My upper denture fits tightly, but my lower denture is always loose. Why is this happening?

Lower dentures are typically always loose. The upper denture uses the palate for suction, but the lower denture does not have a stable surface to rest on.

After teeth are extracted, the lower jaw shrinks or resorbs at a rate four times faster than the upper jaw. As the lower jaw shrinks, the lower denture comes in closer contact with muscle attachments, which dislodge the denture.

Implant-supported dentures are the best solution for securing loose lower dentures.