The position of the retromandibular vein relative to the facial nerve branches can vary among individuals, adding a layer of complexity to surgical planning. In some cases, the vein may cross over or under certain nerve branches, necessitating meticulous dissection to avoid vascular or neural damage. Understanding these variations is critical for optimizing surgical outcomes, minimizing complications, and ensuring the preservation of both vascular and neural integrity. During the routine dissection of the right hemi-faces of 49 human donor bodies preserved for educational use, an unusual anatomical relationship between the extratemporal facial nerve and the retromandibular vein was observed and recorded in three cases (6%). The facial skin flaps were retracted laterally, and the parotid gland was meticulously dissected to expose and examine the nerves and vessels. The retromandibular vein's pathway was traced to identify the main trunk and branches of the extratemporal facial nerve within the parotid gland. The dissection also included the auriculotemporal nerve and the superficial temporal artery. In all three cases, a single facial nerve trunk was identified, with its branching pattern classified as Type V and VI according to Davis (1956) in two cases; in one of the cases, the trifurcation of the main trunk of the facial nerve was observed. The extratemporal facial nerve followed an atypical route, passing deep (medial) to the retromandibular vein, while its temporal branch ran superficially (lateral) to the retromandibular vein. The aforementioned atypical course of the temporal branch places the nerve at a greater risk of injury during the surgical procedures. Recognizing and accounting for such variations is critical in minimizing complications and ensuring patient safety. Level 4 (case-series).

Anatomical details regarding venous drainage of the head and neck are an important matter for surgeons to avoid unnecessary complications such as hemorrhage. This report describes a case of the large venous ring around the mandibular condyle found in the cadaver. The left maxillofacial region of a latex-injected embalmed male cadaver (82 years of age at death) was dissected. The large two maxillary veins ran lateral to the capsule and superior to the mandibular notch and coursed posteroinferiorly to merge, and one trunk was formed at the posterior border of the ramus. It then received the superficial temporal vein superiorly to form the retromandibular vein (RMV). In addition, three maxillary veins were drained from the pterygoid venous plexus (PVP), medial to the ramus, one maxillary vein drained from the PVP into the RMV trunk, while two maxillary veins drained from the PVP into the anterior division of the RMV. All five large veins lateral and medial to the condyle drained from the PVP into the RMV. The knowledge of such an anatomical variation might prevent intraoperative bleeding in the temporomandibular joint region.

PurposeThe superficial middle cerebral vein (SMCV) typically drains into the cavernous sinus, which, in turn, connects to the pterygoid venous plexus via a sphenoidal emissary vein. The latter may course through the foramen ovale. The pterygoid plexus drains in most cases into the retromandibular and facial veins. A peculiar SMCV drainage pathway to the internal jugular vein (IJV) via a parapharyngeal vein was found here.MethodThe anatomic variant reported here was identified by carefully reviewing the archived CT angiogram in a 68-year-old male case.ResultsA double SMCV was found on the right side. The resulting common SMCV trunk passed laterally to the foramen rotundum to empty into the cavernous sinus. A sphenoidal emissary vein joined it, which continued inferiorly through the foramen ovale to the pterygoid plexus. This plexus was connected to a reservoir on the inner side of the lateral pterygoid plate from which a fenestrated parapharyngeal vein left. It had two primary fenestrations, and the proximal one had a fenestrated arm. It reached inferiorly and turned around the external carotid artery. At that level, it received two tributaries: first, the superior thyroid vein and then, the facial vein. The resulting facial-parapharyngeal trunk ended in the IJV. These veins and the carotid arteries, deep to them, were hidden beneath the submandibular gland. The right maxillary vein and the anterior branch of the retromandibular vein were absent.ConclusionThe parapharyngeal vein may be a direct drainage pathway for the SMCV and the pterygoid plexus. It should therefore be acknowledged and spared during various surgical approaches.

Pleomorphic adenoma of parotid gland is the most frequently occurring benign tumour in salivary glands and involvement of superficial or deep lobe is determined in relation to the retromandibular vein on imaging. This case report discusses a 69-year-old female who had pleomorphic adenoma in superficial lobe of parotid gland but misinterpreted as involvement of both lobes on imaging when assessed in relation with retromandibular vein on an MRI. Although extensive literature is available on the anomalous variations in the relationship between the retromandibular vein and the facial nerve, no case reports have documented peritumoral nodule of the superficial lobe growing beneath the retromandibular vein and mimicking as a deep lobe lesion on radiological evaluation. Thus, highlighting the importance of 3D imaging for proper preoperative assessment and to choose an appropriate surgical plan for parotid gland tumors.

This report presents a rare anatomical variation, double fenestration of the External jugular vein on the right side. During the routine dissection of a male cadaver aged 60 years, we observed a unilateral large double fenestration of the External jugular vein on the right side. After its formation from the posterior division of the retromandibular and posterior auricular veins, External jugular vein descended in the posterior triangle of neck. Here, it divided into medial, intermediate, and lateral veins that united again before draining into the subclavian vein. Lateral vein was the largest (7.2cm) and intermediate and medial veins were measuring 6.4cm each. Two large fenestrations, measuring 5.8cm each, arranged like a "double bubble" were seen in the External jugular vein extending from fourth to sixth cervical (C4 to C6) vertebrae. The medial branch of supraclavicular nerve was seen passing superficial to the distal part of External jugular vein. On the left side, the course of External jugular vein showed a standard pattern. Surgeons must be acquainted with the varied anatomy of the superficial neck veins to prevent major bleeding during operative procedures, including carotid endarterectomy, flap operations, & central venous catheterisation.

Anatomical preservation and functional integrity of the facial nerve (FN) are the main concerns of parotid surgery. Even though a variety of anatomical landmarks have been proposed and widely utilized, temporal or permanent postoperative FN palsy is stilla significant comorbidity of parotid surgery. Therefore, the literature must fully elucidate the consistency of the anatomical relationship between the FN and the retromandibular vein (RMV). We conducted a cadaveric study of 24 hemifaces to map the relationship between the FN and the RMV. Threedistinct patterns were identified.Fourteen of the hemifaces were males, and 10 were females. Thirteen cadaveric dissections were performed on the right side and 11 on the left side. Our study found three distinct patterns and proposed a classification system. Type I (66.7%) is when the nerve lies exclusively lateral to the RMV. Type II (29.2%) is when the FN lies superficial to the RMV, but its mandibular branch lies deep to the anterior branch of the RMV, and type III (4.1%) is when the FN lies exclusively medial to the RMV. The FN and RMV relationship is not constant, and surgeons should be aware of every anatomical variation. Especially in cases where the FN is estimated to lie more in-depth to the level of the RMV, a retrograde approach may be required to avoid a FN injury.

A unique venous pattern was observed on the left side of the neck in a 70-year-old male cadaver. Variations were observed in the formation of the external jugular vein (EJV) associated with a hypoplastic internal jugular vein (IJV). The retromandibular vein did not form, and the superficial temporal vein continued as the EJV. The linguofacial and maxillary veins united and drained into the EJV, whereas the posterior auricular vein was absent. In addition, a slit-like fenestration in the EJV was present in the middle of the vein, which was 41.54 mm long. IJV of the same side was hypoplastic throughout its course in the neck, and the external diameter was 6 mm. IJV and EJV are frequently accessed for central venous pressure monitoring or intravenous infusion and are encountered during cervical lymphadenectomy. Awareness of the anatomical irregularities is critical to avert unanticipated complications.

Sagittal split ramus osteotomy is an established procedure used in oral and maxillofacial surgery. Major bleeding is representative intraoperative complication involves vessels such as the inferior alveolar, facial, and maxillary arteries and accompanying veins, in particular the retromandibular vein (RMV). We previously described the RMV course patterns using embalmed cadavers. However, owing to the possible influence of formalin fixation and unclear skeletal classification of the jaws, the present study aimed to use contrast-enhanced computed tomography to confirm the RMV in patients with defined jaw deformities. Twenty patients with orthognathic jaw deformities (40 sides) were included. The RMV and the lateral and posterior views of the mandible were evaluated using contrast-enhanced computed tomography. Course patterns and RMV positions were classified as previously reported. Three patterns were identified in the lateral view. Type A: RMV posterior to the posterior border of the ramus (n=25; 62.5%). Type B: adjoining the posterior border of the ramus (n=12; 30.0%). Type C: anterior to the posterior border of the ramus (n=3; 7.5%). Five course patterns were identified in the posterior view. Pattern I: rectilinear course running medial to the posterior border of the ramus (n=3; 7.5%). Pattern II: diagonal course running medially from immediately posterior to posterior border of the ramus (n=11; 27.5%). Pattern III: rectilinear course running immediately posterior to the posterior border of the ramus (n=12; 30.0%). Pattern IV: diagonal course running from lateral to medial relative to the posterior border of the ramus (n=8; 20.0%). Pattern V: diagonal course running from lateral to immediately posterior relative to the posterior border of the ramus (n=6; 15.0%). In the no-course pattern group, the RMV inferior to the lingula was lateral to its position and superior to that of the lingula. In half of the cases, the left and right sides exhibited different running patterns. We observed no correlation between the skeletal patterns of jaw deformities and the course of the RMV. Type B/Pattern II that runs in a straight line bordering the posterior margin of the ramus requires the most attention during surgery. These findings suggest the possibility of predicting intraoperative bleeding risk.

A traumatic arteriovenous fistula (AVF) is a type of acquired vascular malformation, caused by blunt or penetrating trauma. Traumatic AVFs result in a pathologic connection between arterial and venous vasculature, bypassing the corresponding capillaries. When an intra-operative insult to vasculature within a surgical site is implicated in the subsequent formation of a traumatic AVF, the suspected etiology is iatrogenic. Although the most common etiology of traumatic AVFs of the entire body is iatrogenic trauma, intraoperative vascular insults (ie, ligation and cauterization) are routinely delivered within maxillofacial surgical sites, without formation of an acquired vascular malformation. A traumatic AVF in the pre-auricular region is exceedingly rare and has infrequently been described as a complication following minimally invasive temporomandibular joint (TMJ) surgery, managed with endovascular surgery. We describe a rare case of bilateral TMJ arthroscopies complicated by the formation of a pulsatile, traumatic AVF between the right superficial temporal artery and right retromandibular vein, treated with minimally invasive endovascular embolization by the interventional radiology team. This case report highlights the diagnosis of a traumatic AVF in the pre-auricular region and multi-specialty management of an early complication of minimally invasive maxillofacial surgery.

We report a case of a 15-year-old Indian girl who presented with tinnitus, pain and ear discharge for one month and was preliminarily diagnosed with Chronic Suppurative Otitis Media (CSOM) with mastoiditis. She underwent a routine presurgical CT scan which revealed an aberrant vein, making it essential to exercise caution during surgery for CSOM. The aberrant vessel was identified as a Petrosquamous Sinus. A Petrosquamous Sinus is a persistent fetal vein that connects the transverse sinus with the retromandibular vein and may regress in an individual by birth. Its importance lies in the risk of haemorrhage it carries during otological surgeries. A Digital Subtraction Angiography proved to be a vital step in isolating the path of the vein for better visualisation of the course, thus giving a better idea about the anatomical relations of the vessel during the surgery. The tympanoplasty was performed with care to prevent damaging the vein. The patient had no complications in the postoperative period and made a quick recovery.

Success in skeletal surgery depends on adequate access and exposure of the underlying skeletal structures. The retromandibular approach exposes the ramus condyle region through the posterior border of the mandible by utilizing the space between marginal mandibular and buccal branches of the facial nerve. Length of this safety window and accessibility varies in each individual owing to the differing ramifications of peripheral branches of facial nerve. These variations cannot be adequately assessed through clinical studies. Cadaveric studies permit us to extensively explore the surgical area to demystify the branching pattern and its relationship to the adjacent structures. Thirty well-preserved cadaveric facial halves were dissected using a retromandibular incision. Visibility and accessibility were objectively graded through a scale. The safety window and furcation distance were measured using caliper and scale. The appearance of the retromandibular vein was also noted. Eighteen facial halves showed maximum accessibility wherein the surgeon is expected to visualize the condylar neck, subcondylar region and posterior half of ramus. In 8 facial halves, accessibility was limited to subcondylar and midportion of posterior ramus, and in 8 facial halves, accessibility was limited to the midportion of ramus of the mandible. Safety window ranged from 1.9 to 3.5 cms. Distance between the posterior border of mandible and bifurcation of the facial nerve ranged from 0.5 to 1.5 cms. Facial nerve was encountered in 24 facial halves during the retromandibular approach. Retromandibular vein was encountered in 23 facial halves during the retromandibular approach. The retromandibular approach is a versatile approach to the condyle subcondylar area as it provides much-required visibility and accessibility. The facial nerve branching pattern and intercommunicating branches determine the safety window which is adequate in most cases. The retromandibular vein is a reliable landmark predicting the vicinity of the facial nerve.

As the facial transplantation procedures are becoming more popular and frequent in recent years, for repairing facial trauma, variations in the veins of head and neck needs to be reported time and again. This study was undertaken to examine the course and drainage pattern of the facial vein and external jugular vein on this context and emphasize its surgical implications. The authors studied the head and neck region of 50 embalmed cadavers of both sexes to document normal and variant anatomy of facial, retromandibular, and external jugular veins. In 30% of the head and neck regions, different draining pattern of the above-mentioned veins were observed. One of the rare variation discovered was the splitting of the retromandibular vein to embrace the external carotid artery within the parotid gland. The data about variations in the termination of facial vein, retromandibular vein, and external jugular vein, as observed in the present study might be useful in avoiding accidental injury to these vessels during any surgical intervention in the face as well as neck. Level of Evidence: IV.

Neuromodulators have predominantly been used for the treatment of upper facial lines, but their use has expanded to include lower face and neck treatments. However, the injection sites for these treatments are based on skin surface landmarks, which may pose risks to nearby structures and result in undesired outcomes. To investigate the spatial relationship between the FDA-approved skin surface landmarks for neuromodulator injections in the parotid and submandibular glands and the topographical anatomy of critical facial structures such as the facial artery, facial vein, external carotid artery, and retromandibular vein. A cross-sectional retrospective analysis was conducted on contrast-enhanced cranial CT scans. The scans were analyzed for the morphology and location of the parotid and submandibular glands. Measurements were taken for gland volume, craniocaudal extent, anterior-posterior extent, and distances between the skin surface and gland capsule or nearby structures such as arteries. The study sample consisted of 53 subjects, including 7 males and 46 females, with a mean age of 36.91 years and a mean BMI of 23.28 kg/m2 . The mean volume of the parotid gland was 31.9 ± 3.0 cc in males and 28.5 ± 3.6 cc in females with p < 0.001, while the mean volume of the submandibular gland was 18.2 ± 2.0 cc in males and 14.5 ± 3.4 cc in females with p < 0.001. The mean distances between skin surface and the gland capsule were 5.98 ± 2.2 and 8.84 ± 4.0 mm for the parotid and submandibular gland, respectively. This distance increased with higher age and higher BMI values in a statistically significant manner with p < 0.001. The distances between FDA-approved skin surface landmarks and the parotid and submandibular glands varied significantly depending on gender, age, and BMI. Optimal injection depth and location for neuromodulator treatments cannot be generalized based on these landmarks alone, emphasizing the need for real-time ultrasound imaging guidance.

Retromandibular vein (RMV) and posterior belly of digastric muscle are among the landmarks used to identify facial nerve in parotid surgery. This observational cross-sectional study was done in the Department of ENT &HNS at a tertiary care teaching hospital for a period of 8 years with the aim to aware young otorhinolaryngologist about the relationship of posterior belly of digastric muscle & retromandibular vein with facial nerve and share our experience about preservation of posterior branch of greater auricular nerve. A total of 34 cases of superficial parotidectomies done for pleomorphic adenoma were included in this study. Relationship of facial nerve with retromandibular vein and posterior belly of digastric muscle was noted. Greater auricular nerve was identified, and every attempt was made to preserve its posterior branch. Retromandibular vein was medial to the trunks of facial nerve in 33 (97%) patients. It was lateral to lower division and medial to upper division in one case. Greater auricular nerve was seen to bifurcate into two branches (Anterior and posterior) in 21 (62%) cases while in one case(3%) three branches were seen emerging from main trunk and in another case(3%) first two branches were seen emerging and then anterior branch was further dividing into two. Preservation of posterior branch of greater auricular nerve was possible in 23 (68%) of patients. Posterior belly of digastric muscle was seen as a reliable and constant landmark. Facial nerve was seen superior to upper border of posterior belly of digastric muscle in all cases (100%). No anatomical variation of posterior belly was seen. Retromandibular vein is invariably seen medial to the trunks of facial nerve. Facial nerve is always seen superior to upper border of posterior belly of digastric muscle in almost all cases. Preservation of posterior branch of greater auricular nerve is possible in majority of the cases.

Facial masculinization surgery

Introduction: Development of veins of head and neck is complex. Variations in the venous architecture of head and neck includes persistence or complete obliteration of communication between Internal Jugular Vein (IJV) and External Jugular Vein (EJV) and also partial obliteration in EJV. Knowledge of variations in venous architecture is beneficial to avoid injuries to these veins during interventions like EJV cannulation for diagnostic and therapeutic purposes. Aim: To study the variations in the venous architecture of the neck in the cadavers. Materials and Methods: This descriptive cross-sectional study was conducted in the Department of Anatomy, Calcutta National Medical College, Kolkata, West Bengal, India during December 2017 to December 2019. Total 26 specimens of both male and female cadavers were dissected, and variations in the venous architecture was noted, also each variation was explained in the light of embryology. Results: Retromandibular Vein (RMV) was found to be undivided in all 10 of the variations found in the eight male and two female cadavers. EJV was found to be absent in one specimen among 26 dissected. Communication between IJV and EJV was found in one specimen. In another specimen, EJV was found to be draining into IJV which can be embryologically seen as a communication between IJV and EJV while the caudal part of EJV had degenerated. Conclusion: Undivided RMV, particularly absent posterior division is not very uncommon in male and female in this ethnicity. Absence of common facial vein was more common in male as compared to female. Persistent communication between EJV and IJV were also more in male. Moreover occurrence of facial vein drainage into EJV was also remarkably high.

To assess the diagnostic utility of various radiologic criteria such as the lateral margin or dislocation of the retromandibular vein (RMV), Utrecht line, facial nerve line, Conn's arc, lines passing from the lateral margin of the masseter muscle to the facial nerve trunk or RMV, minimum distance from the fascia to the tumor (MDFT), and direct tracing of the intraparotid facial nerve (DT) for differentiating a parotid deep lobe tumor from a superficial lobe tumor. Twenty-one studies with 2225 participants from PubMed, Embase, Web of Science, Cochrane Library, SCOPUS, and Google Scholar up to March 2022 were analyzed. Sensitivity, specificity, and negative and positive predictive values of the methods were extracted. The diagnostic odds ratio (DOR) of radiologic criteria compared to surgical findings was 18.9109. The area under the summary receiver operating characteristic curve was 0.879. The sensitivity and specificity were 0.6663 and 0.9190. MDFT (DOR 61.2917) and DT (DOR 91.9883) showed superior results as diagnostic landmarks. For tumors crossing the anatomical criteria line, strict way (any tumor crossing the line) could help differentiate a deep lobe tumor more accurately than conventional way (> 50% of the tumor volume located medial to the line). Various radiologic criteria, especially MDFT and DT, showed good diagnostic accuracy for differentiating a parotid deep lobe tumor.

Abstract Introduction Acquired arterio-venous fistulas (AVF) involving the carotid artery are most commonly the result of trauma and catheterisation of the neck vessels. Left untreated, carotid-jugular fistulas (CJF) may precipitate ischaemic neurological symptoms due to thromboembolism or shunting of blood through the AVF. Methods A literature review was performed to determine the incidence and outcomes of acquired carotid-jugular AVFs following carotid endarterectomy (CEA). Electronic searches were performed using three databases, PubMed, EMBASE, and Google Scholar. Results Three case studies met inclusion criteria for analysis. The first case occurred 4-months following a left CEA. CT-angiography and duplex ultrasound identified a pseudoaneurysm arising from the proximal internal carotid artery. A CJF was identified on re-intervention and carotid ligation was performed following unsuccessful attempts to repair the defect. The patient has ongoing mild dysphonia with no other complications at 18 months follow-up. The second case occurred 6 years following right CEA. Catheter angiography revealed an AVF between the right external carotid artery (ECA) and internal jugular vein, treated with coil embolization. The patient made complete neurological recovery and had no further complications at 2 years follow-up. The third case occurred 4 years following right CEA. Catheter angiography identified fistulisation between the lingual branch of the right ECA and right retromandibular vein, treated with transarterial particle embolization. The patient made a complete neurological recovery. Conclusion Carotid-jugular AVFs are rare following CEA. This review proposes that carotid-jugular AVFs may be amenable to both open and endovascular intervention with durable outcomes. Proceduralists should be cognisant of this complication. Take-home message Carotid-jugular arteriovenous fistulas are rare following carotid endarterectomy and may be amenable to both open and endovascular intervention with durable outcomes.

Does three-dimensional intraglandular location predict malignancy in parotid tumors?

Identification of facial nerve displaced vertically in locally invasive mucoepidermoid carcinoma of parotid gland: A rare case discussion