Dey, Jacob K.

Abstract To review key concepts in facial nerve anatomy, physiology, injury mechanisms, and recovery patterns, and to summarize current approaches to classification, evaluation, and management of facial nerve dysfunction following skull base surgery. Narrative review of anatomical, clinical, and evaluative frameworks relevant to facial nerve dysfunction. Academic and clinical contexts involving the assessment and management of facial nerve injury, with emphasis on skull base surgery. Not applicable; this is a literature-based review. Descriptions of facial nerve anatomy and microanatomy; established classification systems for facial nerve injury; mechanisms of injury; patterns of recovery; common clinical presentations of post-surgical facial paralysis; and current grading scales and evaluation protocols. The review synthesizes foundational anatomical principles with contemporary understanding of facial nerve injury and recovery. It outlines the full spectrum of clinical outcomes observed after facial nerve injury, including typical post-surgical paralysis patterns and their natural course. Commonly used facial paralysis grading scales are compared, and standardized evaluation strategies are highlighted to promote consistent assessment across providers. Taken together, the findings provide a comprehensive framework for understanding and evaluating facial nerve dysfunction following skull base surgery. Understanding and treating facial nerve dysfunction requires nuanced knowledge of anatomy, injury mechanisms, recovery trajectories, and standardized evaluation methods. Consolidating these elements offers valuable guidance for skull base surgeons, facial plastic surgeons, and other clinicians caring for patients with facial paralysis, and supports more consistent and informed clinical decision-making.

Eye-tracking provides an objective measure of how observers direct visual attention to presented stimuli and has become an increasingly valuable tool in facial plastic surgery. It offers unique insight into how facial conditions and surgical interventions impact facial attention. A well-designed eye-tracking study can address patient questions about how others look at their face, identify targets for visual improvement, and objectively assess facial plastic surgery outcomes. Significant variability exists in eye-tracking study design and execution within facial plastic surgery, often producing data that are erroneous, difficult to interpret, or not generalizable to clinical practice. There are currently no guidelines for the design of eye-tracking studies in facial plastic surgery. Furthermore, the technical requirements for facial eye-tracking studies differ from those for non-facial studies. This article aims to synthesize the existing literature and authors’ experience to establish basic guidelines for designing eye-tracking studies in facial plastic surgery. We hope this guide will help investigators design high-quality eye-tracking studies to drive meaningful advances in the field of facial plastic surgery.

Background: Facial nerve injury can result in a spectrum of clinical presentations from complete facial paralysis (CFP) to facial synkinesis. Willingness to pay (WTP) and quality-adjusted life years are established metrics used to assess the societal value of treatments. Objective: To quantify the perceived value of surgery for CFP and synkinesis amongst casual observers, as measured by WTP and quality of life indices. Methods: Casual observers were shown standardized videos of faces with complete paralysis, synkinesis, and nonparalyzed controls (eight videos each). Observers were asked to imagine having each condition and to rate their quality of life and WTP for surgical repair. Results: A total of 557 observers were included (mean age 36.5 years, 59% female). Both complete paralysis and synkinesis were associated with reduced quality-adjusted life year indices (0.9 [95% confidence interval [CI] 0.87–0.93]) for synkinesis; 0.86 (95% CI: 0.83–0.89) for complete paralysis, p = 0.0011). The mean WTP was $22,791 for complete flaccid paralysis and $15,718 for synkinesis repair and increased with income. WTP per quality-adjusted-life year gained was $6,844 for complete paralysis and $6,604 for synkinesis ( p > 0.05). Conclusion: Observers perceived surgical repair of CFP and synkinesis as highly valuable and within common cost-effectiveness thresholds.

Background: Facial appearance influences social perception, with laypersons focusing on the central facial triangle; nasal differences may alter gaze patterns, but few studies have quantified this using eye-tracking. Objective: To evaluate how layperson gaze patterns shift in response to different nasal variations as measured by eye-tracking. Methods: In this prospective cohort study, facial images with 30 nasal differences were created using Photoshop to represent a range of phenotypes, such as dorsal hump, crooked nose, and pinched tip, alongside controls. Gaze data were captured via eye-tracking, and linear mixed-effects modeling assessed differences in time spent viewing defined areas of interest, adjusting for participant and image variables. Results: A total of 119 participants (53.8% female) were enrolled. The median age was 40 years, and 82% identified as Caucasian. Among the 30 nasal alterations, only the saddle nose resulted in significantly increased gaze time compared to controls (mean increase: 0.89 s; p < 0.001). Participant age, sex, and gender of the face in the image did not significantly influence gaze behavior. Conclusion: In this study, only the saddle nose attracted greater visual attention from lay observers compared with other nasal variants.

Introduction: Nasal analysis is a challenging skill that otolaryngology trainees must demonstrate competency in on-board examinations. Study objective: To compare where experts and trainees focus their gaze when completing nasal analysis of a patient, as measured by eye tracking software. Methods: Participants of various training levels ( n = 27) were shown photographs of six faces from all standard angles for photographic nasal analysis. Eye-tracking data were collected. Heat and gaze maps, the time to first fixation on areas of interest, duration, and number of fixations were extracted. These metrics were compared between experts and trainees using t -tests and one-way ANOVA. Results: Qualitative comparisons of gaze patterns reveal a more comprehensive and organized approach among experts than trainees. However, quantitative measures of eye-tracking metrics, including the time to first fixations, duration, and number of fixations made by experts and trainees, were similar. Conclusions: Gaze tracking reveals more thorough and efficient eye movements among experts than trainees during nasal analysis. Further study may be useful in the development of learning tools to guide effective nasal analyses.

Background: Variable terminology is used in the literature to describe facial synkinesis and hypertonicity following incomplete recovery from facial paralysis and its associated medical and surgical treatments. Study Objectives: Establish a nomenclature consensus for this condition among a group of facial nerve experts. Design Type: Consensus study. Methods: Using modified Delphi methodology, an international, multidisciplinary group of facial nerve experts reviewed the terminology for the name of the clinical condition and treatments of interest. Online surveys and a virtual discussion were performed to establish consensus, defined a priori as agreement by 80% of the group. Results: Twenty-five facial nerve experts established consensus after three Delphi rounds. Consensus terminology for the condition is “facial synkinesis” with 84% agreement. Medical treatment is termed “chemodenervation” with 100% agreement. Surgical treatments including “selective facial neurectomy,” “selective facial neurotomy,” “selective facial myectomy,” and “selective facial myotomy,” were defined and reached agreement of 100%. Conclusions: This international group of facial nerve experts has recommended standardized nomenclature for the condition of facial synkinesis and its various treatments. While “facial synkinesis” reached consensus as the preferred term, some experts noted it may insufficiently describe the full clinical spectrum, which includes muscle hypertonicity, weakness, and spontaneous twitching.

Background: There is a spectrum of facial paralysis patient presentations from complete flaccid facial paralysis (CFFP) to facial aberrant reinnervation syndrome (FARS). Objective: To objectively compare how laypersons direct attention to faces with different facial paralysis subtypes using eye-tracking technology. Methods: Lay observers freely gazed at standardized videos of 24 individuals’ faces as follows: 8 with CFFP, 8 with FARS, and 8 nonparalyzed Controls performing common facial expressions. Eye-tracking measured observers’ gaze and extracted data as time in milliseconds looking at facial subsites. Mixed effects regression was used for comparative analyses. Results: A total of 85 observers completed the study. For faces at rest, measurable differences in gaze patterns were noted for CFFP faces (more attention spent on nonparalyzed hemiface), whereas FARS and Control faces showed similar symmetric gaze patterns. With dynamic movement (smiling and brow-elevation), gaze patterns for both CFFP and FARS faces became altered and asymmetrical compared with Control faces. Conclusions: Faces with CFFP and FARS are viewed differently by casual observers, which has implications for patient care and future research. While CFFP showed gaze alterations (compared with Control) in both rest and facial expression states, FARS caused gaze alterations only with facial movement.

Background: Facial aberrant reinnervation syndrome (FARS) is a common sequelae of facial nerve injury followed by aberrant reinnervation and recovery. Patients with FARS can present with different patterns of facial synkinesis, facial muscle hypertonicity, and facial spasm/twitching. 1 Synkinesis associated with FARS is described as undesired muscle contraction when a voluntary movement is triggered. One of the most common and bothersome types of facial synkinesis is oral-ocular synkinesis, where patients experience unwanted eyelid closure with movement of the mouth such as smiling or pursing the lips. First-line treatment options for FARS include facial physical therapy and botulinum toxin selective chemodenervation. For patients with persistent or more significant symptoms, there are surgical options, including selective neurectomy and selective myectomy of the involved facial nerve branches and muscles. 2 , 3 Selective myectomy of the orbicularis oculi muscle has been shown to be an effective surgical treatment option for oral-ocular synkinesis. 3 – 4 There is nuance to this procedure, including deciding whether to target the upper eyelid, lower eyelid, or both, as well as which segments and how much of the orbicularis oculi muscle to remove, balancing the goals of improving synkinesis and hypertonicity while avoiding the creation of lagophthalmos. The novel implementation of autologous microfat grafting to the procedure can help improve postoperative eyelid volume and contour and may help prevent the cut edges of the muscle from fusing, thus reducing the likelihood of persistent or recurrent ocular synkinesis. Objective: To describe a selective myectomy of the orbicularis oculi with the novel addition of autologous microfat grafting for the treatment of oral-ocular synkinesis. Methods: This video demonstrates the procedural steps for a selective myectomy of the orbicularis oculi with autologous microfat grafting for a patient with oral-ocular synkinesis due to FARS. In addition, it demonstrates the preparation of harvested abdominal fat that is utilized for the autologous microfat grafting. Results: Selective myectomy of the orbicularis oculi with autologous microfat grafting has been routinely performed safely and effectively by the senior author for treatment of oral-ocular synkinesis. Postoperative aesthetic eyelid shape and functional results have been reassuring with improvements up to 1 year postoperative and a need for additional long-term follow-up. Conclusion: To the authors’ knowledge, a selective myectomy of the orbicularis oculi with autologous microfat grafting has not been demonstrated in video documentation. Autologous microfat grafting may be a helpful addition to selective myectomy of the orbicularis oculi to enhance both eyelid aesthetics and function. Patient Consent Statement: All patients included in the video have consented to the use of videos and photographs of their faces for research and educational purposes. Funding and Conflicts of Interest: The authors have no funding, financial relationships, or conflicts of interest to disclose. Runtime of video: 7 mins 11 secs.