The effect of age and sex on facial mimicry: a three-dimensional study in healthy adults

• Published in: International journal of oral and maxillofacial surgery Vol. 39; no. 10; pp. 990 - 999
• Main Authors: Sforza, C., Mapelli, A., Galante, D., Moriconi, S., Ibba, T.M., Ferraro, L., Ferrario, V.F.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Inc 01.10.2010; Elsevier Ltd; Elsevier
• Subjects: Adult; Age Factors; ageing; asymmetry; Biological and medical sciences; Blinking - physiology; Chin - anatomy & histology; Chin - physiology; Eyelids - anatomy & histology; Eyelids - physiology; Face - anatomy & histology; Facial Asymmetry - pathology; Facial Asymmetry - physiopathology; Facial Expression; Facial Muscles - anatomy & histology; Facial Muscles - physiology; Female; Forehead - anatomy & histology; Forehead - physiology; Humans; Imaging, Three-Dimensional - methods; Lip - anatomy & histology; Lip - physiology; Male; Medical sciences; Middle Aged; mimics; motion analysis; Mouth - anatomy & histology; Mouth - physiology; Muscle Contraction - physiology; Nose - anatomy & histology; Nose - physiology; Otorhinolaryngology. Stomatology; Sex Factors; Smiling - physiology; Surgery; Young Adult; 3D; ageing; asymmetry; mimics; motion analysis; Human; Motion; Stomatology; Ageing; Sex; Treatment; Asymmetry; Surgery; Adult; Face; Age
• ISSN: 0901-5027; 1399-0020; 1399-0020
• DOI: 10.1016/j.ijom.2010.05.011

To assess sex- and age-related characteristics in standardized facial movements, 40 healthy adults (20 men, 20 women; aged 20–50 years) performed seven standardized facial movements (maximum smile; free smile; “surprise” with closed mouth; “surprise” with open mouth; eye closure; right- and left-side eye closures). The three-dimensional coordinates of 21 soft tissue facial landmarks were recorded by a motion analyser, their movements computed, and asymmetry indices calculated. Within each movement, total facial mobility was independent from sex and age (analysis of variance, p>0.05). Asymmetry indices of the eyes and mouth were similar in both sexes (p>0.05). Age significantly influenced eye and mouth asymmetries of the right-side eye closure, and eye asymmetry of the surprise movement. On average, the asymmetry indices of the symmetric movements were always lower than 8%, and most did not deviate from the expected value of 0 (Student's t). Larger asymmetries were found for the asymmetric eye closures (eyes, up to 50%, p<0.05; mouth, up to 30%, p<0.05 only in the 20–30-year-old subjects). In conclusion, sex and age had a limited influence on total facial motion and asymmetry in normal adult men and women.