By Neil Bowdler
BBC science reporter
US surgeons have announced they have succeeded in partially re-animating the faces of patients with severe long-term facial paralysis using a new technique.
Stroke victims are among those who may benefit from the technique
The new procedure, which involves the transfer of tendons within the face, has been performed on 15 patients.
Those affected by facial paralysis often lose voluntary movement of muscles on one side of their face.
The Johns Hopkins University surgeons believe their system marks significant progress in treating the condition.
They claim it is simpler, more effective and the surgery less traumatic than traditional methods.
Facial paralysis can have many causes - from trauma caused by an accident to tumours to strokes.
The result is not only deformity, but also often severe speech problems.
When tackled early, various operative techniques such as nerve grafts can now be used to restore movement.
However, surgery has been less successful on those with long-term paralysis, and it is in this area that surgeons at the Johns Hopkins University School of Medicine say they have made significant progress.
The new surgical technique, called temporalis tendon transfer, sounds gruesome.
A major muscle on the side of the head is severed at the point it joins the jawbone and stretched across the head to attach with mouth muscles, before a relating tendon is then also stretched and reconfigured.
The lead surgeon, Dr Patrick J Byrne, says the results in the 15 patients who have so far undergone the procedure, have been deemed good to excellent, with facial symmetry and speech improved with immediate effect.
"This particular technique address two aspects... the one being improving facial symmetry, the other being the return of a smile," he says.
"When we tighten the muscle around the mouth and along the cheek, we find it helps not only with oral competence - their ability to control their mouth - but it also helps with their speech - they have less of the air escape - they're able to generate better articulation."
Dr Byrne claims the technique is simpler, more effective and the surgery less traumatic than the temporalis sling technique which has been traditionally offered in the past to patients with long-term facial paralysis.
He is also claiming the results of surgery will be easier to predict than with other methods used to date.