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