Research on facial micro-expression analysis has been going on for decades. Micro-expression can reflect the true emotions of individuals, and it has important application value in assisting auxiliary diagnosis and disease monitoring of mental disorders. In recent years, the development of artificial intelligence and big data technology has made the automatic recognition of micro-expressions possible, which will make micro-expression analysis more convenient and more widely used. This paper reviews the development of facial micro-expression analysis and its application in forensic psychiatry, to look into further application prospects and development direction.
Humans ; Forensic Psychiatry ; Artificial Intelligence ; Mental Disorders/diagnosis* ; Facial Expression ; Emotions

OBJECTIVE: To automatically construct lips symmetry reference plane (SRP) based on posed smile, and to evaluate its advantages over conventional digital aesthetic design. METHODS: Eighteen subjects' three-dimensional facial and dentition data were gathered in this study. The lips SRP of experimental groups were used with the standard weighted Procrustes analysis (WPA) algorithm and iterative closest point (ICP), respectively. A reference plane defined by experts based on regional ICP algorithm, served as the truth plane. The angle error values between the lips SRP of WPA algorithm in the experimental groups and the truth plane were evaluated in this study, and the lips SRP of ICP algorithm of the experimental groups was calculated in the same way. The lips SRP based on posed smile as a reference for aesthetic design and evaluate preliminary clinical application. RESULTS: The average angle error between the lips SRP of WPA algorithm and the truth plane was 1.78°±1.24°, which was smaller than that between the lips SRP of ICP and the truth plane 7.41°±4.31°. There were significant differences in the angle errors among the groups (P < 0.05). In the aesthetic design of anterior teeth, automatically constructing the lips SRP of WPA algorithm based on posed smile and the original symmetry plane by re-ference compared with the prosthetic design, the subjects' scores on the lips SRP of WPA algorithm based on posed smile (8.48±0.57) were higher than those on the original symmetry plane (5.20±1.31). CONCLUSION Automatically constructing the lips SRP of WPA algorithm based on posed smile was more accurate than ICP algorithm, which was consistent with the truth plane. Moreover, it can provide an important reference for oral aesthetic diagnosis and aesthetic analysis of the restoration effect. In the aesthetic design of anterior teeth, automatically constructing the lips SRP of WPA algorithm based on posed smile can improve the patients' satisfaction in esthetic rehabilitation.
Esthetics, Dental ; Humans ; Lip ; Smiling ; Tooth ; Workflow

Objective: To investigate the outcomes of masseter nerve-innervated free gracilis muscle transfer for smile reanimation in adults and to explore surgical indications. Methods: A retrospective chart review of 37 patients (11 males, 26 females, with (40.3±12.7) years old)who underwent masseter nerve-innervated free gracilis muscle transfer for smile reanimation between 2016 and 2017 was performed. Patient-reported quality of life (facial clinimetric evaluation, FaCE), physician-reported facial function (eFACE facial grading scale), and oral commissure excursion were compared preoperatively and postoperatively. SPSS 11.0 software was used to analyze the data. Results: Thirty-seven patients were followed up in one year after surgery. Significant postoperative improvements were demonstrated for commissure excursion with smile (preoperatively: (-1.2±3.1) mm, postoperatively: (6.1±3.5) mm, t=-31.1, P<0.01), ipsilateral FaCE (preoperatively: (29.4±14.1), postoperatively: (57.6±23.4), t=-38.1, P<0.01), eFACE score (Composite score t=-35.8, Static score t=-29.1, Dynamic score t=-41.3,Midface score t=-43.9, all P<0.01), respectively. Conclusion: Masseter nerve-innervated free gracilis muscle transfer is an good option for dynamic smile reanimation in adult patients who have undergone treatment for long-standing facial paralysis.
Adult ; Facial Paralysis/surgery* ; Female ; Gracilis Muscle ; Humans ; Male ; Middle Aged ; Nerve Transfer ; Quality of Life ; Reconstructive Surgical Procedures ; Retrospective Studies ; Smiling

OBJECTIVE: To explore the possibility of the Smile Lite MDP (Smile Lite Mobile Dental Photograph) portable dental photography system applying in anterior teeth aesthetic photography, and to provide the chance to simplify aesthetic photography process and facilitate communication among patients, dentists and dental technitians. METHODS: The Smile Lite MDP photography system combined with the smartphone were used to photograph the front occlusal phase photos of anterior teeth. The photographic conditions including the color temperature parameter, the Smile Lite MDP light position and the intensity settings were explored. The best photographic conditions were chosen by blind evaluation within experienced dentists and technicians through the method of the visual analogue scale/score (VAS) evaluation, which went through statistical analysis to figure out the optimum photograghic conditions. Smile Lite MDP photography system was used to photograph the front occlusal phase photos of anterior teeth under the optimum parameter by different magnifications. The width/height ratio of the central incisor and the front width ratio of the upper anterior teeth in those photos were measured and calculated respectively. The accuracy of the anterior teeth photos taken by Smile Lite MDP photography system was analyzed based on the photographs taken by digital single lens reflex (DSLR) camera. RESULTS: The optimum color temperature parameter of Smile Lite MDP portable camera system was 5 000 K, the optimum magnification was 4 times, the best light position was the side lights of Smile Lite MDP, the optimum intensity of lights was 2 grades. Photos taken by the optimum parameters won the highest score during the VAS evaluation and the result of statistical analysis had significant difference compared with other groups (P<0.05). When comparing the photos of the upper anterior teeth taken by the Smile Lite MDP portable photography system using 4 times magnification or by DSLR using the standard parameters, there was no significant difference neither in the width/hieght ratio of the central incisor nor in the front width ratio of the upper anterior teeth (P>0.05). CONCLUSION The Smile Lite MDP portable dental photography system applying in anterior teeth aesthetic analysis photography was capable to show the color and shape of anterior teeth in an accurate way by using the right photography parameters. Therefore, Smile Lite MDP portable dental photography system was considered to be a simple and easy photographic tool in clinical work.
Esthetics ; Esthetics, Dental ; Humans ; Incisor ; Photography ; Smiling

OBJECTIVE: To assess the reproducibility of non-verbal facial expressions (smile lips closed, smile lips open, lip purse, cheek puff) in normal persons using dynamic three-dimensional (3D) imaging and provide reference data for future research. METHODS: In this study, 15 adults (7 males and 8 females) without facial asymmetry and facial nerve dysfunction were recruited. Each participant was seated upright in front of the 3D imaging system in natural head position. The whole face could be captured in all six cameras. The dynamic 3D system captured 60 3D images per second. Four facial expressions were included: smile lips closed, smile lips open, lip purse, and cheek puff. Before starting, we instructed the subjects to make facial expressions to develop muscle memory. During recording, each facial expression took about 3 to 4 seconds. At least 1 week later, the procedure was repeated. The rest position (T0) was considered as the base frame. The first quartile of expressions (T1), just after reaching the maximum state of expressions (T2), just before the end of maximum state of expressions (T3), the third quartile of expressions (T4), and the end of motion (T5) were selected as key frames. Using the stable part of face such as forehead, each key frame (T1-T5) of the different expressions was aligned on the corresponding frame at rest (T0). The root mean square (RMS) between each key frame and its corresponding frame at rest were calculated. The Wilcoxon signed ranks test was applied to assess statistical differences between the corresponding frames of the different facial expressions. RESULTS: Facial expressions like smile lips closed, smile lips open, and cheek puff were reproducible. Lip purse was not reproducible. The statistically significant differences were found on the T2 frame of the repeated lip purse movement. CONCLUSION The dynamic 3D imaging can be used to evaluate the reproducibility of facial expressions. Compared with the qualitative analysis and two-dimensions analysis, dynamic 3D images can be able to more truly represent the facial expressions which make the research more reliable.
Adult ; Face/diagnostic imaging* ; Facial Expression ; Female ; Humans ; Imaging, Three-Dimensional ; Lip/diagnostic imaging* ; Male ; Photogrammetry ; Reproducibility of Results ; Smiling

Emotional information is critical for our social life, in which attentional bias is now a focus in the study on attention. However, the attentional bias processing mechanism of emotional faces still arouses huge controversy. Using similar experimental paradigms and stimuli, the published studies have yielded contradictory results. Some studies suggest that angry faces could automatically stimulate attention, that is, there is an anger superiority effect. On the contrary, lines of growing evidence support the existence of a happiness superiority effect, suggesting that the superiority effect is shown in happy faces rather than angry faces. In the present paper, the behavioral and neuroscience studies of anger and happiness superiority effects are combined. It is found that there are three major reasons for the debate over the two types of effects, which include the choice of stimulus materials, the difference of paradigm setting, and the different stages of emotional processing. By comparatively integrating the previous published results, we highlight that the future studies should further control the experimental materials and procedures, and investigate the processing mechanism of anger and happiness superiority effects by combining cognitive neurobiology means to resolve the disputes.
Anger ; Attentional Bias ; Facial Expression ; Happiness ; Humans

The purpose of the present paper was to review the processing mechanisms of social cues in faces. We summarized researches relative to social cues in faces and discussed the processing mechanism of these cues from the aspects of facial expression, facial attractiveness, gaze and face direction, and lipreading. First, we discussed the general neural mechanism of face information processing and summarized the functions of face areas in the fusiform gyrus, posterior superior temporal sulcus and inferior occipital gyrus. Next, the neural mechanism of emotional face perception was discussed. The processing of emotional faces consists of encodings of perceptual and emotional components. The amygdala plays an important role in the emotional processing of facial expressions. Furthermore, the neural responses to facial expressions may be influenced by multiple factors, such as the type of emotion, the dynamic presentation of the face and the consciousness of facial expressions. With respect to facial attractiveness processing, studies has shown that the reward circuitry is activated by highly attractive faces. However, the influence of facial attractiveness on neural responses remains elusive. It is proposed that the neural responses to facial attractiveness might be modulated by factors such as the task, observer's sex, expectation and other social cues in faces. Eye gaze perception and face view perception are related to visual attention, and the relevant neural circuitry has been found to include attention-related areas, such as the intraparietal sulcus. Finally, research on lipreading reveals its important role in language perception. The auditory cortex and language-related cortex have been shown to be activated by lipreading. In summary, the present evidence may support facial information processing theory. However, the theory could be further improved based on present and future findings. Furthermore, we discussed the deficits in the processing of social cues in individuals with mental disorders and proposed future research directions in this field.
Brain Mapping ; Cues ; Emotions ; Facial Expression ; Humans ; Magnetic Resonance Imaging ; Temporal Lobe ; physiology

OBJECTIVE: To study the clinical effect of integrated sandplay therapy in preschool children with Asperger syndrome (AS). METHODS: A total of 44 preschool children with AS were randomly divided into an experimental group and a control group, with 22 children in each group. The children in the control group were given routine training, and those in the experimental group were given integrated sandplay therapy in addition to the routine training. The treatment response was assess by the Social Responsiveness Scale (SRS), emotional recognition tools and changes in sandplay theme characteristics after 6 months of treatment. RESULTS: Before intervention, there were no significant differences between the two groups in the total score of SRS, the score of each factor of SRS, and correct rates of facial expression recognition of the upright position, inverted position, upper face and lower face (P>0.05). After 6 months of intervention, both groups had significant reductions in the total score of SRS and the score of each factor of SRS (P<0.01); the control group had significant increases in the correct rates of facial expression recognition of all positions except the upright position (P<0.05), while the experimental group had significant increases in the correct rates of facial expression recognition of all positions (P<0.05). Compared with the control group after intervention, the experimental group had significantly lower total score of SRS and scores of all factors of SRS except social perception (P<0.01) and significantly higher correct rates of facial expression recognition of all positions (P<0.01). The experimental group had a significant change in the number of sandplay theme characteristics after intervention (P<0.01). CONCLUSIONS Integrated sandplay therapy can improve social responsiveness and emotion recognition ability in preschool children with AS.
Asperger Syndrome ; Child, Preschool ; Emotions ; Facial Expression ; Humans ; Play Therapy

PURPOSE: This research is to investigate factors that affect dental aesthetics and analyze whether individual perception affects and difference of genders affects the esthetic factors. MATERIALS AND METHODS: Seventy dental students of Chonnam University aged from 25 to 35 years old without periodontal problems were included. Maxillary dental cast for participants were made, and standardized photo was taken with a digital camera. Maximum visual width and the position of gingival zenith of maxillary anterior teeth and maximum height of the maxillary central incisors were measured by a measurement program and the shape of central incisor was categorized. Questionnaire was conducted to evaluate esthetic perception. SPSS program was used to perform statistical analysis. RESULTS: The average visual width ratio of right maxillary anteriors was 1.38:1:0.78 and 1.41:1:0.81 for the left which differ from the golden ratio. The width to height ratio for right and left central incisor was 0.84 and 0.83 respectively. The gingival zenith position was determined to be: mostly, central incisors and canines were located in the distal side, lateral incisors were located in the center. The visual width ratio of right maxillary anterior teeth, ratio of width to height of central incisor, gingival zenith position, crown morphology and amounts of gingival exposure upon smiling were not significantly different between genders, and facial patterns and these dental esthetic factors were not related to aesthetic perception. CONCLUSION: Even though participants had the visual width ratio of maxillary anteriors or ideal width to ideal height of central incisors that did not agree with the golden ratio, they had high satisfaction for dental esthetics. Esthetic perception depends more on subjective judgements of participants than objective indices.
Crowns ; Esthetics ; Esthetics, Dental ; Humans ; Incisor ; Jeollanam-do ; Smiling ; Students, Dental ; Tooth

BACKGROUND: The masseter nerve is a useful donor nerve for reconstruction in patients with established facial palsy, with numerous advantages including low morbidity, a strong motor impulse, high reliability, and fast reinnervation. In this study, we assessed the results of masseter nerve–innervated free gracilis muscle transfer in established facial palsy patients. METHODS: Ten patients with facial palsy who received treatment from January 2015 to January 2017 were enrolled in this study. Three patients received masseter nerve–only free gracilis transfer, and seven received double-innervated free gracilis transfer (masseter nerve and a cross-face nerve graft). Patients were evaluated using the Facial Assessment by Computer Evaluation software (FACEgram) to quantify oral commissure excursion and symmetry at rest and when smiling after muscle transfer. RESULTS: The mean time between surgery and initial movement was roughly 167.7 days. A statistically significant increase in excursion at rest and when smiling was seen after muscle transfer. There was a significant increase in the distance of oral commissure excursion at rest and when smiling. A statistically significant increase was observed in symmetry when smiling. Terzis’ functional and aesthetic grading scores showed significant improvements postoperatively. CONCLUSIONS: Masseter nerve innervation is a good option with many uses in in established facial palsy patients. For some conditions, it is the first-line treatment. Free gracilis muscle transfer using the masseter nerve has excellent results with good symmetry and an effective degree of recovery.
Facial Nerve ; Facial Paralysis ; Free Tissue Flaps ; Humans ; Smiling ; Tissue Donors