RP Mehta, S Zhang, and TA Hadlock , "Novel 3-D video for quantification of facial movement," Otolaryngol Head Neck Surg., 138(4), 468-472, 2008; doi: 10.1016/j.otohns.2007.12.017
OBJECTIVES: To evaluate a novel 3-D geometry video acquisition system (3-D VAS) for quantifying facial movement. METHODS: Ten normal subjects and four patients with facial paralysis underwent recording of facial movement during three facial expressions. Facial feature points of interest were digitally marked on selected images. The maximum 3-D displacement of the brow and oral commissure and palpebral fissure width were determined. RESULTS: Test-retest reliability using the 3-D VAS in normal subjects was high (Spearman correlation coefficients 0.661-0.830, P 0.05). The predicted ratio of left to right facial measurements was 1.00 in normal subjects, and measured mean ratios were 1.05 (brow excursion), 1.01 (palpebral fissure width), and 1.03 (oral commissure excursion), respectively, matching the prediction. The 3-D VAS reliably quantified facial movement on both sides in patients with facial paralysis. CONCLUSIONS: The novel 3-D VAS can accurately and reliably quantify facial movement in healthy subjects. It is promising as a clinical tool to quantify facial movement in patients with facial paralysis.