Q: Dr. Eppley, I had a sliding genioplasty three months ago and now my left lower lip is paralyzed. It affects my smile and when I open my mouth. What surgical procedure can I do to make it better. What type of nerve repair is needed and how is it done?
A:The most common nerve injury from a sliding genioplasty is that of the mental nerve, a sensory nerve that controls the feeling of the lip and chin. Injury to a branch of the facial nerve is different as this is a motor nerve that controls the depressor anguli oris (DAO) muscle which provides a depressor or pull down of the lower lip when smiling.
If you have developed marginal mandibular nerve weakness from a sliding genioplasty (or any other chin surgery), which is a very rare complication from this type of surgery, the only potential resolution is time. This is a monofascicular branch of the facial nerve that has no interconnections with other facial nerve branches so its recovery will be slow. It is not likely that it is cut or torn but stretched. Even if it was inadvertently cut it is too small to find and repair. This is why time is all that can be done with marginal mandibular facial nerve injuries. Many do resolve satusfactorily with time.
Dr. Barry Eppley
Q: Dr. Eppley, I had jaw surgery two times and now have lip damage. Bottom lip seems paralyzed or damaged. (lower lip asymmetry) I saw online and seems others have had the same problem. I have seen it may be hyperplasia of depressor orbis lip muscle or paralysis of lower lip nerve. I don’t know what it is. Do you think it is nerve damage or muscle damage? Is it likely to be permanent damage after jaw surgery or temporary? I has been one year now and still no change. It is less obvious when relaxed but when make ‘O’ shape with lips or kiss shape with lips or smile it pulls down to one side on my right. The left side doesn’t pull down. I did think it was the right side which shows lower teeth when smile which is the problem side but actually I think after research it is the left side which doesn’t show any teeth when smile which is the problem side. I have seen certain solutions are to use Botox but are there any other options? I want something permanent. Can a surgeon correct it with more invasive surgery? Can they maybe correct the problem side or maybe damage the other side so both don’t show lower teeth when smile because personally I think that looks better to only show upper teeth. I really need your help doctor. Please help thanks.
A: What you have is paralysis of the left marginal mandibular branch of the facial nerve. This tiny nerve branch supplies movement to the depressor muscle of the lower lip. With the nerve being paralyzed that side of the lip does not move down normally while the opposite right side does. With no lower lip movement on the left, the normal righth lower lip retraction looks exaggerated and overly pulled down. This lower lip appearance can make one think the side of the lip that moves is the problem when in fact the th higher lower lip side is the culprit of the lower lip asymmetry.
At one year from the injury with no movement, there is no reason for optimism that the paralyzed nerve will start working again. I wouldn’t say it is impossible but very unlikely. There is no method to make the nerve work again other than natural healing. Thus the treatment for lower lip asymmetry from permanent marginal mandibular nerve paralysis is to weaken the opposite side whose muscular movements are exaggerated. This can be done by Botox injections (temporary) or by partial resection of the depressor muscle from an intraoral approach. (permanent)
Dr. Barry Eppley