Impact of Bone Augmentation of Facial Bone Defect around Osseointegrated Implant: A Three Dimensional Finite Element Analysis

(1) Background: When dental implants are placed at the esthetic zone, facial bone fenestration might be expected. This study aimed to evaluate the biomechanical effect of bone augmentation around implants with facial bone fenestration defects using the finite element method. (2) Methods: An anterior maxillary region model with facial concavity was constructed with a threaded implant inserted following the root direction, resulting in apical threads exposure to represent the fenestration model. Several bone coverage levels were simulated by gradually shifting the deepest concavity point buccally, mimicking bone augmentation surgeries with different bone fill results. Oblique forces were applied, and analysis was performed. (3) Results: Peak compressive stress magnitude and distribution varied according to the level of exposure and facial concavity depth. The fenestration model demonstrated a slightly lower peak peri-implant bone stress, smaller implant displacement, and smaller bone volume with strain levels above 200 µ strain. A gradual increase in compressive stress, implant displacement, and bone volume exhibited strain level above 200 µ strain was observed with the increased bone fill level of the facial bone fenestration. (4) Conclusions: Exposure of implants apical threads at the maxillary anterior region does not significantly affect the peri-implant stress and strain results. However, increasing the buccolingual width and eliminating the buccal concavity might increase the peri-implant bone volume exhibited favorable loading levels.

The wHole Story About Fenestrations in LSEC

The porosity of liver sinusoidal endothelial cells (LSEC) ensures bidirectional passive transport of lipoproteins, drugs and solutes between the liver capillaries and the liver parenchyma. This porosity is realized via fenestrations - transcellular pores with diameters in the range of 50-300 nm - typically grouped together in sieve plates. Aging and several liver disorders severely reduce LSEC porosity, decreasing their filtration properties. Over the years, a variety of drugs, stimulants, and toxins have been investigated in the context of altered diameter or frequency of fenestrations. In fact, any change in the porosity, connected with the change in number and/or size of fenestrations is reflected in the overall liver-vascular system crosstalk. Recently, several commonly used medicines have been proposed to have a beneficial effect on LSEC re-fenestration in aging. These findings may be important for the aging populations of the world. In this review we collate the literature on medicines, recreational drugs, hormones and laboratory tools (including toxins) where the effect LSEC morphology was quantitatively analyzed. Moreover, different experimental models of liver pathology are discussed in the context of fenestrations. The second part of this review covers the cellular mechanisms of action to enable physicians and researchers to predict the effect of newly developed drugs on LSEC porosity. To achieve this, we discuss four existing hypotheses of regulation of fenestrations. Finally, we provide a summary of the cellular mechanisms which are demonstrated to tune the porosity of LSEC.

Double unilateral fenestration of the anterior cerebral artery in the pre-communicating segment: a report of a unique case

A unique example of two fenestrations of the pre-communicating (A1) segment of the right anterior cerebral artery (ACA) in a 78-year-old woman was a special case among 388 cadaveric specimens. It was found by a retrospective review of the personal data obtained during graduate and undergraduate studies at the Faculty of Medicine. Two unequal fenestrations of the right A1 segment were associated with the presence of a pseudo anterior communicating artery, hypoplasia of the right posterior communicating artery and the left superior cerebellar artery, absence of the right anterior inferior cerebellar artery, and ectasia of the basilar artery; however, the cerebral arteries were without aneurysm(s) or other pathology. The reason could be the almost equal ACA diameter on both sides.

Management of simple hepatic cyst

Simple hepatic cysts are typically saccular, thin-walled masses with fluid-filled epithelial lined cavities that arise from aberrant bile duct cells during embryonic development. With the development of diagnostic modalities such as ultrasonography, computed tomography and magnetic resonance imaging, simple hepatic cysts are seen with relative frequency in daily clinical examination. US is the most useful and noninvasive tool for the diagnosis of simple hepatic cysts, and can generally differentiate simple hepatic cysts from abscesses, hemangiomas and malignancies. Cysts with irregular walls, septations, calcifications or daughter cysts on US should be evaluated with enhanced CT or MRI to differentiate simple hepatic cysts from cystic neoplasms or hydatid cysts.Growth and compression of hepatic cysts cause abdominal discomfort, pain, distension and dietary symptoms such as nausea, vomiting, a feeling of fullness and early satiety. Complications of simple hepatic cysts include infection, spontaneous hemorrhage, rupture, and external compression of biliary tree or major vessels.Asymptomatic simple hepatic cysts should be observed. Treatment for symptomatic simple hepatic cysts includes percutaneous aspiration, aspiration followed by sclerotherapy, and surgery. The American College of Gastroenterology clinical guidelines recommend laparoscopic fenestration based on its high success rate and low invasiveness. Percutaneous procedures for treatment of simple hepatic cysts are particularly effective for the immediate palliation of patient symptoms; however, they are not generally recommended because of the high rate of recurrence.Management of simple hepatic cysts requires correct differentiation from neoplasms and infections, and the selection of a reliable treatment.

Endovascular Re-routing the Errant Aortic Endoprosthesis

The anatomic complexity of aortic dissection remains a challenge in endovascular treatment. The dissection flap may contain defects allowing accidental guidewire passage from one lumen into the other, and inadvertent device placement into the false lumen can occur. The description of this complication and its bail-out maneuvers are sparse in the literature. Herein, we describe seven patients with errant endoprosthesis re-routed with minimally invasive intervention into the true lumen.

Reconstructive endovascular treatment of basilar artery fenestration aneurysms: A multi-centre experience and literature review

BACKGROUND

Data on outcome after endovascular treatment of basilar artery fenestration aneurysms (BAFAs) is limited. This study presents our multi-centre experience of BAFAs treated by different reconstructive techniques including coils, stent-assisted coiling (SAC), flow diversion and intra-saccular flow disruption with the Woven Endobridge (WEB).

METHODS

Retrospective analysis of 38 BAFAs treated endovascularly between 2003 and 2020. The primary endpoint was complete aneurysm obliteration defined as Raymond-Roy occlusion classification (RROC) I on immediate and follow-up (FU) angiography. The secondary endpoints were procedure-related complications, rate of re-treatment, and clinical outcome.

RESULTS

Endovascular treatment was feasible in 36/38 aneurysms (95%). The most frequent strategy was coiling (21/36, 58%), followed by SAC (7/36, 19%), WEB embolization (6/36, 17%) and flow diversion (2/36, 6%). A successful aneurysm occlusion (defined as RROC 1 and 2) on the final angiogram was achieved in 30/36 (83%) aneurysms including all patients presenting with baseline subarachnoid haemorrhage and 25/36 (69%) were occluded completely. Complete occlusion (RROC 1) was more frequently achieved in ruptured BAFAs (15/25, 60% v. 2/11, 18%; p = 0.031). Procedure-related complications occurred in 3/36 (8%) aneurysms. Re-treatment was executed in 12/36 (33%) aneurysms. After a median angiography FU of 38 months, 30/31 (97%) BAFAs were occluded successfully and 25/31 (81%) showed complete occlusion.

CONCLUSION

Reconstructive endovascular treatment of BAFAs is technically feasible with a good safety profile. Although in some cases re-treatment was necessary, a high rate of final aneurysm occlusion was achieved.

Hemodynamic effects of size and location of basilar artery fenestrations associated to pathological implications

Fenestration is a rare congenital abnormality that refers to a segmental duplication of arteries. It is still not clear about the role of fenestrations in the etiology and pathological evolution of vascular diseases. This study aims to investigate the hemodynamic influence brought by various sizes and locations of fenestration in basilar artery models. A series presumptive fenestration models were established based on a normal basilar artery model with various sizes and locations. Identical boundary conditions were utilized in the computational fluid dynamics simulations and different flow patterns in the fenestration and bifurcation regions were comprehensively analyzed. Wall shear stress (WSS)-related parameters such as oscillatory shear index (OSI) and aneurysm formation index (AFI) were computed and compared. The value of WSS on fenestration increased by the fenestration's tortuosity, and nearly-circular fenestration suffered higher WSS than narrow-strips one. Also, high OSI and low AFI value mainly occurred in the bifurcation region, indicating a high level of turbulence and high risk of aneurysm formation. The location of fenestration mainly changed the impact force of blood flow on the bifurcation and the disorder characteristics of blood flow, while the size of fenestration changed the WSS distribution on the proximal inner wall and bifurcation region of fenestration. In summary, the nearly-circular fenestration should be stratified carefully which may results in a high risk inducing unfavorable vascular wall remodeling.

Outcomes of Total Endovascular Aortic Arch Repair with Surgeon-Modified Fenestrated Stent-Grafts on Zone 0 Landing for Aortic Arch Pathologies

OBJECTIVES

This study evaluated the feasibility and safety of total endovascular aortic arch repair with surgeon-modified fenestrated stent-graft on zone 0 landing for aortic arch pathologies.

METHODS

Between June 2016 and October 2019, 37 consecutive patients underwent total endovascular arch repair with surgeon-modified fenestrated stent-grafts on zone 0 landing. Outcomes included technical success, perioperative and follow-up morbidity and mortality, and branch artery patency.

RESULTS

During the study period, 37 patients were treated with total endovascular aortic arch repair with surgeon-modified fenestrated stent-graft. Twenty-one (56.8%) patients were diagnosed with aortic dissections, 15 (40.5%) patients with aneurysms, and 1 (2.7%) patient required reintervention due to endoleak and sac expansion from previous thoracic endovascular aortic repair for thoracoabdominal aneurysm. The proximal landing zone for all patients were in zone 0, and all branch arteries of aortic arch were reconstructed. Technical success was achieved in 34 cases (91.9%). Three (8.1%) patients had fenestrations misaligned with target arteries, and the chimney technique was applied as a complementary measure. Thirty-day mortality rate was 5.4% (n=2). Thirty-day stroke rate was 5.4% (n=2). Thirty-day reintervention rate was 2.7% (n=1). At a median follow-up of 20 months (range, 3-49 months), 5 (13.5%) patients died, including 2 aortic-related deaths, 1 nonaortic-related death, and 2 deaths of unknown reason. One (2.7%) patient had stroke. Four patients (10.8%) had reintervention during the follow-up, including 2 cases of left subclavian artery occlusion and 2 cases of type II endoleak. The estimated survival (±SE) at 2 years was 72.4%±9.7% (95% CI 53.4%-91.4%). The estimated freedom from reintervention (±SE) at 2 years was 87.4%±5.9% (95% CI 75.84%-98.96%).

CONCLUSIONS

Total endovascular aortic arch repair with surgeon-modified fenestrated stent-grafts on zone 0 landing is an alternate option for the treatment of aortic arch pathologies in experienced centers.

Transcatheter creation of a pulmonary artery to left atrial fenestration in a failing Fontan circulation using the Atrial Flow Regulator (AFR)

Transcatheter creation of an interatrial communication using the Occlutech Atrial Flow Regulator Device for pulmonary hypertension or heart failure is well described. We report a case of an 8-year-old boy with a failing Fontan circulation, in whom the Atrial Flow Regulator was used to successfully create a fenestration between the pulmonary artery and left atrium, improving his clinical condition.

Endonasal Endoscopic Fenestration of Rathke's Cleft Cysts: Whether to Leave the Fenestration Open or Closed?

Introduction  Rathke's cleft cysts (RCC) are generally treated with transsphenoidal fenestration and cyst drainage. If no cerebrospinal fluid (CSF) leak is created, the fenestration can be left open. If CSF is encountered, a watertight closure must be created to prevent postoperative CSF leak, though sellar closure has theoretically been linked with higher recurrence rate. In this study, we investigate the relationship between sellar closure, rate of postoperative CSF leak, and RCC recurrence. Methods  Retrospective review of a prospective database of all endoscopic endonasal RCC fenestrations and cases were divided based on closure. The "open" group included patients who underwent fenestration of the RCC, whereas the "closed" group included patients whose RCC was treated with fat and a rigid buttress ± a nasoseptal flap. The rate of intra- and postoperative CSF leak and radiographic recurrence was determined. Results  The closed group had a higher rate of suprasellar extension (odds ratio [OR]: 8.0, p  = 0.032) and intraoperative CSF leak ( p ≤ 0.001). There were 54.8% intraoperative CSF leaks and no postoperative CSF leaks. Radiologic recurrence rate for the closed group (35.0%) was three times higher than the open group (9.1%; risk ratio [RR] = 3.85, p  = 0.203), but not powered to show significance. None of the radiologic recurrences required reoperation. Conclusion  Maintaining a patent fenestration between an RCC and the sphenoid sinus is important in reducing the rate of radiographic recurrence. Closure of the fenestration may be required to prevent CSF leak. While closure increases the rate of radiographic recurrence, reoperation for recurrent RCC is still an uncommon event.

Apical fenestration in endodontically treated teeth: A report of two cases

Root canal therapy in teeth with root fenestrations can present with pain on apical palpation or persistent pain. The signs and symptoms of root fenestration in the absence of mucosal fenestration may be misleading, which may be misdiagnosed as non-odontogenic pain. Although CBCT is superior to periapical radiographs for the diagnosis of root fenestration, it failed to detect the intact cortical plate in the middle third in our cases. Therefore, the type was different in CBCT from its actual size surgically. Repeated non-surgical root canal treatment would not alleviate pain in the presence of root fenestration and may lead to apical root fracture. Root-resection relieves pain, unless the fenestration is accompanied by fracture. The aim of these two case reports was to describe the diagnosis and treatment of endodontically treated teeth with a persistent pain. Also, the difference of root fenestration type between CBCT and its actual size was described.

Back-Table Modified Stent-Graft for Endovascular Repair of Ascending Aorta

OBJECTIVES

To investigate the effectiveness of modified stent-grafts (SGs) for the management of ascending aortic pathologies.

MATERIALS AND METHODS

From January 2015 to December 2019, 31 individuals were treated by ascending aortic endovascular repair with a back-table modified SG for acute (n=4) or chronic (n=1) type A aortic dissections, penetrating aortic ulcers (n=18), pseudoaneurysms (n=2), anastomotic fistula (n=1), and endoleaks after thoracic endovascular aortic repair (TEVAR) (n=5). The commercially available thoracic aortic SGs were modified with a fenestration or truncation technique on the back-table according to aortography during the operation.

RESULTS

The 30-day mortality and aorta-related mortality rates were 12.9% and 6.5%, respectively. There were 2 strokes, 3 respiratory insufficiencies, and 6 endoleaks during hospitalization. During a mean follow-up of 28.8±16.6 months, the overall survival rates at 1 year and 3 years were both 80.6%. Free from adverse event rates at 1 year and 3 years were 88.9% and 84.7%, respectively. There were 2 deaths during follow-up: One patient died of cachexia 1 month after discharge, and the other patient died of acute myocardial infarction 3 months after discharge. One patient with a pseudoaneurysm underwent open ascending aorta replacement 3 months after discharge for a type Ia endoleak. Another patient suffered from cerebellar infarction 17 months after discharge.

CONCLUSION

The modified SG for endovascular repair of the ascending aorta is a practicable alternative and presents acceptable outcomes in high-risk patients.

Midterm outcomes of fenestrated TEVAR using physician-modified endovascular grafts for zone 2

OBJECTIVES

To summarize the experience and midterm outcomes of physician-modified endovascular grafts for zone 2 thoracic endovascular aortic repair.

METHODS

A retrospective analysis was conducted of 51 consecutive patients (mean age 57.6 ± 12.5 years, 39 males) treated with thoracic endovascular aortic repair using physician-modified endovascular grafts for reconstructing the left subclavian artery from November 2015 to December 2019. The primary endpoints during follow-up were the overall mortality, aorta-related mortality, and major complications. The secondary endpoints were reintervention and the patency of the target branches, the demographics and technical details were also described and analyzed.

RESULTS

Sixty-three thoracic stent-grafts were deployed in 51 patients and emergency surgery was performed in 10 patients (19.6%). Technical success was 94.1% (48/51). The incidence of perioperative complications was 15.7%, and the 30-day mortality was 0%. At a mean follow-up of 42.0 ± 14.4 months (range, 14-63 months), all the left subclavian arteries remained patent. All-cause mortality was 3.9% (2/51) and not aorta-related deaths. Estimated survival at one and three years was 98.0 ± 1.9% and 96.0 ± 2.8%, respectively.

CONCLUSIONS

The physician-modified endovascular grafts is feasible and effective to preserve left subclavian artery in thoracic endovascular aortic repair for aortic arch pathologies with unhealthy proximal landing zone.

Mesenteric Malperfusion Syndromes in Type A Aortic Dissection: Current Management Strategies

Acute type A aortic dissection is a surgical emergency associated with high mortality and morbidity. When complicated with mesenteric malperfusion, its management carries a very high mortality. Many innovations in the field of vascular and cardiothoracic surgery in the last two decades have been tried in the continuous efforts to improve on the surgical outcomes. Although some reports have documented better mortality rates with reperfusion-first strategies, there is still room for improvement in the absence of a general consensus on its management.

Morphology of the temporal skull region in tetrapods: research history, functional explanations, and a new comprehensive classification scheme

The morphology of the temporal region in the tetrapod skull traditionally has been a widely discussed feature of vertebrate anatomy. The evolution of different temporal openings in Amniota (mammals, birds, and reptiles), Lissamphibia (frogs, salamanders, and caecilians), and several extinct tetrapod groups has sparked debates on the phylogenetic, developmental, and functional background of this region in the tetrapod skull. This led most famously to the erection of different amniote taxa based on the number and position of temporal fenestrae in their skulls. However, most of these taxa are no longer recognised to represent natural groupings and the morphology of the temporal region is not necessarily an adequate trait for use in the reconstruction of amniote phylogenies. Yet, new fossil finds, most notably of parareptiles and stem-turtles, as well as modern embryological and biomechanical studies continue to provide new insights into the morphological diversity of the temporal region. Here, we introduce a novel comprehensive classification scheme for the various temporal morphotypes in all Tetrapoda that is independent of phylogeny and previous terminology and may facilitate morphological comparisons in future studies. We then review the history of research on the temporal region in the tetrapod skull. We document how, from the early 19th century with the first recognition of differences in the temporal region to the first proposals of phylogenetic relationships and their assessment over the centuries, the phylogenetic perspective on the temporal region has developed, and we highlight the controversies that still remain. We also compare the different functional and developmental drivers proposed for the observed morphological diversity and how the effects of internal and external factors on the structure of the tetrapod skull have been interpreted.

Intralesional fenestration and corticosteroid injection for symptomatic Ledderhose disease of the foot: Two case reports

The description of corticosteroid injections as a treatment option for Ledderhose disease has received little attention in the literature and often only receives a passing comment in scientific papers. We present a short case series of two patients who underwent corticosteroid injection in combination with fenestration to treat painful Ledderhose disease nodules. Both patients had their lesions injected on two occasions. Significant reduction in pain and lesion volume was seen at 12 months post treatment. Our protocol combines fenestration with the use of triamcinolone acetonide (mixed with local anaesthetic) which we believe conveys further advantage over other steroid preparations or the corticosteroid infiltration alone.

The Mini-Craniotomy for cSDH Revisited: New Perspectives

Background: Chronic subdural hematomas (cSDH) are increasingly prevalent worldwide with the increased aging population and anticoagulant use. Different surgical, medical, and endovascular treatments have had varying success rates. Primary neurosurgical interventions include burr hole drainage of the cSDH and mini-craniotomies/craniotomies with or without fenestration of the inner membrane. A key assessment of the success or failure of cSDH treatments has been symptomatic recurrence rates which have historically ranged from 5 to 30%. Pre-operative prediction of the inner subdural membrane by CT scan was used to guide our decision to perform mini-craniotomies. Release of the inner membrane facilitates the expansion of the brain and likely improves glymphatic flow.

Methods: Consecutive mini-craniotomies (N = 34) for cSDH evacuation performed by a single neurosurgeon at a quaternary academic medical center/Level I trauma center from July 2018-September 2020 were retrospectively reviewed. Patient characteristics [age, gender, presenting GCS, GOS, initial CTs noting the inner subdural membrane, midline shift (MLS), cSDH width, inner membrane fenestration, cSDH recurrence, post-operative seizures, infections, length of stay] were extracted from the EMR.

Results: Twenty nine patients had mini-craniotomies as primary treatment of the cSDH. Mean age = 68.9 ± 19.7 years (range 22–102), mean pre-operative GCS = 14.5 ± 1.1, mean MLS = 6.75 ± 4.2 mm, and mean maximum thickness of cSDH = 17.7 ± 6.0 mm. Twenty four were unilateral, five bilateral, 34 total craniotomies were performed. Thirty three had inner membrane signs on pre-operative head CTs and an inner subdural membrane was fenestrated in all cases except for the one craniotomy that didn't show these characteristic CT findings. Mean operating time = 79.5 ± 26.0 min. Radiographic and clinical improvement occurred in all patients. Mean improvement in MLS = 3.85 ± 2.69. There were no symptomatic recurrences, re-operations, surgical site infections, or deaths during the 6 months of follow-up. One patient was treated for post-operative seizures with AEDs for 6 months.

Conclusion: Pre-operative CT scans demonstrating inner subdural membranes may guide one to target the treatment to allow release of this tension band. Mini-craniotomy with careful fenestration of the inner membrane is very effective for this. Brain re-expansion and re-establishment of normal brain interstitial flow may be important in long term outcomes with cSDH and may be related to the recent interests in brain glymphatics and dural lymphatics.

Surgical management of intracranial arachnoid cysts in pediatric patients: radiological and clinical outcome

OBJECTIVE

Congenital intracranial cysts account for a significant portion of intracranial lesions in the pediatric population. The efficiency of surgical treatment in a pediatric cohort with intracranial arachnoid cysts (ACs) at different locations regarding clinical symptoms and mass effect was evaluated.

METHODS

A retrospective study of all children who underwent surgical treatment of an intracranial AC during an 11-year period (2007-2018) was performed. Demographics, clinical symptoms, and radiological cyst size pre- and postoperatively, as well as the reoperation rate and possible treatment complications, were analyzed.

RESULTS

A total of 116 intracranial cysts at 8 different anatomical locations were surgically treated in 113 children (median age 5 years and 10 months) predominantly by endoscopic technique (84%). The complication rate was 3%, and the reoperation rate was 16%. Preoperative cyst enlargement was significantly more common in infants (p < 0.0001), as was the need for reoperation (p = 0.023). After a median radiological follow-up of 26 months, > 50% reduction of cyst volume was seen in 53 cysts (46%), and 47 cysts (40%) showed a 10%-50% reduction. Acute clinical symptoms improved: nausea and vomiting, accelerated head growth, and headaches improved at 100%, 92% and 89%, respectively. However, chronic symptoms responded less favorably after a median clinical follow-up of 26 months.

CONCLUSIONS

The strategy of predominantly endoscopic treatment with navigation planning is efficient to alleviate clinical symptoms and to significantly reduce the mass effect of pediatric intracranial cysts at different anatomical locations. The subgroup of infants requires close pre- and postoperative monitoring.

Gimme' the Loop: Modifications to the Squid-Capture Technique for Laser-Fenestrated Thoracic Endografting

PURPOSE

Laser-fenestrated thoracic endovascular aortic repair (LfTEVAR) in the aortic arch with covering of the left subclavian artery (LSA) orifice is challenging. To optimize fenestration, the so-called squid-capture technique has been introduced. We present here a modification to the technique that may help improve time-efficiency and safety.

TECHNIQUE:

During the originally proposed squid-capture maneuver, the stent-graft is deployed in a preset snare wire loop, which is used to pull the stent graft toward the penetration device during in-situ fenestration. In preparation, the guidewire needs to be passed through the loop inside the aortic arch, which can be difficult and may predispose for embolic events. We propose here the creation of a "guidewire-through-snare-loop" configuration outside the body, which can then be reliably transferred into the aortic arch. The modified technique was successfully applied in a patient undergoing LfTEVAR for penetrating aortic ulcers.

CONCLUSION

The proposed modification may help facilitate the squid-capture technique for LfTEVAR while saving time and resources. Given that LfTEVAR is becoming more frequently used, it is important to ensure technical success and safety of the procedure.

Left ventricular restrictive physiology in kids with atrial septal defects: Something unexpected!

Atrial septal defect (ASD) associated with left ventricular (LV) diastolic dysfunction (DD) is rare in children. DD is common in elderly patients undergoing ASD closure. Restrictive physiology among children undergoing percutaneous ASD closure is something unexpected that has not been described before in the literature. Hence, we report a child referred to our center for ASD closure in whom an LV DD has been unmasked with a balloon occlusion test and has been managed with pharmacological preconditioning and subsequent ASD closure with good outcome. Albeit rare, LV DD can occur in children undergoing ASD closure.

A Clinical Evaluation of Cone-beam Computed Tomography: Implications for Endodontic Microsurgery

INTRODUCTION

Cone-beam computed tomographic (CBCT) imaging is a valuable diagnostic tool for endodontics. Some studies report that CBCT images have limitations in representing the true clinical presentation. This prospective, in vivo study compared limited field of view (LFOV) CBCT measurements with clinical measurements made during endodontic surgery.

METHODS

Eighty-seven subjects requiring endodontic surgery and LFOV CBCT acquisition of the surgical site were enrolled. Data collection involved clinicians answering standardized questions during the radiographic and surgical assessment. Intraoperatively, data were collected and photographically documented. Postoperatively, CBCT scans were evaluated by 3 calibrated, board-certified specialists: 2 endodontists and 1 oral and maxillofacial radiologist. The 2 subsets of data were compared through statistical analysis to quantify their relationship.

RESULTS

The subjects included 65 maxillary and 29 mandibular teeth from 87 subjects: 25 women and 62 men with an average age of 42 years old. The CBCT evaluators correctly identified the presence or absence of buccal plate fenestrations with 91.0% accuracy (95% confidence interval, 83.1-96.0) with 89.4% sensitivity and 92.9% specificity. The area of fenestrations measured clinically (mean = 19.6 ± 33.4 mm²) was generally larger than the area measured by CBCT imaging (mean across CBCT evaluators = 12.2 ± 19.1 mm²). Fenestration size in the maxillary arch was more likely to be underestimated than in the mandibular arch (P < .0001). Vertical bone height was also underestimated when measured on CBCT imaging.

CONCLUSIONS

Based on the findings of this study, LFOV CBCT imaging accurately identifies the presence or absence of buccal plate fenestrations, yet, when a fenestration is present, underestimates its area.

Evaluation of facial and palatal alveolar bone thickness and sagittal root position of maxillary anterior teeth on cone beam computerized tomograms

Background

Amount of bone covering the facial and palatal surface of the root and the sagittal root position are important parameters while considering an immediate implant placement.

Aims

This study measures the distance from cement-enamel junction (CEJ) to alveolar crest and thickness of alveolar bone of maxillary anterior teeth facially and palatally at 5 different points.

Materials and Methods

CBCT scans of 79 systemically healthy patients were evaluated by two calibrated and independent examiners. Measurements like: 1) distance from CEJ to Crest. 2) Thickness of facial and palatal alveolar bone at five different points a) Crest, b) 2 mm from the crest, c) mid root level, d) apical 3^rd, e) apex. 3) Sagittal root position. 4) Labiopalatal distance at the apex. 5) Length of the bone from apex to the nasal floor for incisors. 6) Presence of fenestrations and dehiscences were assessed.

Results

Healthy maxillary anteriors were evaluated and less than 2 mm bone was seen at all five points, 0.5 to 1 mm bone is seen in all anteriors at crest, 2 mm from crest, midroot, apical 3^rd level. 1 to 2 mm is seen at apex. Labiopalatal width at apex ranged from 3 mm to 13 mm with a mean of 7.45 ± 2.24 mm for centrals, 7.69 ± 2.14 mm for lateral incisors, and 6.76 ± 2.42 mm for canines.

Conclusion

The present study supports the finding of very thin facial bone over maxillary anteriors and frequent occurrence of fenestrations and dehiscences. Pre-treatment evaluation of alveolar bone surrounding the maxillary anteriors is important to avoid complications during implant placement.

Is gelfoam sealing necessary in stapes surgery?

BACKGROUND

Sealing the oval window around the piston after fenestration with Gelfoam^® is a common practice in stapes surgery for otosclerosis.

OBJECTIVES

To analyse the effect of using or not using Gelfoam^® as a sealing material.

METHODS

A retrospective study was performed on 418 patients who underwent stapes surgery from 2013 until 2019. Data were collected from medical records in a tertiary centre. 215 cases in the Gelfoam group and 203 cases in the control group without sealing were included. The main comparisons were made between these two groups in terms of vestibular (primary outcome) and audiological outcomes and complications.

RESULTS

The patients' mean age was 47 years with a mean follow up of 50 months and a female predominance (65.6%, p = .049). There was no significant difference in terms of postoperative vertigo (11.6% vs 8.4%) or audiological outcomes in between Gelfoam and control group respectively. The average postoperative air-bone gap in the Gelfoam group was 4.6 dB vs. 5.3 dB in the control group (p = .634).

CONCLUSION AND SIGNIFICANCE

No difference were identified in vestibular or audiological outcomes during stapes surgery when using or not using Gelfoam^® in the middle ear.

The vascular endothelial growth factor signaling pathway regulates liver sinusoidal endothelial cells during liver regeneration after partial hepatectomy

INTRODUCTION

Liver regeneration after partial hepatectomy is a very complex and well-regulated procedure. It utilizes all liver cell types, which are associated with signaling pathways involving growth factors, cytokines, and stimulatory and inhibitory feedback of several growth-related signals. Liver sinusoidal endothelial cells (LSECs) contribute to liver regeneration after partial hepatectomy. Vascular endothelial growth factor (VEGF) has various functions in LSECs. In this review, we summarize the relationship between VEGF and LSECs involving VEGF regulatory activity in the vascular endothelium.

AREAS COVERED

Maintenance of the fenestrated LSEC phenotype requires two VEGF pathways: VEGF stimulated-NO acting through the cGMP pathway and VEGF independent of nitric oxide (NO). The results suggest that VEGF is a key regenerating mediator of LSECs in the partial hepatectomy model. NO-independent pathway was also essential to the maintenance of the LSEC in liver regeneration.

EXPERT OPINION

Liver regeneration remains a fascinating and significative research field in recent years. The liver involved of molecular pathways except for LSEC-VEGF pathways that make the field of liver further depth studies should be put into effect to elaborate the undetermined confusions, which will be better to understand liver regeneration.