Analysis of Facial Movement in Repaired Unilateral Cleft Lip Using Three-Dimensional Motion Capture

Unilateral cleft lip (UCL) is one of the most common craniofacial deformities. Surgical intervention reconstructs lip and nose anatomy; however, some degree of asymmetry persists after repair. This demonstrates a need for a model for studying and improving outcomes for patients with orofacial clefts. This study's main question was whether there is a significant difference in dynamic facial asymmetry between participants with repaired UCLs and control participants during smiling. Ten pediatric subjects with repaired left UCLs and 12 with no craniofacial diagnoses were recorded performing maximum smiles using a markerless 4D video stereophotogrammetrical system. A facial mesh template containing 884 landmarks was conformed to each initial frame and tracked throughout. Kinetic analysis of smiles was performed by calculating landmark 3D Euclidean distance between frames. Patients with left repaired UCL showed increasing facial asymmetry throughout smiling. Oral commissures, upper, and lower lips demonstrated significantly greater movement on the right side (P < 0.05). Control patients showed facial asymmetry during the first half of smiling, with greater movement on the left side. Displacement difference between right and left was significantly greater at oral commissures and upper lips in patients with repaired ULC compared to control patients. This study provides a highly detailed, quantitative analysis of postoperative UCLs, and help improve outcomes of future repair surgeries.