Morphological Uniqueness: The Concept and Its Relationship to Indicators of Biological Quality of Human Faces from Equatorial Africa

Facial symmetry, averageness, and the level of sex-typical development of dimorphic traits are traditionally associated with various biological quality indicators and should be, therefore, preferred in mate choice. The aim of this study is to propose a concept of morphological uniqueness and uncover its possible associations to putative phenotypic cues of biological quality. In contrast to typicality expressed by averageness, morphological uniqueness quantifies the degree of possessing characteristics unique to particular groups. I employed a combination of geometric morphometric and Bayesian multiple regression to analyze 300 Cameroonian faces, while an additional 1153 faces from eight distinct populations from across four continents were used as a reference sample of the global population to calculate the morphological uniqueness of Cameroonians. I found that morphological uniqueness is positively associated with a feminine facial shape in women and negatively with morphological masculinity in men. Facial symmetry was positively associated with female faces with greater levels of uniqueness; the result for male faces was inconclusive. The faces of both sexes perceived as more attractive had lower levels of morphological uniqueness. Facial distinctiveness showed no relationship to morphological uniqueness in either sex, which indicates that morphological uniqueness and distinctiveness are two complementary approaches to studying facial typicality. In the conclusion, the evolutionary significance of the proposed concept and its potential applicability is discussed.

Preference for Facial Symmetry Depends on Study Design

Facial symmetry is purportedly attractive, though methods for measuring preference for facial symmetry vary between studies. Some studies have used a two-alternative forced choice (2AFC) task, while others have used a ratings task. How researchers manipulate facial symmetry also varies; some studies have used faces manipulated to be more (or perfectly) symmetrical, while others have used faces manipulated to be more asymmetrical. Here, across three studies, we evaluate and compare these different methods. In Studies 1 and 2 (N = 340 and 256, respectively), we compare facial symmetry preferences as measured by the 2AFC and ratings tasks. Across both studies, we consistently found a significant preference for facial symmetry when using the 2AFC task, but not with the ratings task. Additionally, correlations between facial symmetry preferences as measured by the two tasks were weak or showed no association. In Study 3, 159 participants rated the attractiveness of faces manipulated to be either symmetrical or more asymmetrical. The asymmetrical faces were rated as significantly less attractive compared to the original faces, while the difference in attractiveness ratings between the original and symmetrical versions was comparatively much smaller. These studies suggest that preference for facial symmetry depends greatly on the study design.

Depressor Anguli Oris Myectomy versus Transfer to Depressor Labii Inferioris for Facial Symmetry in Synkinetic Facial Paralysis

Background Postparalytic synkinesis presents with a combination of hypo- and hypertonic muscles, leading to facial asynchrony with animation and at rest. One ubiquitous finding is a hypertonic depressor anguli oris (DAO) muscle and a weak depressor labii inferioris (DLI) muscle. The goal of this study was to evaluate the utility of DAO myectomy with or without its transfer to the weakened DLI in improving critical components of the dynamic smile. Methods From 2018 to 2020, this single-center, prospective study included of postparetic facial synkinetic patients with evidence of DAO hypertonicity who underwent DAO myectomy with or without transfer to DLI. Objective facial measurements were used to compare the effectiveness of DAO to DLI transfer to pure DAO myectomy in improving asymmetry of the synkinetic hemiface. Results Twenty-one patients with unilateral postparetic facial synkinesis with DAO hypertonicity were included; 11 underwent DAO myectomy, while 10 underwent DAO to DLI transfer. Baseline demographics and facial measurements were similar between the groups. DAO myectomy resulted in increased modiolus resting position, closed-mouth smile modiolus angle and excursion, open-mouth smile modiolus angle, excursion, dental show, and decreased lower lip height deviation. DAO to DLI transfer demonstrated similar findings but lacked significant increase in excursion and resulted in worsened lower lip height deviation. Conclusion These findings illustrate the utility of DAO myectomy in improving imbalance in the synkinetic patient and necessitate further technical refinements for DAO transfers or a different approach for improving lower lip depression in this subgroup of patients.

Effects of Mime Therapy With Sensory Exercises on Facial Symmetry, Strength, Functional Abilities, and the Recovery Rate in Bell's Palsy Patients

Background and Objectives: Bell palsy is the sudden lower motor neuron paralysis of the facial nerve, characterized by acute unilateral peripheral facial muscle weakness. Physiotherapy has been proven to be beneficial in the rehabilitation of patients with Bell palsy and is important to prevent permanent contractures of the paralyzed facial muscles. A physiotherapy technique includes electrical stimulation and mime therapy to help in restoring lost muscle functions. Also, sensory exercises include varied normality solutions administered. This study aimed to find the effects of mime therapy with sensory exercises on facial symmetry and functional abilities among Bell palsy patients. Methods: A total number of 30 participants were recruited for an interventional study and conveniently assigned into three groups (n=10), where group A received electrical stimulation with facial exercises, group B received electrical stimulation with mime therapy, and group C received a combination of electrical stimulation, mime therapy, and sensory exercises. Each group received 18 sessions; each session was for 60 minutes per day, six days per week, for three weeks. Then, all the participants were assessed using the Sunnybrook facial grading system and the facial disability index. Results: Intragroup analysis showed a significant difference within all three groups (P<0.05). Besides, the intergroup comparison showed maximum recovery in group C followed by groups B and A. Conclusion: A combination of mime therapy and electrical stimulation along with sensory exercises provides the most beneficial intervention to improve facial function and reduce facial synkinesis in Bell palsy individuals. Hence, sensory exercises are recommended as an adjunct to electrical stimulation and mime therapy for the line of treatment for individuals with Bell palsy.

K-Pop's Ingredients of Success

This research paper examines the training hours, physical appearances, and on-screen personalities as potential factors of success in today’s K-pop industry in an attempt to understand such global success. The top 10 most popular male K-pop groups were chosen as this paper’s samples based on the criteria of album sales and music video views. The research method of content analysis was employed to measure certain aspects of each factor; the total training hours, average facial scores based on rules of symmetry, and frequencies of introverted or extroverted behaviors were collected for each group. For the majority, groups that went through extensive training periods, had high facial symmetry scores, and leaned more toward introverted personalities on average were found to be among the most popular and successful. It is important to note, however, that the last outcome may have been due to South Korea’s societal expectations and culture.

The correlation study on mandibular deviation and cervical vertebrae posture in patients with mandibular asymmetry

Background: To explore the degree of skeletal mandibular deviation and the change of mandible position in patients with mandibular deformity and its correlation with cervical posture in patients with jaw deformity using CBCT and to provide the reference for clinical diagnosis and treatment planning. Methods: CBCT images from 30 adult patients with skeletal mandibular deviation and 30 adult individuals with facial symmetry were analyzed and imported in Invivo 5 to reconstruct a 3D hard-tissue surface model. A reference frame was set up and 20 measurements of the mandible and cervical vertebrae were performed to calculated. The difference between the three-dimensional position of the mandible and the posture of cervical spine were analyzed in patients with mandibular asymmetry and normal people. Results: Compared with the normal maxillofacial symmetry groups, there were significant differences in the degree of skeletal mandibular asymmetry and cervical deviation in the mandibular deviation groups(P ＜ 0.05). A strong positive, linear correlation was found in patients with mandibular deviation between the deviation of the mandible and cervical vertebrae posture. Conclusion: There is an inherent correlation between the occurrence of mandibular deviation and the deflection of cervical posture, and they interact on each other. The deformity of mandible affects the three-dimensional posture of the cervical vertebra and can cause different degrees of cervical deflection. The degree of mandible deviation and cervical vertebrae posture in patients with mandibular asymmetry are greater than those in individuals with facial symmetry. Compared with the patients with normal jaw, the deformity among the patients with skeletal mandibular asymmetry has a tendency to tilt forward and bend forward. The abnormal posture of the cervical spine will also affect the three-dimensional position of the mandible, causing the lower 1/3 of the face to appear facial asymmetry with the deflection of the head and neck posture.