Stylomastoid Foramen Research Articles

MORPHOMETRIC STUDY OF THE STYLOID PROCESS AND ITS CLINICAL IMPLICATIONS

Background: Styloid process is a slender, cylindrical spur of bone fused with the inferior aspect of the temporal bone in front of the stylomastoid foramen. Present study aimed to evaluate the length, angulation, interstyloid distance and styloid ratio to highlight their possible etiological importance in clinical and surgical conditions. Interstyloid distance is used for sexual dimorphism. Excessive length and angulation of styloid process is clinically important, as it may cause Eagle's syndrome. Material And Methods: The study was done on both sides of 52 dry human skulls of unknown age and sex without any obvious deformity. Each skull was carefully examined for the presence of elongated styloid process (length>30 mm). The length was measured using Vernier caliper and interstyloid distance was measured using divider. Angle of styloid process with the Reid's baseline and styloid ratio was also calculated. Results: Out of 52 skulls, elongated styloid process was observed in thirteen skulls, amongst them eight skulls (15.38%) with unilateral and ve (9.62%) with bilateral elongation. Rest of the skulls (n=39) had lengths varying from 20-30 mm. Mean angle between styloid process and Reid's baseline was 51.13°. Average interstyloid distance was 75.42 mm while 70-80 mm was the most common range. Styloid ratio varied from 3-4. Conclusions: Unilateral elongated styloid process was found more frequently as compared to bilateral. The results can be used as a baseline data for identication of male and female skull by calculating the interstyloid distance. The ndings of the present study may be of utmost importance in the examination of styloid process in patients with symptoms of stylalgia.

Congenital aural atresia and first branchial cleft anomalies: Cholesteatoma and surgical management.

ObjectivesTo describe the prevalence and significance of first branchial cleft anomalies in children with congenital aural atresia.MethodsRetrospective cohort study and case series. Patients were included if they had ICD‐10 code Q16.0, Q16.1, Q16.9, Q17.2, or Q17.9 in their medical record and were seen at UCSF Benioff Children's Hospital from 2012 to 2020 for aural atresia. Children were categorized as having aural atresia and first branchial cleft anomalies if the presence of a first branchial cleft anomaly was noted in otolaryngology provider notes; otherwise, they were categorized as aural atresia alone. Patients with aural atresia and first branchial cleft anomalies were included in the case series.ResultsAmong 125 children with congenital aural atresia, 5 (4%) were identified with first branchial cleft anomalies. In all cases, an epithelialized tract was noted to originate from the inferior aspect of the middle ear cleft, exiting the temporal bone in an inferomedial position adjacent to the stylomastoid foramen, with a cutaneous exit point inferior to the expected location of the native ear canal. There was no association with sex, microtia grade, or laterality of atresia; however, children with aural atresia and first branchial cleft anomalies were significantly more likely to have syndromes such as Goldenhar and Treacher Collins (p = .04) than those with aural atresia alone.3/5 (60%) children with aural atresia and first branchial cleft anomalies presented with cholesteatoma compared with 1/120 (0.8%) children with aural atresia alone, a significant difference (p < .001). All four children over the age of two have undergone surgical management. In two of these, excision of the branchial cleft anomaly could be combined with atresiaplasty, with normal hearing results in both cases.ConclusionsAural atresia can be associated with comorbid anomalies of the head and neck. First branchial cleft anomalies can be suspected based on characteristic clinical appearance and confirmed with computed tomography showing a typical course through the temporal bone. When present in the context of congenital aural atresia, first branchial cleft anomalies are associated with a significantly increased risk for cholesteatoma, often necessitating surgical management with favorable hearing outcomes.Level of evidence4.

138 Neuroprotection in the Facial Nerve

INTRODUCTION: Facial nerve injury is disabling for patients with skull base brain tumors or head trauma. NAD+ is a key cofactor in metabolism and is an important component in axonal survival. Exogenous NAD+ prolongs axonal survival after axotomy in both in vitro and in vivo studies. Additionally, axonal survival is improved by blocking enzymes that decrease NAD+ levels (ex SARM1). Nicotinamide precursors like nicotinamide mononucleotide (NMN) have demonstrated neuroprotective benefits in aging and cellular death. METHODS: We developed a model of facial nerve injury by subjecting mice to 200 Hz of vibratory injury to the facial nerve distal to the stylomastoid foramen using SARM1KO and littermate controls, as well as mice implanted with intraventricular pumps containing 400 mM NMN or saline one week before facial nerve injury. EMG was performed using the NIM Nerve Monitoring System. Whisker movements were recorded and scored daily using Vibrissae observation scale. NAD+ metabolite levels were measured using liquid-chromatography/mass-spectrometry. NF200 immunofluorescence of facial nerves was performed. RESULTS: SARM1KO mice demonstrated robust axoprotection to vibratory injury for both 15 and 30 second durations and regained normal whisker movement in significantly less time compared to controls. Post-injury, SARM1 KO facial nerves required a lower stimulus current to elicit electrical responses in vibrissae muscles. We then used intracranial NMN delivery to test if raising NAD+ levels is axoprotective. NMN delivery increased brain NAD+ 1.5-fold. NMN significantly shortened the time to normal whisker movement, required a lower stimulus current for muscle response, and showed increased axonal integrity by NF200 staining. CONCLUSION: Continuous delivery of the NAD+ metabolite, NMN, allows for neuroprotective benefits in the vibratory neuropraxia nerve injury model, likely through sustained elevated NAD+ levels. These benefits are magnified through inhibition of the NADase enzyme, SARM1. This research demonstrates NMN as a neuroprotective pretreatment adjuvant in patients undergoing planned surgical invention where facial nerve injury is a possible outcome.

Preoperative Magnetic Resonance Image and Computerized Tomography Findings Predictive of Facial Nerve Invasion in Patients with Parotid Cancer without Preoperative Facial Weakness-A Retrospective Observational Study.

Simple SummaryFacial nerve invasion in parotid cancer affects survival outcomes as well as functional outcomes after surgery-based treatment. Normal facial muscle function before surgery does not always exclude the possibility of involvement of the facial nerve by a tumor. Especially in patients without facial palsy, accurate evaluation of invasion before surgery is necessary to plan optimal facial nerve resection and reconstruction. Various findings are obtained from preoperative radiological findings, such as CT and MRI. We evaluated the role of these radiological findings in predicting nerve invasion. Large tumor, spiculated margin, and anterolateral location may suggest a high risk of nerve involvement even in patients with normal preoperative facial function. These findings may help surgeons to avoid unexpected facial nerve invasion and to make adequate surgical plans to get optimal oncological and functional outcomes. (1) Background: Facial nerve resection with reconstruction helps achieve optimal outcomes in the treatment of facial nerve invasion (FNI) of parotid cancer. Preoperative imaging is crucial to predict facial nerve reconstruction. The radiological findings of CT or MRI may predict FNI in the parotid cancer even without facial paralysis. Methods: We retrospectively reviewed the records of 151 patients without facial nerve paralysis before surgery who had undergone tumor resection. Previously untreated parotid cancers were included. (2) Results: The median follow-up duration was 62 months (range: 24–120 months). The FNI (+) group (n = 30) showed a significantly worse 5-year overall survival compared with the FNI (−) group (75.5 vs. 93.9%; hazard ratio = 4.19; 95% confidence interval: 1.74–10.08; p = 0.001). The tumor margin, tumor size, presence in the anterolateral parotid region (area 3), retromandibular vein involvement, distance from the stylomastoid foramen to the upper tumor margin, and a high tumor grade were significant factors related to FNI in the univariate analysis. A spiculated tumor margin, the tumor size (2.2 cm), and presence in area 3 were factors predicting FNI in the logistic regression model (p = 0.020, 0.005, and 0.050, respectively; odds ratio: 4.02, 6.40, and 8.16, respectively). (3) Conclusions: The tumor size (≥2.2 cm), spiculated margin, and presence in area 3 as presented in CT and MRI may help clinicians preoperatively predict FNI in patients with parotid cancer and establish an appropriate surgical plan.

Facial neuritis in coronavirus disease 2019 associated mucormycosis: study on clinico-radiological correlates.

To elucidate the aetiopathogenesis of facial neuritis in coronavirus disease 2019 associated mucormycosis. A retrospective review was conducted of coronavirus disease 2019 associated mucormycosis patients who presented with peripheral facial nerve palsy from January 2021 to July 2021. The clinico-radiological details of four patients were assessed to examine the potential mechanism of facial nerve involvement. Serial radiological evaluation with contrast-enhanced computed tomography and contrast-enhanced magnetic resonance imaging revealed infratemporal fossa involvement in all cases, with the inflammation extending along fascial planes to reach the stylomastoid foramen. Ascending neuritis with an enhancement of the facial nerve was demonstrated in all cases. The likely explanation for facial palsy in patients with coronavirus disease 2019 associated mucormycosis, backed by radiology, is the disease abutting the facial nerve at the stylomastoid foramen and causing ascending neuritis of the facial nerve.

The effect of charge-balanced transcutaneous electrical nerve stimulation on rodent facial nerve regeneration

This study aimed to investigate the effect of charge-balanced transcutaneous electrical nerve stimulation (cb-TENS) in accelerating recovery of the facial function and nerve regeneration after facial nerve (FN) section in a rat model. The main trunk of the left FN was divided and immediately sutured just distal to the stylomastoid foramen in 66 Sprague–Dawley rats. The control group had no electrical stimulus. The other two groups received cb-TENS at 20 Hz (20 Hz group) or 40 Hz (40 Hz group). Cb-TENS was administered daily for seven days and then twice a week for three weeks thereafter. To assess the recovery of facial function, whisker movement was monitored for four weeks. Histopathological evaluation of nerve regeneration was performed using transmission electron microscopy (TEM) and confocal microscopy with immunofluorescence (IF) staining. In addition, the levels of various molecular biological markers that affect nerve regeneration were analyzed. Whisker movement in the cb-TENS groups showed faster and better recovery than the control group. The 40 Hz group showed significantly better movement at the first week after injury (p < 0.0125). In histopathological analyses using TEM, nerve axons and Schwann cells, which were destroyed immediately after the injury, recovered in all groups over time. However, the regeneration of the myelin sheath was remarkably rapid and thicker in the 20 Hz and 40 Hz groups than in the control group. Image analysis using IF staining showed that the expression levels of S100B and NF200 increased over time in all groups. Specifically, the expression of NF200 in the 20 Hz and 40 Hz groups increased markedly compared to the control group. The real-time polymerase chain reaction was performed on ten representative neurotrophic factors, and the levels of IL-1β and IL-6 were significantly higher in the 20 and 40 Hz groups than in the control group (p < 0.015). Cb-TENS facilitated and accelerated FN recovery in the rat model, as it significantly reduced the recovery time for the whisker movement. The histopathological study and analysis of neurotrophic factors supported the role of cb-TENS in the enhanced regeneration of the FN.

CT-Based Intraoperative Navigation for Quick Identification of the Stylomastoid Foramen During Hypoglossal-Facial Nerve Anastomosis.

To present the ability of standard intraoperative neuronavigation to reliably identify the stylomastoid foramen, thus providing a quick and effective recognition of the facial nerve at its exit from the skull base. We describe the technical nuances of this procedure by presenting two surgical cases who underwent hypoglossal-facial nerve anastomosis for complete facial nerve palsy occurring post removal of a giant vestibular schwannoma 6 months earlier. CT-based neuronavigation allowed a quick and reliable identification of the stylomastoid foramen and of the facial nerve at its exit from the skull. The entire procedure lasted for 3 hours. Three months after the anastomosis, the first signs of facial muscle reinnervation were visible. The use of neuronavigation during hypoglossal-facial nerve anastomosis is a simple and cost-effective strategy to decrease operative duration and increase surgical effectiveness.

ОПРЕДЕЛЕНИЕ ВНЕШНЕЙ ФОРМЫ ШИЛОСОСЦЕВИДНОГО ОТВЕРСТИЯ МЕТОДОМ СНЯТИЯ СЛЕПОК

The stylomastoid foramen is the final section of the facial canal and the gate for the exit of the facial nerve from the base of the skull. There is evidence that anatomical variation of this foramen may be a risk factor for facial nerve injury leading to facial palsy or Bell's palsy. The depth of the facial nerve at the level of the stylomastoid foramen may potentially play a key role in the etiology of Bell's palsy, which requires further study.

A Handy Landmark (Triangle Technique) for Identification of the Facial Nerve during Parotid Surgery

The parotid glands are paired major salivary glands located in front of the tragus and below the ear lobule at the retromandibular area (behind the mandibular ramus and in front of the mastoid process of the temporal bone) on each side of the upper neck. The facial nerve is one of the most important structures encountered during parotidectomy. The neurovascular structures that pass through the parotid gland from lateral to medial are facial nerve, retromandibular vein, external carotid artery, superficial temporal artery and maxillary artery. Branches of the great auricular nerve enter the gland from the neck and remains superficial. Parotid surgery is indicated in certain pathological conditions namely benign and malignant neoplasm, chronic inflammatory diseases, sialolithiasis, intra-parotid cysts/sinuses and lymphadenopathy; and many more. The importance of the facial nerve and methods of identification are enumerated by the multiple anatomical landmarks during parotidectomy. The triangle landmark is one of these anatomical landmarks considering the base of the styloid process, tragal cartilage to tragal pointer and the origin of the posterior belly of the digastric muscle at the mastoid tip. Facial Nerve and the Parotid Gland: The intra-temporal facial nerve exits from the stylomastoid foramen slightly posterior to the styloid process and anteromedial to the mastoid process. The main trunk is approximately 1.3 cm in length enters into the parotid gland and divides into cervico-marginal and zygomatico-temporal branches; and of course, buccal branches (upper and lower buccal) remain common in both the divisions. The cervico-marginal branches supply the muscles of the mouth and neck; and zygomatico-temporal branches supply the muscles of the forehead and eye. The facial nerve arbitrarily divides the gland into superficial and deep lobes.Aim of the Study: The aim of this study was to locate the facial nerve trunk (FNT) very easily. Quickly and accurately at the point where the long axis along the tragal pointer from the tragus and posterior belly of the digastric from the mastoid tip meets over the styloid process.

Anatomical description of the extratemporal facial nerve under high-definition system: a microsurgical study in rats.

To describe the microsurgical anatomical aspects of the extratemporal facial nerve of Wistar rats under a high-definition video system. Ten male Wistar rats (12-15 weeks old), without veterinary diseases, weighing 220-280 g, were used in this study. All animals in this study were submitted to the same protocol and by the same surgeon. A 10-mm incision was made below the bony prominence of the right or left ear, and extended towards the angle of the mandible. The dissection was performed and the main branches of the facial nerve were dissected. The main trunk of the facial nerve has a length of 0.88 ± 0.10 mm and a length of 3.81 ± 1.03 mm, measured from its emergence from the stylomastoid foramen to its bifurcation. Seven branches originating from the facial nerve were identified: posterior auricular, posterior cervical, cervical, mandibular, buccal, temporal, and zygomatic. The anatomy of the facial nerve is comparable to that of humans, with some variations. The most observed anatomical division was the distribution in posterior auricular, posterior cervical, cervical, mandibular, buccal, temporal, and zygomatic branches. There is no statistical difference between the thickness and distance of the structures compared to the contralateral side.

Morphological and Morphometric Analysis of Stylomastoid Foramen in Dry Human Skulls and its Clinical Implications

Introduction: Stylomastoid foramen present between two processes which are styloid process and mastoid process. Facial nerve and stylomastoid arteries are transmitted through the stylomastoid foramen. Facial canal gets terminated in the stylomastoid foramen. Stylomastoid foramen has a site for facial nerve block. Complications reduced by localization of foramen.&#x0D; Aim: The aim of this study was to analyse the morphology and morphometry of stylomastoid foramen.&#x0D; Materials and Methods: Damaged skulls were excluded and 60 dry human skulls without any damage were taken for this study. By using digital vernier caliper length and breath of the stylomastoid foramen was measured. Then the statistical analysis was done using SPSS software and paired t-tests were done for comparison.&#x0D; Results: The length and breadth of the right stylomastoid foramen was 2.39 ± 0.18 mm and 0.85 ± 0.12 mm and the left stylomastoid foramen was 2.18 ±0.33 mm and 1.13 ± 0.38 mm. From the paired t-tests it was very clear that the difference between the breath of right and left stylomastoid foramen was significant (p&lt;0.05) and difference between the length of right and left stylomastoid foramen was not significant (p&gt; 0.05).&#x0D; Conclusion: The narrow size of stylomastoid foramen varied from individual skull to other. The accurate value for length and breadth, was measured to determine the variations of facial nerve emerging through it. The change in length and breadth of stylomastoid foramen can be correlated with its clinical aspects with reference to facial nerve.

Morphological Characteristic and Incidence of Elongate Styloid Process in South Indian Population: A Case Series

Introduction: Styloid process is a slender osseous projection, cylindrical and sharp projection of the temporal bone, located in front of stylomastoid foramen. Styloid process is from Reichert’s cartilage of the second branchial arch, this is a part of the splanchnocranium. This is Connected to the hyoid bone through the Stylohyoid ligament. The morphology of the Styloid process is due to hormonal and genetic changes. Orthopantomography is a radiographic method used to visualise mandibles. It also provides a rotational view of the jaw. The aim of the study is to analyse the elongation of the Styloid process in the South Indian population.&#x0D; Materials and Methods: The study was conducted in dental institutions with convenience sampling. The random orthopantomogram sample was collected from a dental institution. Total number of orthopantomogram involved in the study was 80 (40-males and 40-females) that is used to examine elongation of the Styloid process in the South Indian population. The minimised sampling bias is done by stratification according to age and gender.&#x0D; Statistical Analysis: The data were analysed by using SPSS software. The probability value p&lt; 0.05 is considered as significant and the value p&gt;0.05 was considered as not significant.&#x0D; Results: This study showed various types of Styloid processes in males and females. However we concluded that there is a difference in shape of Styloid processes. The most common type of the Styloid process found in males is pseudo articulated (32.5%) whereas in females the most common type of Styloid process found is uninterrupted (37.5%)&#x0D; Conclusion: From the current study we have concluded that the pseudo articulated Styloid process is more in males whereas uninterrupted is more in females. Only retrospective studies were done so far. Therefore in future studies with live models and larger sample size should be conducted.

A Case Report on a Patient With Unrecovered Bell’s Palsy of 2 Years Duration Treated With Non-Interventional Pulsed Radio Frequency Electrical Current

Patents with unrecovered Bell’s palsy or a mono facial paresis from other conditions that affect the facial nerve as in Ramsey Hunt disorder, iatrogenicity or disease, often find that their condition causes long term paresis in the facial muscles with functional, psychological and social impacts upon their lives. Previous treatments to the local inflammation occurring in the facial nerve as it exits the stylomastoid foramen with ultrasound, non-stimulating electrical currents and electrical functional muscle stimulation of the compromised facial muscles, often do not restore full function to the affected side of the face. A non-interventional pulsed radio frequency (NI-PRF) electrical current has been observed to stimulate the facial nerve with fasciculations occurring in the main branch of the VII th nerve and its concomitant branches to the upper, middle and lower areas of the face resulting in improved motor function. This commences immediately within the first treatment in acute Bell’s Palsy and only 4-6 treatments are required to assist most patients. Prolonged conditions that were previously thought unrecoverable (after years) have restored motor control and this usually occurs between 1 – 3 months of treatment. Treatment requisite does not have to be continuous and can be given twice weekly or even once weekly over the period mentioned above. Even if treatment is interrupted the condition continues to improve. This would have both an economic and efficient time saving impact on these patients. The main case history of an unrecovered Bell’s palsy of 2 years duration is discussed in this report and demonstrates marked improvement after only six treatments. Electroacupuncture is often included in the above treatments as an adjunct to increase circulation and improve muscle activity

Mengenali Facial Palcy pada Trauma Wajah dan Tatalaksana Pembedahan

Bell's palsy is the most common neurological disorder affecting the cranial nerves with an onset that is rapid and unilateral, and it is common cause of facial paralysis worldwide. Bell's palsy occurs due to compression or enlargement of the stylomastoid foramen and causes nerve obstruction or damage caused by trauma, infection, inflammation, autoimmune, ischemic. This article aims to review bell's palsy, specifically motor nerve alignment, surgical disorders and management of bell's palsy. Source searches were carried out on online portals for journal publications such as Google Scholar (scholar.google.com) and the National Centre for Biotechnology Information/NCBI (ncbi.nlm.nih.gov), with the keyword “Facial palcy, dan Bell’s palcy”. In the United States, the annual incidence of Bell's palsy is approximately 23 cases per 100,000 people. Permanent facial paralysis and non-transient functional deficits are the main indications for surgical reconstruction of facial nerve function. The indications for surgery depend on the severity of the nerve lesion, blunt trauma that causes nondegenerative neuropraxia does not require surgical reconstruction, whereas disorders leading to degenerative neurotmesis require surgery.

Osteological studies of skull base neurovascular area in reference to infratemporal approach to skull basec

Surgical approaches to the lateral skull base often lead to tearing of vessels and piecemeal removal of the tumour. This study is aimed to delineate exact relationship of the various foramina at the lateral skull base. The coronal dimensions of the jugular foramina are larger as compared to sagittal with right sided dominance also noticed in the case of carotid canal. The width of “Keel” separating the carotid and jugular foramina normally varies from 0.4 to1.4 centimetres and may not always suggest the erosion of the foramen of skull base scans, unless the erosion is associated with irregularity or demineralization the thickness of this keel really depends upon relative size of the vessels and location of foramina. Area between stylomastoid foramen, carotid canal and jugular foramen is roughly wedge shaped. The angle subtended by carotid and jugular at the stylomastoid foramen is about 36.84whereas the location of stylomastoid foramen and internal carotid axis pose an angle of 83:16. The angle subtended by stylomastoid and jugular at carotid on an average 59:31. The space between these structures is measured to be 0.642centimetres which can be verified on tomograms. By using these measurements, the precise location of the upper end of the vessels could be predicted, whereas the superior stump could be clamped with minimal exposure of the skull base and identification and location of the last four cranial nerves is found out. This could avoid injuries and subsequent morbidity while carrying out surgery in this region.

An evaluation of the prevalence of elongated styloid process in Taiwanese population using digital panoramic radiographs

Background/purposeStyloid process (SP) was an anatomical structure located in front of the stylomastoid foramen and the occurrence of styloid process elongation was uncertainly reported. The purpose of this study was to survey, using digital panoramic radiography, the lengths of styloid process (SP) and the prevalence of elongated SP in the Taiwanese population. Their relationships with age, gender and laterality were also determined. Materials and methodsA total of 539 patients (including 53 that were referred from the Department of Otorhinolarygngology with clinical symptoms) were studies retrospectively. Panoramic radiographic examinations were performed on all these patients at the Outpatient clinics of the Department of Stomatology, Taichung Veterans General Hospital between January 2019 and December 2019. Patients were divided into groups according to their age and gender. The length of SP from the base of temporal bone junction to the tip of the process was measured using the Sirona software. Data were analyzed using SPSS version 22.0 based on tests of Chi-square, Mann–Whitney U and Kruskal Wallis tests. Statistical significance was set at p < 0.05. ResultsA total of 539 (240 males and 299 females) digital panoramic radiographs were measured and evaluated in this study. The mean length of SP was 30 ± 0.7 mm on the right side and 29 ± 0.7 mm on the left side. The average length of SP on both sides was 29.5 ± 0.7 mm. In those cases with symptomatic Eagle syndrome, the mean length of SP was 32 ± 0.8 mm on the right side and 33 ± 0.8 mm on the left side (average 32.5 ± 0.8 mm). These lengths were statistically different between the general population and the symptomatic patients. Furthermore, the mean length of SP was 29 ± 0.7 mm in females and 30 ± 0.7 mm in males. The length of the SP grew progressively with age, and was more clearly seen within subjects from 41 to >60 years of age (p < 0.005). Meanwhile, the prevalence of elongated SP in our study was 41.5% on the right side and 36.2% on the left side, with female predominance. ConclusionThe mean length of SP was 30 ± 0.7 mm (right side) and 29 ± 0.7 mm (left side). The prevalence of elongated SP was 41.5% on the right side, and 36.2% on the left side. Our findings were consistent with some previous studies that were differences related with age, and were more prominent in those patients with symptoms.

Intratemporal Facial Nerve Anatomy and its Variations in 30 Cases of Cadaveric Temporal Bones.

It is important for the ENT surgeon to be familiar with the anatomy of the facial nerve and to prevent iatrogenic injury to nerve as it shows variations in its intratemporal course. Present study was done to delineate the intratemporal course of facial nerve and observe its variations. Thirty wet cadaveric temporal bones were dissected in the temporal bone dissection laboratory in the Department of Otorhinolaryngology and Head Neck Surgery, Government Medical College, Patiala. The length of intratemporal segments of facial nerve, its relationship with important bony landmarks, and the presence of any anomaly or variations in its course were observed. The mean length of labyrinthine, tympanic and mastoid segment was found to be 4.28 ± 0.605mm, 10.40 ± 1.416mm and 12.34 ± 0.915mm respectively in the dissected specimens. The first and second genu angle varied between 50°-90° and 90°-120° respectively. Facial canal dehiscence was present at the level of first genu in 10% of cases and at the level of tympanic segment in 33%. Distance between chorda tympani origin and stylomastoid foramen varied between 4 and 6mm with mean value of 5.31 ± 0.603mm. Chorda-facial angle was found to be in the range of 20° to 31° with mean of 25.30° ± 2.90°. The tympanomastoid segment of facial nerve has variations in length and in its relations with various middle ear structures. The facial canal, as it traverses the temporal bone, may display bony dehiscence, variations, and anomalies in its natural course, having its own clinical and surgical significance.

Image-guided, surgical robot-assisted percutaneous puncture of the foramen ovale and foramina stylomastoideum: a cadaveric study.

Image-guided, surgical robot-assisted percutaneous puncture of the foramen ovale and foramina stylomastoideum: a cadaveric study.

Perineural Invasion of the Intratemporal Facial Nerve: How Far Proximally Do We Chase the Positive Margin?

To determine recurrence patterns in patients with head and neck cancers requiring facial nerve sacrifice and to determine the optimal management of the positive proximal facial nerve margin. Case series with chart review. Tertiary care center. One hundred fifty-five patients with head and neck malignancies who underwent sacrifice of the facial nerve between March 1, 1999 and October 31, 2020. Demographics, preoperative facial nerve function, prior oncologic treatment, histologic type, operative details, adjuvant treatment, recurrence patterns, and overall survival were reviewed. Recurrence rates and recurrence location. Thirteen patients (8%) had positive proximal margins on final pathologic evaluation. Six of 13 (46%) experienced disease recurrence. No disease recurred proximally along the facial nerve. The recurrence rate was 26% for negative proximal facial nerve margins. Segments of the facial nerve biopsied included: extratemporally (n = 78), at the stylomastoid foramen (36), mastoid segment (22), second genu (7), tympanic (6), geniculate (3), labyrinthine (1), and IAC (2). Median patient follow-up was 30.3 months. Our data suggest that a conservative approach to a positive proximal facial nerve margin is optimal with respect to operative planning, patient morbidity, and disease recurrence patterns. Recurrence proximally along the facial nerve is an exceedingly rare event and the necessity of biopsy proximal to the geniculate ganglion, and in some cases even to the second genu, is called into question.

"Branching Patterns of the Facial Nerve within the Parotid Gland Among Sudanese"

The extratemporal component of the facial nerve starts when the facial nerve exits the stylomastoid foramen [1,2]. In the adult, it is protected laterally by the mastoid tip, tympanic ring, and mandibular ramus, whereas in children younger than 2 years it is relatively superficial