If the lips gums and the chin are numb even after 3 months of extraction then you should visit your dentist. May be some nerve is effected during extraction. Your sinus problem has nothing to do with the extraction as you got the lower teeth extracted. For sinus problem you can consult some physician. For more info on wisdom tooth you can visit the following link on our website.....http://www.identalhub.com/article_problems-after-removal-of-wisdom-teeth-254.aspx