Facial Rehabilitation Research Articles

Factors that facilitate or hinder the use of the facial rehabilitation webtool MEPP 2.0: a comparative study in the Quebecer health system

BackgroundRecently, our research team developed an open source and free website called the MEPP website (for the Mirror Effect Plus Protocol) to efficiently provide mirror therapy for patients with facial palsy. Previous studies demonstrated that the first version of the MEPP website improved user experience and likely optimized patients’ performance during facial therapy. Nevertheless, compliance was found to be low despite a generally positive opinion of the website, and in light of our earlier findings, MEPP 2.0—a revised and enhanced version of the MEPP 0.1—was created. The purpose of this study was to examine and contrast various factors that help or impede institutional partners of the Quebec health care system from using the MEPP 2.0 website in comparison to its initial version.MethodsForty-one patients with facial palsy and nineteen clinicians working with this population were enrolled in a within-subject crossover study. For both the MEPP 1.0 and MEPP 2.0, user experience was assessed for all participants. Embodiment was assessed in patients, and factors influencing clinical use were assessed by clinicians. Qualitative comments about their experiences were also gathered. Descriptive statistics and reliability measures were calculated. Differences between the two MEPP versions were assessed using the linear mixed model.ResultsOverall, patients appreciated more the MEPP 2.0 (OR = 4.57; p < 0.001), and all clinicians preferred the MEPP 2.0 over the MEPP 1.0. For patients, it seems that facial ownership, as well as possession and control of facial movements, was significantly better with the MEPP 2.0. For clinicians, the MEPP 2.0 specifically allowed them to self-evaluate their intervention and follow up with more objectivity. The use of the MEPP 2.0 was also modulated by what their patients reported. Qualitatively, options to access an Android app and needs for improving the exercises bank were mentioned as hindering factors.ConclusionsThe updated version of the MEPP website, the MEPP 2.0, was preferred by our different partners.Trial registrationhttps://www.isrctn.com/ISRCTN10885397. The trial was registered before the start of the study on the 1st December 2023

Combining early lower eyelid surgery with neuromuscular retraining for synkinesis prevention after facial palsy: the role of the eye in aberrant facial nerve regeneration.

Facial synkinesis (FS) is a distressing sequela of facial palsy (FP) characterized by involuntary, simultaneous movements of facial muscles occurring during voluntary facial expressions. Treatment of synkinesis is challenging, and preventive methods are needed. This study evaluated the efficacy of physical facial nerve rehabilitation (PFNR) therapy alone vs. PNFR with eyelid surgery to correct lagophthalmos and prevent the onset of synkinesis. Twenty five outpatients were randomized to receive either PFNR alone (neuromuscular retraining and Kabat proprioceptive neuromuscular facilitation) or PNFR and early (90 days after FP onset) eyelid surgery (involving a conservative oculoplastic correction for lagophthalmos with epiphora or ectropion). Comprehensive otolaryngological assessments and Magnetic Resonance Imaging (MRI) were conducted. Synkinesis progression was measured using Another Disease Scale (ADS) at baseline, 3-, 6-, 12-, and 24-months post-treatment. The data were analyzed with ANOVA, τ-test, Chi-Square analyses. Patients undergoing eyelid surgery with PFNR showed faster (p < 0.001) and better recovery of facial movements (p < 0.05) than patients receiving PFNR alone comparing T0 and T12 (p < 0.0001). No synkinesis were observed in the PFNR plus surgery group while 37% of patients in PFNR alone had synkinesis (p = 0.03). At 24 months, none of the patients in the surgery group presented synkinesis. Combining early surgical treatment of paralytic lagophthalmos or epiphora with PFNR accelerated functional recovery and reduced synkinesis in patients with FP compared to facial rehabilitation alone. Further investigations in larger populations with long-term follow-up are needed. https://clinicaltrials.gov/study/NCT06538103, NCT06538103.

Three-dimensional evaluation of facial asymmetry and its association to occlusal and muscular imbalance in young women.

Diagnosing asymmetries and restoring functional balance are challenges in facial rehabilitation and aesthetic procedures. This cross-sectional observational study aimed to evaluate whether occlusal imbalance and the electromyographic activity of the masseter and temporalis muscles in young women may be associated with facial asymmetry. Fifty women (mean age ± standard deviation: 22.5 ± 2.7), without temporomandibular dysfunction and with balanced facial profiles, were divided into two groups categorized by receiver operating characteristic analysis: symmetric (n=25) and asymmetric (n=25). The variables included the evaluation of asymmetry through clinical examination, quantification of asymmetry using stereophotogrammetry through the root mean square method, asymmetry of occlusal contacts, and electromyographic activity of the masseter and temporal muscles in both latero-lateral and antero-posterior directions. The mean asymmetry indices were compared using Welch's t-test and the Mann-Whitney test. The impact of occlusal and muscular imbalance on facial asymmetry was assessed through linear regression analysis. A significant difference was observed between the groups in the asymmetry of occlusal contacts, with a considerable effect size (p<0.01 - Cohen's d=0.73). The imbalance in the electromyographic activities of the masseter and temporal muscles was considered a predictor of facial asymmetry (F=4.00, p<0.02, R²=0.15). Occlusal imbalance and electromyographic activity of the masseter and temporal muscles are associated with facial asymmetry. Key words:Facial asymmetry, masticatory muscles, stereophotogrammetry, occlusion, electromyography.

Normal Facial Function in the Sunnybrook Facial Grading System: Is the 100% Score too Restrictive?

The primary objective of this study was to describe the distribution of the Sunnybrook Facial Grading System scores in the general population. Secondary objectives included analyzing the effects of age, gender and facial side on these scores. Two speech therapists specializing in facial motor skill assessment evaluated the healthy participants using the Sunnybrook Facial Grading System, first with the right hemiface as a reference and then with the left hemiface as a reference. The study was conducted in our ENT department from September 2022 to June 2023. One hundred eleven healthy participants were included (57 women and 54 men), aged 18 to 79 years. SFGS composite scores (SFGS-Total) and sub-scores at rest (SFGS-Rest) and in movement (SFGS-Movement) were studied according to three age categories (18-39 years) (40-59 years) and (60-79 years) and gender. Inter-rater reliability was collected between the two evaluators with Cronbach's alpha. Taking the right hemiface as a reference, SFGS-Total scores ranged from 65% to 100% (median = 96, IQR [91-100]). When the left hemiface was considered as the reference, scores ranged from 78% to 100% (median = 95; IQR [90-100]). Right and left SFGS-Total scores showed high inter-rater reliability (respectively α = 0.953 and α = 0.926). There was a slight negative correlation between age and SFGS-Total scores. By embracing a more realistic approach that acknowledges natural variations and asymmetry in facial movements, we can enhance patient care and promote a more holistic understanding of facial rehabilitation outcomes.

Rehabilitation Surgery for Peripheral Facial Nerve Injury after Facial Trauma.

Introduction Facial trauma can cause damage to the facial nerve, which can have negative effects on function, aesthetics, and quality of life if left untreated. Objective To evaluate the effectiveness of peripheral facial nerve direct end-to-end anastomosis and/or nerve grafting surgery for patients with facial nerve injury after facial trauma. Methods Fifty-nine patients with peripheral facial nerve paralysis after facial injuries underwent facial nerve rehabilitation surgery from November 2017 to December 2021 at Ho Chi Minh City National Hospital of Odontology. Results All 59 cases of facial trauma with damage to the peripheral facial nerve underwent facial nerve reconstruction surgery within 8 weeks of the injury. Of these cases, 25/59 (42.3%) had end-to-end anastomosis, 22/59 (37.3%) had nerve grafting, and 12/59 (20.4%) had a combination of nerve grafting and end-to-end anastomosis. After surgery, the rates of moderate and good recovery were 78.4% and 11.8%, respectively. All facial paralysis measurements showed statistically significant improvement after surgery, including the Facial Nerve Grading Scale 2.0 (FNGS 2.0) score, the Facial Clinimetric Evaluation (FaCE) scale, and electroneurography. The rate of synkinesis after surgery was 34%. Patient follow-up postoperatively ranged from 6 to > 36 months; 51 out of 59 patients (86.4%) were followed-up for at least 12 months or longer. Conclusion Nerve rehabilitation surgery including direct end-to-end anastomosis and nerve grafting is effective in cases of peripheral facial nerve injury following facial trauma. The surgery helps restore nerve conduction and improve facial paralysis.

Characterizing the Impact of Facial Rehabilitation on Acute Facial Paralysis.

Evidence on facial rehabilitation therapy (FRT) for acute facial paralysis (FP) remains limited. We present a retrospective review of patients with acute FP who have received FRT with physical therapists within 1 year of FP onset as determined by Sunnybrook Facial Grading Scale (SFGS) composite scores. A total of 702 patients with a clinical diagnosis of FP were referred to a university rehabilitation program between January 1, 2015 and January 1, 2022. Seventy-six patients met the criteria, defined as FP diagnosis <12 months before FRT initiation, ≥3 therapy sessions, and sufficient follow-up data. Average number of treatment sessions between SFGS scores was 7.7. History of cancer, sex, number of treatment sessions, and initial SFGS score were correlated with change in SFGS. Time to treatment was not correlated with change in SFGS score. SFGS improved with each additional treatment session (p < 0.01). Each additional point in the initial SFGS was correlated with less change in the final SFGS score (p < 0.01). FRT can provide meaningful improvement in functionality for patients with acute FP, regardless of time to treatment. Furthermore, patients who present with poorer functionality at baseline and those who undergo more treatment are most likely to see SFGS improvement. Research comparing the effect of facial rehabilitation with other treatment modalities and to a control cohort is warranted.

Post-parotidectomy facial nerve rehabilitation outcomes: Comparison between benign and malignant neoplasms.

Facial nerve dysfunction can be a devastating trouble for post-parotidectomy patients. To assess rehabilitation outcomes concerning patients with post-parotidectomy facial nerve dysfunction, comparing benign versus malignant neoplasms. Prospective study enrolling adults who underwent parotidectomy with facial nerve sparing between 2016 and 2020. The Modified Sunnybrook System (mS-FGS) was used for facial assessments. Physiotherapy began on the first post-operative day with a tailored program of facial exercises based on Neuromuscular Retraining, to be performed at home 3 times/day. From the first outpatient consultation, Proprioceptive Neuromuscular Facilitation was added to the treatment of cases with moderate or severe facial dysfunctions. Benign and malignant groups had a statistically significant improvement in mS-FGS (p < 0.001 and p = 0.005, respectively). There was no significant difference between groups regarding treatment duration or number of physiotherapy sessions performed. The history of previous parotidectomy resulted in more severe initial dysfunctions and worse outcome. Age over 60 years and initially more severe dysfunctions impacted the outcome. Patients with benign and malignant parotid neoplasms had significant and equivalent improvement in postoperative facial dysfunction following an early tailored physiotherapy program, with no significant difference in the final facial score, treatment duration, or number of sessions required.

A Combined Approach of Facial Neuromuscular Rehabilitation and Surgical Reconstruction in the Remediation of Facial Palsy: A Multidisciplinary Team Approach.

Facial neuromuscular rehabilitation (fNMR) is an evidence-based practice for the treatment of peripheral facial palsy (PFP). Surgical reconstruction can be indicated for patients who demonstrate poor or no recovery to support symmetry, function, and aesthesis. There is paucity of research demonstrating the therapeutic benefit of a multidisciplinary team (MDT) in facial recovery of this specific subpopulation of patients. This article will outline the role of specialist facial therapy in the remediation of PFP, focusing on those who undergo surgical reconstruction to optimize their facial recovery. Case studies are used to demonstrate surgical and therapeutic outcomes as well as the results of a patient survey conducted for a service evaluation. We discuss the role of the MDT in supporting recovery as well as the role of targeted fNMR. The term fNMR is often used interchangeably with facial therapy or facial rehabilitation. We will refer to fNMR as a technique of facial rehabilitation.We aim to demonstrate that an MDT approach to the treatment of people with facial palsy provides positive outcomes for this surgical population and that future research would be beneficial to support this service delivery model.

Health Care Professional-Supported Co-Design of a Mime Therapy-Based Serious Game for Facial Rehabilitation.

This research letter presents the co-design process for RG4Face, a mime therapy-based serious game that uses computer vision for human facial movement recognition and estimation to help health care professionals and patients in the facial rehabilitation process.

Assessing Facial Palsy: Does Feedback Improve Assessment Using the eFACE and Sunnybrook Facial Grading System?

To explore learning effects when applying the clinician-graded electronic facial function scale (eFACE) and the Sunnybrook Facial Grading System (Sunnybrook). Surgeons, facial rehabilitation therapists, and medical students were randomly allocated to the eFACE (n = 7) or Sunnybrook (n = 6) and graded 60 videos (Massachusetts Eye and Ear Infirmary open-source standard set); 10 persons with normal facial function and 50 patients with a wide variation of facial palsy severity. Participants received an introduction and individual feedback after each set of 10 videos. Scores were compared to the reference score provided with the set. Multilevel analysis was performed to analyze learning effect. A learning effect was only found for the eFACE, with significant difference scores in set 1 and 2 compared to set 6, and no significant difference scores in the following sets. The difference score was associated with the reference score (severity of facial palsy) for eFACE (β = -0.19; SE = 0.04; p < 0.001) and Sunnybrook (β = -0.15; SE = 0.04; p < 0.001). Age of participants was also associated with the difference score in the eFACE group (β = 0.18; SE = 0.03; p < 0.001). No differences in scores were found between groups of participants. The eFACE showed a learning effect of feedback while the Sunnybrook did not. NA Laryngoscope, 134:3105-3111, 2024.

Reconstructing Smiles: Maxillofacial Prosthesis

Maxillofacial prosthesis are required for the reconstruction of head and neck deformities in patients with congenital anomalies or defects which are acquired like trauma, surgery, infection, burns, or cancer . These defects might need both extra oral and intraoral prosthetic rehabilitation. Re-evaluating the materials used in the field of maxillofacial prosthesis is beneficial because facial rehabilitation is necessary for the person to live a comfortable life. In addition to addressing the functional and aesthetic impairment, the prosthodontic therapy of these patients should focus on ensuring psychological wellbeing. From wax, metal, leather, rubber, etc., to the most recent biomedical material, like polymers, the materials have come a long way. While the new materials have shown some fantastic qualities, they have certain disadvantages. We are still looking for a material that possesses all the necessary qualities to rehabilitate maxillofacial deformities in the best way possible.

Analysis of the influencing factors of short-term and long-term facial nerve function after vestibular schwannoma resection via suboccipital retrosigmoid approach

Objective: To summarize the experience of facial nerve(FN) preservation in microsurgical treatment of vestibular schwannoma (VS) resection via suboccipital retrosigmoid approach and to analyze the influencing factors of facial function prognosis in short-term and long-term period. Methods: Patients with VS who underwent microsurgery via suboccipital retrosigmoid approach by the skull base surgery team in Huashan Hospital from January 2013 to February 2018 were enrolled. A total of 308 patients were included in this study, including 132 males and 176 females. The average age was 47.9 year-old (Range: 17-79 year-old). The patient's clinical data and FN function prognosis were recorded. Univariate and multivariate analysis by SPSS 23.0 statistical software were performed to evaluate the factors affecting facial function prognosis and its recovery. Results: Gross total resection was achieved in 304 cases, and subtotal resection was in 4 cases. The facial nerve preservation rate anatomically was 99.4%. The facial nerve of 2 cases was thin due to large tumor compression and severed, and a one-stage reconstruction was performed during surgery.Of the 308 patients, 300 cases were successfully followed up, and 8 cases were lost to follow-up. The mean follow-up time was 52 months. In short-term (2 weeks after surgery), satisfactory facial nerve function (House-Brackmann (H-B) grade Ⅰ-Ⅱ) was achieved in 96 cases, and 212 cases were unsatisfactory function (H-B grade Ⅲ-Ⅵ). After 1 year, 198 were satisfactory function and 97 were unsatisfactory. After 3 years, 219 were satisfactory function and 75 were unsatisfactory. Five years later, 155 were satisfactory function and 34 were unsatisfactory. According to the results of logistic regression analysis, the impact factors of FN function in short-term were tumor size (P=0.011) and stimulation threshold (ST) of EMG monitoring (P<0.001). The impact factors in long-term were tumor size (P=0.005), ST of EMG monitoring (P=0.005) and FN rehabilitation training. Conclusions: Tumor diameter is an independent factor related to FN function, and the larger the tumor, the worse the postoperative FN function. The ST of EMG (ST≤0.05 mA) can predict short-term and long-term FN function. The systematic facial rehabilitation training can effectively promote the recovery of FN after surgery.

Comparison of Objective Facial Metrics on Both Sides of the Face Among Patients with Severe Bell's Palsy Treated with Mirror Effect Plus Protocol Rehabilitation Versus Controls.

Objective: The extent to which the healthy hemiface dynamically contributes to facial synchronization during facial rehabilitation has been largely unstudied. This study compares the synchronization of both hemifaces in severe Bell's palsy patients who either received facial rehabilitation called "Mirror Effect Plus Protocol" (MEPP) or basic counseling. Methods: Baseline and 1-year postonset data from 39 patients (19 = MEPP and 20 = basic counseling) were retrospectively analyzed using Emotrics+, a software that generates facial metrics with artificial intelligence (AI) algorithms. Paired t-tests were used for intrasubject comparisons of hemifaces, and mixed model analysis were used to compare between groups. Results: For voluntary movements, a significant difference in favor of the MEPP group was only found for smiling (p = 0.025*). However, at 1-year postonset, the control group showed significant variability between hemifaces for most synkinesis measurements [nasolabial fold (p = 0.029*); eye area (p = 0.043*); palpebral fissure (p = 0.011*)]. Conclusion: In this study, a better synchronization of both hemifaces was found in the MEPP group. Interestingly, motor adaptation in movement amplitude of the healthy hemiface seemed to contribute to this synchronization in MEPP patients. Further studies are needed to standardize the procedure of AI measurements and to adapt it for clinical use.

A 20-Year Experience with Tissue Expansion for Large Cervical Fascial Defects: An Algorithm Based on Different Clinical Flap Designs.

Over the past 20 years, we have designed various types of expanded cervical flaps for large facial defects and achieved excellent tissue matching. This study was performed to propose a treatment strategy for flap selection for the reconstruction of different facial units. The authors retrospectively reviewed the application of cervical expanded flaps for facial rehabilitation in our department between January 2003 and January 2023. The study included 122 patients with unilateral (62.3%) and bilateral (37.7%) facial deformities ranging from the zygomatic arch to the chin. The median area of the tissue defect was 15.2 × 8.5 cm2 (ranging from 6 × 4 cm2 to 27 × 12 cm2). The expansion period ranged from 61 to 175 days (mean: 86.5 days). Maximum and minimum sizes of pre-expanded cervical flaps were 30 × 13 cm2 to 7 × 5 cm2. All the flaps could be summarized into type 1, an advanced expanded cervical flap; type 2, a wing-shaped expanded cervical flap with overlapping tissue expansion; and type 3, an expanded single-lobed transposition flap rotated based on the anterior neck. Cervical flaps reliably meet the reconstructive requirements for different facial units, especially for large cutaneous defects in the clinic. The selection of these flaps can be planned preoperatively according to the location and size of the defect or lesion.

The Florence multi-resolution 3D facial expression dataset

In the literature, several 3D face datasets have been collected, aiming at advancing the field of 3D face analysis from different perspectives. Data collection generally follows specific research needs, and the existing 3D face datasets all have different characteristics that are tailored for investigating different tasks, encompassing face recognition, facial expressions and emotions analysis, 3D face reconstruction. However, the majority of these datasets are either collected with high-resolution scanners, or consumer level devices, such as the Kinect, the latter being motivated by the burdensome and costly process of collecting high-quality scans. Differently from 2D imagery, the difference in resolution in 3D data represents a non negligible problem that is under-investigated, and still prevents the successful development of methods that can work in real scenarios. In this paper, we propose a new 3D face dataset, named “Florence Multi-Resolution 3D Facial Expression” (Florence 3DMRE), which aims at bridging the gap between high- and low-resolution 3D face datasets. Its peculiarity consists in (1) including high-resolution (HR) models obtained with a HR scanner, and paired samples collected with a Kinect sensor, (2) LR and HR scans are synchronized and capture extreme and asymmetric facial deformations as used in facial rehabilitation exercises. In total, our dataset consists of 14 subjects, each performing 19 complex and asymmetric expressions. For each of them, we collected a high-resolution scan, and an RGB-D sequence. Finally, to highlight the value of the dataset and the challenges it introduces, we use the collected data to perform baseline experiments for cross-resolution 3D face recognition and reconstruction. The dataset is released for research purposes only, and complies to GDPR for data treatment. The dataset can be found at this link.

Measuring the Potential Effects of Mirror Therapy Added to the Gold Standard Facial Neuromuscular Retraining in Patients With Chronic Peripheral Facial Palsy: Protocol for a Randomized Controlled Trial.

Facial neuromuscular retraining (fNMR) is a noninvasive physical therapy widely used to treat peripheral facial palsies. It consists of different intervention methods that aim to reduce the debilitating sequelae of the disease. Recently, the use of mirror therapy in the acute facial palsy and postsurgical rehabilitation contexts has shown promising results, suggesting its use as an adjunct to fNMR in treating patients with later stages of paralysis, such as the paretic, early, or chronic synkinetic. The main aim of this study is to compare the efficacy of an added mirror therapy component with fNMR in patients with peripheral facial palsy (PFP) sequelae in 3 different stages. The specific objectives of this study are to measure the effects of combined therapy compared to fNMR alone on (1) participants' facial symmetry and synkinesis, (2) quality of life and psychological aspects of the participants, (3) motivation and treatment adherence, and (4) different stages of facial palsies. This study is a randomized controlled trial that compares the effect of fNMR combined with mirror therapy (experimental group: n=45) with fNMR alone (control group: n=45) in 90 patients with peripheral facial palsy presenting with sequelae 3-12 months after onset. Both groups will receive 6 months of rehabilitation training. Facial symmetry and synkinesis; participants' quality of life; and their psychological factors, motivation, and compliance will be assessed at baseline (T0), 3 months (T1), 6 months (T2), and 12 months (T3) postintervention. Outcome measures are (1) changes in facial symmetry and synkinesis assessed with facial grading tools, (2) quality of life changes with patient questionnaires, and (3) therapy motivation with a standardized scale, as well as adherence to treatment with metadata. Changes in facial symmetry and synkinesis will be judged by 3 assessors blinded to group assignment. Mixed models and Kruskal-Wallis, chi-square, and multilevel analyses will be conducted according to the appropriate variable type. Inclusion will start in 2024 and is anticipated to be completed in 2027. The 12-month follow-up will be completed with the last patient in 2028. We expect patients included in this study to experience improvement in facial symmetry, synkinesis, and quality of life, regardless of group assignments. A potential benefit of mirror therapy for facial symmetry and synkinesis could be noted for patients in the paretic phase. We hypothesize better motivation and adherence to treatment for the mirror therapy group. The results of this trial may provide new guidelines for PFP rehabilitation with patients dealing with long-term sequelae. It also fills the need for robust evidence-based data in behavioral facial rehabilitation. PRR1-10.2196/47709.

Trading mental and physical health in vestibular schwannoma treatment decision.

Observation, radiotherapy and surgery are treatment options in vestibular schwannomas (VS). Decision making differs between centers and is usually based on tumor characteristics (e.g., size) and the expected physical health (PH) outcome (i.e., hearing and facial function). However, mental health (MH) is often under-reported. The objective of the present study was to ascertain the impact of VS treatment on PH and MH. PH and MH were assessed in a prospective cross-sectional study including 226 patients with unilateral sporadic VS before and after surgical removal (SURG). Quality-of-life (QoL) was estimated by self-rating questionnaires: general Short-Form Health Survey (SF-36), Penn Acoustic Neuroma Quality-of-Life Scale (PANQOL), Dizziness Handicap Inventory (DHI), Hearing Handicap Inventory (HHI), Tinnitus Handicap Inventory (THI), and Facial Disability Index (FDI). QoL changes over time as well as predictive factors were accessed by multivariate analyses of covariance (MANCOVA). In total, 173 preoperative and 80 postoperative questionnaires were analyzed. There was a significant PH deterioration related to facial function (FDI, PANQOL-face) after surgery. In line with facial rehabilitation, however, FDI improved within the first five years after surgery and did not differ compared to the preoperative patient cohort, eventually. In contrast, MH (i.e., PANQOL-anxiety) and general health (i.e., PANQOL-GH) improved with surgery and correlated with the extent-of-resection. Physical and mental health is significantly influenced by VS surgery. While PH might decrease after surgery, MH potentially increases when patient is cured. Practitioners should take MH into account before advising an incompletely VS treatment (e.g., subtotal resection, observation or radiosurgery).

Designing Effective Visual Feedback for Facial Rehabilitation Exercises: Investigating the Role of Shape, Transparency, and Age on User Experience.

Facial expression recognition technology has been utilized both for entertainment purposes and as a valuable aid in rehabilitation and facial exercise assistance. This technology leverages artificial intelligence models to predict facial landmark points and provide visual feedback, thereby facilitating users' facial movements. However, feedback designs that disregard user preferences may cause discomfort and diminish the benefits of exercise. This study aimed to develop a feedback design guide for facial rehabilitation exercises by investigating user responses to various feedback design methods. We created a facial recognition mobile application and designed six feedback variations based on shape and transparency. To evaluate user experience, we conducted a usability test involving 48 participants (24 subjects in their 20s and 24 over 60 years of age), assessing factors such as feedback, assistance, disturbance, aesthetics, cognitive ease, and appropriateness. The experimental results revealed significant differences in transparency, age, and the interaction between transparency and age. Consequently, it is essential to consider both transparency and user age when designing facial recognition feedback. The findings of this study could potentially inform the design of more effective and personalized visual feedback for facial motion, ultimately benefiting users in rehabilitation and exercise contexts.

Novel Baseline Facial Muscle Database Using Statistical Shape Modeling and In Silico Trials toward Decision Support for Facial Rehabilitation.

Backgrounds and Objective: Facial palsy is a complex pathophysiological condition affecting the personal and professional lives of the involved patients. Sudden muscle weakness or paralysis needs to be rehabilitated to recover a symmetric and expressive face. Computer-aided decision support systems for facial rehabilitation have been developed. However, there is a lack of facial muscle baseline data to evaluate the patient states and guide as well as optimize the rehabilitation strategy. In this present study, we aimed to develop a novel baseline facial muscle database (static and dynamic behaviors) using the coupling between statistical shape modeling and in-silico trial approaches. Methods: 10,000 virtual subjects (5000 males and 5000 females) were generated from a statistical shape modeling (SSM) head model. Skull and muscle networks were defined so that they statistically fit with the head shapes. Two standard mimics: smiling and kissing were generated. The muscle strains of the lengths in neutral and mimic positions were computed and recorded thanks to the muscle insertion and attachment points on the animated head and skull meshes. For validation, five head and skull meshes were reconstructed from the five computed tomography (CT) image sets. Skull and muscle networks were then predicted from the reconstructed head meshes. The predicted skull meshes were compared with the reconstructed skull meshes based on the mesh-to-mesh distance metrics. The predicted muscle lengths were also compared with those manually defined on the reconstructed head and skull meshes. Moreover, the computed muscle lengths and strains were compared with those in our previous studies and the literature. Results: The skull prediction's median deviations from the CT-based models were 2.2236 mm, 2.1371 mm, and 2.1277 mm for the skull shape, skull mesh, and muscle attachment point regions, respectively. The median deviation of the muscle lengths was 4.8940 mm. The computed muscle strains were compatible with the reported values in our previous Kinect-based method and the literature. Conclusions: The development of our novel facial muscle database opens new avenues to accurately evaluate the facial muscle states of facial palsy patients. Based on the evaluated results, specific types of facial mimic rehabilitation exercises can also be selected optimally to train the target muscles. In perspective, the database of the computed muscle lengths and strains will be integrated into our available clinical decision support system for automatically detecting malfunctioning muscles and proposing patient-specific rehabilitation serious games.

Hyaluronic Acid in Facial Rehabilitation—A Narrative Review

Background: Hyaluronic acid fillers (HAF) are a versatile tool in esthetic medicine. They also have a potential for medical indications including facial rehabilitation. Materials and methods: We performed a literature search on PUBMED and Google Scholar until December 2022. Clinical trials, clinical studies, review articles, systematic reviews, meta-analyses, case series, and case reports were considered for review. Keywords “facial rehabilitation”, “acne scars”, “traumatic scars”, “oral restoration”, “facial lipoatrophy”, “facial asymmetry”, “periocular correction”, “nasal obstruction”, “ear lobe restoration”, “morphea”, AND “hyaluronic acid filler” were used to select articles. Results: We prepared a narrative review on the use of HAF for correction of facial asymmetry and asymmetric lips, improvement of different types of scars, improvement of the jaw line, improvement of ear lobes, periocular and oral restoration, and the treatment of nasal obstruction and morphea en coub de sabre. The amount of HA used in these indications is often less than 1 mL. The bolus technique, fanning, and dual-plane injections can be utilized for treatment. Duration of clinical effects depends upon the anatomical region and is usually maintained between 2 months and 2 years. Adverse events are often mild and temporary. Vascular occlusion is a severe adverse event, but it has not been reported yet for these medical indications. Repeated injections are recommended to obtain a longer-lasting improvement. In cases of morphea, only stable and non-inflammatory plaques should be treated. The advantage of HAF compared to permanent and semipermanent fillers is the availability of hyaluronidase for rapid removal of filler material and to revise overcorrection. Conclusions: HAF play an auxiliary role in facial rehabilitation. Knowledge of filler qualities, anatomy, and underlying diagnoses is important for their safe application. More prospective controlled trials are necessary to improve evidence.