped appearance to your face and help take the emphasis off of your wider jawline.  When injected by a trained professional with an aesthetic eye, this combination is extremely powerful in creating more balance and harmony to your overall face.I hope that helps and wish you the very best!-Gregory A Buford MD FACSBoard Certified Plastic Surgeon and Author

The square appearance of the lower face is due to large maseters- muscles of chewing, and a disproportionally small chin
The muscles can be injected with Botox to create a more oblique outline to the lower face and the chin can be enhanced with a filler to bring it forward- that will improve the overall symmetry and your anatomical lines
Good luck

Yes , fillers if chosen properly , can enlarge and and lengthen your chin to some degree.  A more permanent soloution is a chin implant to balance your face.  Seek well qualified board certified Dr to perform the injection or the surgery.