For many who endure such nerve damage, they recover after 12 months; however, others may never fully recover.[36] While there is not currently much modern medicine can do for these patients, the cutting edge of care is now nerve grafting. These grafts are taken from the masseter muscle, which controls mouth movement, or the hypoglossal nerve which controls the tongue. To avoid denervation caused by lack of stimulus, surgery should be done as soon as possible; however, it is often difficult to determine if a patient will recover naturally or whether nerve grafting is required.