Botox as chin implant? I want my chin bigger. (photo)

Botox is a neuromodulator that works by relaxing muscles that lead to facial wrinkles. The medication can also be inserted into the masseter (jaw) muscle, which causes it to relax and decrease in size. This treatment is recommended for patients who have a square jawline or those that suffer from pain or tension due to teeth clenching or grinding. Botox will not help to bring out a recessed chin, however. 
Dermal fillers work to create fullness in the chin for a more proportionate facial profile. Fillers like Voluma are specifically designed for larger areas like the chin and offer results that can last up to two years. These fillers are placed by an injection, with no anesthesia or downtime needed. You will need to repeat the treatment every one or two years to maintain your positive results. Always work with a board-certified dermatologist and expert injector for both these treatments to ensure an optimal outcome. 

Thank you for your question. 
Botox is used to soften lines by minimizing the corresponding muscle movement. Botox treatments last about three to four months. Dermal Filler is used to restore volume loss and can sometimes be used to enhance facial features, such as the chin, this is call a non-surgical augmentation of the chin/jawline. Dermal filler treatments can last six months to twelve months depending on the type of filler used and how quickly a patient metabolizes the product. Surgery (chin implant) is an option for those patients looking for a permanent solution.  
It would be best for you to schedule an in-person consult with a board-certified physician who is experienced in your area of concern. 
Best of luck!