People, who have experienced facial paralysis as a result of trauma/tumour/infection, may require a surgical procedure to the facial nerve to help restore their facial activity. If there is a propensity for the biting muscle, known as the masseter to contribute to smile and laughter in normal subjects; should patients be screened pre-operatively to identify if their masseter is active within their non-paralysed side of their face?
If so, this should be used to influence the choice of nerve graft used. That is to say, a masseteric graft procedure versus alternative grafts known as the hypoglossal, auricular and sural which innervate the tongue, ear and ankle respectively.
An audit was undertaken to review the outcomes of seventeen people with loss of their facial nerve activity as a result of trauma, tumour invasion or surgical procedure, who underwent surgical reanimation of their face via a masseter to facial nerve graft.
Seventeen people underwent masseteric nerve transfer to reanimate their facial activity at QEHB. Of those seventeen, twelve regained smile activity; five of those acquired spontaneous activation during this expression plus regained normal activation of the facial musculature during speech. Seven people could activate their facial muscles to achieve a voluntary smile, but had limited or no activation during speech. 3 experienced failure of the nerve graft and therefore no activation of their facial muscles throughout the affected side was seen. One was lost to follow up and one sadly RIP as a result of progression of their disease.
Five people went onto further plastic surgery, those who experienced a failure of the graft; two received a modified temporalis myoplasty and the other a static sling. Two people required "face lifts" to improve the efficacy of the masseteric activity via the reduction of excess skin which arose as a result of muscle atrophy pre-operatively.
Massteric nerve transfer was effective at regaining smile activation in 70 % of cases, However only ~30% acquired spontaneous expression and speech.
Should preoperative screening of master coactivation in normal smile be assessed prior to surgery to establish if a masseteric nerve graft should be used ? If masseteric activation is nor present preoperatively, should the patients be offered a different procedure which would be more effective and save them from repeated surgeries and the NHS money from failed or substandard outcomes?
Identification of spontaneous recruitment of masseter muscles during smile and laughter. It will allow us to extend our knowledge into laughter as well as smile reanimation. It will also potentially improve outcome as those who demonstrate spontaneous masseter activation during smile preoperatively, are more like to benefit from a massteric nerve graft, rather than any other non - facial nerve donor graft, plus they have a greater opportunity to regain spontaneity of their smile.
This work was presented at Physiotherapy UK 2019