When we place a chin implant, it is right below the mental nerves, which supply sensation to the chin and lower lip. 5 years is a long time to have numbness, and it is not clear whether or not chin implant removal would lead to Restoration of sensation. Who could consider requesting a CAT scan of your mandible, and this will show the relationship of the chin implant to the mental nerves. If the implant was placed too high, and is impinging upon one of the nerves, implant removal may be considered. Sometimes, misalignment of a chin implant can be determined during a physical examination. Please consider Consulting with a reputable facial plastic surgeon so you can gain Clarity. I hope this helps. Sincerely, Dr Joseph