First of all, the teeth are a whole. To change the position of tooth deformity, all teeth usually need to move "cooperatively", which improves the occlusal relationship of the whole tooth. Moreover, even if other teeth don't need to move, they need to be fixed on healthy teeth that don't need to move during orthodontic treatment, so as to forcibly adjust the position of deformed teeth. So generally speaking, the upper and lower teeth need to be corrected together. As for you, you are now 25 years old and can be completely corrected, provided that your teeth are healthy at present. I hope I can help you.