The IL-1ß-p65 axis stimulates quiescent odontogenic epithelial cell rests via TGF-ß signalling to promote cell proliferation of the lining epithelia in radicular cysts: A laboratory investigation.

AIM: Cyst formation of the jaws is frequently accompanied by the proliferation of odontogenic epithelial cells located in the periodontal ligament (PDL), which consists of heterozygous cells and includes the most fibroblasts. The lining epithelium of radicular cyst, an odontogenic cyst of inflammatory origin, is derived from the proliferation of the remnants of the Hertwig epithelial root sheath (odontogenic epithelial cell rests of Malassez; ERMs) in the PDL. ERMs are maintained at a lower proliferative state under physiological conditions, but the regulatory mechanisms underlying the inflammation-dependent enhanced-proliferative capabilities of ERMs are not fully understood. The aim of this study was to evaluate the effects of cytokine pathway association between TGF-ß signalling and IL-1ß signalling on the regulation of odontogenic epithelial cell proliferation using radicular cyst pathological specimens and odontogenic epithelial cell lines. METHODOLOGY: Immunofluorescence analyses were performed to clarify the expression levels of Smad2/3 and Ki-67 in ERMs of 8-week-old mouse molar specimens. In radicular cyst (n = 52) and dentigerous cysts (n = 6) specimens from human patients, the expression of p65 (a main subunit of NF-κB), Smad2/3 and Ki-67 were investigated using immunohistochemical analyses. Odontogenic epithelial cells and PDL fibroblastic cells were co-cultured with or without an inhibitor or siRNAs. Odontogenic epithelial cells were cultured with or without TGF-ß1 and IL-1ß. The proliferative capabilities and Smad2 phosphorylation levels of odontogenic epithelial cells were examined. RESULTS: Immunohistochemically, Smad2/3-positivity was increased, and p65-positivity and Ki-67-positivity were decreased both in ERMs and in the epithelial cells in dentigerous cysts, a non-inflammatory developmental cyst. In contrast, p65-positive cells, along with the expression of Ki-67, were increased and Smad2/3-positive cells were decreased in the lining epithelia of radicular cysts. Co-culture experiments with odontogenic epithelial cells and PDL fibroblastic cells revealed that PDL cells-derived TGF-ß1/2 and their downstream signalling suppressed odontogenic epithelial cell proliferation. Moreover, TGF-ß1 stimulation induced Smad2 phosphorylation and suppressed odontogenic epithelial cell proliferation, while IL-1ß stimulation reversed these phenotypes through p65 transactivation. CONCLUSIONS: These results suggest that IL-1ß-p65 signalling promotes odontogenic epithelial cell proliferation through suppressing TGF-ß-Smad2 signalling, which would be involved in the pathogenesis of radicular cysts.

Assessment of bone regeneration after maxillary radicular cyst enucleation with or without bone grafting materials: a retrospective cohort study.

OBJECTIVE: The limitations of spontaneous bone healing underscore the necessity for exploring alternative strategies to enhance bone regeneration in maxillary radicular cyst cases. This retrospective study aimed to assess the impact of a bone substitute material (i.e., Bio-Oss) on bone volume regeneration following maxillary radicular cyst enucleation using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: Seventy-three patients with maxillary radicular cysts were divided into two groups: one undergoing guided bone regeneration (GBR) with Bio-Oss and absorbable collagen membrane (n = 35), and the other receiving cyst excision alone (n = 38). Volumetric measurements using Amira software on CBCT scans evaluated bone regeneration, with cystic lesion shrinkage rates calculated. Intergroup comparisons utilized independent sample t-tests (P < 0.05), and linear regression analysis assessed the influence of preoperative cyst volume and group on bone healing. RESULTS: Both groups showed similar success rates in bone formation at the 12-month follow-up, with no significant differences between them (mean (SD), control: 75.16 (19.17) vs. GBR: 82 (20.22), P > 0.05). Linear regression analysis revealed a negative correlation between preoperative cyst volume and bone regeneration in both groups (P < 0.05). CONCLUSION: Bio-Oss may not significantly enhance bone augmentation in maxillary radicular cysts. In addition, preoperative cyst volume negatively affected the shrinkage rate of cystic lesions. CLINICAL RELEVANCE: Clinicians should consider patient-specific factors such as anatomy and lesion size when determining the need for bone substitute materials. Future research could focus on optimizing treatment protocols and alternative regenerative strategies to improve patient outcomes in maxillary cyst cases.

Differentiation of radicular cysts and radicular granulomas via texture analysis of multi-slice computed tomography images.

OBJECTIVES: This study aimed to establish a method for differentiating radicular cysts from granulomas via texture analysis (TA) of multi-slice computed tomography (CT) images. METHODS: A total of 222 lesions with multi-slice computed tomography images acquired at our hospital between 2013 and 2022 that were pathologically diagnosed were included in this study. Cases of contrast-enhanced images, severe metallic artefacts, and lesions that were not sufficiently large to be analysed were excluded. The images were chronologically divided into a training group and a validation group. The radiological characteristics were determined. Subsequently, a TA was performed. Pyradiomics software was used for the TA of three-dimensionally segmented volumes extracted from 2 mm slice thickness images with a soft-tissue algorithm. Features that differed significantly between the two lesions in the training group were extracted and used to create machine-learning models. The discriminative ability of these models was evaluated in the validation group using receiver operating characteristic curve analysis. RESULTS: A total of 131 lesions, comprising 28 radicular cysts and 103 granulomas, were analysed. Forty-three texture features that exhibited significant variations were extracted. A support vector machine and decision tree model, with areas under the curves of 0.829 and 0.803, respectively, were created. These models showed high discriminative abilities, even for the validation group, with areas under the curve of 0.727 and 0.701, respectively. Both models showed superior performance compared with that of the models based on radiographic findings. CONCLUSION: Discriminatory models were established for the TA of radicular cysts and granulomas using CT images.

CITED1 expression in odontogenic cysts.

BACKGROUND: Originating from odontogenic tissue, Odontogenic cysts are pathological cavities lined with epithelial cells and surrounded by fibrous connective tissue. This study investigated expression of CITED1 protein in different types of odontogenic cysts. MATERIAL AND METHOD: 40 keratocysts, 40 radicular cysts, and 40 dentigerous cysts were excised and processed for routine paraffin wax embedding protocol. Macroscopic and panoramic radiographies images were used for diagnosis. Demographical properties and dental parameters were recorded. Cystic tissues were stained with hematoxylin-eosin dye and CITED1 antibody. Semi-quantitative analysis was performed for immune staining. The protein-protein interaction network, hub gene detection and KEGG analysis were conducted using Cytoscape software. RESULT: Odontogenic keratocysts was imaged with 6-8 layered epithelial cells and fibrous cyst walls with inflammatory cells. Radicular cysts had stratified squamous epithelium with varying thickness, ciliated cells, and Rushton hyaline bodies. Dentigerous cysts presented hyperplastic non-keratinized epithelium, fibrous tissue, rete ridges, and inflammatory cells. CITED1 immunoexpression was highest in odontogenic keratocysts, followed by radicular cysts, and lowest in dentigerous cysts. Nuclear and cytoplasmic CITED1 expression was significantly elevated in odontogenic keratocysts compared to radicular and dentigerous cysts. The top five targets of CITED1 were identified, primarily showing enrichment in hormone and cancer related pathways. CONCLUSIONS: Positive CITED1 expression in all three types of odontogenic cysts suggest a potential role for CITED1 in the pathogenesis of odontogenic cysts, particularly in keratocysts. Further investigations are needed to elucidate the exact mechanisms underlying the differential expression of CITED1 and its implications for the development and progression of odontogenic cysts.

Immunohistochemical expression of SPARC in odontogenic keratocysts: a comparative study with other odontogenic cysts.

BACKGROUND: Secreted protein acidic and rich in cysteine (SPARC) has been shown to modulate aggressive behavior in several benign and malignant tumors. Little is known about SPARC expression in odontogenic keratocyst (OKC), an odontogenic cyst with an aggressive nature. To the best of our knowledge, only one study has been investigated the expression of this protein in OKCs. This study aimed to characterize SPARC expression in OKCs. Additionally, to determine whether SPARC is associated with aggressive behavior in OKCs, SPARC expression in OKCs was compared with radicular cysts (RCs), dentigerous cysts (DCs) and calcifying odontogenic cysts (COCs). These odontogenic cysts showed no or less aggressive behavior. METHODS: SPARC expression was evaluated in 38 OKCs, 39 RCs, 35 DCs and 14 COCs using immunohistochemistry. The percentages of positive cells and the intensities of immunostaining in the epithelial lining and the cystic wall were evaluated and scored. RESULTS: Generally, OKCs showed similar staining patterns to RCs, DCs and COCs. In the epithelial lining, SPARC was not detected, except for ghost cells in all COCs. In the cystic wall, the majority of positive cells were fibroblasts. Compared between 4 groups of odontogenic cysts, SPARC expression in OKCs was significantly higher than those of RCs (P < 0.001), DCs (P < 0.001) and COCs (P = 0.001). CONCLUSIONS: A significant increase of SPARC expression in OKCs compared with RCs, DCs and COCs suggests that SPARC may play a role in the aggressive behavior of OKCs.

Periapical foreign body findings - histological and radiological comparison.

OBJECTIVE: This study aimed to clarify the perceptibility of periapical foreign materials in imaging compared with histopathology. We hypothesized that dentoalveolar imaging is sufficient to detect periapical foreign bodies. MATERIAL AND METHODS: Radiological and histopathological records of patients diagnosed with periapical granuloma or radicular cyst from 2000 to 2013 were evaluated retrospectively. Patients with histologically verified foreign bodies were included in the study and their pathological samples and radiological images were reviewed. The outcome variable was radiologically detectable foreign material. The predictor variables were histopathological diagnosis, type of inflammation, type and number of foreign bodies, imaging modality, and site of foreign material. RESULTS: Compared to the histopathological diagnosis of foreign bodies as the gold standard, the level of radiologic detectability was mild. Histologically verified foreign material could be detected by imaging in 32/59 (53.5%) patients. Histological diagnosis, type of inflammation, type or number of foreign bodies, imaging modality or site of foreign material had no association with radiological detectability (p > 0.05). CONCLUSIONS: According to our results, histopathology is a more accurate diagnostic tool than radiology in periapical foreign bodies or foreign body reactions. Clinicians should keep in mind the limitations of imaging when setting the diagnosis and planning treatment.

[Treatment tactics for patients with retention cysts, odontogenic cysts, mucocele and other pathologies of the maxillary sinuses as preparation for a sinus lift]. / Lechebnaya taktika v otnoshenii retentsionnykh kist, odontogennykh kist, mukotsele i drugikh zabolevanii verkhnechelyustnoi pazukhi pri podgotovke k sinus-liftingu.

OBJECTIVE: The aim the studi. Differential diagnosis of retention cysts of the maxillary sinus with odontogenic cysts, acute and chronic sinusitis, aspergillosis, and mucocele in preparation for sinus-lifting surgery. MATERIAL AND METHODS: The analysis of the case histories of 265 patients aged 18-65 years of both sexes who were treated at the dental clinic «Rudenta Family¼ from 2016 to 2021 was carried out. On the basis of clinical symptoms and data of cone-beam computed tomography (CBCT), a description of the pathologies of HPV is given for the purpose of differential diagnosis and correct interdisciplinary interaction with ENT doctors for the purpose of dental implantation in the lateral parts of the upper jaw. RESULTS: In 90 (out of 265) patients (34%), a change in the condition of the maxillary sinus mucosa was detected. 18 patients (7%) for preoperative preparation were sent to the ENT department of the FSBI «CCB with polyclinic¼ of the UDP of the Russian Federation with diagnoses: chronic maxillary sinusitis of various etiologies and mucocele. In this group of patients, sinus lifting followed by dental implantation was performed 6 months after endoscopic maxillofacial surgery under the control of CBCT. Retention cyst Retention cysts of the maxillary sinus were of different sizes in 62 (23.4%) patients and, depending on the size and localization of the sinus-lifting was performed with simultaneous removal of the cyst, or without removal of the cyst. CONCLUSION: Retention cysts do not need to be removed as a preoperative preparation for sinus lifting. In the case of large sizes and difficulty in peeling the Schneider membrane, retention cysts are removed by a dental surgeon during antral augmentation as one of the stages of the operation. In such pathologies as odontogenic cyst, acute and chronic sinusitis, aspergillosis, mucocele, interdisciplinary interaction of ENT doctor and dentist is necessary. Differential diagnosis of maxillary snus pathology is carried out on the basis of clinical data and a picture of cone-beam computed tomography.

Surgical and prosthodontics management of a perforating giant radicular cyst in anterior maxilla: A case report.

Radicular cyst is the most common type of odontogenic cyst associated with the apex of non-vital teeth. The lining of the radicular cyst usually arises from the epithelial rests of Malassez. These cyst usually persists even after the elimination of microbial load from the root canals. Surgical removal is deemed necessary for the management. For larger lesions extending to the facial or palatal cortical plates, additional regenerative procedures such as bone grafting along with collagen membrane are warranted. This case report describes the surgical and prosthetic management of a giant radicular cyst that was perforating the cortical plates in the anterior maxilla.

Preserving the vitality of teeth adjacent to a large radicular cyst in periapical microsurgery: a case report with 4-year follow-up.

BACKGROUND: Radicular cysts may enlarge considerably, cause extensive bone destruction, and jeopardize the integrity of the associated vital teeth. The different treatment approaches are aimed mainly at eliminating the cystic epithelial membrane while reducing the risk of injury to vital structures. Contrary to other treatment modalities, preapical surgery offers an unequivocal single occasion resolution for the patient. However, it has been associated with higher risk of collateral damages. CASE PRESENTATION: A patient presented with a large radicular cyst originating from a maxillary lateral incisor. The adjacent central and canine teeth initially failed to exhibit responses to sensibility tests but showed signs of vitality. Microsurgical management was aimed at enucleating the cystic membrane while maintaining adjacent teeth vitality. Upon careful and controlled cyst enucleation under the dental operating microscope, the neurovascular bundle of one of the involved teeth was visualized and its integrity was maintained throughout the procedure. RESULTS: The procedure was successful and follow up recalls revealed recovery of normal sensibility of tooth 11 and 13 with complete bone regeneration around their apices. CONCLUSION: Within the limitation of the present case report, we demonstrated that complete excision of large periapical cyst can be performed without sacrificing the vitality of the adjacent teeth, by preserving the integrity of their neurovascular supply through controlled microsurgical enucleation, and by a potential apical vascular repair ensuing unintended injury. Diagnosing the pulp vitality of non-offending teeth whose apices protrude into the cystic lumen is a complex process and can be misleading. Pressure from the growing cyst can inhibit vital teeth responses to neural-based sensibility tests leading to false negative results. Thus, in such cases, the use of blood perfusion-based vitality testing is recommended for correct initial diagnosis.

Immunohistochemical analysis of ADAMTS-1, versican and pEGFR expressions in periapical granuloma and radicular cyst.

BACKGROUND: ADAMTS expression can be associated with several inflammatory processes, and has been correlated with tumorigenesis of some neoplasms, but its participation in the development of periapical lesions has not been investigated. Therefore, our objective was to verify the expression of ADAMTS-1, versican and pEGFR in Periapical Granuloma (PG) and in the Radicular Cyst (RC) since they are the most common lesions of the periapex. METHODS: 25 samples of RC and 10 of PG were used. As a control, 10 samples of inflammatory fibrous hyperplasia (IFH) and 10 of dental follicle (DF) were used. The expression of these proteins was investigated using immunohistochemistry. RESULTS: In the epithelium of RC, IFH and DF, the expression of ADAMTS-1 was greater in DF than in RC (p < .001). Versicano showed greater expression in IFH than in RC, DF than in RC (p < .001). pEGFR showed greater expression in IFH and RC than in DF (p < .01 and p < .05, respectively). In connective tissue, ADAMTS-1 expression was greater in PG and RC than in IFH and DF (p < .001). Versicano showed greater expression in PG, RC and IFH compared to DF (p < .001). In pEGFR there was a higher expression in PG when compared to RC, IFH and DF (p < .001). Greater immunostaining occurred in the RC than in the DF (p < .001). CONCLUSIONS: Our results suggest that the studied proteins may participate in the pathogenesis of PG and RC, through the interaction of these proteins, in the remodeling of the ECM (versican) by ADAMTS-1, producing bioactive fragments, which could activate EGFR, contributing to the formation, growth and maintenance of injuries.

[Three-dimentional radiographic features of 67 maxillary radicular cysts].

OBJECTIVE: To analyze the three-dimensional radiographic characteristics of maxillary radi-cular cysts using cone-beam computed tomography (CBCT) and spiral CT. METHODS: Clinical records, histopathological reports, and CBCT or non-enhanced spiral CT images of 67 consecutive patients with maxillary radicular cysts were retrospectively acquired, and radiographic features, including size, shape, expansion, internal structure and relationship with the surrounding tissues, were analyzed. The lesions were divided into three types according to the involved tooth number, as follows: type Ⅰ (single tooth), the epicenter of the cyst was located at the apex of a nonvital tooth, without involvement of the neighbo-ring tooth; type Ⅱ (adjacent tooth involvement), the cyst was located at the apex of a nonvital tooth with involvement of the mesial and/or distal tooth root; and type Ⅲ (multi-teeth), the cyst involved the apexes of ≥4 teeth. Besides, these cysts were classified as another three types on sagittal views, as follows: centripetal, the root apex was oriented centripetally to the center of the cyst; palatal, the cyst was located mainly at the palatal side of the apex; and labial/buccal, the cyst was located mainly at the labial/buccal side of the apex. RESULTS: Totally, 67 patients with maxillary radicular cysts were acquired, including 38 males and 29 females, and their ages ranged from 13 to 77 years. Among them, 46 lesions (68.7%) were located in the anterior maxilla and 65 (97.0%) were round or oval. Labial/buccal cortex expansion was present in 43 cases (64.2%) and palatal cortex expansion in 37 cases (55.2%). The nasal floor was invaded in 27 cases (40.3%), the maxillary sinus was invaginated in 26 cases (38.8%), and root resorption was present in 9 cases (13.4%). The average diameter of lesions was (20.89±8.11) mm mesio-distally and (16.70±5.88) mm bucco-palatally. In spite of the 4 residual cysts, the remaining 63 lesions included 14 type Ⅰ, 26 type Ⅱ and 23 type Ⅲ cysts according to the involved tooth number. Besides, the 63 lesions included 46 centripetal, 15 palatal and 2 buccal cysts on sagittal views. CONCLUSION: The maxillary radicular cysts were frequently well-circumscribed round or oval radiolucency, with significantly different sizes. According to the involved tooth number, it can be divided into single tooth, adjacent tooth involvement and multi-teeth types. On sagittal views, the root-cyst relationship was centripetal in most cases, while a minority of cysts expanded palatally or buccally.

The Development of Large Radicular Cysts in Endodontically Versus Non-Endodontically Treated Maxillary Teeth.

Background and Objectives: Large radicular cysts of the maxilla present a clinical challenge, as they may cause recurrent infection, severe alveolar bone loss and disruption of the nasal and maxillary sinus floors. The aim of this study was to evaluate the effect of previous root canal treatment on the clinical presentation of large maxillary radicular cysts. Materials and Methods: All cases of radicular cysts treated at the Oral and Maxillofacial Surgery Department of a tertiary public hospital over a period of six years (2012-2018) were evaluated. Histologically confirmed radicular cysts of the maxilla with a maximal dimension of over 15 mm were included. Demographic data of the patients, clinical presentation and radiographic features of the lesions were analyzed. Results: A total of 211 inflammatory cysts were treated in the study period, of these 54 histologically diagnosed radicular cysts in the maxilla were found to have a maximal dimension of over 15 mm. The mean age of patients with large maxillary radicular cysts was 43.3 years, 57.6% of which were male and 42.4% female. The lateral incisor was the most common tooth affected (46.3%). The mean size of the large radicular cysts was 25 mm. Then, 83.8% of the cysts were observed in teeth with previous endodontic treatment. Teeth without endodontic treatment presented clinically with significantly fewer acute symptoms in comparison to teeth with previous endodontic treatment. Conclusions: the vast majority (83.8%) of large maxillary radicular cysts were associated with endodontically treated teeth. Previous endodontic treatment was correlated to increased frequency of clinical symptoms.

OPTIMIZATION OF LOCAL ANESTHESIA OF DENTAL PATIENTS DURING CYSTECTOMIES OF RADICULAR CYSTS THAT HAVE GROWN INTO THE MAXILLARY SINUS OR NASAL CAVITY.

OBJECTIVE: The aim: To provide clinical evaluation of the effectiveness of anesthesia for cystectomy of radicular cysts that have grown into the maxillary si-nus or nasal cavity using different techniques of endonasal block-ade of the nasopalatine nerve. PATIENTS AND METHODS: Materials and methods: Clinical observations were conducted on 52 patients of different age and sex. These patients were diagnosed with large radicular cysts (more than 3.0 cm in diameter) that had grown into the maxillary sinus (33 cases) or into the nasal cavity (19 cases). The surgical excisions of cysts (oroantral cystectomies) were performed un-der local potentiated anesthesia. Patients were divided into two clinical groups, depending on the methods used for endonasal blockade of the nasopalatine nerve: the main and the control group. Patients in the main group underwent endonasal blockade of the nasopalatine nerve at the point of its emergence from the pterygopalatine ganglion. In the control group, the neural blockade was performed at the entry of this nerve into the incisive canal. Pain sensitivity and perception in patients were studied using subjective and objective methods. The data was analyzed by means of the Pearson's chi - square tests. RESULTS: Results: During the enucleation of radicular cysts that grew into the inferior nasal meatus and maxillary sinus in patients of the main group there was no pain observed. There were no manifestations of pain-induced stress neither from the side of autonomic system, nor physical or emotional manifestations of pain, which confirmed the effectiveness of nasopalatine nerve anesthesia. In patients of the control group during similar operation the full effect of local anesthesia was achieved in 56.0% of cases (χ2 - 9,270, р = 0,003). The rest of the patients during cystectomies showed some signs of pain-induced stress from the side of autonomic system or in the form of physical or emotional manifestations. CONCLUSION: Conclusions: Endonasal blockade of the nasopalatine nerve at the point of its emergence from the pterygopalatine ganglion invariably provided a complete analgesia during enucleation of radicular cysts that have grown into the maxillary sinus or nasal cavity. Anesthesia of the nasopalatine nerve at its entry into the incisive canal allows pain-less cystectomy of radicular cysts that have spread to the front of the inferior nasal meatus from the front teeth.

Heterogeneity of fibroblasts from radicular cyst influenced osteoclastogenesis and bone destruction.

AIM: To analyze the heterogeneity of fibroblasts isolated from the fibrous capsules of radicular cysts and explore the effects of fibroblast subsets on bone destruction. METHODOLOGY: Radicular cysts were divided into groups according to varying perilesional sclerosis identified by radiograph. Colony-forming units (CFUs) were isolated from the fibrous capsules of cysts, by which Trap + MNCs were induced, and the expression of osteoclastogenesis-related genes was compared among groups by real-time PCR. The variances in gene profiles of CFUs were identified by principal component analysis, and then, CFUs were divided into subsets using cluster analysis. The induction of Trap + MNCs and related gene expression was compared among subsets, and osteoclastogenic induction was blocked by IST-9 or bevacizumab. The fibroblast subsets in cysts were investigated by retrospective immunostaining with IST-9, VEGF-A, and CD34. A fibroblast subset that underwent gene editing by CRISPR/Cas was injected into the site of bone defects in animal models, and the in vivo effects on osteoclastogenesis were investigated. RESULTS: The fibroblast CFUs isolated from radicular cysts with perilesional unsclerotized cysts induced more Trap + MNCs than those with perilesional sclerotic cysts (p < .05). Most fibroblast CFUs from unsclerotized cysts belonged to Cluster 2, which induced more Trap + MNCs (p < .05) and highly expressed genes facilitating osteoclastogenesis; these results were different from those of Cluster 1 (p < .05), in which most CFUs were isolated from perilesional sclerotic cysts or controls (p < .05). The high expression of EDA + FN and VEGF-A was investigated in both the fibroblasts of Cluster 2 and the fibrous capsules of unsclerotized cysts (p < .05), and the number of Trap + MNCs induced by Cluster 2 was decreased by treatment with IST-9 and bevacizumab (p < .05). Consistently, EDA exon exclusion significantly decreased the osteoclastogenic induction of fibroblasts from Cluster 2 in vivo (p < .05). CONCLUSION: The fibrous capsules of radicular cysts contain heterogeneous fibroblasts that can form subsets exhibiting different effects on osteoclastogenesis. The subset, which depending on the autocrine effects of EDA + FN on VEGF-A, mainly contributes to the osteoclastogenesis and bone destruction of radicular cysts. The regulation of the proportion of subsets is a possible strategy for artificially interfering with osteoclastogenesis.

The extra domain A of fibronectin facilitates osteoclastogenesis in radicular cysts through vascular endothelial growth factor.

AIM: To analyse the effects of the alternatively spliced fibronectin (FN) gene and its isoforms on osteoclastogenesis in radicular cysts. METHODOLOGY: Specimens of radicular cysts were collected surgically from 22 patients whose radiolucent periapical areas were measured on digital panoramic radiographs before surgery. The associations between the radiolucent areas and FN isoforms, vascular endothelial growth factor (VEGF) expression or micro-vessel density, as well as the relationships amongst them, were analysed by immunohistochemical staining using the antibodies IST-9, BC-1, P1F11, VEGF and CD34. Fibroblasts isolated from those specimens were used to induce Trap + MNCs, and the effects of induction were assessed by blocking FN containing extra domain A (EDA + FN), COX-2 or VEGF in vitro. The effects of EDA exon knockout using CRISPR/Cas system were also assessed. Quantitative PCR was used to analyse relative expression of FN isoforms and osteoclastogenic genes. Data were analysed using linear regression, Spearman's rank correlation analysis, chi-square test and Student's t-test; P < 0.05 was considered significant. RESULTS: Micro-vessel density and EDA + FN staining were positively associated with the size of radiolucent periapical areas (mm2 ; P < 0.05), consistent with a positive association between Trap + MNCs and VEGF expression in fibroblasts (P < 0.05). Blocking the interaction between EDA + FN and fibroblasts inhibited Trap + MNC formation. In addition, EDA exon knockout decreased VEGF expression and inhibited Trap + MNC formation to the extent of blocking VEGF by bevacizumab, but osteoclastogenic induction was restored by recombinant VEGF. Using retrospective clinicopathological data, VEGF staining was shown to be positively associated with EDA + FN staining, micro-vessel density and the size of radiolucent areas (P < 0.05). CONCLUSION: In fibrous capsules of radicular cysts, the alternatively spliced isoform EDA + FN generated by fibroblasts stimulated VEGF expression via an autocrine effect and then facilitated osteoclastogenesis. Both blockage of VEGF and EDA exon knockout could be used to inhibit bone destruction.

Relationship between mast cells and E-cadherin in odontogenic keratocysts and radicular cysts.

OBJECTIVE: This study aimed to evaluate tryptase and E-cadherin protein expression in odontogenic keratocysts (OKCs) and radicular cysts (RCs) and their relationship with lesion size. MATERIALS AND METHODS: Thirty OKC and 30 RC cases were analyzed by immunohistochemistry. Tryptase expression was quantitatively assessed using the quantification of mast cells, and expression of E-cadherin was semi-quantitatively analyzed estimating the proportion of positive cells: 1 = less than 25% of immunopositive cells; 2 = 26 to 50% of immunopositive cells; 3 = 51 to 75% of immunopositive cells; 4 = more than 75% of immunopositive cells. Data on cystic lesion sizes were obtained from patients' clinical files, based on previous radiographic exams, and the lesions were categorized into three groups: group 1 (< 2 to 2 cm); group 2 (> 2 to 4 cm), and group 3 (> 4 cm). RESULTS: Higher mast cell means were found for RCs, with the predominance of degranulated mast cells in both OKCs and RCs (p = 0.082). Concerning the epithelial component, a higher concentration of degranulated mast cells was detected in RCs (p = 0.000). Regarding connective tissue, degranulated mast cells were more evident in OKCs (p = 0.762). A negative correlation was observed between E-cadherin expression and total number of mast cells (p = 0.011), degranulated mast cells (p = 0.040), and degranulated mast cells in both superficial (p = 0.035) and deep connective tissues (p = 0.009). Concerning lesion size, a negative correlation with total number of mast cells (p = 0.016) and number of degranulated mast cells (p = 0.049) was observed, both in the epithelial components. Herein, the larger the lesion size, the lower the number of degranulated mast cells in the epithelium (r = - 0.271; p = 0.49), suggesting that these cells play a role in the initial cystic expansion phase. CONCLUSION: The higher expression of tryptase in degranulated mast cells was linked to a lower expression of E-cadherin, which may be related to a change in the epithelial permeability in these lesions, contributing to increased cystic content and lesion growth. CLINICAL RELEVANCE: Evidence of the relationship between mast cells and E-cadherin in the growth of odontogenic cysts was studied.

Morphological characteristics of radicular cysts using computed tomography.

The purpose of this study was to evaluate computed tomography (CT) findings of radicular cysts with a focus on location, size, and condition of the surrounding bone. Subjects comprised 60 men and 86 women (mean age 47.2 years) with histopathologically confirmed radicular cysts who underwent CT examination between 2012 and 2014. Mesiodistal and buccolingual diameters were measured at the location where the lesion appeared to be largest on CT axial images. Of the 146 cases, 103 lesions were in the maxilla and 43 were in the mandible. Mesiodistal diameter of the maxillary lesions was significantly larger than that of the mandibular lesions. However, the ratio of mesiodistal diameter to buccolingual diameter in the mandible was significantly larger than that in the maxilla. Bone expansion was more significant in the maxilla than in the mandible. Mesiodistal and buccolingual diameters in only the maxilla and perilesional sclerotic radiolucency in images of both jaws were significantly associated with the severity of clinical symptoms. The findings suggest that radicular cysts in the maxilla are accompanied by bone expansion in the mesiodistal and buccolingual directions and those in the mandible progress in the mesiodistal direction without bone expansion. Clinical acute symptoms (pain and swelling) are correlated with lesion size in the maxilla; such a correlation is not clear for mandibular lesions, and discovery of mandibular lesions may, therefore, be delayed.

Assessment of conformity between clinical (radiological) and histopathological diagnoses of chronic inflammatory periapical lesions treated with apicoectomy. Clinical and histopathological diagnoses of periapical lesions. Research article.

OBJECTIVES: Periapical inflammation is one of the most common pathologies within the jaws, leading to the destruction of periodontal ligaments, bone resorption and the formation of periapical granulomas or radicular cysts. The final diagnosis can be made only on the basis of histopathological examination. The aim of the study was to assess the conformity between clinical and histopathological diagnosis of inflammatory periapical lesions treated with apicoectomy. MATERIALS AND METHODS: The case histories of 52 patients subjected to surgical treatment at the Clinic of Conservative Dentistry with Endodontics between 2008 and 2018 were analyzed. Demographic data (age, gender), clinical (radiological) diagnosis, and data on the presence of sinus tracts and causal tooth were obtained from patients' records. RESULTS: In the light of clinical and radiological examination, 32 (61.5%) periapical granulomas, 18 (34.6%) radicular cysts and 2 (3.9%) periapical scars were diagnosed, whereas the result of histopathological examination revealed granuloma in 34 (65.4%) cases and in 18 (34.6%) - radicular cyst. For clinical diagnosis of granuloma, the result coincided with the result of the histopathological examination in 28 cases, and in the case of cysts in 14. The analysis showed a significant relationship between the clinical and histopathological diagnoses (p <0.05). CONCLUSIONS: The study emphasizes the importance of histopathological assessment for the proper diagnosis of periapical lesions. CLINICAL RELEVANCE: The article emphasizes the high importance of histopathological examination for the correct diagnosis of chronic inflammatory periapical lesions.

The fibroblast of radicular cyst facilitate osteoclastogenesis via the autocrine of Fibronectin containing extra domain A.

OBJECTIVE: To investigate the alternative spliced isoforms of Fibronectin (FN) in the stroma of radicular cysts and analyze the associations between these isoforms and the osteoclastogenic effects of fibroblasts. METHODS AND MATERIALS: The specimens of radicular cysts were stained with immunohistochemistry, and the associations between each FN isoform and clinical parameters were assessed. The fibroblasts isolated from cysts or jaw bone were cultured to induce the Trap + MNCs. In the conditioned medium, the Fibronectin containing extra domain A (EDA + FN) was neutralized by antibody IST-9, and the EDA exon of fibroblasts was knockout by CRISPR/Cas system, for assessing the osteoclastogenic effects. The mRNA level of FN isoforms and the osteoclastogenesis-related genes were analyzed by quantitive PCR. RESULTS: EDA + FN staining was positively associated with the size of the lesions (p < 0.05). In contrast with the controls, the ratio of EDA + FN/total FN in the fibroblasts from radicular cysts was significantly higher (p < 0.05), and positively associate with Trap + MNCs counting, it was consistent with increased expression of COX-2, IL-6, IL-17, and the RANKL/OPG (p < 0.05). The Trap + MNCs counting and osteoclastogenesis-related genes were decreased by IST-9 blocking and EDA exon knockout in fibroblasts, but the blockage of the interaction between EDA + FN and pre-osteoclasts exhibited little effects on Trap + MNCs formation. CONCLUSION: The microenvironment of the fibrous capsule of radicular cysts facilitates the splicing of EDA exon, it endues EDA + FN with autocrine effects on fibroblast itself, and it increases the expression of osteoclastogenesis-related genes, by which the osteoclastogenesis in radicular cysts could be initiated.

Development of an in vitro model to study tooth cystogenesis.

AIM: To describe an in vitro experimental model of cystic structure formation to conduct research on radicular cyst development. METHODOLOGY: To form spheroid structures, various numbers (1 × 104 , 5 × 104 or 1 × 105 ) of epithelial cells (HaCaT and Cal27) were seeded in 96-well plates previously coated with 1.5% low-melting agarose. After 24 h, the spheroids were collected, embedded in 3D collagen matrix and transferred to 24-well plates previously coated with polymerized collagen and kept for up to 21 days. Images of spheroids were captured at each time-point (1, 5, 9, 15 and 21 days), and samples underwent histological and confocal microscopy analyses. Spheroid area, perimeter and cell dispersion were measured. One-way Anova was used for statistical analysis. RESULTS: Both epithelial cell lines were able to generate regular and circular spheroids after 24 h of incubation regardless of cell density. Spheroid structures in the collagen matrix were uniform in most samples until day 15, when several spots that appeared to be new cultures were seen. Spheroids from HaCaT were significantly more stable than those from Cal27 (P < 0.05). Starting on the third day, the examination of histological sections revealed a cavity with epithelial lining morphology, similar to a pathological radicular cyst. CONCLUSIONS: This study describes an experimental model of cystogenesis in vitro that may be used to test theories and investigates the effects of different growth factors during cyst development and maintenance.