Ouch! That sounds like quite a serious burn, and I am sorry to hear about the continued problem that you have had. If you have marks of trauma that are still present this long after the trauma, it is time for you to speak with your doctor
about this problem. In general, the face is one of the first parts of the body to heal when it is injured. This is because it has an excellent blood supply, which is one of the main keys to healing well. When wounds like the one you describe on your face don't heal quickly, it is important to understand why not. Could it be that there is a bacterial infection that is preventing appropriate healing? Could there be something about the extent of the trauma that is greater than what was originally thought? Could you have some condition that is preventing the healing, such as diabetes? Are you still smoking or using other products that could cause delayed healing? In addition to these questions, there are many more that your doctor will ask to make sure that you heal appropriately. He or she may do other testing as well. Again, please speak with your doctor.