Background: The gracilis free muscle transfer (GFMT) is considered a powerful tool in dynamic facial reanimation but lacks consensus on the optimal donor nerve for pediatric populations. Objective: To compare outcomes in pediatric patients receiving a GFMT for facial reanimation based on donor nerve as measured by commissure excursion, facial symmetry, and spontaneity. Method: A systematic review using PubMed, EMBASE, and Google Scholar was conducted to identify articles that investigated primary GFMT for facial reanimation using a variety of donor nerves for reinnervation in patients under 20 years old. Quantitative meta-analysis stratified by donor nerve was conducted. Results: A total of 19 articles with 304 patients were included in our meta-analysis. The masseteric, cross-facial nerve graft, and dual-innervation techniques were included. Pediatric GFMT significantly improves commissure excursion regardless of donor nerve. There were no significant differences between groups in facial symmetry. Conclusion: Significant improvement in oral commissure excursion is seen following GFMT no matter the donor nerve source. Data on reported outcomes in pediatric patients are limited and heterogenous, which limits conclusions on facial symmetry and spontaneity following this procedure. Future research using standardized outcome reporting is needed to determine the optimal nerve to power a GFMT in facial reanimation.

Modified free functional split gracilis flap design for periorbital and perioral smile reanimation in patients with total flaccid facial paralysis: A cadaveric study.

This systematic review aims to describe and compare outcomes of innervation techniques for gracilis free muscle transfers for facial reanimation in the pediatric population. CINAHL, PubMed, and SCOPUS were systematically queried from inception to November 18, 2025. Eligible studies included pediatric patients (≤ 18 years old) who underwent free gracilis muscle transfer for facial reanimation. Outcomes extracted included commissure excursion, facial asymmetry, validated instruments, patient satisfaction, and complications. Study quality was assessed using the Joanna Briggs Institute appraisal tool. A total of 15 retrospective studies were included for review, covering cross-facial nerve graft, masseteric innervation, and dual-innervation. The mean age at time of surgery was 9.0 ± 0.8 years with a mean follow-up time of 3.0 ± 0.5 years. Muscle innervation was achieved primarily with CFNG (52.1%), followed by masseteric (33.2%). Masseteric innervation generally produced the largest amount of commissure excursion (range: 6.1-8.6 mm), while CFNG also yielded moderate improvements (range: 4.6-6.9 mm). Overall satisfaction was high for all innervation techniques, ranging from 83% to 100%. Complications were infrequent and minor. Gracilis free muscle transfer is safe and effective for pediatric facial reanimation. Masseteric innervation provides strong, volitional smiles, while CFNG provides spontaneous smiles, with dual-innervation offering a balance of the two.

Background and Objectives: The masseteric artery (Ma) enters the masseter muscle (Mm) together with the masseteric nerve (Mn) via the mandibular notch. Morphological detail on the intramuscular course of the Ma and its relationship to the Mn remains scarce to date. When utilizing the Mn in facial reanimation surgery, a constant relationship between the Ma and Mn could be used for intramuscular orientation when preparing the Mn and for an indirect localization via ultrasound. This study examines the intramuscular course of the Ma and its relationship to the Mn. Materials and Methods: Sixty hemicrania obtained from thirty postmortem individuals aged between 54 and 99 years and embalmed using the Thiel methods were examined. Results: Four types of Ma were identified according to their endpoint in the Mm. In 5% of cases, no Ma could be identified (Type 0), 48.3% (Type 1) terminated within the upper third, 41.7% (Type 2) in the middle third, and 5% (Type 3) in the lower third. The Ma consistently entered the Mm inferior and in 85% of cases additionally slightly posterior to the Mn. The main trunk of the Ma crossed the Mn in the upper third of the Mm in 31.7% of cases, in the middle third in 23.3%, and in the lower third in 1.7% of cases. Of these, 13.3% had the Ma crossing the Mn. Smaller branches crossed the Mn in 45% of cases. Conclusions: If an Ma is present, it may be used for intramuscular orientation and indirect location of the Mn via the mandibular notch. Since the Ma reaches the lower third of the muscle in only a few cases, it is unsuitable for intramuscular orientation to locate the Mn via a distal approach.

Introduction: Cross-facial nerve graft with free functional muscle transfer (FFMT) is a mainstay approach for facial reanimation. However, the effect of delay between cross-facial nerve graft and FFMT procedures is unknown. Objective: To measure the effect of delay between cross-facial nerve graft and FFMT among patients with facial nerve paralysis, as measured by clinician-graded assessments longitudinally. Methods: Patients who underwent both cross-facial nerve graft and gracilis FFMT, which was performed from 2016 to 2023, were retrospectively reviewed. Primary outcomes were time to first facial movement and time to spontaneous smile. Results: This study included 31 patients with cross-facial nerve graft and FFMT. Time between procedures did not adversely impact reinnervation. Between single and dual innervation patients, there was no difference in time to first facial movement (198, interquartile [IQR: 152.5-290 days] vs. [146, IQR: 116-196 days] [p = 0.089]) and time to spontaneous smile ([297.5, IQR: 200.25-409 days] vs. [282, IQR: 202-464 days] [p = 0.779]). Conclusion: Delays between cross-facial nerve graft and FFMT do not adversely impact time to first facial movement or spontaneous smile. Mature grafts may potentially remain viable for prolonged periods of time and thereby create opportunities for patients.

Externally validated scoring systems for facial nerve injury after vestibular schwannoma (VS) resection are lacking. We aimed to derive and externally validate a scoring system predictive of poor long-term facial nerve outcome after microsurgical resection of VS. Patients who underwent microsurgical resection of VS by a retrosigmoid approach at Johns Hopkins Hospital between July 2016 and April 2024 were included. An optimal stepwise multivariable logistic regression model predicting poor facial nerve outcome (House-Brackmann >2) at last follow-up was derived with a scoring system. Predictive metrics were compared with the previously published Facial Nerve Outcome Score (FNOS). An additional model using only preoperative factors was derived. External validation of accuracy and calibration was performed in Stanford Healthcare and University of Cincinnati Medical Center. In 360 VS patients, 80 patients (22%) experienced poor facial nerve outcome at last follow-up (3.1 ± 2.3 years). Gross total resection was achieved in 304 patients (84%). The optimal logistic regression model based on 316 patients with available data included abnormal renal function (odds ratio [OR] = 8.3, 95% CI [1.4-48.5], P < .001), neuroma size ≥2.2 cm (OR = 3.3, [1.7-6.6], P < .001), and stimulation threshold postresection (weak stimulation OR = 7.1, [3.1-16.2], P < .001). The 7-point acoustic neuroma score outperformed FNOS in our cohort (area under the receiver operating curve [AUC] = 0.807 [0.742-0.872] vs FNOS AUC = 0.696 [0.622-0.771], P < .001). Calibration plots showed excellent calibration. On external validation, AUCs of 0.713 [0.555-0.870] and 0.729 [0.547-0.911] were derived, with favorable calibration plots. A preoperative model excluding nerve stimulation threshold additionally performed well. A calculator was deployed at https://facialnervefunction.shinyapps.io/Facial_Nerve_Function_Calculator/. The acoustic neuroma 7 model can be used for patient counseling and for identifying high-risk patients for facial weakness while aiding in earlier referral for facial reanimation surgery.

An unanswered question in facial reanimation surgery is how to improve the results of conventional primary cross-facial nerve grafts. In this study, we designed a study to determine whether vascularizing cross-facial nerve grafts with shorter lengths following intra-oral insets, provides sufficient neural input to the targeted smile-mimetic muscles without the need for a concomitant "babysitter" procedure. In a retrospective review of practice over 5 years on facial palsy patients with smile asymmetry, we performed a combination of the intra-oral vascularized nerve graft (VNG) which connects the buccal branches of the facial nerve, that supply the smile-mimetic muscles, on either side of the face; the "Koshima-type" procedure. This VNG is performed in combination with a forked fascicular transfer of the masseteric nerve, which is coapted to the zygomatic branches of the facial nerve (Group I). In Group II, only the "Koshima-type" procedure was performed without a "babysitter" procedure, which only connected the buccal branches of the facial nerve on either side (Group II). Both approaches were statistically compared in cases of acute facial palsy (within 24 months of onset), in those with no pre-existing synkinesis. Statistical analysis was performed using the Mann-Whitney test. Of a total of 13 patients in the overall cohort; seven in Group I and six in Group II, there was a significant improvement in both groups in terms of an open mouth smile following surgery (p < 0.001), with no statistically significant difference between them (p = ns); but in terms of snarl movement, only patients in Group II showed significant improvement in upper lip elevation (p < 0.05). The "Koshima-type" procedure alone is sufficient in providing optimal and spontaneous smile reanimation, without the need for a "babysitter" procedure, provided it is performed within 24 months in facial palsy patients with no clinical or neurophysiological evidence of reinnervation.

This study aimed primarily to establish a precise surgical anatomical guide for masseteric-to-facial nerve (MN-FN) anastomosis using reproducible anatomical landmarks. The secondary objective was to identify novel and reliable landmarks to facilitate the localization and dissection of the masseteric nerve (MN) during facial reanimation procedures. A cadaveric study was performed on 22 hemifaces from 11 formalin-fixed cadavers. Standardized preauricular and temporal scalp incisions were used to expose the facial nerve (FN) and identify the MN. Distances from the tragus, zygomatic arch, and relevant bony landmarks to the MN were measured. Angles and depths were recorded bilaterally. Statistical analyses included Wilcoxon signed-rank test (p < 0.05). For the primary objective, the MN was consistently located deep to the zygomatic arch, at a mean distance of 2.6 ± 0.4cm anterior to the tragus and a mean depth of 1.2 ± 0.3cm. The trajectory formed an average angle of 52.1 ± 6.2° with the zygomatic arch. These parameters were symmetrical bilaterally (p > 0.05), confirming their reproducibility. For the secondary objective, we identified a new "subzygomatic triangle" bordered by the zygomatic arch, posterior masseter border, and condylar neck. The MN was reliably found within this triangle in all specimens (12/12, 100%), with significantly reduced depth variability compared to standard techniques (p = 0.018). This study defines reproducible anatomical references and introduces a novel landmark to enhance the safety and precision of MN-FN anastomosis in facial reanimation surgery.

Multivector gracilis muscle transfer for smile reanimation in long-standing facial paralysis: Simultaneous upper and lower lip construction.

Importance: This review aims to assess the current landscape of implantable and prosthetic devices for dynamic facial reanimation. Evaluation will include mechanisms, reported effectiveness, and clinical feasibility. Observations: This scoping review included 34 primary studies published since 2000, focusing on prosthetic and implantable devices for dynamic facial reanimation. Four major categories emerged: electromyography-functional electrical stimulation (EMG-FES) systems, artificial muscles, electromagnetic actuators, and wearable prosthetics. Most research addressed periocular reanimation, particularly blinking, and several studies discussed midface and smile restoration. EMG-FES systems were the most represented and robust across animal invivo models. Artificial muscle, electromagnetic actuators, and wearable prosthetics mostly remain in theoretical stages. Conclusions and Relevance: Although not yet fully viable, implantable and prosthetic devices show potential to complement or one day replace current surgical approaches to facial reanimation. EMG-FES systems offer the most viable near-term options. Clinically, these technologies may offer customizable, dynamic facial movement restoration, especially for patients with limited surgical options. Continued innovation and long-term safety studies will be essential.

Background: Past studies demonstrate that certain facial features systematically affect first impressions of psychological traits. However, no previous studies have examined how individual differences in facial health affect first impressions of psychological traits. Methods: In this study, we asked a large sample of fairgoers to give their first impressions of psychological traits in response to viewing videos of unilateral facial paralysis patients with varying degrees of facial functioning. Then, we used linear mixed-effects regression models to understand how individual differences in facial health predict first impressions. Results: Our results replicate previous findings regarding first impressions of faces, such as the attractiveness halo effect, as well as age (maturity) and gender (masculinity) effects. More importantly, our results reveal that facial health, as measured by a clinician-graded scale, is a significant predictor of first impressions. Specifically, we found that individuals with better dynamic facial health (as assessed by clinicians) were perceived to be more competent and more affiliative, but not more dominant, than individuals with lower levels of dynamic facial functioning. Conclusions: Our results have important implications for personalized medicine via the development and refinement of individually tailored therapies to improve facial reanimation surgery outcomes.

Comparison of hypoglossal nerve transfer and hypoglossal jump nerve graft techniques for facial reanimation: A systematic review.

Oncologic ablation in the head and neck region frequently results in the sacrifice of peripheral nerves and their target organs. This inevitably can compromise facial expression, ocular protection, oral competence, speech, swallowing, and cutaneous sensation, causing functional and aesthetic impairment. The application of principles from peripheral nerve surgery in these instances provides the opportunity to minimize these morbidities. For facial reanimation, targeted nerve transfers, cross-facial nerve grafting, and nuances for functioning free muscle transplantation are delineated to restore smile and spontaneous blink function. Dynamic tongue reconstruction is described for hypoglossal nerve innervated muscle flaps combined with conventional fasciocutaneous flaps for improved swallow function, bulk, and lining. Sensory reconstruction includes interposition and cross-face sural grafts to supraorbital/supratrochlear, infraorbital, lingual, and mental nerves, including corneal and lacrimal gland neurotization as potentially vision-saving procedures.

Smiling in the East and the West: Anatomical, cultural and sociological considerations in facial reanimation surgery

Facial paralysis is a potential complication of acoustic neuroma treatment, and hypoglossal-facial nerve anastomosis (HFA) is a well-established reconstructive option. We report a case of dynamic facial reanimation using a free latissimus dorsi (LD) muscle flap in a patient previously treated with HFA who remained unable to produce a spontaneous smile. A 64-year-old woman, 5 years postacoustic neuroma resection and subsequent HFA, presented with preserved facial tone but distressing involuntary synkinetic movements and inability to smile spontaneously. A V-shaped neurovascular LD muscle flap was harvested and innervated primarily by the contralateral facial nerve (CLFN), with end-to-side coaptation of the distal stump of the thoracodorsal nerve (TDN) to the ipsilateral masseteric nerve (ILMN). The zygomatic branch innervated by the hypoglossal nerve was selectively transected to mitigate adverse eyelid movements, and its end was coapted to the distal stump of the TDN to preserve orbicularis oculi tone. Postoperatively, the patient achieved synchronous oral commissure elevation and lower eyelid movement, effectively restoring a true spontaneous smile and a "smiling eye" appearance. To the best of our knowledge, this is the first report of CLFN-innervated LD muscle transfer for smile reanimation following HFA. This combination may offer a viable strategy to restore natural facial expressions in patients with complete facial paralysis.

Purpose: Pediatric neoplastic facial paralysis presents challenges in planning surgical reanimation. Methods: A review of pediatric patients with facial paralysis secondary to malignant tumors was conducted. Oncological data, functional status, chronology, and degree of paralysis were recorded. Surgical indications and techniques were documented. Postoperative outcomes included facial nerve function and survival. Results: A total of 14 patients were analyzed. The most common tumor location was the posterior fossa (n = 12). Most patients showed stability of the tumoral disease (n = 11). Facial paralysis occurred mainly after tumor surgery (n = 12). The House-Brackmann (HB) grade at diagnosis was IV (n = 2), V (n = 3), and VI (n = 7). Two patients had bilateral paralysis, with HB grade V (n = 1) and VI (n = 1) respectively. Facial reanimation was performed on 10 patients, with a median paralysis-to-surgery interval of 15 months (2-21). Surgical techniques included interposition nerve grafts, cross-facial nerve grafts, or regional nerve transfers. At 12 months, 9 patients improved to HB grades III-IV, the Sunnybrook score improving from 7.5 (5-55) to 44 (34-67). The deaths of 3 patients were documented. The remaining patients maintained stable facial function. Conclusion: Our experience with facial reanimation surgery in oncological patients is positive, most patients remaining with stable oncological status and good functional outcomes.

Drawing It Out: Operative Diagrams as Cognitive and Communication Maps in Facial Reanimation Surgery.

Introduction: Facial paralysis secondary to skull base recurrences or facial nerve tumors presents a significant challenge, as tumor resection usually worsens facial function. Objective: The aim of this study is to show an alternative approach, ensuring facial reanimation irrespective of the evolution of the tumor, the so-called "take the facial nerve out of the picture." Methods: Retrospective study of patients with a skull base recurrence or a facial nerve tumor who underwent facial reanimation prior to tumor management. Facial function was assessed using the House-Brackmann and Sunnybrook Facial Grading Scale. Results: Four patients with skull base recurrences and eight with facial nerve tumors underwent facial reanimation with nerve transfers (n = 11) and a microvascular flap (n = 1) before tumor treatment. In all cases, facial function improved to House-Brackmann grades III or IV, with improvement of average Sunnybrook Facial Grading Scale scores from 25.25 (standard deviation [SD] 20.45) to 57.67 (SD 10.3) (p = 0.004). Three patients with skull base recurrence underwent tumor resection uneventfully, while the eight patients with facial nerve tumor remain observed. Conclusions: Early facial reanimation can preserve long-term facial function, facilitate tumor resection, and provide flexibility in managing complex skull base recurrences and facial nerve tumors.

Future innovations for the treatment of facial nerve paralysis.

The Use of Nerve Allografts in Facial Nerve Repair and Facial Reanimation.