OBJECTIVE: To investigate the changes and symmetry of facial soft tissue during posed smile, to analyze the feature of posed smile in different gender, and verify the reproducibility of posed smile. METHODS: Three-dimensional (3D) facial images of 41 adults (16 males and 25 females with an average age of 26.76±2.70 years) which were taken by FaceScan three-dimensional sensor, including one rest position and two posed smile images. Then these images were imported into 3D soft tissue analysis software for model repositioning. 3D morphable model method (3DMM) was carried out to automatic landmarks setting. After that, the measurement of the eyes, cheeks, nose and perioral area were carried out for 3D soft tissue analysis. Finally, the changes and symmetry of the soft tissues between the two expression states and the gender differences during the posed smiles were compared. Meanwhile, the reproducibility of posed smile was statistically tested. RESULTS: Compared with the rest position, except for nasolabial angle (1.45°±7.65°), the measurements of 3D soft tissue in other region were changed in posed smile (P < 0.001). It should be noted that the eye region was also significantly changed (P < 0.001). Furthermore, the prominent feature of posed smile was that the alar base length became longer, the upper and lower vermilions were narrow and thin, and the mentolabial furrows became shallow. Meanwhile the chin extended anteriorly while the mouth retracted; During posed smile, the labial fissure asymmetry [2.78 (1.73, 3.49) mm], mid-infraorbital asymmetry [2.36 (1.22, 3.27) mm] and outercanthal asymmetry [2.31(1.29, 2.80) mm] were most apparent. Compared with the rest position, the asymmetry was not significantly increased except for cheilion and alar curvature points during the posed smile (P>0.05). In the posed smile, the changes of the right palpebral fissure height and the thickness of lower vermilion (|Li-Stoi| _z) of males were greater than those of females (P < 0.05), and asymmetry of exocanthion and cheekbone increased more than that of females (P < 0.05). There was no obvious difference between the two posed smiles. CONCLUSION In this study, during the posed smile the soft tissues of the eyes, cheeks, nose, lips and chin changed in different degrees, and the asymmetry of cheilion and alar curvature point was greater than that of the rest position; In addition, the reproducibility of posed smile was excellent, which can be a reference for clinical aesthetics and functional research of smile.
Humans ; Smiling/physiology* ; Female ; Male ; Adult ; Imaging, Three-Dimensional/methods* ; Face/anatomy & histology* ; Young Adult ; Facial Expression

OBJECTIVES: This study aimed to analyze the correlations and proportional relationships between maxillary anterior teeth (MAT) and facial measurements in Han Chinese individuals with the most attractive smiles, as evaluated by dental professionals. METHODS: Ten dentists with more than 5 years of clinical experience from different professional directions in a tertiary stomatological hospital were selected to evaluate the smile attractiveness of volunteers by visual analogue scale (VAS). Eighty-eight Han volunteers with the most attractive smile were selected. The perceived width of the MAT, the dimensions (height and width) of the maxillary central incisors (MCI), and the facial dimensions (intercanthal distance, interzygomatic distance, interalar distance, facial height and lower facial height) of the volunteers were measured on the frontal photos of the smile, digital oral model, and 3D face model. Pearson correlation analysis was performed to analyze linear correlations, and regression analysis was carried out to explore the proportional relationships. Reliability analysis using the intraclass correlation coefficient verified the stability of these proportional relationships. In addition, the correlations between MAT perceived width and the proportional relationships of (MCI) height to width ratio, with facial dimensions were explored and their reliability was verified. RESULTS: In Han Chinese individuals with the most attractive smiles, as evaluated by dental professionals, the Pearson correlation coefficients among MAT perceived widths were 0.813, 0.389, and 0.560. A proportional relationship existed between the lateral incisor and central incisor, and the ratio was 0.729. No significant correlations were found between MCI and the inner canthal distance, zygomatic distance, interalar distance, facial height, or the lower one-third facial height except for a negative correlation (r=-0.357) between MCI height and facial height in males and a positive correlation (r=0.249) between MCI width and interalar width when genders were combined. CONCLUSIONS Correlations exist among MAT perceived widths in Han Chinese individuals with the most attractive smiles, as evaluated by dental professionals. Partial correlations are observed between MCI height and width and facial measurements. The perceived width of the lateral incisor can serve as a reference indicator for predicting the perceived width of the central incisor, providing a reference for the aesthetic restoration of MAT in the Han ethnicity population.
Adult ; Female ; Humans ; Male ; China ; Esthetics, Dental ; Face/anatomy & histology* ; Incisor/anatomy & histology* ; Maxilla/anatomy & histology* ; Smiling ; East Asian People

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

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

PURPOSE: The feasibility and differential effects of two music therapy methods (interventions with preferred music vs. classical relaxation music) were done to examine the effects on agitation and anxiety in patients weaning off mechanical ventilation. METHODS: This pilot study was conducted using a crossover design. Six patients listened to preferred music choices and classical relaxation music. Anxiety scores were measured using the Richmond Agitation Sedation Scale (RASS), State-Trait Anxiety Inventory (STAI), and visual analog scale (VAS). RESULTS: Patients showed a significant decrease in agitation and anxiety after both the preferred and classical relaxation music interventions. The difference in the effects of preferred music and that of classical relaxation music was not significant. As for feasibility, patients exhibited a change in agitated behaviors after the music interventions by not trying to take off medical devices and quietly listening to the music, and by smiling and moving lips along with the lyrics while listening. CONCLUSION: Music interventions which centered on either patients' preferences or classical relaxation music to enhance relaxation, helped reduce agitation and anxiety during the mechanical ventilation weaning process.
Anxiety ; Cross-Over Studies ; Dihydroergotamine ; Humans ; Lip ; Methods ; Music Therapy ; Music ; Pilot Projects ; Relaxation ; Respiration, Artificial ; Smiling ; Ventilation ; Visual Analog Scale ; Weaning

OBJECTIVE: To analyze the long-term changes in maxillary arch widths and buccal corridor ratios in orthodontic patients treated with and without premolar extractions. METHODS: The study included 53 patients who were divided into the extraction (n = 28) and nonextraction (n = 25) groups. These patients had complete orthodontic records from the pretreatment (T1), posttreatment (T2), and postretention (T3) periods. Their mean retention and postretention times were 4 years 2 months and 17 years 8 months, respectively. Dental models and smiling photographs from all three periods were digitized to compare the changes in three dental arch width measurements and three buccal corridor ratios over time between the extraction and nonextraction groups. Data were analyzed using analysis of variance tests. Post-hoc multiple comparisons were made using Bonferroni correction. RESULTS: Soft-tissue extension during smiling increased with age in both groups. The maximum dental width to smile width ratio (MDW/SW) also showed a favorable increase with treatment in both groups (p < 0.05), and remained virtually stable at T3 (p > 0.05). According to the MDW/SW ratio, the mean difference in the buccal corridor space of the two groups was 2.4 ± 0.2% at T3. Additionally, no significant group × time interaction was found for any of the buccal corridor ratios studied. CONCLUSIONS: Premolar extractions did not negatively affect transverse maxillary arch widths and buccal corridor ratios. The long-term outcome of orthodontic treatment was comparable between the study groups.
Bicuspid ; Dental Arch ; Dental Models ; Esthetics* ; Humans ; Smiling