The objective of the research is to determine whether the MyotonPRO has a valid and reliable application in facial, head and neck surgery. In addition, the study aims to compare this new technology with current electromyography.

Facial paralysis has significant aesthetic, functional and psycho-social morbidity. The diagnosis and monitoring of neuromuscular recovery is limited to clinical examination, electromyography (EMG) and electroneurography (ENoG). EMG and ENoG is invasive for the patient and has practical and cost disadvantages. The MyotonPRO is a handheld device, which is pain-free and quick to use. Therefore this research is assessing MyotonPRO technology for this clinical application and may be effective at evaluating rehabilitative and surgical interventions. Phase 1 - Variation of measurements Phase 2 - Mimic muscle dysfunction assessment Phase 3 - Peri-operative Mimic and temporalis muscle assessment Phase 4 - Phase 3 including electromyography Phase 5 - Temporalis and mimic muscle assessment following facial reanimation surgery

Inclusion Criteria:

1. unilateral peripheral facial nerve palsy
2. Mental capacity to give consent
3. The patient is able to sit independently

Exclusion Criteria:

1. Adults who have undertaken strenuous exercise within the last twenty-four hours
2. Adults taking prescription medication with a known effect on the mechanical properties of muscle (e.g. benzodiazepines) or receiving antispasmodic medications (e.g. botulinum A toxin)
3. Adults with poor mobility (unable to lie prone).
4. Adults with a body mass index (BMI) >30 kg/m2 . Muscle measurements may be inaccurate with excessive subcutaneous tissue