"Deep masseteric triangular area to define masseter neurovascular bundle: A cadaveric study".

INTRODUCTION: Facial reanimation procedures are used in the treatment of the disorder that impairs mimetic function and jeopardizes physical and psychological health, and one of the most important instruments of these techniques is the masseteric neurovascular bundle (NVB) and proper identification at the mandibular notch level. In the current study, a triangular area (deep masseteric triangle, DMT) on the lateral surface of the masseter muscle that was identified to help reliable determination of the masseteric NVB at the mandibular notch level. MATERIAL AND METHODS: 40 parotideomasseteric region dissections were performed in 10 female and 10 male donated cadavers. Structures lateral to the masseter muscle were removed. The edge length of the masseter muscle on the zygomatic arch side was measured. After the edges of the DMT were measured, the masseteric NVB was found by dissection and its distance (depth) from the skin line was measured. RESULTS: The mean lengths of the superior, posterior, and anterior margins were 17.3 (±4.5) mm, 25.9 (±6.2) mm, and 26.3 (±6.5) mm, respectively. The total length of the upper edge of the masseteric muscle attached to the zygomatic arch averaged 52.7 (±5.2) mm. The masseteric neurovascular bundle was detected at a depth of approximately 17 mm from the skin of the parotideamasseteric region. DISCUSSION: The visualization of the DMT can be used as an important landmark for access to branch-free part of the masseteric nerve. Moreover, an specific approach for masseteric NVB localization can be established by drawing a line between the mandibular angle and the midpoint of the upper edge of the DMT. This technique can greatly improve the accuracy of both masseteric nerve harvesting and masseteric nerve block procedures.

The tortuous course of the anterior ethmoidal artery in the orbit: A cadaveric study.

AIM: The study aimed to define the coursing pattern of the anterior ethmoidal artery (AEA) in the orbit to minimize complications during endoscopic interventions. MATERIALS AND METHODS: A total of ten formalin-fixed cadaveric halves were included in the study. Orbital regions were shown with a superior approach. The superior rectus and superior oblique muscles, as well as the connective tissue and vessels were removed to observe the path of the anterior ethmoidal artery. Measurements such as the width of the artery, the anterior-posterior length of the U formation, the length of the intraorbital part of the ophthalmic artery, and the distance of the AEA from its opthalmic origin to the anterior ethmoidal foramen were made. RESULTS: Ten of the AEAs originated from the ophthalmic artery. The AEA branches originated from the ophthalmic artery approximately 18.4 mm after the orbital artery entered the orbital, and the mean width of the AEAs was 0.82 mm. In seven of the total anterior ethmoidal arteries, they coursed in the intraethmoidal cavities below the cranial base. The mean distance from the origin of AEAs to the medial wall of the orbit was 4.9 mm. After leaving the ophthalmic artery, seven of the AEAs were coursing forward and turned back ('U' turn formation), which have proximately 1.5 mm in anteroposterior direction. CONCLUSION: The anterior ethmoidal artery is 0.8 mm wide, originates from the distal part of the ophthalmic artery, entering the orbit after a 1.5 mm U-turn.

The Upper Attachment of the Uncinate Process and Anterior Ethmoidal Artery.

OBJECTIVE: Variations in the upper attachment of the uncinate process (UP) are important because they can affect frontal sinus drainage and change the morphology. Functional endoscopic sinus surgery (FESS) is the primary technique used to treat chronic medically refractory rhinosinusitis. Uncinectomy is the basis of FESS technique to obtain the best possible result from surgery. The anterior ethmoidal artery (AEA) enters the nasal cavity through the orbital medial wall (lamina papyracea) may also be affected by the upper attachment of the UP. The aim of this study was to investigate a possible link between UP variations and the course of the AEA. MATERIALS AND METHODS: This retrospective, computed tomography (CT)-based, anatomic study was conducted on 200 healthy adults (100 females and 100 males) by screening bilateral paranasal sinus images. The upper attachment of the UP was classified in 6 types (1-6) based on the Liu classification. The AEA was divided into 4 types (A-D) based on location: anterior to the frontal sinus (A), between the frontal sinus and the middle nasal turbinate (B), and anterior to the posterior ethmoidal cells (C and D). All the CT images were evaluated simultaneously by 2 anatomists and 1 radiologist. RESULTS: Of the total cases (200 right and 200 left side), 48.8% were type 1 UP attachment, 11.0% type 2, 12% type 3, 9% type 4, 18% type 5, and 1.2% type 6. The AEAs were classified as 12.2% type A, 71.8% type B, 15.2% type C, and 0.8% type D. CONCLUSION: The course of the AEA through the nasal cavity was observed to shift anteriorly from the ethmoidal bulla to the frontal sinus in patients with UP attached to the lamina papyracea and middle turbinate. Remarkably, the AEA always coursed anterior from the middle nasal turbinate line.

Prespecialist perceptions of three-dimensional heart models in anatomical education.

PURPOSE: This article aims to discuss the use of three-dimensional (3D) printed models of vascular variation cases as an educational tool for undergraduate and postgraduate anatomy students. METHODS: This advanced study involved ten anatomy assistants who were provided with five distinct cases of congenital cardiovascular variations, each accompanied by a computed tomography angiography (CT-A) and 1:1 solid model format. The residents were asked to generate perceptions for both formats and then compare these perceptions based on identifying the variation, defining the structural features, and evaluating relevant educational perspectives. RESULTS: The vascular origin measurement values compared to the statistically evaluated real values of the related cases showed that models were 1:1 identical copies. Qualitative assessment feedback from five stations supported the usefulness of 3D models as educational tools for organ anatomy, simulation of variational structures, and overall medical education and anatomy training. Models showcasing different anatomical variations such as aortic arch with Type 2 pattern, a right-sided aortic arch with Type 2 pattern, an aberrant right subclavian artery, arteria lusoria in thorax, and a left coronary artery originating from pulmonary trunk in an Alcapa type pattern allow for better analysis due to their complex anatomies, thus optimizing the study of variation-specific anatomy. The perception level in the 3D model contained higher points in all of the nine parameters, namely identification of cardiovascular variations, defining the vessel with anomaly, aortic arch branch count and appearance order, feasibility of using it in peers and student education. 3D models received a score 9.1 points, while CT-A images were rated at 4.8 out of 10. CONCLUSION: 3D printed anatomical models of variational cardiovascular anatomy serve as essential components of anatomy training and postgraduate clinical perception by granting demonstrative feedback and a superior comprehension of the visuospatial relationship between the anatomical structures.

Variations of the extracranial segment of vertebral artery as a bleeding risk factor.

BACKGROUND: Standart interventional procedures such as screw instrumentation, aortic arch endovascular surgery and cervical nerve blockade may be of fatal risk due to anatomic reason of variations in the proximal part of the vertebral artery (VA). The aim of this study is to study the VA variations of the extracranial segments to evaluate the frequency of the incident to demonstrate the importance of clinical condition strategy. METHODS: The prevalence of variations and morphometric measurements of the VA in three-dimensional computed tomographic angiography (3D-CTA) scans were studied. Total 400 VA was investigated for the aortic arch origin of the VA, diameter of the VA, its level of entry into the transverse foramen, the dominance sides, and related basilar artery course. RESULTS: 3D-CTA radiographs of 200 Anatolian patients (120 men and 80 women with age range 17-90 years). In most cases (approximately 94%), both sides of VA were the first branch of subclavian artery. While all the right VAs was branched from the subclavian artery, 6% of the left VAs were branched from the aortic arch. 2/3 of them originated from the proximal of the subclavian artery and 1/3 from the distal. The VA which were originating from the proximal of the classical anatomic pattern tended to enter the transverse foramen more distally than C6 level. VAs with a different level of entry than C6 are left-sided and aortic arch originated (out of 8 cases 3 had a level of entry at C5 and 2 at C4). The outer diameter ranges of the prevertebral part of the VA of subclavian origin and left VA of aortic arch origin were 3.2-3.6 mm and 3.2-3.6 mm, respectively. While the diameters of the right and left VAs were almost the same in approximately 20% cases, the left VA was dominant in up to 60% of cases. A significant relationship was found between the side of the dominant VA and in the course of the basilar artery. CONCLUSIONS: The relationship between the dominant side of VA and the course of the basilar artery of its own vessel has never been reported elsewhere. Such anatomical variations, routine preoperative 3D-CTA evaluation is mandatory to prevent the VA injury when C5-C2 instrumentation, anterior cervical decompression, cervical nerve blockade and aortic arch surgery are planned.

Multidisciplinary Assessment of Planning and Resection of Complex Bone Tumor Using Patient-Specific 3D Model.

Oncological interventions in thoracic cavity have some important problems such as choice of correct operative approaches depending on the tumor, size, extension, and location. In sarcoma surgery, wide resection should be aimed for the curative surgery. Purpose of this study was to evaluate pre-operative planning of patient-specific thoracic cavity model made by multidisciplinary surgeon team for complex tumor mass for oncological procedures. Patient's scans showed a large mass encroaching on the mediastinum and heart, with erosion of the adjacent ribs and vertebral column. Individual model of this case with thoracic tumor was reconstructed from the DICOM file of the CT data. Surgical team including six interdisciplinary surgeons explained their surgical experience of the use of 3D life-size individual model for guiding surgical treatment. Before patients consented to surgery, each surgeon explained the surgical procedure and perioperative risks to her. A questionnaire was applied to 10 surgical residents to evaluate the 3D model's perception. 3D model scans were useful in determining the site of the lesion, the exact size, extension, attachment to the surrounding structures such as lung, aorta, vertebral column, or vascular involvement, the number of involved ribs, whether the diaphragm was involved also in which order surgeons in the team enter the surgery. 3D model's perception was detected statistical significance as < 0.05. Viewing thoracic cavity with tumor model was more efficient than CT imaging. This case was surgically difficult as it included vital structures such as the mediastinal vessels, aorta, ribs, sternum, and vertebral bodies. A difficult pathology for which 3D model has already been explored to assist anatomic visualization was mediastinal osteosarcoma of the chest wall, diaphragm, and the vertebral column. The study helped to establish safe surgical line wherever the healthy tissue was retained and enabled osteotomy of the affected spinal corpus vertically with posterior-anterior direction by preserving the spinal cord and the spinal nerves above and distal the tumor. 3D tumor model helps to transfer complex anatomical information to surgeons, provide guidance in the pre-operative planning stage, for intra-operative navigation and for surgical collaboration purposes. Total radical excision of the bone tumor and reconstructions of remaining structures using life-size model was the key for successful treatment and better outcomes. The recent explosion in popularity of 3D printing is a testament to the promise of this technology and its profound utility in orthopedic oncological surgery.