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 2010-10, Vol.39 (10), p.990-999
• Main Authors: Sforza, C, Mapelli, A, Galante, D, Moriconi, S, Ibba, T.M, Ferraro, L, Ferrario, V.F
• Format: Article
• Language: English
• Subjects: Adult; Age Factors; ageing; asymmetry; Biological and medical sciences; Blinking - physiology; Chin - anatomy & histology; Chin - physiology; Dentistry; 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
• ISSN: 0901-5027; 1399-0020
• DOI: 10.1016/j.ijom.2010.05.011

Abstract 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.