[MiR-132-3p negatively regulates CAMTA1 to promote Schwann cell proliferation and migration and alleviates I-125 seeds-induced exacerbation of facial nerve injury in rats].

OBJECTIVE: To investigate the regulatory effect of miR-132-3p on calmodulin-binding transcription activator 1 (CAMTA1) and Schwann cell activity in rats with facial nerve injury (FNI) treated with I-125 seeds. METHODS: Rat Schwann cells were irradiated with I-125 seeds and transfected with miR-132-3p mimic, miR-132-3p inhibitor or sh-CAMTA1. The expressions of S100B and ß-tubulin Ⅲ in the cells were detected with immunofluorescence assay, and the expressions of miR-132-3p and CAMTA1 protein were determined using RT-qPCR and Western blotting, respectively. EdU staining and Transwell assay were used to evaluate the changes in cell proliferation and migration ability. In a rat model of FNI, I-125 seeds were implanted into the facial tissues near the facial nerve 2 weeks before modeling, and miR-132-3p mimic was injected subcutaneously in the face after modeling. The pathologies of the facial nerve was assessed by HE, LFB and immunofluorescence staining. The targeting relationship between miR-132-3p and CAMTA1 was verified using StarBase v2.0 database and dual-luciferase reporter assay. RESULTS: Rat Schwann cells showed high expressions of S100B and ß-tubulin Ⅲ. I-125 seeds radiation significantly decreased miR-132-3p expression and repressed proliferation and migration of the cells (P < 0.001). Overexpression of miR-132-3p or CAMTA1 knockdown obviously enhanced proliferation and migration of the Schwann cells, while miR-132-3p knockdown produced the opposite effect. MiR-132-3p negatively regulated CAMTA1 expression. In the rat models of FNI, miR-132-3p injection significantly inhibited CAMTA1 expression and attenuated I-125 seeds-induced exacerbation of FNI. CONCLUSION: Overexpression of miR-132-3p suppresses CAMTA1 expression and promotes Schwann cell proliferation and migration to alleviate I-125 seeds-induced exacerbation of FNI in rats.

Porous Organic Materials in Tissue Engineering: Recent Advances and Applications for Severed Facial Nerve Injury Repair.

The prevalence of facial nerve injury is substantial, and the restoration of its structure and function remains a significant challenge. Autologous nerve transplantation is a common treatment for severed facial nerve injury; however, it has great limitations. Therefore, there is an urgent need for clinical repair methods that can rival it. Tissue engineering nerve conduits are usually composed of scaffolds, cells and neurofactors. Tissue engineering is regarded as a promising method for facial nerve regeneration. Among different factors, the porous nerve conduit made of organic materials, which has high porosity and biocompatibility, plays an indispensable role. This review introduces facial nerve injury and the existing treatment methods and discusses the necessity of the application of porous nerve conduit. We focus on the application of porous organic polymer materials from production technology and material classification and summarize the necessity and research progress of these in repairing severed facial nerve injury, which is relatively rare in the existing articles. This review provides a theoretical basis for further research into and clinical interventions on facial nerve injury and has certain guiding significance for the development of new materials.

Appropriate dosage, timing, and site of intramuscular injections of brain-derived neurotrophic factor (BDNF) promote motor recovery after facial nerve injury in rats.

INTRODUCTION/AIMS: Daily intramuscular injections of fibroblast growth factor 2 (FGF2) but not of brain-derived neurotrophic factor (BDNF) significantly improve whisking behavior and mono-innervation of the rat levator labii superioris (LLS) muscle 56 days after buccal nerve transection and suture (buccal-buccal anastomosis, BBA). We explored the dose-response of BDNF, FGF2, and insulin growth factor 2 (IGF2) on the same parameters, asking whether higher doses of BDNF would promote recovery. METHODS: After BBA, growth factors were injected (30 µL volume) daily into the LLS muscle over 14, 28, or 56 days. At 56 days, video-based motion analysis of vibrissal whisking was performed and the extent of mono- and poly-reinnervation of the reinnervated neuromuscular junctions (NMJs) of the muscle determined with immunostaining of the nerve with ß-tubulin and histochemical staining of the endplates with Alexa Fluor 488-conjugated α-bungarotoxin. RESULTS: The dose-response curve demonstrated significantly higher whisking amplitudes and corresponding increased mono-innervation of the NMJ in the reinnervated LLS muscle at concentrations of 20-30 µg/mL BDNF administered daily for 14-28 days after BBA surgery. In contrast, high doses of IGF2 and FGF2, or doses of 20 and 40 µg/mL of BDNF administered for 14-56 days had no effect on either whisking behavior or in reducing poly-reinnervation of endplates in the muscle. DISCUSSION: These data suggest that the re-establishment of mono-innervation of whiskerpad muscles and the improved motor function by injections of BDNF into the paralyzed vibrissal musculature after facial nerve injury have translation potential and promote clinical application.

[A sampling survey of intraoperative facial nerve monitoring in China].

Objective: This study aims to investigate the current application and the level of knowledge of intraoperative facial nerve monitoring among medical staff in China. Methods: A comprehensive online questionnaire was conducted among medical professionals across different regions in China from October 2022 to February 2023. The survey exclusively targeted departments specializing in otolaryngology, head and neck surgery, neurosurgery, and oral and maxillofacial surgery. The questionnaire covered various aspects including general information, intraoperative facial nerve monitoring practices, training history, indications for monitoring, parameters used during monitoring procedures, as well as factors influencing its implementation. Results: A total of 417 participants from 31 provincial, municipal, and autonomous regions were included. Intraoperative facial nerve monitoring was found to be implemented in 227 (54.4%,227/417) repondents of 53 institutions (24.9%, 53/213). The top three indications for implementing this technique were acoustic neuroma, parotid gland surgery, and modified middle ear surgery (mastoidectomy). Herein 81.1%(184/227) medical staff involved in intraoperative facial nerve monitoring had received relevant training, 57.3%(130/227)-92.1%(209/227) reported a lack of clear description regarding recording thresholds, stimulation currents/frequencies/wave widths. Conclusion: The majority of the institutions surveyed have not yet adopted intraoperative facial nerve monitoring. Furthermore, significant gaps concerning the procedure exist. It is imperative to establish standards or guidelines to promote its better development and application.

The involvement of Neuregulin-1 in the process of facial nerve injury repair through the utilization of dental pulp stem cells.

BACKGROUND: Facial nerve injury often results in poor prognosis due to the challenging process of nerve regeneration. Neuregulin-1, a human calmodulin, is under investigation in this study for its impact on the reparative capabilities of Dental Pulp Stem Cells (DPSCs) in facial nerve injury. METHODS: Lentivirus was used to transfect and construct Neuregulin-1 overexpressed DPSCs. Various techniques assessed the effects of Neuregulin-1: osteogenic induction, lipid induction, Reverse Transcription Polymerase Chain Reaction, Western Blot, Cell Counting Kit-8 assay, wound healing, immunofluorescence, Phalloidin staining, nerve stem action potential, Hematoxylin-eosin staining, transmission electron microscopy, and immunohistochemistry. RESULTS: Neuregulin-1 effectively enhanced the proliferation, migration, and cytoskeletal rearrangement of DPSCs, while simultaneously suppressing the expression of Ras homolog gene family member A (RhoA) and Microfilament actin (F-actin). These changes facilitated the neural differentiation of DPSCs. Additionally, in vivo experiments showed that Neuregulin-1 expedited the restoration of action potential in the facial nerve trunk, increased the thickness of the myelin sheath, and stimulated axon regeneration. CONCLUSION: Neuregulin-1 has the capability to facilitate the repair of facial nerve injuries by promoting the regenerative capacity of DPSCs. Thus, Neuregulin-1 is a significant potential gene in the reparative processes of nerve damage.

Ocular-oral synkinesis caused by partial injury of the zygomatic and buccal branches of the facial nerve after mid-face trauma.

BACKGROUND: Facial nerve paralysis induced by acute traumatic facial nerve injuries limited to the zygomatic and buccal branches shows unique complications, such as strong co-contractions of the lower facial muscles around the lips during voluntary blinking (ocular-oral synkinesis). We investigated the characteristics of facial complications after facial nerve injury in the mid-face area and reported the treatment results. METHODS: A total of 21 patients with facial nerve injuries to the zygomatic and/or buccal branches were evaluated for the degree of facial synkinesis and mouth asymmetry. Patients with mild-to-moderate symptoms were treated using physical rehabilitation therapy combined with botulinum toxin (Botox) injection, and patients with severe or uncontrolled symptoms were treated using surgical therapy. RESULTS: Initial/final mean synkinesis scores and mouth asymmetry degrees were 2.17/1.75 and 0.85/0.66 in the physical therapy group and 3.11/0.78 and 2.41/-0.31 in the surgery group, respectively. Physical therapy with Botox injection alone did not show significant improvements in synkinetic symptoms of the patients with mild-to-moderate synkinesis (p > 0.05), whereas surgical therapy resulted in significant improvements in synkinesis and mouth asymmetry (p < 0.05). CONCLUSIONS: Surgical treatment is an effective adjustment procedure for the management of facial complications in patients with severe or uncontrolled synkinesis after facial nerve injury to the mid-face area.

Electroacupuncture Promotes Functional Recovery after Facial Nerve Injury in Rats by Regulating Autophagy via GDNF and PI3K/mTOR Signaling Pathway.

OBJECTIVE: To explore the mechanism of electroacupuncture (EA) in promoting recovery of the facial function with the involvement of autophagy, glial cell line-derived neurotrophic factor (GDNF), and phosphatidylinositol-3-kinase (PI3K)/mammalian target of rapamycin (mTOR) signaling pathway. METHODS: Seventy-two male Sprague-Dawley rats were randomly allocated into the control, sham-operated, facial nerve injury (FNI), EA, EA+3-methyladenine (3-MA), and EA+GDNF antagonist groups using a random number table, with 12 rats in each group. An FNI rat model was established with facial nerve crushing method. EA intervention was conducted at Dicang (ST 4), Jiache (ST 6), Yifeng (SJ 17), and Hegu (LI 4) acupoints for 2 weeks. The Simone's 10-Point Scale was utilized to monitor the recovery of facial function. The histopathological evaluation of facial nerves was performed using hematoxylin-eosin (HE) staining. The levels of Beclin-1, light chain 3 (LC3), and P62 were detected by immunohistochemistry (IHC), immunofluorescence, and reverse transcription-polymerase chain reaction, respectively. Additionally, IHC was also used to detect the levels of GDNF, Rai, PI3K, and mTOR. RESULTS: The facial functional scores were significantly increased in the EA group than the FNI group (P<0.05 or P<0.01). HE staining showed nerve axons and myelin sheaths, which were destroyed immediately after the injury, were recovered with EA treatment. The expressions of Beclin-1 and LC3 were significantly elevated and the expression of P62 was markedly reduced in FNI rats (P<0.01); however, EA treatment reversed these abnormal changes (P<0.01). Meanwhile, EA stimulation significantly increased the levels of GDNF, Rai, PI3K, and mTOR (P<0.01). After exogenous administration with autophagy inhibitor 3-MA or GDNF antagonist, the repair effect of EA on facial function was attenuated (P<0.05 or P<0.01). CONCLUSIONS: EA could promote the recovery of facial function and repair the facial nerve damages in a rat model of FNI. EA may exert this neuroreparative effect through mediating the release of GDNF, activating the PI3K/mTOR signaling pathway, and further regulating the autophagy of facial nerves.

Subclassification of Koos grade 4 vestibular schwannoma: insights into tumor morphology for predicting postoperative facial nerve function.

OBJECTIVE: Koos grade 4 vestibular schwannoma (KG4VS) is a large tumor that causes brainstem displacement and is generally considered a candidate for surgery. Few studies have examined the relationship between morphological differences in KG4VS other than tumor size and postoperative facial nerve function. The authors have developed a landmark-based subclassification of KG4VS that provides insights into the morphology of this tumor and can predict the risk of facial nerve injury during microsurgery. The aims of this study were to morphologically verify the validity of this subclassification and to clarify the relationship of the position of the center of the vestibular schwannoma within the cerebellopontine angle (CPA) cistern on preoperative MR images to postoperative facial nerve function in patients who underwent microsurgical resection of a vestibular schwannoma. METHODS: In this paper, the authors classified KG4VSs into two subtypes according to the position of the center of the KG4VS within the CPA cistern relative to the perpendicular bisector of the porus acusticus internus, which was the landmark for the subclassification. KG4VSs with ventral centers to the landmark were classified as type 4V, and those with dorsal centers as type 4D. The clinical impact of this subclassification on short- and long-term postoperative facial nerve function was analyzed. RESULTS: In this study, the authors retrospectively reviewed patients with vestibular schwannoma who were treated surgically via a retrosigmoid approach between January 2010 and March 2020. Of the 107 patients with KG4VS who met the inclusion criteria, 45 (42.1%) were classified as having type 4V (KG4VSs with centers ventral to the perpendicular bisector of the porous acusticus internus) and 62 (57.9%) as having type 4D (those with centers dorsal to the perpendicular bisector). Ventral extension to the perpendicular bisector of the porus acusticus internus was significantly greater in the type 4V group than in the type 4D group (p < 0.001), although there was no significant difference in the maximal ventrodorsal diameter. The rate of preservation of favorable facial nerve function (House-Brackmann grades I and II) was significantly lower in the type 4V group than in the type 4D group in terms of both short-term (46.7% vs 85.5%, p < 0.001) and long-term (82.9% vs 96.7%, p = 0.001) outcomes. Type 4V had a significantly negative impact on short-term (OR 7.67, 95% CI 2.90-20.3; p < 0.001) and long-term (OR 6.05, 95% CI 1.04-35.0; p = 0.045) facial nerve function after surgery when age, tumor size, and presence of a fundal fluid cap were taken into account. CONCLUSIONS: The authors have delineated two different morphological subtypes of KG4VS. This subclassification could predict short- and long-term facial nerve function after microsurgical resection of KG4VS via the retrosigmoid approach. The risk of postoperative facial palsy when attempting total resection is greater for type 4V than for type 4D. This classification into types 4V and 4D could help to predict the risk of facial nerve injury and generate more individualized surgical strategies for KG4VSs with better facial nerve outcomes.

The "low preauricular" transmasseteric anteroparotid (TMAP) technique as a standard way to treat extracapsular condylar fractures.

Condylar fracture treatment is a debated topic among maxillofacial surgeons. Various surgical techniques are used today, each one with advantages and disadvantages. The aim of this study is to present and evaluate our technique adopted for treatment of any type of extracapsular condylar fractures. Between 2020 and 2022, 16 condylar fractures were treated. In two patients with bilateral condylar fractures, the present technique was compared to the mini-retromandibular approach. All the patients were checked for clinical and radiological outcomes, facial nerve injury, scar visibility and presence of salivary complications. Dental occlusion was always restored, and facial nerve damage or salivary disorders were not observed. The skin incision, limited to the caudal two-thirds of the auricle, made the scar almost invisible and greatly improved the surgical field in the condylar neck area, facilitating the treatment. The proposed technique provides easier internal fixation for both neck and base condylar fractures with good cosmetic results, ensuring better protection of the facial nerve and parotid gland. The surgical technique described has not shown disadvantages in terms of operational difficulty, results, and complications. This novel surgical technique could represent a new choice in the treatment of extracapsular condylar fractures, although further studies are needed to support this new proposal.

Application of diffusion tensor imaging of the facial nerve in preoperative planning for large vestibular schwannoma: a systematic review.

The accurate identification and preservation of the facial nerve (FN) during vestibular schwannoma (VS) surgery is crucial for maintaining facial function. Investigating the application of diffusion tensor imaging (DTI) in preoperative planning for large VS surgery is provided. PubMed, Cochrane Library, Science Direct, ISI Web of Science, Embase, and additional sources were searched to identify cohort studies about the preoperative DTI usage for the FN tracking before large VS (≥ 2.5 cm) surgery published between 1990 and 2023. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed; the Newcastle-Ottawa Scale was used to assess the risk of bias and to evaluate limitations based on selection/outcome biases. A total of 8 publications yielding 149 VS (mean size 3.66 ± 0.81 cm) were included. Surgical concordance with preoperative DTI FN tracking was 91.67% (range 85-100%). Overall DTI reliability was 88.89% (range 81.81-95.83%). Larger tumor size predicted either DTI inaccurate finding or complete DTI failure (p = 0.001). VS size above > 3.5 cm was associated with a higher risk of DTI failure (p = 0.022), with a higher risk of inaccurate DTI finding preoperatively (p = 0.033), and with a higher House-Brackman score postoperatively (p = 0.007). Application of DTI in larger VS surgery is a valuable FN identification along with electrophysiological monitoring and neuronavigation, therefore also in its preservation and in lowering risk of complications. DTI represents a valuable adjunct to electrophysiological monitoring and neuronavigation in FN identification, applicable not only for smaller, but also larger VS.

Optimizing Facial Function in Patients With High-Risk Recurrent Pleomorphic Adenoma and a History of Facial Nerve Injury.

BACKGROUND: Parotid pleomorphic adenoma (PA) patients present significant diagnostic and surgical challenges rendering them high risk for facial nerve injury. Recurrent PA patients often present with history of facial nerve injury or previous reanimations making salvage of the facial nerve or previous reanimations significantly more complex. The study aim is to share our experience with this high risk for facial nerve injury population and review the literature. METHODS: Adult patients with recurrent PA and history of facial nerve injury with at least 3 months of follow-up were analyzed for demographics, facial palsy history, previous head and neck surgeries, previous facial paralysis reconstruction, preoperative imaging, surgical approach, and postoperative outcomes. RESULTS: Four female patients were identified with an average age of 62 years. All patients underwent an initial protective dissection of the facial nerve or previous reanimation reconstruction by the facial nerve reconstructive team followed by the extirpative team. The average number of previous head and neck surgeries was 5, the number of recurrences was 2, and follow-up was 20 months. Half had prior dynamic facial reanimation. Two patients underwent complete preextirpative dissection of the facial nerve resulting in neuropraxia, which recovered completely after an average of 143 days. A third patient presented with 2 recurrences, both during and after reanimation with a dually innervated free functional muscle transfer. The reconstruction was salvaged, and motion was achieved. A fourth patient presented with benign preoperative findings, but intraoperative findings confirmed malignancy, necessitating facial nerve sacrifice, followed by immediate intratemporal grafting of the facial nerve and masseteric nerve transfer. Motion appeared 139 days postoperatively. CONCLUSIONS: A multidisciplinary effort should be implemented in this high risk for facial nerve injury population with the primary goal of protecting the facial nerve or any previous reanimation procedures, yet with preparedness to apply any reconstructive strategy based on intraoperative findings.

[Professor LI De-hua's experience in treating facial nerve injury after total parotidectomy with blade needle based on jingjin theory].

The paper summarizes the academic thought and clinical experience of professor LI De-hua in treatment of facial nerve injury after total parotidectomy with blade needle based on jingjin (muscle region of meridian, sinew/fascia) theory. This disease is located at muscle regions of hand-/foot-three yang meridians; and the sinew/fascia adhesion is its basic pathogenesis, manifested by "transversely-distributed collaterals" and "knotted tendons". In treatment, the knotted tendons are taken as the points. Using the relaxation technique of blade needle, the lesions of sinews/fascia are dissected and removed to release the stimulation or compression to the nerves and vessels so that the normal function of sinews/fascia can be restored.

Topography of the frontal branch of the facial nerve and its clinical implication for temporal direct browplasty.

Due to anatomic proximity to the surgical site, iatrogenic trauma to the frontal branch of the facial nerve (FbFN) with resultant brow paralysis is a recognized major complication of temporal direct browplasty. This study was aimed to elucidate the course of the FbFN in the area superolateral to the brow in order to facilitate safer temporal direct browplasty by preventing facial nerve injury. Forty-five hemifaces from 32 embalmed Korean cadavers were dissected. A horizontal line connecting the tragion to lateral canthus was established. Then, an oblique line passing through the lateral canthus and 45° to the horizontal line was used as reference line. The mean distance from the lateral canthus to the points where the FbFN cross the reference line was measured. The angle between the FbFN and reference line at the crossing points were also recorded. After crossing the zygomatic arch, FbFN continues in an anteriorly inclining curve across the temporal region, passing near the lateral end of the brow as it heads toward frontalis muscles. During the course, the FbFN laying in the innominate fascial layer was divided into 3 branches. The anterior and posterior branch of FbFN crossed the reference line superiorly and laterally at 3 and 4 cm from the lateral canthus, respectively. In conclusion, the oculofacial surgeon must bring the dissection plane of the forehead tissue more superficially around the 3 cm superolaterally to the lateral canthus in the direction of 45° from the horizontal line in order to avoid nerve injury.

Long-term outcomes of facial nerve decompression by transmastoid versus middle cranial fossa approach for traumatic facial paralysis.

OBJECTIVES: To evaluate and compare the long-term results of patients who underwent facial nerve decompression surgery with either transmastoid-supralabyrinthine (TMSL) or combined transmastoid- middle cranial fossa (MCF) approach for traumatic facial nerve paralysis. MATERIALS AND METHODS: This is a single-center retrospective case-control study. The medical records of traumatic facial paralysis patients with House Brackmann (HB) Grade 6 who underwent facial nerve decompression surgery at via either TMSL or MCF approach between January 2011 and December 2017 were reviewed. The patients who had otic capsule involvement and total sensorineural hearing loss, therefore underwent translabyrinthine facial nerve decompression, and the patients follow-up period has not yet reached four years were excluded from the study. Postoperative HB score and hearing status were compared. RESULTS: Eleven patients were operated with MCF approach (group 1), while 9 patients with TMSL approach (group 2). Average age of patients was 20.04 + 15.2 (range:4-47) years. Three (15 %) patients were female, while 17 (85 %) was male. Geniculate ganglion (90 %) was the most affected segment of the facial nerve. Facial nerve edema was observed in all cases, while intraneural hematoma were encountered in 4 (20 %) cases. Statistically significant improvement in median HB scores were reached in both groups, and no significant difference was observed in post-operative HB scores between both techniques. No significant difference in median AC 0,5-4 khZ and BC 0,5-3 kHz thresholds was observed between both techniques. CONCLUSION: Even middle fossa approach is the best surgical technique to explore geniculate ganglion and labyrinthine segment of facial nerve, the functional results of transmastoid supralabrynthine approach, which is not needed craniotomy with low complication rate are as successful as middle fossa approach in selected patients.

Establishment of a facial nerve trunk crush injury model and evaluation of facial nerve self-healing in rats.

INTRODUCTION/AIMS: To facilitate further investigation into the mechanisms of facial nerve regeneration, a simple and reliable model of facial nerve crush injury is essential. Nevertheless, the establishment of such models lacks standardization and repeatability, while the healing capacity of the nerve is often overlooked, potentially affecting future studies. METHODS: We made facial nerve trunk crush injury models with different pressing times and detected the changes from the distal nerves to the motoneurons via behavior analysis, electrophysiological test, and histomorphometry analysis. RESULTS: It revealed a particular capacity for self-healing following facial nerve crush damage because there was almost no facial motoneuron apoptosis in the MC group during the observation period, and rats in MC group had total facial paralysis in behavioral tests following surgery and varying degrees of recovery 28 days postoperatively with no treatments. As the pressing time increased, the latency, wave amplitude, nerve fiber damage degree, nerve axon ratio, myelin thickness, electroneurograph (ENoG) value, ultrastructural damage, abnormal morphological changes, and the buccal muscle atrophy of each MC group gradually increased or got worse during the observation period. However, after 28 postoperative days, only the ENoG values of the M10min and M12min groups were beyond 90%, indicating no self-healing. DISCUSSION: It suggests that a stable model of peripheral facial palsy may be created by applying a 12.5 cm mosquito clamped to the facial nerve trunk for at least 10 min, which laid the foundation for the subsequent research to objectively evaluate facial nerve regeneration.

Surgical management and the prognosis of iatrogenic facial nerve injury in middle ear surgery: a 20-year experience.

BACKGROUND: Iatrogenic facial nerve injury is one of the severest complications of middle ear surgery, this study aims to evaluate surgical management and prognosis in the era of improved surgical instruments. METHODS: Patients suffered from facial nerve paralysis after middle ear surgery between January 2000 and December 2019 were retrospectively collected. Demographic characters, primary disease and surgery, details of revision surgery were analyzed. RESULTS: Forty-five patients were collected, of whom 8 were injured at our center and 37 were transferred. For 8 patients injured at our center, seven (87.5%) ranked House-Brackmann (H-B) grade V and one (12.5%) ranked H-B VI before revision surgery; postoperatively, two (25.0%) patients recovered to H-B grade I, four (50.0%) recovered to H-B II, and the other two (25.0%) recovered to H-B III. For 37 patients transferred, thirteen (35.1%) ranked H-B grade V and 24 (64.9%) ranked H-B VI preoperatively, final postoperative grade ranked from H-B grade I to grade V, with H-B I 6 (16.2%) cases, H-B II 6 (16.2%) cases, H-B III 18 (48.6%) cases, H-B IV 5 (13.5%) cases and H-B V 2 (5.4%) cases. The most vulnerable site was tympanic segment (5, 62.5% and 27, 73.0% respectively). Twenty-one (46.7%) patients suffered from mild injury and 24 (53.3%) suffered from partial or complete nerve transection. For surgical management, twenty-one (46.7%) patients received decompression, nineteen (42.2%) received graft and 5 (11.1%) received anastomosis. Those decompressed within 2 months after paralysis had higher possibility of H-B grade I or II recovery (P = 0.026), those received graft within 6 months were more likely to get H-B grade III recovery (P = 0.041), and for patients underwent anastomosis within 6 months, all recovered to H-B grade III. CONCLUSIONS: Tympanic segment is the vulnerable site. If facial nerve paralysis happens, high-resolution computed tomography could help identify the injured site. Timely treatment is important, decompression within 2 months after paralysis, graft and anastomosis within 6 months lead to better recovery.

Treatment of extracapsular fractures of the mandibular condylar process: A retrospective evaluation of 377 cases.

BACKGROUND/AIM: Mandibular condylar fractures represent 25%-35% of all mandibular fractures. Despite profound research, there is still a controverse debate about treating these fractures conservatively or by open reduction and internal fixation (ORIF). The aim of this study is to analyse the outcome after open and closed treatment of extracapsular mandibular condyle fractures regarding general characteristics, post-treatment malocclusion, facial nerve palsy (FNP), maximum mouth opening (MMO) and parotid complications. METHODS: A retrospective cohort of 377 fractures (350 open, 27 closed treatment) was reviewed by reference to clinical and radiological pre- and postoperative documentation. Follow-up period was 12 months. Pearsons' chi-square-test, correlations, Kruskal-Wallis test and t-test were carried out for statistical analysis. RESULTS: The dominant type of fracture was type II in Spiessl and Schroll classification (50.1%). In the open treated fractures, the most common approach was retromandibular transparotid (91.7%). Post-treatment malocclusion occurred in 18.0% and was significantly increased in bilateral fractures (p = .039), in luxation fractures (p = .016) and in patients with full dentition (p = .004). After open reduction and internal fixation (ORIF), temporary FNP was documented in 7.1% whereas a permanent paresis occurred in 1.7%. FNP was significantly associated with high fractures (p = .001), comminution (p = .028) and increased duration of surgery (p = .040). Parotid complications were significantly associated with revision surgery (p = .009). Post-treatment reduction of MMO mainly occurred in female patients (p < .001) as well as in patients with bilateral fractures (p < .001), high fractures (p = .030) and concomitant mandibular (p = .001) and midfacial fractures (p = .009). CONCLUSION: Malocclusion seems to be the most frequent long-term complication after open reduction and osteosynthesis of extracapsular mandibular condyle fractures. We suggest ORIF by a transparotid approach to be an appropriate treatment with a low complication rate regarding especially FNP for extracapsular fractures of the mandibular condyle.

Expression and Role of Toll-like Receptors in Facial Nerve Regeneration after Facial Nerve Injury.

Facial nerve palsy directly impacts the quality of life, with patients with facial nerve palsy showing increased rates of depression and limitations in social activities. Although facial nerve palsy is not life-threatening, it can devastate the emotional and social lives of affected individuals. Hence, improving the prognosis of patients with this condition is of vital importance. The prognosis of patients with facial nerve palsy is determined by the cause of the disease, the degree of damage, and the treatment provided. The facial nerve can be easily damaged by middle ear and temporal bone surgery, trauma or infection, and tumors of the peripheral facial nerve or tumors surrounding the nerve secondary to systemic disease. In addition, idiopathic, acquired immunodeficiency syndrome and autoimmune diseases may damage the facial nerve. The treatment used for facial paralysis depends on the cause. Treatment of facial nerve amputation injury varies depending on the degree of facial nerve damage, comorbidities, and duration of injury. Recently, interest has increased in Toll-like receptors (TLRs) related to innate immune responses, as these receptors are known to be related to nerve regeneration. In addition to innate immune cells, both neurons and glia of the central nervous system (CNS) and peripheral nervous system (PNS) express TLRs. A comprehensive literature review was conducted to assess the expression and role of TLRs in peripheral nerve injury and subsequent regeneration. Studies conducted on rats and mice have demonstrated the expression of TLR1-13. Among these, TLR2-5 and TLR7 have received the most research attention in relation to facial nerve degeneration and regeneration. TLR10, TLR11, and TLR13 increase during compression injury of the facial nerve, whereas during cutting injury, TLR1-5, TLR8, and TLR10-13 increase, indicating that these TLRs are involved in the degeneration and regeneration of the facial nerve following each type of injury. Inadequate TLR expression or absence of TLR responses can hinder regeneration after facial nerve damage. Animal studies suggest that TLRs play an important role in facial nerve degeneration and regeneration.