Facial mobility and recovery in patients with unilateral facial paralysis

Objective (a) To quantify longitudinal 3D changes in facial soft tissue movements in adults with unilateral facial paralysis, and (b) to compare the patients' movements with an age- and sex-frequency matched control group. Settings and Sample Population Prospective 3D facial movement data of 36 patients and 68 control participants. Patients' data were collected within 6 weeks of onset of symptoms (baseline) and then at 3 and 12 weeks after baseline. Materials and Methods The 3D facial movement data were collected during different facial animations. Mean group measurements of displacement, velocity and asymmetry were computed. Two sample t tests were used to test for significant group differences, and linear mixed models were fit to test for significant changes over time in the patient group. Also, 3D dynamic modelling and vector plots were computed to isolate the patients' abnormal movements and/or paralysis. Results The patients' mean baseline movements were significantly less for both the paralysed and contralateral sides of the face with much greater movement asymmetry than the controls. Patients' mean measures improved significantly from baseline to 12 weeks. The measures were closer to, but fell short of, the control values. Conclusion In unilateral facial paralysis, the contralateral facial side was affected by the paralysis and may be tethered or limited in its movement by the paralysed side. The comprehensive measurement set and 3D facial mapping effectively tracked patient recovery and isolated paralysed facial regions. The 3D measures can be used for diagnosis and outcome assessment of different treatments.