"Muscle foreshortening after free gracilis transfer for smile: Where, when, why?"

BACKGROUND: Gracilis free muscle transfer (GFMT) remains the standard for smile restoration in patients with long-standing facial palsy. Resting oral commissure lateralization (ROCL) following GFMT is aesthetically unappealing and can cause functional problems including dysarthria and oral incompetence. The risk factors for ROCL following GFMT are poorly understood. METHODS: Of all patients who underwent GFMT for smile restoration from 2003 - 2021, patients with subsequent ROCL were identified from a facial nerve database using pre-determined search criteria. Medical records were reviewed to identify potential risk factors for muscle foreshortening. RESULTS: Of 412 patients who underwent successful GFMT since 2003, we identified 41 (10%) patients who subsequently developed ROCL. ROCL rates varied significantly based on gracilis innervation source, with ipsilateral CN VII innervation and dual-innervation (cross-facial nerve graft (CFNG) plus ipsilateral nerve-to-masseter (NTM)) demonstrating the highest foreshortening rates (27.3% and 15.4%, respectively), compared to the lowest rates of foreshortening when gracilis was innervated by CNFG alone (3.2%), p=0.005. Patients with a history of radiation to the surgical field were significantly more likely to develop ROCL (22%) compared to those without a history of radiation (8.6%), p<0.001. Furthermore, the rate of ROCL was significantly higher among patients who underwent concurrent stabilization of the nasolabial fold using a wide band of fascia lata (20.8%) compared to those who did not (6.6%), p<0.001. CONCLUSIONS: Herein we report potential risk factors for ROCL following GFMT for smile restoration, including innervation source, radiation history, and concurrent fascia lata static suspension.

Does supercharging with cross-face nerve graft enhance smile in non-flaccid facial paralysis patients undergoing selective neurectomy?

BACKGROUND: Cross face nerve grafting (CFNG) is a well-established nerve transfer technique in facial reanimation; however, no study has assessed outcome of supercharging the smile with CFNG in patients with synkinesis. The goal of this study was to examine the smile outcome in non-flaccid facial paralysis (NFFP) patients after supercharging with CFNG during selective neurectomy. METHODS: NFFP patients who underwent CFNG with end-to-side coaptation to a smile branch on the paralyzed side during selective neurectomy were retrospectively identified and their charts were reviewed. Pre-operative and post-operative facial function was assessed with the electronic clinician-graded facial function tool (eFACE), and an automated computer-aided facial assessment tool (Emotrics). Smile metrics were compared pre-operatively, in early post-operative time (EPO, <6 months), and late post-operative time (LPO, >9 months) when CFNG contribution would be expected. RESULTS: Thirteen cases were performed between June 2019 and December 2021. No objective smile metrics improved following supercharging with CFNG. Oral commissure excursion improved by 1.23 points in eFACE (p = .812), and by 0.84 in Emotrtics (p = .187) from EPO to LPO. EFACE dynamic score was improved by 0.08 points from EPO to LPO (p = .969). CONCLUSIONS: Using CFNG for supercharging the smile during selective neurectomy in NFFP patients may not enhance smile. Longer term results following supercharging and long term natural history of selective neurectomy should be assessed.

Understanding the Relationship Between Facial Nerve Branch Sacrifice and Selective Neurectomy Outcome.

Introduction: While there is great interest in selective neurectomy (SN) for patients with synkinesis, outcomes can be inconsistent. Objective: To examine the relationships between intraoperative facial nerve branch transection and both postoperative outcome and functional deficits. Methods: SN cases, with minimal follow-up of 4 months, were retrospectively identified between 2019 and 2021; outcome was assessed using FaCE instrument, eFACE and Emotrics. Correlations between intraoperative facial nerve branch preservation or transection, and functional outcome and new functional deficits were examined. Results: Fifty-six cases were performed: 88% were females, and median age was 53 years (range 11-81). Mean follow-up was 19.5 months (range 4-42). Oral commissure excursion improved in patients where all smile branches were preserved, no vertical vector smile branches were transected, and more than three smile antagonist branches were transected. A linear trend between smile antagonist branch sacrifice and favorable smile outcome was found. Lower lip movement was improved in patients in whom more than half of the identified lower lip branches were transected. Thirty percent of patients experienced untoward postoperative functional deficits, from which 47% recovered with interventions. Conclusions: Several correlations between SN intra-operative decisions and outcome were identified; new or worsening functional deficit rate can be high. However, chemodenervation or fillers can help diminish these deficits.

Pre-Operative Factors May Predict Outcome in Selective Neurectomy for Synkinesis.

Background: While there has been great interest in offering selective neurectomy (SN) to patients with nonflaccid facial palsy (NFFP), postoperative outcomes are inconsistent. Objective: To assess overall SN outcome in NFFP patients and to examine correlation between preoperative factors and SN outcome. Methods: SN cases were retrospectively identified between 2019 and 2021. Patient factors and facial function were assessed using chart review, the Facial Clinimetric Evaluation (FaCE), the electronic clinician-graded facial function tool (eFACE), and an automated computer-aided facial assessment tool (Emotrics). Correlations between preoperative factors and patients outcome were established. Results: Fifty-eight SN cases were performed; 88% were females, and median age was 53 years (range 11-81). Outcome assessment was 8 months on average (1-24 months). Postoperatively, multiple eFACE and Emotrics parameters improved significantly, including ocular, perioral, and synkinesis metrics. In preoperative factors assessment, age >50, facial palsy (FP) duration >2 years, poor preoperative facial function, and nontrauma etiology all correlated with greater improvements compared with younger patients, those with shorter duration facial palsy, trauma etiology, and better preoperative facial function. Conclusions: SN can significantly improve facial function; we have identified several preoperative factors that correlated to outcome.

Favorable Outcome Perception in Facial Selective Neurectomy.

OBJECTIVE: Facial selective neurectomy (SN) improves facial function by denervation of muscles antagonistic to the smile in nonflaccid facial paralysis (NFFP) patients. This study aims to assess whether and which objective facial function metrics affect favorable SN outcome in NFFP patients, as perceived by facial nerve (FN) practitioners. STUDY DESIGN: Retrospective cohort study. SETTING: NFFP patients who underwent SN at the facial nerve center. METHODS: Standardized preoperative and postoperative facial photographs of patients undergoing SN were analyzed using clinician-graded measures (eFACE) and automated facial measurement (Emotrics). Favorable outcome was ranked subjectively by 3 independent FN practitioners. Correlations between objective metrics and favorable subjective outcome were examined. RESULTS: Fifty-eight SN cases were included. Oral commissure excursion with smile, interlabial distance, and lower lip movement were all considered statistically significantly important for favorable outcome perception. Each +1 mm of smile excursion increases the odds of a favorable outcome by 75.4% (odds ratio [OR]: 1.754). Each +1 mm of interlabial distance asymmetry decreases the odds of a favorable outcome by 24.7% (OR: 0.753). Each +1-point change in lower lip movement eFACE score increases the odds of a favorable outcome by 2.7% (OR: 1.027). CONCLUSION: Several smile metrics contribute to favorable SN outcome perception among FN practitioners. Smile excursion, interlabial distance, and lower lip movement were significant predictors of success. These observations may be extrapolated to other facial reanimation interventions and serve surgeons and patients during counseling and expectation management, and during surgery.

Freeing the Animal Model: A Modular, Wirelessly Powered, Implantable Electronic Platform.

SUMMARY: Fully implantable electronic devices in freely roaming animal models are useful in biomedical research, but their development is prohibitively resource intensive for many laboratories. The advent of miniaturized microcontrollers with onboard wireless data exchange capabilities has enabled cost-efficient development of myriad do-it-yourself electronic devices that are easily customizable with open-source software ( https://www.arduino.cc/ ). Likewise, the global proliferation of mobile devices has led to the development of low-cost miniaturized wireless power technology. The authors present a low-cost, rechargeable, and fully implantable electronic device comprising a commercially available, open-source, wirelessly powered microcontroller that is readily customizable with myriad readily available miniature sensors and actuators. The authors demonstrate the utility of this platform for chronic nerve stimulation in the freely roaming rat with intermittent wireless charging over 4 weeks. Device assembly was achieved within 2 hours and necessitated only basic soldering equipment. Component costs totaled $115 per device. Wireless data transfer and wireless recharging of device batteries was achieved within 30 minutes, and no harmful heat generation occurred during charging or discharging cycles, as measured by external thermography and internal device temperature monitoring. Wireless communication enabled triggered cathodic pulse stimulation of the facial nerve at various user-selected programmed frequencies (1, 5, and 10 Hz) for periods of 4 weeks or longer. This implantable electronic platform could be further miniaturized and expanded to study a vast array of biomedical research questions in live animal models. CLINICAL RELEVANCE STATEMENT: The clinical relevance of electrical stimulation in neural recovery remains controversial, and long-term neural stimulation in small animal models is challenging. We have developed a low-cost, fully implantable, wirelessly powered nerve stimulation device to facilitate further research in nerve stimulation in animal models.

Post Facelift Facial Paralysis: A 20-Year Experience.

INTRODUCTION: Facial nerve (FN) injury during a facelift is a relatively rare but potentially devastating complication. Despite extensive literature discussing facial nerve anatomy and danger zones, few studies describe detailed management, FN exploration intraoperative findings, and outcome following post-facelift facial paralysis (PFFP). We review a 20-year experience in managing iatrogenic PFFP. METHODS: PFFP patients were retrospectively identified between 2002-2022. Demographic data, operative details from the facelift procedure, post-facelift facial function, medical and surgical management, intraoperative findings, and long-term outcome were analyzed. RESULTS: 25 patients who experienced PFFP were referred for evaluation over the past 20 years. Eight patients required FN exploration, of which 6 underwent nerve repair; all recovered to some degree, with 50% achieving essentially normal facial function. 14 patients underwent non-surgical management including physical therapy, chemodenervation and filler therapy. Of these non-surgical patients who were not lost to follow up, 50% achieved normal facial function and 42% achieved near-normal facial function. The single patient who had no spontaneous improvement presented outside the re-innervation window and was not an operative candidate. CONCLUSION: PFFP outcome depends on injury type and location, accurate assessment and appropriate treatment; however, overall prognosis is quite favorable. FN exploration is warranted when nerve transection is suspected. Observation is suitable for patients demonstrating early signs of recovery. Patients presenting beyond a reasonable re-innervation window will be offered other facial reanimation techniques. When FN exploration is required, outcomes may be superior in a facial nerve center setting. Adjunctive interventions for symmetry improvement while awaiting recovery are available.

Facial Filler in Facial Paralysis: A Prospective Case Study and Multidimensional Assessment.

Background: Facial filler is emerging as a nonsurgical alternative for addressing static asymmetry in facial paralysis (FP). Objectives: To elucidate the patient experience for facial filler and to facilitate preprocedure counseling and education. Materials and Methods: Patients receiving hyaluronic acid filler for FP at a tertiary academic medical center were prospectively recruited. Primary outcomes included patient-reported pain, facial symmetry (on a visual analog scale), and the results of quality-of-life surveys (FACE-Q satisfaction with facial appearance [SFA], FACE-Q psychosocial distress [PSD], Patient Health Questionnaire-9 [PHQ-9], and Euro Quality of Life 5-Dimension [EQ5D]) preprocedure and at 1 and 14 days postprocedure. Results: Twenty patients (90% women, average age 55 ± 11) completed the study. Sites of filler included the cheek, lower lip, nasolabial fold, chin, and temple regions. Patients reported minimal pain at postprocedure days (PPDs) 1 and 14. Patient-perceived symmetry scores improved significantly (p < 0.0001), as did FACE-Q SFA and FACE-Q PSD scores (p < 0.0001, <0.0001) when comparing preprocedure with PPD 14. Depression, assessed by PHQ-9, and the anxiety/depression domain of EQ5D, decreased after treatment (p = 0.016, 0.014) but no change was observed in the other domains of EQ5D. Conclusion: Facial filler for FP can be performed with minimal morbidity (pain, impact on daily routine, and complications) and leads to improvements across multiple psychosocial domains.

Commentary on: "Chemodenervation Algorithm: Functional and Aesthetic Considerations for Facial Harmony in Patients with Post-Facial Paralysis Synkinesis," by Hetzler et al.

In this commentary, we discuss Hetzler et al.'s article, "Chemodenervation Algorithm: Functional and Aesthetic Considerations for Facial Harmony in Patients with Post-Facial Paralysis Synkinesis." The authors do an excellent job of presenting a guide for practitioners to use when initiating chemodenervation treatment for patients with nonflaccid facial paralysis. Standardization of outcome assessment tools and rigorous data collection will further refine treatment algorithms.

Middle Fossa Decompression for Recurrent Facial Palsy: Prevalence and Surgical Outcomes.

OBJECTIVE: To investigate the surgical outcomes in patients treated for recurrent facial nerve palsy (RFP) at a quaternary facial nerve referral center. METHODS: A retrospective chart review was performed on 132 patients with RFP who presented to our institution's facial nerve clinic from 2001 to 2021. Records were analyzed for etiology of palsy, facial nerve function, and recurrence rates. Pre- and post-operative audiometric outcomes were also assessed in surgically managed patients. RESULTS: 6.8% of RFP patients underwent surgical decompression. For patients who did not undergo surgery, the House-Brackmann (HB) score was 2.9 ± 1.3 (SD) at the initial clinic visit, and 2.4 ± 1.3 (SD) at the last clinic visit. This difference was significantly different (p = 0.01, t-test). For surgical patients, the pre-operative HB score was 2.9 ± 0.9 (SD) and post-operative HB score was 1.8 ± 0.6 (SD), which were significantly different (p = 0.01, t-test). The number of facial palsy episodes also decreased pre- and post-operatively from 3.5 ± 0.8 (SD) to 0.2 ± 0.4 (SD) episodes, which were significantly different (p < 0,001, t-test). Audiometric outcomes were not significantly different pre- and post-surgery (p = 0.31, t-test for PTA; p = 0.34, t-test for WRS). CONCLUSION: Facial nerve decompression for RFP patients with incomplete functional recovery may be an effective treatment for decreasing the frequency and severity of facial palsy episodes. LEVEL OF EVIDENCE: 4 Laryngoscope, 133:1222-1227, 2023.

Lower Facial Nerve Nomenclature Clarification: Cervical Branch Controls Smile-Associated Lower Lip Depression and Dental Display.

OBJECTIVE: In head and neck ablative surgery, traditional teaching is that the key facial nerve branch to preserve along the plane of the lower border of the mandible is the marginal mandibular branch (MMb), which is considered to control all lower lip musculature. The depressor labii inferioris (DLI) is the muscle responsible for pleasing lower lip displacement and lower dental display during natural emotive smiling. STUDY DESIGN: To understand the structure/function relationships of the distal lower facial nerve branches and lower lip musculature. SETTING: In vivo extensive facial nerve dissections under general anesthesia. METHODS: Intraoperative mapping was performed in 60 cases, using branch stimulation and simultaneous movement videography. RESULTS: In nearly all cases, the MMb innervated the depressor anguli oris, lower orbicularis oris, and mentalis muscles. The nerve branches controlling DLI function were identified 2 ± 0.5 cm below the angle of the mandible, originating from a cervical branch, separately and inferior to MMb. In half of the cases, we identified at least 2 independent branches activating the DLI, both within the cervical region. CONCLUSION: An appreciation of this anatomical finding may help prevent lower lip weakness following neck surgery. Avoiding the functional and cosmetic consequences that accompany loss of DLI function would have a significant impact on the burden of potentially preventable sequelae that the head and neck surgical patient frequently carries.

Embellishing Emotrics for a More Complete Emotion Analysis: Addition of the Nasolabial Fold.

Background: The nasolabial fold (NLF) greatly contributes to facial aesthetics; changes to NLF depth and vector are disfiguring in patients with facial paralysis (FP). NLF parameters are integral to clinician-graded outcomes, but automated programs currently lack NLF identification capabilities. Objective: To incorporate an automated NLF identification and quantification function into the facial landmark program, Emotrics, and to compare new Emotrics-derived NLF data to clinician-graded electronic facial paralysis assessment (eFACE) data for accuracy. Methods: Photographs of 135 patients with FP were marked bilaterally, using identification markers manually placed on each NLF. A machine learning model was trained to automatically localize the markers using these data. Once Emotrics accurately identified the NLF and its corresponding vector, photographs of 20 additional patients who underwent facial reanimation procedures were assessed by the algorithm. Results: The enhanced Emotrics algorithm successfully identified the NLF, and measured the vector from midline, in a series of patients with FP. NLF vector data closely matched corresponding eFACE parameters. Furthermore, changes in NLF presence and vector were detected following facial reanimation procedures. Conclusion: The Emotrics program now provides critical NLF data, providing objective parameters for clinicians interested in changing NLF dynamics after FP.

Voluntary and Spontaneous Smile Quantification in Facial Palsy Patients: Validation of a Novel Mobile Application.

Introduction: Restoration of spontaneous smiling is a key goal in facial reanimation. A major obstacle to quantifying recovery of spontaneous smiling is the current lack of a uniform and objective means of smile quantification. Objective: To compare the facial movements during smiling in patients with facial paralysis as measured by an automated application and human observers. Methods: Video recordings of 25 patients with unilateral facial palsy (FP) watching humorous videos were utilized. Application-derived smile timestamping was compared with manual observer interpretation. Internal reliability of measurements was evaluated through a test-retest approach. Results: Application-derived smile identification demonstrated almost perfect agreement with manual interpretation (kappa 0.861, p < 0.001). There was no statistically significant difference in mean number of smiles between detection method (p = 0.354). Automated smile identification demonstrated a high degree of specificity (95.4%), accuracy (93.1%), positive-predictive value (94.7%), and negative-predictive value (91.8%). This method demonstrated a high degree of reliability (kappa 0.864, p < 0.01). Conclusion: The novel "SmileCheck" mobile phone application performed accurate and reliable smile quantification in FP patients in comparison with manual observation.

Surgical Management of Facial Paralysis: Demographic and Socioeconomic Associations.

Objective: To determine demographic and socioeconomic variables associated with whether surgery is performed for patients with facial paralysis (FP). Background: Management of FP may include elective surgery dependent on patient goals of care and physician experience. Methods: The 2016 State Inpatient Database and State Ambulatory Surgery Services Database for six states were queried to identify patients with FP. These patients were then stratified based on receiving surgery for FP. Demographic and socioeconomic information was collected. Multivariable logistic regression modeling was used to identify predictors of undergoing FP surgery, as well as the hospital setting in which surgery was performed. Results: Of 20,218 patients with FP, 515 underwent surgery. Black patients were significantly less likely to undergo surgery (p < 0.001), as were patients with Medicaid or self-pay insurance (p < 0.001). Those living in rural areas were also less likely to receive surgery (p = 0.001). Individuals receiving surgery in the inpatient setting were more likely to have private insurance, whereas those in the ambulatory setting were more likely to have Medicare (p < 0.001). Conclusion: Several variables are correlated with whether FP is managed surgically, including insurance status, race, and type of residential area.

Effect of Filler Therapy on Psychosocial Distress in Facial Paralysis: Patients with Major Asymmetry Derive Greater Benefit.

Background: Facial filler is an effective nonsurgical treatment option for improving facial symmetry in patients with facial paralysis (FP). Objective: To compare the effects of filler among patients with FP that is self-perceived as major or minor asymmetry, by measuring psychosocial distress. Methods: In this prospective cohort study of patients with FP undergoing filler at a tertiary academic center, patients were classified as having minor or major self-perceived asymmetry using a visual analog scale (VAS). FACE-Q Appearance-Related Psychosocial Distress was administered before and after filler. Descriptive statistics and a random-effects generalized linear model assessed the relationship between perceived facial asymmetry and change in psychosocial distress. Results: A total of 28 patients participated. Twenty-five (89%) patients were female with median age of 54 (interquartile range [IQR]: 49-66). Median VAS score was 2 (IQR: 1-3.5, 0 = completely asymmetric, 10 = no asymmetry). Psychosocial distress improved in all patients after filler. In multivariable modeling, patients with major asymmetry experienced 2.45 (confidence interval: 0.46-4.44, p = 0.016) points more improvement in psychosocial distress than patients with minor asymmetry. Age, gender, and FP duration were not associated with change in psychosocial distress. Conclusion: Facial filler treatment was seen to improve psychosocial distress in patients with FP, especially by those with more self-perceived deficit.

Facial Nerve Exploration for Known or Suspected Transection: The Massachusetts Eye and Ear Experience.

Background: There is no ideal test to determine likelihood of spontaneous recovery after post-traumatic and postsurgical facial palsy (FP). Objective: Among patients with unexpected FP undergoing facial nerve (FN) exploration for suspected discontinuity, we endeavored to discern whether intraoperative findings, repair type, and time to exploration impact FN recovery, as measured by electronic Facial Clinimetric Evaluation (eFACE) and FaCE scales. Methods: Retrospective cohort study of 42 adult patients who underwent FN exploration. Results: FN injury resulted from either surgery (n = 29) or trauma (n = 13). Average time to repair was 68.4 (standard deviation 79.6) days. Postoperative improvements were observed in total eFACE (73.3-86.5; p < 0.0001) and FaCE (21.5-38.1; p = 0.0214) scores. Distal FN injuries were most common (n = 29) and had best recovery (percentage change in eFACE 57.2% vs. 34.3% main trunk, p = 0.0306). Discontinuity injuries (n = 33) repaired with primary coaptation (n = 18) had noninferior outcomes compared with cable graft repair (n = 16; percentage change in eFACE 49.6% vs. 39.2%, p = 0.3470). Denervation times <3 months yielded better recovery using percentage change in eFACE score (56.9% vs. 33.1%, p = 0.0270). Conclusions: Surgical exploration for unexpected FP allows for direct visualization of anatomical nerve status and timely repair.

Development of an interdisciplinary microtia-atresia care model: A single-center 20-year experience.

Objectives: Microtia and aural atresia are congenital ear anomalies with a wide-ranging spectrum of phenotypes and varied functional and psychosocial consequences for patients. This study seeks to analyze the management of microtia-atresia patients at our center over a 20-year period and to propose recommendations for advancing microtia-atresia care at a national level. Methods: We performed a retrospective analysis of data from patients presenting to the Massachusetts Eye and Ear (Boston, MA) for initial otolaryngology consultation for congenital microtia and/or aural atresia between 1999 and 2018. Results: Over the 20-year study period, 229 patients presented to our microtia-atresia center at a median age of 7 years. The severity of microtia was most commonly classified as grade III (n = 87, 38%), 61% (n = 140) of patients had complete atresia, the median Jahrsdoerfer grading scale score was 6 (range 0-10), and 81 patients (35%) underwent surgery for microtia repair. For hearing rehabilitation, 30 patients (64%) underwent bone conduction device implantation and 17 patients (36%) underwent atresiaplasty. The implementation of an interdisciplinary, longitudinal care model resulted in an increase in patient (r = 0.819, p < .001) and surgical volume (microtia surgeries, r = 0.521, p = .019; otologic surgeries, r = 0.767, p < .001) at our center over time. Conclusion: An interdisciplinary team approach to microtia-atresia patient care may result in increased patient volume, which could improve aesthetic and hearing outcomes over time by concentrating care and surgical expertise. Future work should aim to establish standardized clinical consensus recommendations to guide the creation of high-quality microtia-atresia care programs. Level of Evidence: 4.

The Tinel Sign and Myelinated Axons in the Cross-Face Nerve Graft: Predictors of Smile Reanimation Outcome for Free Gracilis Muscle Transfer?

Introduction: During a two-stage free gracilis muscle transfer (FGMT) to restore smile to patients with facial paralysis, some surgeons assess nerve regeneration through the cross-face nerve graft (CFNG) with the Tinel sign and a nerve biopsy. Objective: To test whether ultimate smile reanimation outcomes are correlated with (1) the Tinel sign or (2) myelinated axons of the biopsied CFNG at the time of FGMT. Methods: Retrospective case series was performed at a tertiary care facial nerve center. Dynamic smile outcomes were quantified with Emotrics analysis of pre- and postoperative photographs. Results: Of the 113 FGMT surgeries by CFNG performed since 2002, 92 patients had pre- and postoperative photo-documentation. Most patients (89%, N = 82) had a positive Tinel sign at the time of FGMT; however, 14 patients with positive Tinel signs were deemed failures. Interestingly, 4 patients with a negative Tinel sign went on to have successful dynamic outcomes and 16 patients lacking myelinated axons in their CFNG biopsy ultimately achieved successful smile outcomes. Conclusion: Although the majority of patients had a positive Tinel sign and myelinated axons in the CFNG at the time of FGMT, the presence or absence of either factor did not predict ultimate smile outcome in this series.

Automated Spontaneity Assessment after Smile Reanimation: A Machine Learning Approach.

BACKGROUND: Recreation of a spontaneous, emotional smile remains a paramount goal of smile reanimation surgery. However, optimal techniques to reliably restore spontaneity remain unknown. Dual automated machine-learning tools were used to develop an objective tool to analyze spontaneous smiling. The feasibility of this tool was tested in a sample of functional free muscle transfers. METHODS: Validated humorous videos were used to elicit spontaneous smiles. Automated facial landmark recognition (Emotrics) and emotion detection software (Affdex) were used to analyze video clips of spontaneous smiling in nine normal subjects and 39 facial reanimation cases. Emotionality quotient was used to quantify the ability of spontaneous smiles to express joy. RESULTS: The software could analyze spontaneous smiling in all subjects. Spontaneous smiles of normal subjects exhibited median 100 percent joy and 0 percent negative emotion (emotional quotient score, +100/0). Spontaneous smiles of facial palsy patients after smile reanimation, using cross-facial nerve graft, masseteric nerve, and dual innervation, yielded median emotional quotient scores of +82/0, 0/-48, and +10/-24 respectively (joy, p = 0.006; negative emotion, p = 0.034). CONCLUSIONS: Computer vision software can objectively quantify spontaneous smiling outcomes. Of the retrospective sample of cases reviewed in this study, cross-facial nerve graft-innervated gracilis functional free muscle transfer achieved a greater degree of emotionality during spontaneous smiling than masseteric or dually innervated transfer. Quantification of spontaneous smiling from standard video clips could facilitate future, blinded, multicenter trials with sufficient long-term follow-up to definitively establish the rates of spontaneity from a range of reanimation procedures. CLINICAL QUESTION/LEVEL OF EVIDENCE: Diagnostic, IV.