The Immunohistochemical Expression of REV-7 in Various Human Cancer Pathology Specimens: A Systematic Review.

The purpose of this systematic review is to summarize all existing evidence, regarding the immunohistochemical expression of REV-7 in different human cancer pathology specimens. Moreover, the association of REV-7 expression with disease severity (clinical course), patients' survival, prognosis, and response to various treatments, such as chemotherapy and irradiation, was investigated. Three databases (PubMed, Scopus, and Cochrane) were systematically screened, from inception to September 2, 2023, as suggested by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Only studies using immunohistochemical staining for REV-7 in paraffin-embedded cancer tissues were included. Nine studies met the inclusion criteria and were included in the final qualitative synthesis. All nine studies were retrospective and non-comparative ones. Selected studies reported immunohistochemical expression of REV-7 in different types of cancer, including testicular cancer, ovarian cancer, esophagus squamous cell carcinoma, prostate cancer, colorectal cancer, diffuse large B-cell lymphoma, breast cancer, lung cancer, and skin cancer. High REV-7 expression was associated with faster disease progression, resistance to available treatment options, and worse prognosis in the majority of included studies. These results indicate that immunohistochemical staining of REV-7 protein could potentially be used as a predictive tissue marker in certain cases. Promising results, arising from REV-7 inactivation experiments, render REV-7 targeting a potential therapeutic strategy for future cancer management, especially in the cases of chemoresistant or radioresistant disease.

Predictive tissue markers in testicular germ cell tumors: Immunohistochemical expression of MLH1 and REV-7 proteins.

PURPOSE: Testicular Germ Cell Tumors (TGCTs) are the most frequent solid malignancies in young adult men. Regardless of differences in their cell of origin, all TGCTs are considered highly curable malignancies. However, approximately 3-5% of all TGCTs do not respond to platinum-based chemotherapies. The purpose of our paper is to investigate whether immunohistochemical expression of MLH1 and REV-7 can be used as predictive tissue markers for TGCTs. MATERIAL AND METHODS: The main demographic and clinicopathological characteristics of 64 male patients with TGCTs who underwent orchiectomy from 2007 to 2022 were retrospectively obtained from two large Oncology Clinics in Greece. Both patients with chemosensitive and chemoresistant disease were included. Immunohistochemical staining for MLH1 and REV-7 proteins was applied in specimens of these patients. RESULTS: 31 seminomas and 33 non-seminomas were included. 48 patients had chemosensitive disease, while 16 had chemoresistant disease. 53 specimens showed preserved MLH1 expression, while 11 specimens had lost MLH1 expression. Expression of MLH1 was only significantly associated with patients' age. 16 specimens showed positive REV-7 expression, while 48 specimens were REV-7 negative. Interestingly, 50% of patients with chemoresistant disease and 16,7% of patients with chemosensitive disease were REV-7 positive. This difference was statistically significant. Moreover, REV-7 positivity was significantly associated with chemoresistance, various clinicopathological parameters and patients' prognosis and survival. CONCLUSION: Loss of MLH1 expression was only found to be significantly associated with lower patients' age. Positive immunohistochemical REV-7 expression was significantly associated with various clinicopathological parameters, while it was also associated with significantly lower survival and greater hazard. REV-7 positive percentages were significantly higher in patients with chemoresistant disease. Our findings imply that immunohistochemical staining for REV-7 could potentially be used as a predictive tissue marker for TGCT tumors. Moreover, targeting of REV-7 protein, could represent a potential therapeutic strategy for chemoresistant TGCT cases. The implementation of well-designed studies on a larger scale is of utmost importance, in order to draw safer conclusions. Additional studies are needed so as to draw safer conclusions.

Evaluation of Vitamin D-enriched Bone Graft in Surgically-induced Critical-sized Bone Defects: An Experimental Study.

BACKGROUND: Restoration of bone defects in the craniac vault may require the use of autografts, allografts, xenografts, or synthetic grafts. There are promising data that vitamin D may play a positive role in graft incorporation. The purpose of the present study is the evaluation of the impact of vitamin D addition to human-derived bone grafts in the healing of critical-sized bone defects in porcine skulls. MATERIALS AND METHODS: Four identical critical-sized defects were created in the calvaria of 8 adult Landrace Large White pigs. The first defect was left blank as control, the second defect was filled with human-derived bone graft, the third defect was filled with human-derived bone graft enriched with a low concentration of vitamin D (2 mg/mL), and the fourth defect was filled with human-derived bone graft enriched with a high concentration of vitamin D (10 mg/mL). The animals were sacrificed after 12 weeks. Harvested tissue specimens were qualitatively evaluated by histology. New bone formation (bone volume/tissue volume) was quantitatively measured by histomorphometry. RESULTS: Signs of bone formation were evident in all bone sockets. Mean values of the bone volume/tissue volume of the 4 defects were 10.91%, 11.05%, 10.40% and 10.87% respectively, at 12 weeks. In 5 animals, high concentration of vitamin D caused a significant improvement in bone formation in relation to controls. In 3 animals, a high concentration of vitamin D was associated with decreased bone formation compared with controls. No statistical difference was observed in the graft healing among the 4 graft sites ( P > 0.05). CONCLUSIONS: The results of this study have shown that the addition of vitamin D to human-derived bone grafts does not have a significant effect on bone formation and graft incorporation in critical-sized bone defects of the porcine calvaria. Further high-quality studies are needed to fully elucidate the role of vitamin D in bone formation and bone graft union.

Primary immature teratoma of the thigh: a review.

Teratomas are a subtype of germ cell tumors composed of a variety of somatic tissues derived from more than one of the three germinal layers (ectoderm, endoderm and mesoderm). They can be classified as mature tumors and immature tumors. Teratomas most commonly arise at the sacrococcygeal region and the gonads. The occurrence of a teratoma outside the common gonadal and midline locations is exceptional. This review article lists the reported primary and metastatic malignant teratomas in extragonadal locations and discusses the possible explanation for the atypical location, their treatment and prognosis.

Primary Synovial Sarcoma of the Kidney: Diagnostic Approach and Therapeutic Modalities for a Rare Nosological Entity.

Synovial sarcoma (SS) is a rare mesenchymal entity that represents 5-10% among soft tissue sarcomas (STS). Primary renal synovial sarcoma (PRSS) is an uncommon, rapidly growing tumor, with potential metastatic dissemination. The main prognostic factors of PRSS include tumor size and histologic grade, while translocation t (X; 18) (p11.2; q11.2) (fusion of SYT gene -chromosome 18- with SSX genes (1, 2 or 4)-chromosome X) is the most common pathognomonic sign. Aggressive surgical resection of the tumor along with concomitant regional lymphadenectomy is the treatment of choice for PRSS, while additional en bloc resection of the adjacent affected organs is often performed. To date, the role of preoperative or postoperative chemotherapy remains equivocal. The prognosis of patients with PRSS is poor, as the 5-year survival rate is only 20-30% and further deteriorates when a high mitotic activity is detected. Local recurrence even after complete R0 surgical excision remains the most frequent cause of death. The aim of this review was to meticulously discuss clinical features, histogenesis, and morphological and immunochemical findings of PRSS, while the role of current diagnostic and therapeutic management of this aggressive neoplasm was emphasized.

Evaluating e-Learning in the Pathology Course During the COVID-19 Pandemic.

Purpose: Synchronous and asynchronous e-learning is a promising and effective educational method for the delivery of medical lessons. Due to the public health measures implemented during the COVID-19 pandemic, our Pathology Department faced the challenge of a total online transition of the lessons. Therefore, the aim is to evaluate the aspects of the applied e-learning method they received. Materials and Methods: At the end of the semester when e-learning was applied, we designed a structured questionnaire consisting of 17 items via Google Forms, which took the students between 5 and 7 minutes to complete. Of the 257 students registered on the Pathology course in the fifth semester, 207 students (80.5%) returned completed valid questionnaires. Results: Fifteen of the seventeen components of the e-learning Pathology questionnaire were evaluated highly by the vast majority of the students. The two remaining items, the HIPON platform and the Microlabs e-lessons, were evaluated highly by almost half the students. Approximately 93% of medical students answered that e-learning could be integrated with real class lessons in the medical curriculum: 62.8% (N = 130) of students answered to a great extent, and 30.4% (N = 63) answered to a small extent. Statistically significant differences were found between the demographic characteristics of the participants (gender, permanent residence, working status) and their evaluation of the e-learning items. Conclusion: E-learning was successfully implemented for the delivery of the pathology lessons and was widely accepted by the students, providing evidence for its future integration into the medical curriculum. Our findings illuminate various aspects of the students' experience with e-learning, and we strongly recommend that the students' evaluation and perspective be taken into consideration by the faculty in the development of policies for higher-quality medical education.

Polycystin-1 regulates cell proliferation and migration through AKT/mTORC2 pathway in a human craniosynostosis cell model.

Craniosynostosis is the premature fusion of skull sutures and has a severe pathological impact on childrens' life. Mechanical forces are capable of triggering biological responses in bone cells and regulate osteoblastogenesis in cranial sutures, leading to premature closure. The mechanosensitive proteins polycystin-1 (PC1) and polycystin-2 (PC2) have been documented to play an important role in craniofacial proliferation and development. Herein, we investigated the contribution of PC1 to the pathogenesis of non-syndromic craniosynostosis and the associated molecular mechanisms. Protein expression of PC1 and PC2 was detected in bone fragments derived from craniosynostosis patients via immunohistochemistry. To explore the modulatory role of PC1 in primary cranial suture cells, we further abrogated the function of PC1 extracellular mechanosensing domain using a specific anti-PC1 IgPKD1 antibody. Effect of IgPKD1 treatment was evaluated with cell proliferation and migration assays. Activation of PI3K/AKT/mTOR pathway components was further detected via Western blot in primary cranial suture cells following IgPKD1 treatment. PC1 and PC2 are expressed in human tissues of craniosynostosis. PC1 functional inhibition resulted in elevated proliferation and migration of primary cranial suture cells. PC1 inhibition also induced activation of AKT, exhibiting elevated phospho (p)-AKT (Ser473) levels, but not 4EBP1 or p70S6K activation. Our findings indicate that PC1 may act as a mechanosensing molecule in cranial sutures by modulating osteoblastic cell proliferation and migration through the PC1/AKT/mTORC2 cascade with a potential impact on the development of non-syndromic craniosynostosis.

Giant Sclerosing Epithelioid Fibrosarcoma of the Thigh: A Case Report.

CASE: We present a case of a 35-year-old-man with a giant sclerosing epithelioid fibrosarcoma (SEF) of the thigh. The patient presented with a history of a painful thigh mass. Plain radiographs revealed a soft-tissue mass with extensive calcifications, whereas on magnetic resonance imaging, a lobulated mass between the adductors and the posterior muscles of the thigh was noted. A wide en block resection was undertaken, and the histopathology confirmed the diagnosis of SEF. Postoperative radiation therapy was followed. The patient had no signs of recurrence at the 4-year follow-up. CONCLUSION: The clinicopathological, imaging characteristics, and treatment options of this rare soft-tissue tumor are discussed.

c-Fos/ c-Jun transcription factors in non-small cell lung carcinoma.

During lung carcinoma development, progression and metastasis, a variety of gross (chromosome) and specific (gene) genomic alterations are detected in dysplastic, neoplastic, and progressively malignant transformed epithelia as early or late genetic events. Oncogenes' overactivation combined with suppressor genes silence are crucial genetic events in malignant and pre-malignant epithelia. Especially, deregulation of crucial signalling transduction pathways that interact with strong transcription factors - such as c-Fos and c-Jun - leads to an aberrant expression of other critical genes responsible for cell homeostasis. Upregulation of c-Fos and c-Jun leading to other oncogenes overactivation seems to be correlated with aggressive biological behaviour in non-small cell lung carcinomas (NSCLCs). In the current special molecular article we explored the role of c-Fos/c-Jun complex deregulation in NSCLC based on their interactions with other genes that demonstrate modified expression profiles.

Osseous Healing in Surgically Prepared Bone Defects Using Different Grafting Materials: An Experimental Study in Pigs.

Regeneration of large jaw bone defects still remains a clinical challenge. To avoid incomplete bone repair, bone grafts have been advocated to support the healing process. This study comparatively evaluated new bone formation among a synthetic graft substitute, a human bone derivative, and a bovine xenograft. Materials were placed in 3 out of the 4 bone cavities, while 1 deficit was left empty, serving as a control, in mono-cortical defects, surgically prepared in the porcine calvaria bone. Animals were randomized in 2 groups and euthanized at 8 and 12 weeks. Harvested tissue specimens were qualitatively evaluated by histology. New bone formation was quantitatively measured by histomorphometry. Maximum new bone formation was noticed in defects grafted with beta-tricalcium phosphate b-TCP compared to the other bone substitutes, at 8 and 12 weeks post-surgery. Bovine and human allograft induced less new bone formation compared to empty bone cavity. Histologic analysis revealed that b-TCP was absorbed and substituted significantly, while bovine and human allograft was maintained almost intact in close proximity with new bone. Based on our findings, higher new bone formation was detected in defects filled with b-TCP when compared to bovine and human graft substitutes.

The effect of experimental periodontitis, experimental diabetes and their combination on the serum levels of adiponectin, leptin, IL-6, IL-18, MCP-1, RANTES and sICAM-1 in rats.

AIM: Periodontitis is often associated with diabetes mellitus and may be considered one of the chronic complications of this disease. Increasing evidence indicates that periodontal disease (gingivitis and periodontitis) has an adverse effect on glycemic control and participates in the pathophysiology of complications related to type 2 diabetes mellitus. Thus, this study aimed to evaluate the influence of obesity on clinical periodontal parameters of patients with type 2 diabetes mellitus with stage II or III periodontitis grade C after conventional periodontal treatment. METHODS: For this study, 36 patients, aged 25 to 65 years, were evaluated; 20 patients with type 2 diabetes mellitus and moderate to severe periodontitis (Non-Obese Group) and 16 patients with type 2 diabetes mellitus with obesity and moderate to severe periodontitis (Obese Group). These patients underwent conventional periodontal treatment and were evaluated using plaque index, probing depth, clinical attachment level, bleeding on probing and gingival crevicular fluid analysis, as well as laboratory tests of glycated hemoglobin, fasting glycemia, total cholesterol, and fractions of triglycerides. Periodontal and laboratory parameters were evaluated at baselineand six months. RESULTS: The results showed improvements in periodontal and clinical laboratory parameters(p less than 0.05) in the evaluated periods; however, the non-obese group presented significantly better results when compared to the obese group. CONCLUSION: It can be concluded that the presence of obesity may hinder the improvement of periodontal clinical parameters after conventional periodontal treatment in patients with diabetes mellitus and periodontitis.

A Clinicopathological Analysis of S100A14 Expression in Colorectal Cancer.

BACKGROUND/AIM: The calcium-binding protein S100A14 is involved in processes related to tumorigenesis and tumor propagation, such as proliferation, apoptosis, motility and invasiveness. Our aim was to investigate its role in colorectal cancer. PATIENTS AND METHODS: One hundred and seven patients (65 men and 42 women) were included in this study. They had been diagnosed with colorectal cancer and undergone complete resection of their primary tumor. Tissue samples from archival blocks of their normal and malignant colorectal tissues were used for immunohistochemical assessment of S100A14 expression. S100A14 levels were evaluated using image analysis and associated with various clinicopathological parameters and prognosis. RESULTS: S100A14 expression was reduced in malignant tissues when compared to normal intestinal mucosa in cases of T3-T4 tumors (p=0.017). Moreover, as far as S100A14 levels in malignant tissues are concerned, they were lower in T3-T4 tumors (p=0.001), N2 disease (p=0.034) and M1 disease (p=0.019). Finally, very high S100A14 production (>75th percentile) was associated with shorter disease-specific (HR=3.584, p=0.045) and relapse-free survival (HR=4.527, p=0.007) in multivariate survival analysis. CONCLUSION: S100A14 expression is decreased in advanced colorectal cancer. However, cases with very high S100A14 levels have a worse survival.

CRH Promotes the Neurogenic Activity of Neural Stem Cells in the Adult Hippocampus.

Local cues in the adult neurogenic niches dynamically regulate homeostasis in neural stem cells, whereas their identity and associated molecular mechanisms remain poorly understood. Here, we show that corticotropin-releasing hormone (CRH), the major mediator of mammalian stress response and a key neuromodulator in the adult brain, is necessary for hippocampal neural stem cell (hiNSC) activity under physiological conditions. In particular, we demonstrate functionality of the CRH/CRH receptor (CRHR) system in mouse hiNSCs and conserved expression in humans. Most important, we show that genetic deficiency of CRH impairs hippocampal neurogenesis, affects spatial memory, and compromises hiNSCs' responsiveness to environmental stimuli. These deficits have been partially restored by virus-mediated CRH expression. Additionally, we provide evidence that local disruption of the CRH/CRHR system reduces neurogenesis, while exposure of adult hiNSCs to CRH promotes neurogenic activity via BMP4 suppression. Our findings suggest a critical role of CRH in adult neurogenesis, independently of its stress-related systemic function.

Lazaroid U-74389G in liver ischemia-reperfusion injury: A swine model.

Reactive oxygen species have a key role in liver ischemia-reperfusion (I/R) injury. In the present study, the effect of the anti-oxidant compound lazaroid U-74389G in preventing liver I/R injury was investigated in a swine model. Ischemia was produced by portal vein occlusion. Two sets of experiments were performed, each with two groups (n=7 per group). In the first group, the potential protective effect of an intracaval injection of U-74389G after a 30-min ischemia, followed by a 60-min reperfusion period was assessed (biopsies at 0, 15, 30 and 90 min experimental time). In the second set, the effect of intracaval U-74389G injection after 30 min of ischemia, followed by a longer reperfusion period of 120 min was determined (biopsies at 0, 15, 30 and 150 min experimental time). Liver malondialdehyde, hepatocyte vacuolation-degeneration, venous congestion, inflammatory cell infiltration, sinus congestion-dilation and Chiu score of intestinal damage were determined at up to 150 min of reperfusion. In the second set of experiments, the Chiu score of intestinal damage was improved by the administration of U-74389G (3.17±0.40 vs. 4.33±0.21; P=0.030). However, in the two sets of experiments, the liver inflammatory reaction was more pronounced in the U-74389G groups (P=0.017 for the first set, P=0.021 for the second set). No significant effect of U-74389G on any other parameters was detected. In conclusion, intestinal damage due to portal venous congestion and reflow appears to be mitigated by the lazaroid U-74389G; however, intracaval administration of U-74389G does not appear to exert any protective effects against liver I/R-induced inflammation.

Recurrent aggressive mesenteric desmoid tumor successfully treated with sorafenib: A case report and literature review.

BACKGROUND: Desmoid tumors (DT) are locally advanced but histologically benign monoclonal neoplasms that can occur from any musculoaponeurotic structure. The aim of this report is to analyze a rare clinical case of an aggressive intra-abdominal DT successfully treated with sorafenib. CASE SUMMARY: A 36-year-old man presented with increasing colicky abdominal pain and a self-palpable mass in his left abdomen. Fourteen years earlier he was diagnosed with a large intra-abdominal tumor, which adhered to the left colonic flexure, part of the major gastric curvature and the spleen. Subsequent exploratory laparotomy revealed a voluminous mass in the epigastrium, arising from the posterior surface of the stomach and invading the superior mesenteric vessels, transverse mesocolon and the small bowel mesentery. As the tumor was unresectable, a jejunojejunal bypass was performed. Traditional therapeutic interventions proved insufficient, and the patient was started on sorafenib with a subsequent full-disease response. CONCLUSION: DT's pathogenesis has been associated with mutations in the adenomatous polyposis coli (APC) gene or beta-catenin gene CTNNB1, sex steroids or previous surgical trauma. Local treatment modalities, such as surgery or radiotherapy, are implemented in aggressively progressing or symptomatic patients. Sorafenib is a hopeful therapeutic option against DTs, while several pharmacological agents have been successfully used.

Management of primary retroperitoneal synovial sarcoma: A case report and review of literature.

BACKGROUND: Synovial sarcoma (SS) is a rare type of soft tissue sarcoma that is usually developed from areas where synovial tissue exists, especially at the extremities. Nevertheless, several cases of retroperitoneal SS (RSS) have been described. We herein report a case of RSS presented in our institution. CASE SUMMARY: A 69-year-old female patient was admitted with a large, palpable, firm mass in the right abdominal space SS. Computerized tomography scan depicted a concentric, sharply marinated retro-peritoneal lesion which was displacing the right kidney and the lower edge of the liver. Subsequently, the patient underwent surgical excision of the mass with additional right nephrectomy and resection of the right adrenal gland and a part of the diaphragm. The final histological diagnosis of the tumour was grade II monophasic RSS. CONCLUSION: RSS is encountered in the biphasic type, the monophasic fibrous, and the monophasic epithelial category as well. Relevant clinical manifestations are not always documented at early stages. Therefore, the final diagnosis is posed after complete histological examination taking into consideration the results of immunochemistry and genetic analysis. Therapeutic approach happens often late when metastases at the lungs and the liver are apparent. Thus, 5-year survival rates remain low.

Collision Tumors of the Gastrointestinal Tract: A Systematic Review of the Literature.

BACKGROUND/AIM: Collision tumors are rare neoplasms which consist of two or more distinct neoplasms that develop adjacent to one another and coexist with no or minimal intermingling between them. Their diagnosis is often incidental and their behavior remains widely unknown. Several theories have been proposed regarding their pathogenesis. The objective of this study was the evaluation of current evidence on collision tumors of the gastrointestinal tract regarding their pathology, biological behavior and treatment approach. MATERIALS AND METHODS: The PubMed and Cochrane bibliographical databases were searched from January 1997 to July 2018 (last search: July 5th, 2018) for studies reporting on collision tumors of the gastrointestinal tract that also included a therapeutic approach. RESULTS: Forty-seven studies reporting on collision tumors of the gastrointestinal tract were identified. They reported collectively on 53 cases (43 males, 10 females) with collision tumors of the esophagus, stomach, small intestine and large intestine. The vast majority (96.2%) of tumors consisted of two distinct histological components and only two cases involved a greater number of histological subtypes. Fifty-one patients underwent a surgical or endoscopic tumor resection, accompanied in 22 cases by adjuvant or neoadjuvant therapy. The remaining two patients underwent palliative operations. In total, three patients experienced immediate postoperative complications. CONCLUSION: Collision tumors of the gastrointestinal tract, despite their rare nature, constitute a quite interesting field of study. This review offers a thorough insight into the clinicopathological characteristics and biological behavior of these rare tumors.

Computational imaging of aortic vasa vasorum and neovascularization in rabbits using contrast-enhanced intravascular ultrasound: Association with histological analysis.

OBJECTIVE: Neoangiogenesis is pathophysiologically related to atherosclerotic plaque growth and vulnerability. We examined the in vivo performance of a computational method using contrast-enhanced intravascular ultrasound (CE-IVUS) to detect and quantify aortic wall neovascularization in rabbits. We also compared these findings with histological data. METHODS: Nine rabbits were fed with a hyperlipidemic diet. IVUS image sequences were continuously recorded before and after the injection of a contrast agent. Mean enhancement of intensity of a region of interest (MEIR) was calculated using differential imaging algorithm. The percent difference of MEIR before and after the injection of microbubbles (d_MEIR) was used as an index of the density of plaque or/and adventitial neovascularization. Aortic segments were excised for histological analysis. RESULTS: CE-IVUS and histological analysis were performed in 11 arterial segments. MEIR was significantly increased (~20%) after microbubble injection (from 8.1±0.9 to 9.7±1.8, p=0.016). Segments with increased VV/neovessels in the tunica adventitia (histological scores 2 and 3) had significantly higher d_MEIR compared with segments with low presence of VV/neovessels (score 1); 40.5±22.9 vs. 8±14.6, p=0.024, respectively. CONCLUSION: It is possible to detect VV or neovessels in vivo using computational analysis of CE-IVUS images, which is in agreement with histological data. These findings may have critical implications on vulnerable plaque assessment and risk stratification.

Evaluation of an In Situ Hardening ß-Tricalcium Phosphate Graft Material for Alveolar Ridge Preservation. A Histomorphometric Animal Study in Pigs.

The purpose of this study was to investigate the effectiveness of a resorbable alloplastic in situ hardening bone grafting material for alveolar ridge preservation in a swine model. Seven Landrace pigs were used. In each animal, the maxillary left and right deciduous second molars were extracted, and extraction sites were either grafted with a resorbable alloplastic in situ hardening bone substitute, composed of beta-tricalcium phosphate (ß-TCP) granules coated with poly(lactic-co-glycolic) acid (PLGA), or left unfilled to heal spontaneously. Animals were euthanized after 12 weeks, and the bone tissue was analyzed histologically and histomorphometrically. Linear changes of ridge width were also clinically measured and analyzed. Pronounced bone regeneration was found in both experimental and control sites, with no statistically significant differences. At the experimental sites, most of the alloplastic grafting material was resorbed and remnants of the graft particles were severely decreased in size. Moreover, experimental sites showed, in a statistically nonsignificant way, less mean horizontal dimensional reduction of the alveolar ridge (7.69%) compared to the control sites (8.86%). In conclusion, the ß-TCP/PLGA biomaterial performed well as a biocompatible resorbable in situ hardening bone substitute when placed in intact extraction sockets in this animal model.