Jaw reduction surgery involves the removal of bone and reshaping of the jawline to achieve a more desirable facial appearance. While this surgery can improve facial symmetry, it can also potentially affect your ability to withstand blows to the face, such as those that occur in MMA or kickboxing. The strength of your chin and ability to withstand impact is largely determined by bone structure and muscle strength, so it's possible that jaw reduction surgery could weaken your chin and make you more susceptible to getting knocked out. However, the extent of this impact will depend on the specifics of your surgery and your individual anatomy. It's important to discuss your concerns with your surgeon and your coach/trainer to get a better understanding of how the surgery may affect your martial arts career. Your surgeon can provide information about the risks and benefits of the surgery, as well as any potential impacts on your jaw strength and ability to withstand impact. Your coach or trainer can provide guidance on how to adjust your training regimen to account for any changes in your physical abilities. In addition, it's important to consider the recovery process after jaw reduction surgery. This surgery can involve a significant recovery period and may require restrictions on physical activity, including martial arts training, for a period of time. You should discuss the recovery process with your surgeon and ensure that you have a clear understanding of what to expect before undergoing the surgery. Overall, it's important to carefully consider the potential risks and benefits of jaw reduction surgery before undergoing the procedure, especially if you are involved in contact sports like MMA or kickboxing. It's also important to work closely with your surgeon and coach/trainer to ensure that you are making informed decisions about your health and your athletic career. Best of luck !