Your gums can be affected by many things which you may not realize. Bone loss, weight gain, weight loss and any change in medication can alter your dentures fit. If you have gone through any of these changes above your dentures could need a reline. Patients that have had teeth extracted will need to have a reline done 8-12 months after their extractions due to the rapid bone loss and shrinking of the gums that will occur in that time.