Vascular survey of the maxillary vestibule and gingiva-clinical impact on incision and flap design in periodontal and implant surgeries.

OBJECTIVES: Currently, empirical clinical findings on the blood supply of the maxillary vestibule are not backed up with sufficient literature. The purpose of this study was to investigate the mucosal and periosteal vascular supply in the maxillary vestibule macroscopically and radiographically to improve surgical strategies and flap designs. MATERIALS AND METHODS: Thirty head corpses were selected (9 dentate, 11 partially edentulous, 10 edentulous). Twenty-six corpses were injected by red latex milk and embalmed with Thiel solution. Four cadavers were prepared for corrosion casting. Arterial path and anastomoses in the maxillary vestibule of dentate, partially edentulous and edentulous ridges, were analyzed macroscopically and by computed tomography (CT). RESULTS: Transverse periosteomucosal anastomoses were detected in the posterior and esthetic zones of the maxillary vestibule. The buccal branches penetrated the interdental septum toward the palate. In the esthetic zone, superior labial artery (SLA) supplied the mucosa and the infraorbital artery (IOA) supplied the periosteum. Corrosion casting showed anastomoses between IOA and nasal septal branches. CT analysis revealed ipsilateral and contralateral anastomoses between SLA and IOA. In dentate ridges, mucosal star-shaped terminal branches were detected. CONCLUSIONS: The macroscopic and radiographic vascular survey analysis revealed the anatomical background behind several clinically documented phenomena related to oral and periodontal surgeries. CLINICAL RELEVANCE: This study permits clinicians to design less invasive flaps when releasing incisions in the maxillary vestibule during periodontal and implant surgeries. Our observations strongly point to the significance of an undamaged periosteum to prevent compromised flap revascularization and wound healing disturbances.

Analysis of blood supply in the hard palate and maxillary tuberosity-clinical implications for flap design and soft tissue graft harvesting (a human cadaver study).

OBJECTIVES: The aim of the present study is to provide a detailed macroscopic mapping of the palatal and tuberal blood supply applying anatomical methods and studying specific anastomoses to bridge the gap between basic structural and empirical clinical knowledge. MATERIALS AND METHODS: Ten cadavers (three dentate, seven edentulous) have been prepared for this study in the Department of Anatomy, Semmelweis University, Budapest, Hungary, and in the Department of Anatomy of the Medical University of Graz. All cadavers were fixed with Thiel's solution. For the macroscopic analysis of the blood vessels supplying the palatal mucosa, corrosion casting in four cadavers and latex milk injection in other six cadavers were performed. RESULTS: We recorded major- and secondary branches of the greater palatine artery (GPA) and its relation to the palatine spine, different anastomoses with the nasopalatine artery (NPA), and lesser palatal artery (LPA) as well as with contralateral branches of the GPA. Penetrating intraosseous branches at the premolar-canine area were also detected. In edentulous patients, the GPA developed a curvy pathway in the premolar area. The blood supply around the maxillary tuberosity was also presented. CONCLUSION: The combination of different staining methods has shed light to findings with relevance to palatal blood supply, offering a powerful tool for the design and execution of surgical interventions involving the hard palate. CLINICAL RELEVANCE: The present study provides clinicians with a good basis to understand the anatomical background of palatal and tuberal blood supply. This might enable clinicians to design optimized incision- and flap designs. As a result, the risk of intraoperative bleeding and postoperative wound healing complications related to impaired blood supply can be minimized.

Applied anatomy of screw placement via the posterior arch of the atlas and anatomy-based refinements of the technique.

PURPOSE: To present a method of posterior arch and lateral mass screw (PALMS) insertion and to prove its feasibility. METHODS: Four formalin-fixed specimens and 40 macerated atlas vertebras were used to describe the relevant anatomy. The height of the posterior arch was measured on 42 consecutive patients using standard CT of the cervical spine. The operative technique and the special CT reconstructions used for preoperative planning are described. Eight patients underwent posterior fixation using this technique. RESULTS: We described the relevant anatomy and important anatomical landmarks of the posterior arch of the atlas. PALMS placement was modified according to these anatomical findings. Fifteen PALMSs were placed in eight patients using this technique without vascular or neural injury. CONCLUSION: It is feasible to place PALMS using the described technique. CT angiography is of crucial importance for preoperative planning using the described special reconstructions. The arch posterior to the lateral mass (APLM) is defined as the bone stock situated posterior to the lateral mass, respecting its convergence. The ideal entry point for a PALMS is on the APLM above the center of the converging lateral mass. A complete or incomplete ponticulus posticus and a retrotransverse foramen or groove can be used as an accessory landmark to refine the entry point.

Reconstruction of the Exenterated Orbit with an Island Pericranial Flap: A New Surgical Approach.

Reconstruction of the bony socket after orbital exenteration is a matter of much debate. Prompt defect closure with a microvascular flap is desirable but involves a major surgical procedure and hence, places considerable burden on the patient. The new surgical technique presented here permits a technically simpler wound closure with fewer complications after orbital exenteration. Methods: Between May 2014 and June 2022 in the ENT department of Regensburg University, nine patients underwent exenteration and reconstruction with a pericranial flap. The flap was raised via a broken line incision in the forehead or endoscopically, incised in a roughly croissant-like shape, then introduced into the orbit through a tunnel in the eyebrow. A retrospective analysis of the patients and considerations about determining the size, shape, and vascular supply of the flap are presented. Results: Flap healing was uncomplicated in all cases. Only 6 weeks after surgery, the flap was stable, making it possible to start adjuvant therapy and prosthetic rehabilitation swiftly. The flap is adapted to the near cone-shape of the orbit. The mean (± standard deviation) surface area of the measured orbits is (39.58 ± 3.32) cm2. The territory of the angular artery provides the periosteal flap arterial blood supply. Venous drainage is via venous networks surrounding the artery. Conclusions: Use of the pericranial flap makes it possible to close the orbital cavity promptly with minimal donor site defect and a short operating time, thereby minimizing the surgical risk and speeding up physical and psychological recovery.

Three-dimensional structure of the basal lamella of the middle turbinate.

The middle turbinate's basal lamella (3BL) is a variable landmark which needs to be understood in endoscopic transnasal skull base surgery. It comprises an anterior frontal and a posterior horizontal part and appears in its simplest depiction to be "L"-shaped, when viewed laterally. In this study we analyzed its 3D morphology and variations focusing on a precise and systematic description of the anatomy. CBCTs of 25 adults, 19 cadavers and 6 skulls (total: 100 sides) were investigated with the 3DSlicer software, creating 3D models of the 3BL. We introduced a novel geometrical classification of the 3BL's shape, based on segments. We analyzed their parameters and relationship to neighboring structures. When viewed laterally, there was no consistent "L"-shaped appearance of the 3BL, as it is frequently quoted. A classification of 9 segment types was used to describe the 3BL. The 3BLs had in average of 2.95 ± 0.70 segments (median: 3), the most frequent was the horizontal plate (23.05% of all segments), next a concave/convex plate (22.71%), then a sigma plate (22.37%). Further types were rare. We identified a horizontal plate in 68% of all lateral views whilst 32% of the 3BLs were vertical. A sigma-concave/convex-horizontal trisegmental 3BL was the most common phenotype (27%). Globally, the sigma-concave/convex pattern was present in 42%. The 3BL adhered the ethmoidal bulla in 87%. The segmenting method is eligible to describe the 3BL's sophisticated morphology.

A different technique for sutureless coronary bypass grafting.

Introduction: Many coronary anastomotic devices have been designed to replace manual stitching in coronary surgery; however, interestingly, none of them became widespread. Our aim was to work out an easy and fast endoluminal vessel-to-vessel stent bridge distal anastomotic technique. Materials and methods: Ten coronary arteries of eight fresh human hearts were used in this study. The anastomosis was performed with the implantation of a graft vessel into the lumen of the coronary artery by performing stent fixation. The technique is described and photo documented in detail. The durability and the conductibility of the anastomosis were examined with intraluminal endoscopy, functional streaming test, and a coloring of the vessels. Results: The anastomosis had great results in all cases. Obstruction, dissection, or dislocation of the vessels was not observable. Conclusions: This study confirmed the ex-vivo feasibility of the described technique. This method can be an easy, fast, and reliable method applied in the endoscopic distal coronary artery anastomosis surgery. The development of stents adapted to this method and the in-vivo testing of this technique are necessary for the future.

MRI, CT and high resolution macro-anatomical images with cryosectioning of a Beagle brain: Creating the base of a multimodal imaging atlas.

Most common methods that directly show macro- or microscopic anatomy of the brain usually require the removal of the organ from the neurocranium. However, the brain can be revealed in situ by using proper sectioning techniques. Our aim was to both improve the cryosectioning method, test its limits and create a high-resolution macro-anatomical image series of a Beagle brain, which at the time of the study did not exist. A two-year-old female Beagle has been scanned with CT and MRI ante and post mortem, then the arteries of the head were filled with red resin. After freezing to -80°C, a neurocranium block was created and was embedded into a water-gelatin mix. Using a special milling device and a DSLR camera, 1112 consecutive RGB-color cryosections were made with a 100 µm layer thickness and captured in high resolution (300 dpi, 24-bit color, and pixel size was 19.5 x 19.5 µm). Image post-processing was done with Adobe Photoshop CS3 and Thermo Scientific Amira 6.0 softwares, and as a result of the proper alignment and coregistration, visualization and comparing was possible with all the applied imaging modalities (CT, MRI, cryosectioning) in any arbitrary plane. Surface models from the arteries, veins, brain and skull were also generated after segmentation in the same coordinate system, giving a unique opportunity for comparing the two-dimensional and three-dimensional anatomy. This is the first study which focuses directly to this high-definition multimodal visualization of the canine brain, and it provides the most accurate results compared to previous cryosectioning studies, as using an improved method, higher image quality, more detailed image, proper color fidelity and lower artefact formation were achieved. Based on the methodology we described, it can serve as a base for future multimodal (CT, MR, augmented- or virtual reality) imaging atlases for medical, educational and scientific purposes.

The role of fissula ante fenestram in unilateral sudden hearing loss.

The cause of unilateral sudden sensorineural hearing loss (SNHL) remains unclear in many clinical cases. Perilymphatic leakage through a fissula ante fenestram (FAF) fistula is one possible reason. We present four clinical cases with proven FAF fistula, discovered during surgical exploration. All patients experienced partial hearing recovery after surgical coverage of the fistula. We suggest FAF as a possible site for perilymphatic leakage, representing an anatomical correlate for sudden unilateral SNHL. We recommend early exploratory tympanotomy with special attention to the bony region, anterior to the oval window, in cases of severe sudden SNHL and suspected FAF.