Masseter-facial neurorrhaphy for facial palsy reanimation: What happens after masseter denervation? Histomorphometric and stomatognathic functional analysis

Masseteric Atrophy Following Masseteric Nerve Transfer: Radiographic Findings of Asymmetry in the Paralyzed Face?

OBJECTIVES

To characterize the effect of facial reanimation using masseteric nerve transfer on the masseter muscle itself, examining whether there is any demonstrable atrophy postoperatively.

METHODS

Electronic medical records of adult patients who underwent facial reanimation using masseteric nerve transfer at our institution over a 15-year period were reviewed. To account for the impact of postoperative radiation, randomly selected patients who underwent radical parotidectomy without nerve transfer and received postoperative radiation served as controls in a 1:1 fashion against those who underwent masseteric nerve transfer with postoperative radiation.

RESULTS

Twenty patients were identified who underwent masseteric nerve transfer and had sufficient pre- and postoperative imaging to assess masseter volume (mean age 58.2, 60% female). Of the four patients who did not receive postoperative radiation, each demonstrated masseteric atrophy on the side of their nerve transfer, with a mean reduction in masseter volume of 20.6%. The remaining 16 patients were included in the case-control analysis accounting for radiation. When compared with controls, those in the study group were found to have a statistically significant difference in atrophy (p = 0.0047) and total volume loss (p = 0.0002). The overall reduction in masseter volume in the study group was significantly higher compared with the control group, at 41.7% and 16.6%, respectively (p = 0.0001).

CONCLUSION

Facial reanimation utilizing masseteric nerve transfer appears to result in atrophy of the denervated masseter when compared with the contralateral muscle. This volume deficit may lead to further facial asymmetry for patients undergoing comprehensive reanimation surgery.

LEVEL OF EVIDENCE

3 Laryngoscope, 134:4514-4520, 2024.

Dynamic Repair Surgery for Late-Stage Facial Paralysis: Advances in Restoring Movement and Function

Purpose: Facial paralysis results from congenital or acquired facial nerve damage, leading to significant cosmetic and functional deficits. Surgical resection of parotid and midface tumors can cause facial paralysis, necessitating effective treatment strategies. This review addresses the challenge of restoring movement and function in late-stage facial paralysis, focusing on dynamic repair techniques involving nerve and muscle transplantation. Methods: The review encompasses studies on dynamic repair surgery for late facial paralysis, including techniques such as local muscle flap with pedicle transfer, vascularized nerve flap with pedicle transfer, and multiple muscle flap procedures. A systematic literature search was conducted using PubMed, Web of Science, and Google Scholar, covering studies from 2000 to 2024. Keywords included "dynamic repair", "late-stage facial paralysis", "nerve and muscle transplantation", "muscle flap", and "tendon transposition". Included were clinical studies, systematic reviews, and meta-analyses reporting surgical outcomes. Exclusion criteria included studies with insufficient data and non-peer-reviewed articles. Results: Dynamic repair techniques involving nerve and muscle transplantation are essential for treating late-stage facial paralysis. Each surgical method has strengths and limitations. The masseter muscle flap demonstrates high success rates, although it can cause horizontal tension and jaw contour issues. The temporalis muscle flap is effective for smile restoration but may lead to temporal concavity. The gracilis muscle flap is widely used, especially with dual nerve innervation, showing high success in spontaneous smiles but requiring a longer recovery period. The latissimus dorsi flap is effective but can cause edema and shoulder issues. The serratus anterior free flap offers flexibility with precise vector positioning but may not achieve adequate lip elevation and can cause cheek swelling. Combined multi-flap surgeries provide more natural facial expressions but increase surgical complexity and require advanced microsurgical skills. Conclusions: Dual nerve innervation shows promise for restoring spontaneous smiles. One-stage surgery offers faster recovery and reduced financial burden. Comprehensive patient evaluation is crucial to select the most suitable surgical method. Dynamic repair techniques involving nerve and muscle transplantation provide effective solutions for restoring function and aesthetics in late-stage facial paralysis. Future research should focus on long-term outcomes, patient satisfaction, and standardizing surgical protocols to optimize treatment strategies.

Facial reanimation using free partial latissimus dorsi muscle transfer: Single versus dual innervation method

The aim of the present study was to analyze the consequences of partial free latissimus dorsi muscle flap with nerve splitting technique (Partial LD transfer) for facial reanimation and compare outcomes according to innervation method (singer versus dual innervation). Patients with complete unilateral facial paralysis underwent either the single (ipsilateral masseteric nerve only) or dual (ipsilateral masseteric nerve plus contralateral buccal branch of the facial nerve) nerve innervation method for facial reanimation. An assessment was carried out to compare the outcomes between the single and dual innervation. Total of 21 patients were involved in this study. In the single innervation group, 7 out of 8 patients developed a voluntary smile. However, none were able to achieve a spontaneous smile. On the other hand, 9 out of 13 patients developed a voluntary smile and 3 out of 13 patients achieved a spontaneous smile. The mean increases of smile excursion assessed by Emotrics software and Terzis grades showed no significant differences between two groups. Within the limitations of the study it seems that partial LD transfer approach utilizing the dual innervation method has a positive effect on achieving a spontaneous smile and could be a valuable option for facial reanimation.

Impact of COVID19 on Maxillofacial Fractures in the Province of L’Aquila, Abruzzo, Italy. Review of 296 Patients Treated With Statistical Comparison of the Two-Year Pre-COVID19 and COVID19

The aim of this study was to understand the impact of the COVID-19 pandemic on the epidemiology of maxillofacial trauma in a regional trauma center in L’Aquila, Abruzzo, Italy, during the first wave of the pandemic and comparted it to an equivalent period from 2015 to 2018. The authorshave retrospectively analyzed personal data, site of trauma, etiology, and mechanism of injury. Statistical analysis has been carried out utilizing IBM SPSS Statistics software (IBM Corp., Armonk, NY) and significance was accepted for P values of <0.05. From January 2015 to December 2020, a total of 296 were analyzed. In Pre-COVID era, 195 patients were evaluated, 130 males (66.6%) and 65 females (33.4%). Zygomatic-malar complex fractures were the most common site of trauma in both genders (53%), followed by mandibular fractures (23%) and orbital ones (15%). The highest incidences of injuries were recorded between 15 and 34 years (21%) with the most common etiology attributed to road accidents traumas (49%). In COVID19 era, the authors recorded 101 traumas, 58 males (57.4%), 43 females (42.6%). Zygomatic-malar complex fractures were confirmed as the most common ones in both genders (41%). The most common etiology was related to casual domestic accident and assaults (37% and 30%, respectively). There was no statistically significant difference in terms of incidence in the comparison of Pre-COVID19 and COVID19 periods (P > 0.05) as opposed to the etiology in which the road traffic accidents decreased in favor of domestic accidents and interpersonal assaults (P < 0.05). Our scientific study represents the first epidemiologic study related to the impact of COVID-19 on maxillo-facial trauma in the Province of L’Aquila, Abruzzo, Italy. A decrease in the number of Maxillofacial injuries related to road traffic accidents can be demonstrated as the benefit of lockdown, however, a significant increase in the number of physical assaults shows how isolation and restrictions have had a highly negative psychological impact on society.

Comparison of results utilizing one-step and two-step triple innervation techniques

A retrospective comparison between two groups of patients who underwent one-step or two-step triple innervation was performed to reveal the role of scar tissue in axonal regeneration. The surgical technique used was the same in all cases, but the first group underwent a one-time triple innervation procedure, while patients in the second group underwent delayed performance of neurorrhaphies between the distal ends of the cross-face grafts and the terminal branches of the injured facial nerve. The Wilcoxon signed-rank test for paired groups showed a statistically significant improvement in both facial symmetry and voluntary movements in both groups of patients. Separately, the Mann-Whitney test confirmed no statistically significant difference between the two groups regarding the restoration of facial symmetry and voluntary movements, and the development of postoperative synkinesis. A comparison of median values for each spontaneous parameter between the groups revealed greater effectiveness of the two-step surgery, with both blinking and laughing demonstrating better results. The greater effectiveness of the double-step technique in restoring spontaneous movements strongly supports the use of a two-stage triple innervation technique in patients with facial palsy.