Numbness After Chin Liposuction and Implant

If the numbness involves both sides of the chin, it might be simply due to swelling, stretching, and bruising around the mental nerves, particularly if the numbness is not complete. In that case, watchful waiting may be all that's required.
Cutting of the mental nerves on both sides, or complete numbness might well require removal of the implant to allow for some nerve recovery. Your surgeon will have a better idea of the status of those nerves since he was the one there at surgery. It's usually best to go with his advice.
Has it improved at all?

Numbness of the chin and lower lip after chin implant is not uncommon but rarely happens after liposuction of the chin or neck area.

There are two large nerves, the Mental Nerves which supply sensation or feeling to the chin and lower lip and which exit the chin bone just below the "eye teeth".

During the course of dissecting a pocket in which to place the chin implant these nerves can be stretched or injured, resulting in numbness of the chin and lower lip.

Permanent nerve damage is VERY RARE, because the nerves lie high on the mandible (chin bone) above where the chin implant is placed.

Typically numbness improves and returns to normal by 4-6 weeks.

The numbness is typically caused by stretching and injury to the nerve by the surgery, not by compression by the implant, thus I have never removed the implant because of the appearance of numbness.

If sensation has not returned or become better by 6 weeks you may have permanent numbness. Since the cause is typically nerve injury by surgery, I doubt that removal of the implant will correct the problem.

The numbness that has resulted in the lower lip is most likely the result of the chin implant and not the liposuction in the neck. Since it has only been two weeks, one should wait before having the implant removed for approximately three to four months to see if it comes back. If it does not come back, then the implant can be considered for removal for a period of time before re-implanting it. The nerve was most likely stretched at the time of surgery and will most likely come back.