Eosinophilic/ T cell chorionic vasculitis.

No abstract available.

Treatment of Gingival Recession Defects with Pouch and Tunnel Technique Using Connective Tissue Graft and Lyophilized Chorion Membrane in Smokers.

BACKGROUND The chorion membrane has been used for several decades as an allograft in tissue repair and various periodontal regenerative procedures. The present study, conducted at a single center in India, aimed to evaluate and compare the clinical outcomes of 26 gingival recession sites in chronic smokers treated using a pouch and tunnel technique with connective tissue graft (CTG) and lyophilized chorion membrane (LCM). MATERIAL AND METHODS The study included 22 smokers with 26 sites of recession defect, with Miller's class I and class II gingival recession, which were allotted into control and test groups. The control group (13 sites) was treated with CTG, and the test group (13 sites) was treated with LCM. Clinical parameters like recession depth, recession width, relative clinical attachment level (RCAL), relative gingival position, width of attached gingiva, and width of keratinized gingiva were recorded at baseline and 6 months postoperatively. Visual analogue scores for pain and wound-healing index scores were assessed in the first week after surgery. RESULTS All clinical parameters showed significant improvements from baseline to 6 months postoperatively in the control and test groups. Recession width, RCAL, width of attached gingiva, and width of keratinized gingiva demonstrated significant differences, whereas mean root coverage percentage and recession depth did not show any significant differences between the study groups at 6 months postoperatively. CONCLUSIONS This study supports the role of LCM allograft as a scaffold to promote soft tissue regeneration and has demonstrated a favorable role for its use in root coverage procedures in patients who smoke.

The chick embryo chorioallantoic membrane patient-derived xenograft (PDX) model.

The chick embryo chorioallantoic membrane (CAM) CAM is an extraembryonic membrane generated by the fusion of the chorion with the vascularized allantoic membrane. It performs multiple functions during embryonic development, including respiration, calcium transport from the eggshell, acid-base homeostasis, and ion/water reabsorption from the allantoic fluid. The CAM is a widely used model for the study of angiogenesis, anti-angiogenesis, tumor growth, and metastasis as well as drug efficacy. Ethical approval is omitted if experiments are terminated at embryonic day 14 in most countries, facilitating screenings of pharmacological or physics-based therapies with high reproducibility at large scales supporting the 3Rs principle. Being naturally immunodeficient, the chick embryo accepts transplantation from various tissues and species without immune response. This review article is focused on the analysis of the literature and personal data concerning the effects of patient-derived xenografts (PDX) on the CAM.

Critical Role of the Cortical Alveolus Protease Alveolin in Chorion Hardening In Vivo at Medaka Fertilization.

Alveolin is a cortical alveolus proteinase that is secreted in the perivitelline space (PVS) at fertilization to act on the chorion. Purified alveolin is known to induce chorion hardening in vitro by processing zona pellucida B (ZPB), a major chorion component. However, in vivo function of alveolin remains unclear; thus, in this study, the effects of alveolin efficiency (Alv-/-) at the organism level were investigated using the medaka, Oryzias latipes. The Alv-/- fertilized eggs were mechanically fragile; however, they developed normally and left offspring as long as they were carefully handled before hatching. A mechanical press test showed that the Alv-/- fertilized eggs were six times more fragile than the wild-type eggs. They were 35% larger owing to the enlarged PVS, 34% thinner, and permeable to even 10 kDa FITC-dextran. These results are consistent with the transmission electron microscopy observation that the periphery of the inner layers was highly porous in the Alv-/- chorion. In chorion hardening, the alveolin-mediated processing of ZPB and the transglutaminase (TGase)-mediated crosslinking of chorion components are the key steps. This study was the first to show that alveolin also processed TGase concomitantly with ZPB, which greatly facilitated the crosslinking. Thus, alveolin was concluded to be the primary trigger for chorion hardening in vivo. Furthermore, fertilization in a balanced salt solution could partially improve the impaired chorion hardening of the Alv-/- eggs fertilized in water, probably through an alveolin-independent mechanism.

Labor induction in twin pregnancies: Does the perinatal outcome differ according to chorionicity?

OBJECTIVE: To compare perinatal outcomes following induction of labor in dichorionic versus monochorionic twin pregnancies. STUDY DESIGN: A retrospective cohort study analyzing all women with twin pregnancies who underwent induction of labor in a single university-affiliated tertiary medical center. The cohort included 290 women who were divided into 2 groups according to chorionicity: (1) dichorionic twin pregnancies (n = 203); (2) monochorionic twin pregnancies (n = 87). Induction of labor methods included oxytocin infusion, extra-amniotic balloon catheter and artificial amniotomy. Primary outcome was defined as mode of delivery. Secondary outcomes included maternal and neonatal adverse events. RESULTS: Primary outcome did not differ between groups, with vaginal delivery rate of 92.1% in the dichorionic group and 94.2% in the monochorionic group. Women with dichorionic twins delivered later compared to monochorionic twins (38.00 weeks vs. 36.43 weeks, respectively, p < 0.001). While no differences were observed in Apgar scores or umbilical cord pH measurements, dichorionic twins were less frequently admitted to the neonatal intensive care unit compared to monochorionic twins (2.4% vs. 3.4%, p = 0.01 for 1st twin; and 6.9% vs. 10.3%, p = 0.089 for 2nd twin). Multivariate logistic regression adjusting outcomes to potential confounders, found gestational age at delivery to be the only variable significantly associated with neonatal intensive care unit admission rates (odds ratio 0.236, 95% confidence interval 0.152-0.366, p < 0.001). CONCLUSION: Labor induction might be considered for both di- and monochorionic uncomplicated twin pregnancies with excellent vaginal delivery rates. The higher rates of neonatal adverse outcomes among monochorionic twins are presumably related to earlier gestation age at delivery.

Pyoderma gangrenosum and dehydrated human amnion/chorion membrane: a potential tool for an orphan disease.

OBJECTIVE: Pyoderma gangrenosum (PG) is an often-misdiagnosed, painful, inflammatory and ulcerative skin disorder. It is an orphan disease, where standard wound treatments such as sharp surgical debridement are contraindicated. This retrospective case series sought to evaluate the application of dehydrated human amnion/chorion membrane (DHACM) as a skin substitute in cases that were refractory to a range of standard-of-care techniques. METHOD: This retrospective case series involved wounds which failed to close with standard escalating treatments, including anti-inflammatory and immunosuppressive therapies. Subjects were transitioned to DHACM and wound sizes were monitored until closure. RESULTS: Wounds (n=5) for all three subjects had stalled with standard therapies for at least 2.5 months but responded quickly to routinely applied DHACM treatments, and closure was achieved in each case. CONCLUSION: This retrospective pilot case series examined the use of DHACM as an alternative wound treatment for PG patients failing standard therapies. DHACM treatments re-initiated the trajectory towards wound closure for each stalled PG ulcer. The results suggest a treatment algorithm starting with early recognition, wound closure via treatment escalation, and lastly a gradual reduction in treatment for durable closure. DHACM treatment should be formally evaluated as an adjunct to PG ulcers that have remained refractory to more commonly used immunomodulating therapies.

Mesothelial fusion mediates chorioallantoic membrane formation.

In amniotic vertebrates (birds, reptiles and mammals), an extraembryonic structure called the chorioallantoic membrane (CAM) functions as respiratory organ for embryonic development. The CAM is derived from fusion between two pre-existing membranes, the allantois, a hindgut diverticulum and a reservoir for metabolic waste, and the chorion which marks the embryo's external boundary. Modified CAM in eutherian mammals, including humans, gives rise to chorioallantoic placenta. Despite its importance, little is known about cellular and molecular mechanisms mediating CAM formation and maturation. In this work, using the avian model, we focused on the early phase of CAM morphogenesis when the allantois and chorion meet and initiate fusion. We report here that chicken chorioallantoic fusion takes place when the allantois reaches the size of 2.5-3.0 mm in diameter and in about 6 hours between E3.75 and E4. Electron microscopy and immunofluorescence analyses suggested that before fusion, in both the allantois and chorion, an epithelial-shaped mesothelial layer is present, which dissolves after fusion, presumably by undergoing epithelial-mesenchymal transition. The fusion process per se, however, is independent of allantoic growth, circulation, or its connection to the developing mesonephros. Mesoderm cells derived from the allantois and chorion can intermingle post-fusion, and chorionic ectoderm cells exhibit a specialized sub-apical intercellular interface, possibly to facilitate infiltration of allantois-derived vascular progenitors into the chorionic ectoderm territory for optimal oxygen transport. Finally, we investigated chorioallantoic fusion-like process in primates, with limited numbers of archived human and fresh macaque samples. We summarize the similarities and differences of CAM formation among different amniote groups and propose that mesothelial epithelial-mesenchymal transition mediates chorioallantoic fusion in most amniotic vertebrates. Further study is needed to clarify tissue morphogenesis leading to chorioallantoic fusion in primates. Elucidating molecular mechanisms regulating mesothelial integrity and epithelial-mesenchymal transition will also help understand mesothelial diseases in the adult, including mesothelioma, ovarian cancer and fibrosis. This article is part of the theme issue 'Extraembryonic tissues: exploring concepts, definitions and functions across the animal kingdom'.

Impact of tissue porosity and asymmetry on the oxygen uptake of the human placenta: A numerical study.

INTRODUCTION: This study proposes a computational fluid dynamics model of a human placenta's independent exchange unit (placentome) to assess the effect that the inner villi distribution and decidual veins (DVs) location and number, have on the oxygen uptake. METHODS: The internal placentome porosity distribution was altered in symmetric morphology, while asymmetry was introduced by varying the location and number of DVs. The DV asymmetry was introduced by either displacing them circumferentially, thereby changing the angle between them, or by adding DVs in the inlet cross-section. The results were analyzed by the changes in the normalized oxygen mass fraction and the oxygen uptake. RESULTS: Oxygenated blood was shown to be delivered deeper into the placentome when the area of non-homogeneous porosity was larger. The largest oxygen uptake was achieved in the asymmetric model with the smallest angle distance between the DVs, where a 10% decrease relative to the farthest case was obtained. Placing DVs adjacent to the spiral artery opening enhanced the drainage of oxygenated blood. DISCUSSION: This study demonstrates the importance of the local porosity distribution for the proper perfusion of the intervillous space and proposes a novel approach to improve our understanding of the role of the DVs in placental oxygen uptake.

Triple pregnancy - etiology and early diagnosis.

OBJECTIVE: To provide an overview of the etiology and early dia-gnosis of triple pregnancy, with emphasis on the possibilities of ultrasound and magnetic resonance (MR) imaging. METHODOLOGY: Processing of data from the available literature on the issue of triple pregnancy. CONCLUSION: Spontaneous triple pregnancy conception is rare. In most cases, it is a concept associated with assisted reproduction methods. Multiple pregnancy is associated with a higher incidence of complications during pregnancy and childbirth, but it also has its own specific complications. Chorionicity and amnionicity of multiple pregnancies are two important parameters in determining the strategy of dispensary care in pregnancy and management of childbirth. The use of ultrasound and MR imaging is crucial for their accurate determination in early pregnancy.

A Multicenter, Randomized, Controlled, Clinical Trial Evaluating Dehydrated Human Amniotic Membrane in the Treatment of Venous Leg Ulcers.

BACKGROUND: This randomized controlled trial evaluated the safety and effectiveness of weekly and biweekly applications of dehydrated human amnion and chorion allograft (dHACA) plus standard of care compared to standard of care alone on chronic venous leg ulcers. METHODS: This open-label randomized controlled trial included patients with chronic venous leg ulcers at eight wound care centers across the United States. The primary endpoint was the proportion of healed ulcers at 12 weeks. Secondary endpoints included the proportion of ulcers achieving 40 percent closure at 4 weeks and the incidence of adverse events. RESULTS: Among 101 patients screened for eligibility, 60 were eligible and enrolled. At 12 weeks, significantly more venous leg ulcers healed in the two dHACA-treated groups (75 percent) than in the standard-of-care group (30 percent) ( p = 0.001) even after adjustment for wound area ( p = 0.002), with an odds ratio of 8.7 (95 percent CI, 2.2 to 33.6). There were no significant differences in the proportion of wounds with percentage area reduction greater than or equal to 40 percent at 4 weeks among all groups. The adverse event rate was 63.5 percent. Among the 38 adverse events, none were graft or procedure related, and all were resolved with appropriate treatment. CONCLUSIONS: dHACA and standard of care, either applied weekly or biweekly, significantly healed more venous leg ulcers than standard of care alone, suggesting that the use of aseptically processed dHACA is advantageous and a safe and effective treatment option in the healing of chronic venous leg ulcers. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, I.

cAMP Response Element-Binding Protein Controls the Appearance of Neuron-Like Traits in Chorion Mesenchymal Cells.

BACKGROUND: Mesenchymal stromal cells (MSC) from bone marrow have been reported to undergo the initial phases of neural differentiation in response to an increase of intracellular cAMP. We investigated the possibility that a similar effect applies to chorion-derived MSC. METHODS: The intracellular concentration of cAMP was increased either by forskolin, to promote its synthesis, or by inhibitors of its degradation. The consequent reduction in the expression of mesenchymal markers was associated with the appearance of neuron-like morphology in a subset of cells. The effect was measured and characterized using biomarkers and an inhibitor of cAMP response element-binding protein (CREB). RESULTS: The dramatic morphological change induced by all the treatments that promoted intracellular cAMP was transient and peaked on the third day. After that, cells returned to the typical fibroblast-like appearance within 24 hours. The distinctive morphology was associated to the expression of neuregulin 1, doublecortin, neuron-specific class III ß-tubulin, and required cAMP response element-binding protein activity. Basic-fibroblast growth factor (b-FGF) treatment increased both the timeframe and number of cells undergoing the morphological change induced by the effect of forskolin. As opposite, arginine-vasopressin (AVP) and sphingosine-1-phosphate (S1P) reduced it. CONCLUSIONS: We conclude that cAMP and the ensuing CREB activation trigger a preliminary step towards neuronal differentiation of chorion-derived MSC. However, likewise other MSC, the stimulus is not sufficient to promote stable differentiation.

Clinician-reported chorionicity and zygosity assignment using single-nucleotide polymorphism-based cell-free DNA: Lessons learned from 55,344 twin pregnancies.

OBJECTIVE: Prenatal chorionicity assessment relies on ultrasound, which can be confounded by many factors. Noninvasive assessment of zygosity is possible using single nucleotide polymorphism (SNP)-based cell-free DNA testing. Our objective was to determine the relationship between provider-reported chorionicity and SNP-cfDNA assignment of twin zygosity. METHODS: All twin pregnancy blood samples received by a reference laboratory between September 27, 2017 and September 8, 2021 were included. Chorionicity assignment was requested on the requisition, recorded as; monochorionic (MC), dichorionic, or "don't know". SNP-cfDNA zygosity results, monozygotic (MZ) or dizygotic (DZ), were correlated with chorionicity assignment. RESULTS: 59,471 twin samples (median gestational age = 12.0 weeks at draw) were received and analyzed; 55,344 (93.1%) received zygosity assignment. SNP-cfDNA reported 16,673 (30.1%) MZ and 38,671 (69.9%) as DZ. Provider-reported chorionicity was compared to the zygosity assignment for each case. Of 6283 provider-reported MC twins, 318 (5.1%) were reported as DZ using SNP-cfDNA. CONCLUSION(S): One in 20 suspected MC twin pregnancies were reported as DZ using SNP-cfDNA. Approximately 30% of 55,344 twin pregnancies were found to be MZ, including cases where chorionicity was unknown. SNP-cfDNA zygosity assessment is a useful adjunct assessment for twin pregnancies, particularly those reported as MC or without determined chorionicity.

The Effect of the Amnion-Chorion or Collagen Membrane as a Matrix on the Microenvironment During a Regenerative Endodontic Procedure.

INTRODUCTION: During regenerative endodontic procedures, the microenvironment of the canal is formed by the degree of disinfection and release of ions from the applied materials onto the top surface. This study aimed to characterize the effects of amnion-chorion membrane and collagen membrane on pulp-dentin regeneration compared to calcium silicate cements (CSCs), focusing on cell migration, mineralization potential, anti-inflammation, and angiogenesis. METHODS: Two CSCs and 2 membranes were used: ProRoot MTA (Dentsply, Tulsa, OK, USA), RetroMTA (BioMTA, Seoul, Korea), Collagen Membrane (Genoss, Suwon, Korea), and BioXclude (amnion-chorion membrane; Snoasis Medical, Colorado, USA). Transwell and scratch assays were used to evaluate cell migration and wound healing. Mineralization potential was evaluated using alkaline phosphatase activity, Alizarin red S staining, and quantitative real-time polymerase chain reaction for the expression of marker genes. Quantitative real-time polymerase chain reaction was used to measure the levels of angiogenic genes and inflammatory mediators. An endothelial tube formation assay was used to assess angiogenesis. RESULTS: The membranes showed superior migration and wound healing compared with CSCs. Except for RetroMTA, ProRoot MTA and the 2 membranes showed high alkaline phosphatase activity and mineralization nodule formation and upregulated mRNA expression of markers for mineralization. Membranes upregulated the mRNA of angiogenesis genes and increased the capillary tube formation of endothelial cells compared to CSCs. Furthermore, the membrane matrix decreased the expression of inflammatory genes. CONCLUSIONS: Collagen membrane and Amnion-chorion membrane showed prominent cell migration, angiogenesis, and healing effects against inflammation, as well as comparable mineralization potential compared to CSCs, recommending the use of membrane as a matrix.

Rare spontaneous monochorionic dizygotic twins: a case report and a systematic review.

BACKGROUND: Monochorionic dizygotic twins are a rare condition, mostly related to assisted reproductive technology. This type of twinning is burdened by the same risk of pregnancy complications found in monochorionic monozygotic pregnancies. CASE PRESENTATION: We report a case of spontaneous monochorionic dizygotic twins sharing situs inversus abdominalis and isolated levocardia, with only one twin affected by biliary atresia with splenic malformation syndrome. We also conducted a literature review of the 14 available documented monochorionic dizygotic twin gestations spontaneously conceived. CONCLUSIONS: It is still unclear how this unusual type of twinning can occur in spontaneous conception. The evidence so far suggest the importance to timely diagnose the chorionicity, in order to adequately manage the typical complications associated with monochorionicity.

Neurotoxicity of tetrabromobisphenol A and SiO2 nanoparticle co-exposure in zebrafish and barrier function of the embryonic chorion.

Silicon dioxide nanoparticles (n-SiO2) absorb tetrabromobisphenol A (TBBPA) and modify its bioavailability and toxicity in the aquatic phase; embryonic chorion is an efficient barrier against nanoparticles (e.g., SiO2) and influences their toxicity. However, few studies have investigated developmental neurotoxicity in fish after co-exposure to TBBPA and n-SiO2, especially considering the barrier function of the chorion. In the present study, zebrafish embryos were exposed to TBBPA (50, 100, and 200 µg/L) alone or in combination with n-SiO2 (25 mg/L) until 24 or 120 h post fertilization (hpf), in the presence and absence of the chorion. The results confirmed that TBBPA exposure alone significantly downregulated the expression of neurodevelopment marker genes (mbp, alpha-tubulin, shha, and gfap), altered acetylcholinesterase activity and acetylcholine content, and affected locomotor behavior at different developmental stages. Moreover, the results indicated that n-SiO2 promoted TBBPA-induced neurotoxic effects in zebrafish larvae at 120 hpf, including further repression of the transcription of CNS-related genes, disruption of the cholinergic system, and decrease in the average swimming speed under dark/light stimulation. However, scanning electron microscopy/energy dispersive spectroscopy analysis revealed that at 24 hpf, the embryonic chorion efficiently blocked n-SiO2 and consequently decreased the bioaccumulation of TBBPA and TBBPA-induced neurotoxicity in dechorionated zebrafish embryos. Taken together, the results demonstrate that n-SiO2 affected the bioavailability and neurodevelopmental toxicity of TBBPA, and their combined toxicity to zebrafish embryos was mitigated by embryonic chorion, which will facilitate risk assessment on n-SiO2 and TBBPA and improve understanding the function of the fish embryonic chorion.

Human chorion-derived mesenchymal stem cells suppress JAK2/STAT3 signaling and induce apoptosis of cholangiocarcinoma cell lines.

Cholangiocarcinoma (CCA) is an aggressive malignancy arising from the damaged epithelial cells of the biliary tract. Previous studies have reported that the multi-potent mesenchymal stem cells (MSCs) activate a series of tumor signaling pathways by releasing several cytokines to influence tumor cell development. However, the roles and mechanisms of human chorion-derived MSCs (CH-MSCs) in cholangiocarcinoma progression have not been fully addressed. This present study aims to examine the effects of conditioned media derived from CH-MSCs (CH-CM) on CCA cell lines and investigate the respective underlying mechanism of action. For this purpose, MSCs were isolated from chorion tissue, and three cholangiocarcinoma cell lines, namely KKU100, KKU213A, and KKU213B, were used. MTT assay, annexin V/PI analysis, and JC-1 staining were used to assess the effects of CH-CM on proliferation and apoptosis of CCA cells, respectively. Moreover, the effect of CH-CM on caspase-dependent apoptotic pathways was also evaluated. The western blotting assay was also used for measuring the expression of JAK2/STAT3 signaling pathway-associated proteins. The results showed that CH-CM suppressed proliferation and promoted apoptosis of CCA cell lines. CH-CM treatment-induced loss of mitochondrial membrane potential (∆Ψm) in CCA cell lines. The factors presented in the CH-CM also inhibited JAK2/STAT3 signaling, reduced the expression of BCL-2, and increased BAX expression in CCA cells. In conclusion, our study suggests that the CH-CM has a potent anti-cancer effect on cholangiocarcinoma cells and thus provides opportunities for use in alternative cell therapy or in combination with a conventional chemotherapeutic drug to increase the efficiency of CCA treatment.

Chorion-derived perinatal mesenchymal stem cells improve cardiac function and vascular regeneration: Preferential treatment for ischemic heart disease.

BACKGROUND: Stem cell therapy has emerged as a novel treatment for heart failure after myocardial infarction (Ml). Bone marrow-derived mesenchymal stem cells (BM-MSCs) are commonly considered because of their accessibility and usability. However, their therapeutic potential remains controversial. In our previous in vitro study, chorion-derived mesenchymal stem cells (C-MSCs) and umbilical cord-derived mesenchymal stem cells (UC-MSCs) demonstrated an ability to differentiate into cardiomyocytes and neural cells, respectively. Thus, we examined whether C-MSCs had a better differentiation potential in an MI animal model. METHODS: MI was induced by ligation of the left anterior descending artery, and DiI-labeled MSCs were injected into the border of the infarcted myocardium. The left ventricular ejection fraction (LVEF) and fractional shortening (FS) were measured using echocardiograms. Masson's Trichrome staining was performed to evaluate the viable myocardium. Alpha-sarcomeric actin (α-SA), cardiac troponin-T (cTnT), and isolectin were immunolabeled to evaluate differentiation and capillary formation. RESULTS: After 8 weeks, the LVEF and FS significantly increased to a greater extent in the C-MSC-injected group with maintenance of viable myocardium, as compared to in the control, UC-MSC-, and BM-MSC-injected groups (p < 0.05). Compared to UC-MSCs and BM-MSCs, C-MSCs significantly increased the capillary density (p < 0.05) and demonstrated higher expressions of cTnT and α-SA. CONCLUSIONS: In conclusion, compared to UC-MSCs and BM-MSCs, C-MSCs showed a better therapeutic efficacy in a rat MI model.

Title-comparison of coronally advanced flap with chorion membrane vs coronally advanced flap with connective tissue graft in the treatment of multiple gingival recessions: a split-mouth randomised controlled study.

Background: The importance of esthetics has escalated over the years. The purpose of any perioplastic surgery is to address gingival recession while ensuring predictable root coverage and a pleasing appearance. An array of surgical procedures have been recommended for the management of recession defects. The present study compares the clinical and patient related outcome measures of coronally advanced flap with chorion membrane and connective tissue graft in the management of multiple adjacent gingival recessions. Methods: The study was a prospective randomized controlled trial which included eight systemically healthy patients with an age range of 30-44 years with 36 labial/buccal, multiple adjacent, Cairo's RT1 gingival recession defects, bilaterally.  CAF+CM was performed on one side whereas CAF+CTG was performed on the other side. The two groups were compared clinically at three and six months postoperatively. Results: There was statistically significant decrease in recession depth, recession width, probing depth and clinical attachment level in both the groups from baseline to three and six months. However, intergroup comparisons revealed no statistically significant difference. At six months, both groups showed statistically significant improvements in keratinized tissue width and gingival thickness. The gingival thickness of the CAF+CM group increased significantly at three and six months. In terms of root coverage aesthetic score (RES), there was no significant difference observed between the two groups. In terms of patient reported outcome measures (PROMS), patients preferred the CAF+CM technique. Conclusion: Within the limits of the current study, the use of chorion membrane resulted in considerable root coverage and increased gingival thickness. Periodontal regeneration can be facilitated by the distinctive features of the chorion membrane. Coronally advanced flap plus chorion membrane is a novel approach for root coverage procedures.