Uneven jaw & round face, will masseter Botox help me? (Photos)

I think you have a few options. Masseter Botox may very well help, but possibly not to the exteny you are looking for. If you are considering surgical options, jawline contouring can reduce the width of you face by essentially shaving down the jaw bone to create a slimmer appearance. With that, you may also consider a genioplasty. The lower portion of your face is short, which also contributes to the roundness of your face. By lowering your chin, you can create more facial balance, and elongate your jawline, which will help to reduce the overall appearance of a wide jaw. This procedure can also help to correct the asymmetry as well. Another thought could be buccal fat removal. This will help to reduce the fullness in your cheeks and lift a little off the jawline. You definitely have some choices, but it depends on your desired outcome and if you are even considering surgical options.

The facial muscles are supported by the bone and teeth of the jaws.

It looks like you likely have an underdeveloped maxilla.

Need to see wide smile but I think you may be good candidate for DNA Appliance.

Ira L Shapira DDS, D,ABDSM, D,AAIPM, FICCMO, MICCMO
Editor in Chief: CRANIO..Journal of Craniomandibular and Sleep Practice.
Past Chair, Alliance of TMD Organizations
Diplomat, Academy of Integrative Pain Management
Diplomate, American Board of Dental Sleep Medicine
Diplomate, American Board Sleep and Breathing
Vice-President Regent, Master & Fellow, International College of CranioMandibular Orthopedics
Board Eligible, American Academy of CranioFacial Pain
Professor Neuromuscular Orthodontics and CranioMandibular Orthopedics University of Castellon
Dental Section Editor, Sleep & Health Journal
Past CranioFacial Pain Section Editor, CRANIO: Journal of Craniomandibular and Sleep Practice
Member, American Equilibration Society

Member, Academy of Applied Myofunctional Sciences
Member, Academy of Cosmetic Dentistry
Life Member, American Dental Association

There is definitely a masseter component to your full lower face. Botox or another neuromodulator will help but not completely thin your face. I would try it and in skilled hands the worst that can happen is you have less jaw clenching for a while.

From your photos it appears you are a candidate for masseter Botox. The treatment is done in the office with final results seen after 14 days. The results will gradually fade over three to four months typically. See an expert injector near you to learn more.