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The objectives of the present study were to comprehensively evaluate all the published cases on compound odontoma associated with calcifying odontogenic cyst (COaCOC) in the English literature and to describe the clinical, imaging and therapeutic variables for this condition. In August 2020, an electronic search of the PubMed / MEDLINE, Web of Science, ScienceDirect, Springer, and Scopus databases was carried out. The eligibility criteria included publications with enough information to confirm the diagnosis. Furthermore, we present a clinical case of a 16-year-old male patient with OCCaC, who was treated with enucleation, obtaining favorable and functional results. A total of 32 cases reported in the literature that met the inclusion and exclusion criteria, including ours, were analyzed and discussed. The mayority of the patients were women (n = 17) with an average age of 14.4 years, the maxilla was the most affected bone (n = 22) and the maxillary anterior region was the area with the highest number of cases (n = 18), the main clinical presentations were the volume increase (n = 14) and asymptomatic (n = 14). The choice treatment was enucleation (n = 26) and, in most cases, no recurrence was reported (n = 20). This study allows to update the characteristics of the OCCaC, giving an effective vision of how to treat this rare pathological association made up of two conditions that are completely different from each other.

Objective : The purpose of this multicenter retrospective study was to report the clinical and radiological features of 92 glandular odontogenic cysts (GOCs) diagnosed over a 20-year period. Study Design : Histologically confirmed cases of GOC were retrospectively reviewed from four Oral Pathology laboratories in South Africa and Brazil to categorize the clinical and radiological spectrum of GOCs. Results : The mean age of patients was 46 years (range 17-87) with a male-to-female ratio of 1.2:1. GOCs had a mandibular predilection (68%), with 42% of all cases located anteriorly. Additionally, 42% of cases crossed the midline. Radiologically, most lesions were unilocular (53%) and uniformly radiolucent (97%), with well-demarcated borders (93%). Cortical expansion (62%), loss of cortical integrity (71%), and maxillary sinus (67%) and nasal cavity encroachment (72%) were common findings. Significant differences in lesions between the two countries were discovered in sex predilection, clinical signs and symptoms, and lesion locations within the mandible and maxilla. Conclusion : GOCs present with a wide spectrum of clinical and radiological features, ranging from cysts with typical GOC-like presentations to more aggressive lesions. The need for advanced imaging in the surgical planning of GOCs exhibiting radiological signs of aggression is justified based on the high recurrence rate.

Odontogenic keratocysts (OKCs) and orthokeratinized odontogenic Cysts (OOCs) are distinct clinicopathological entities. OKC appears to behave in a way more similar to that of a neoplasm, such as ameloblastoma (AB). The aim of this study is to compare the influence of Ki-67, Cyclin D1 and COX-2 in the diagnosis and pathogenesis of OKC, OOC and AB.A cross-sectional observational study of 41 samples was organized into 3 groups: (1) OKC n=22; (2) AB n=13 and (3) OOC n=6. Paraffin blocks were sectioned and stained with hematoxylin and eosin (HE). Immunohistochemical study using Bond Polymer Refine Red Detection Kit, Leica, Wetzlar, Germany, was performed for the following antibodies: Ki-67, Cyclin D1 and COX-2. Double blind immunostaining was quantified subjectively. Staining: nuclear or cytoplasmic; nuclear (Ki-67 and Cyclin D15% positive) and cytoplasmic (COX-2; 1; 1-30 cytoplasm: 2; 31-60 cytoplasm; 3; 61-100 cytoplasm). Considering positive stained 61-100 cytoplasms.The expression of Ki-67 was higher in the OKC group than in the AB group (p0.05). Cyclin D1 showed a higher expression in OKC vs. OOC and OKC vs. AB (p0.05). Finally, expression of COX-2 was higher in OKC vs AB (p0.05).COX-2, Ki-67 and Cyclin D1 show statistically significant differences between the groups, suggesting that they could be useful tools in the differential diagnosis between OKCs and OOC and a predictive indicator for their biologic behaviour. The higher expressions of these 3 markers of OKC vs AB highlight once more the aggressive behaviour of this now re-considered cystic lesion. These markers could prove useful in the choice of more aggressive surgical treatment in OKCs as their behaviour appears to be similar to that of a neoplasm.

Objectives The objective of this study was to demonstrate the clinical, radiologic, and histologic features of orthokeratinized odontogenic cyst (OOC); determine the characteristics of multiple OOCs; and present rare but significant manifestations of OOC. Study Design A clinical, radiologic, and histopathologic study of 65 primary and 2 recurrent OOC cases was performed retrospectively along with a comprehensive literature review. Results OOCs shared similar radiologic findings with odontogenic keratocyst, yet some showed features that have not been previously described: root resorption and radiopaque foci. Histologic review revealed a unique histiocytic lining and some findings suggestive of the multipotentiality of the odontogenic epithelium. The analysis of patients with multiple OOCs demonstrated that multiple OOCs occurred synchronously with a marked predilection for young male adults. Two unusual cases were also identified: an OOC combined with a BRAFV600E ameloblastoma and a recurrent OOC with malignant transformation. Conclusions This largest series presents previously unreported radiographic and histopathologic features that can be seen in OOC. Multiple OOCs have clinical characteristics distinct from those of solitary cases. The first reported OOC associated with ameloblastoma suggests the involvement of oncogenic mutations in odontogenic tumorigenesis. Although OOC shows a low recurrence rate, the possibility of malignant transformation of recurrent OOCs should be emphasized.

Abstract introduction Odontogenic Keratocysts are benign, developmental, locally aggressive odontogenic cystic lesions with a high risk of recurrence. As such, the most effective treatment modalities remain controversial. The mainstay of treatment remains enucleation with or without decompression. The use of adjunctive therapies is widely reported. Aims To review our experience of OKCs and therefore identify the treatment modality, if any single one, with the lowest rate of recurrence. We also aimed to identify any common themes linking those patients experiencing cystic recurrence. Methods Data was collected on 50 patients treated at UHCW NHS Trust over a 14 year period (2005-2018) via an anonymised database. Surgical pathways were analysed, including details of the location of the cysts and the use of adjunctive therapies, namely; mechanical debridement, cryotherapy, and the use of Carnoy’s solution. Results 56 keratocysts, both primary (91%, n = 51) and recurrent (9%, n = 5) were included. 6% of patients had a pre-existing diagnosis of Gorlin-Goltz Syndrome (n = 3). Enucleation was performed in an approximately 3:1 ratio to decompression with secondary enucleation (n = 41:15). 27% patients had adjunctive therapies (n = 15). There was a 12% recurrence rate (n = 6) found only within the group of primary cysts that had been enucleated alone. Notably, there were no recurrences in those cysts that had undergone adjunctive therapy. None of the cysts that underwent initial decompression or marsupialisation recurred. Following surgical intervention, no tertiary recurrent cysts were detected post-operatively. Conclusions This study demonstrates the advantage of establishing a correct diagnosis prior to definitive treatment. Initial decompression in selected patients followed by enucleation, along with adjunctive therapies show a benefit in reducing recurrences. However, in the absence of high-quality evidence for the most effective management of Odontogenic Keratocysts, finding a common approach will remain controversial.

Glandular odontogenic cyst (GOC) is a very rare jaw cyst accounting for 0.2% of all odontogenic cysts. It presents usually in adults with a slight male predominance. It shows radiological, histopathological and even immunohistochemical overlap with low grade intraosseous mucoepidermoid carcinoma (MEC) but their distinction is crucial. A 57-year-old woman with bilocular radiolucency in the anterior mandible crossing the midline is described here. Microscopy features were consistent with glandular odontogenic cyst but multiple MEC-like islands were seen in the capsule, creating a diagnostic head trip with low grade intraosseous MEC. However, the absence of cellular atypia and epidermoid and intermediate cells led to a final diagnosis of GOC, with close follow-up of the patient recommended. This rare finding shows the relation between GOC and MEC or the origin of MEC from GOC.

In this study, we aimed to systematically review and critically appraise the available literature concerning the effectiveness of marsupialisation and decompression on the reduction of cystic jaw lesions. The 'Preferred Reporting Items for Systematic Reviews and Meta-Analysis' guidelines were followed and the study protocol was registered at the 'International Prospective Register of Systematic Reviews' (CRD42019116099). Six main databases were searched: Embase, LILACS, PubMed, Scopus, The Cochrane Library, and Web of Science. Searches were complemented with three grey literature sources: Google Scholar, ProQuest, and Open Grey. Any reduction measures, compared with preoperative status or other procedures, were considered. Risk of bias was assessed using the Joanna Briggs Institute Critical Appraisal Tool. Thirty-one studies were included, of which five were judged with low, 24 with moderate, and two with high risk of bias. Considering surgical approach, 20 studies assessed the decompression and 11 the marsupialisation technique. Most studies considered these techniques as preliminary treatments, followed by enucleation. From 1088 lesions found, most were odontogenic keratocysts (33.8%), followed by unicystic ameloblastomas (21.0%), dentigerous cysts (20.6%), and radicular cysts (8.4%). Large lesions and younger individuals frequently presented more favourable responses to treatment and anatomical location was not associated with lesion reduction overall. The intervention duration generally ranged between one to two years. In conclusion, marsupialisation and decompression were mostly considered as preliminary treatments, followed by enucleation. Lesion reduction was generally considered insufficient for these techniques to be used as definitive therapies, although benefits concerning the diminished invasiveness of the secondary surgery were often proposed.

The odontogenic keratocyst (OKC) is a potentially aggressive odontogenic lesion and there is an ongoing debate regarding its biological behavior and classification. The present systematic review aims to assess the expression of the p53 protein in the odontogenic keratocyst in comparison to the dentigerous cyst and ameloblastoma. We searched MEDLINE, Web of Science and Scopus for immunohistochemical studies reporting OKC's, dentigerous cysts and solid/multicystic ameloblastomas. The Risk Difference between the lesions expressing the p53 was the effect measure and a P value

BACKGROUND Although pathology in the maxillary and mandibular bones is rare in young patients, the differential diagnosis is broad. The World Health Organization (WHO) updated its classification of maxillofacial bone pathology in 2017. Using these updated guidelines, a systematic review of common maxillofacial bone lesions in the pediatric population was performed. METHODS A PubMed search was conducted capturing English language articles from inception to July 2020. Thirty-one articles were identified that described the frequency of maxillofacial bone pathology. Data were extracted and organized using the WHO 2017 classification of odontogenic and maxillofacial bone tumors. Prevalence data were analyzed among diagnostic categories and geographical regions. The SAS version 9.4 was used to complete statistical analyses. RESULTS The articles included patients from birth to a maximum age of 14 to 19 years. The most common odontogenic cysts included radicular cyst (42.7%) and dentigerous cyst (39.0%) followed by odontogenic keratocyst (15.0%). Among odontogenic bone tumors, odontoma (49.3%) was most common followed by ameloblastoma (29.1%). The most common nonodontogenic bone tumor was fibrous dysplasia (42.4%), and the most common malignant bone tumor was osteosarcoma (75.0%). Significant variations were found by geographic region, with dentigerous cyst more common than radicular cyst, and ameloblastoma more common than odontoma in African and Asian countries (P

BACKGROUND Cyclooxygenase-2 protein is a critically important mediator in inflammation that influences proliferation, apoptosis, angiogenesis and metastasis. Previous works showed a relationship between cyclooxygenase-2 and tumourigenesis in humans and animal models. In epithelial odontogenic tumours and cysts, increased cell proliferation and survival have been linked to its pathogenesis and tumour development. The aim of the present study was to analyse the immunohistochemical expression of cyclooxygenase-2 in solid ameloblastoma and odontogenic keratocyst and its association with proteins related to cell proliferation and apoptosis. METHODS This study was conducted on 40 cases from the Pathological Anatomy Service, University of Chile. The cases were diagnosed as solid ameloblastoma (n = 21) and odontogenic keratocyst (n = 19) according to WHO 2017. Slides prepared from paraffin-embedded sections were immunohistochemically stained for cyclooxygenase-2, cyclin D1, Ki-67, p63 and Bcl-2. Statistical evaluation was performed by the Shapiro-Wilk test, ANOVA Mann-Whitney test and Spearman's correlation coefficient (p

Purpose Carnoy's solution (CS), the gold standard for adjunctive chemical cautery in treatment of odontogenic keratocysts (OKCs), has been banned for 7 years, leading to substitution with the non-chloroform containing modified Carnoy's solution (MC) without data to support its effectiveness. We performed this study to compare the earlier data with CS to the more current outcomes with MC. Methods A retrospective cohort study was conducted on patients diagnosed with OKC and treated by a single surgeon (GHB) with enucleation and curettage (EC), peripheral ostectomy, and application of CS or MC. The primary predictor variables were use of CS or MC. The primary outcome variables were recurrence (yes vs. no) and time to recurrence. Secondary variables included demographics, anatomic location, and whether teeth adjacent to the lesion were extracted. Statistical analyses included chi-squared test/Fisher's exact test, Wilcoxon rank sum test, and Kaplan-Meier curves. Results 77 patients, 36 patients in the CS group and 41 in the MC group, met inclusion criteria, including at least 1 year of follow-up time. Characteristics of the groups were similar: median age 41.5 and 46, 61% and 71% male gender, 81% and 90% posterior, and 64% and 50% mandibular lesions, respectively. Overall recurrence was similar, 14.29%, with 5 (13.9%) recurrences in the CS group and 6 (14.6%) in the MC group (P = 0.92). Median time to recurrence was 24 months for both groups. Preserving adjacent teeth was associated with a significant increase in recurrence (P = 0.0036). Conclusion Based on this comparison of retrospective outcome data, we found no significant difference in recurrence rate or distribution of time to recurrence between OKCs treated with CS or MC. Aggressiveness of surgical technique is likely a predictive factor in recurrence rate. Future studies should focus on prospective studies and continuing follow-up of the MC group.

Carnoy's solution (CS) is routinely used as adjuvant therapy in the management of odontogenic keratocyst (OKC) and a few other benign lesions. The purpose of this study was to explore the evidence of its application and efficacy in benign lesions other than OKC. We have systematically reviewed published articles to identify the evidence of CS in benign jaw lesions other than OKC following the PRISMA guidelines. The search was conducted in PubMed, Google Scholar, Semantic Scholar, and Cochrane Library database, to find relevant articles from 1980 to March 2020. Finally, 39 studies were analysed in this review. It included studies where CS was used as an adjunct for the benign lesion of the jaw and followed for a minimum of 6 months. Thirty-nine studies with 11 different types of lesion were reported where CS was used as an adjuvant and application time was restricted to 3-5minutes. Recurrence were reported only in ameloblastoma cases [unicystic=10.98% (10/91), mixed=18.18% (26/143)]. Meta-analysis was not possible as all studies were non-controlled in nature. Based on the available data, there was no strong evidence for the use of CS as an adjuvant in the benign lesion of the jaw. Prospective and randomised control studies are recommended for the best stratification for the use of CS.

Objective: A large maxillary odontogenic cyst could intrude into the maxillary sinus. The traditional approach following surgery for such a cyst is the Caldwell-Luc procedure However the traditional CDL procedure is associated with more complications and damage of the sinus mucosa. The purpose of this study was to assess a new method with easier operation, which not only prevented postoperative infection but also caused less damage to the maxillary sinus mucosa.Methods: A large odontogenic cyst in the maxillary sinus of 40 patients was diagnosed through radiographic imaging and postoperative histopathology. Twenty patients were treated with maxillary sinus saline irrigation after cyst resection surgery, while 20 patients underwent the traditional Caldwell-Luc procedure. The therapeutic efficacy was evaluated by clinical examination and radiographic imaging; the longest follow-up was 36 months.Results: The postoperative recovery of the 20 patients treated with sinus irrigation. Six patients had mild swelling (30%), 12 had moderate swelling (60%), and 2 had severe swelling (10%); 16 had mild pain (80%), 4 had moderate pain (20%), and 0 had severe pain (0%). Among the 20 patients treated by the Caldwell-Luc approach. Immediately postoperatively, 2 patients had mild swelling (10%), 12 had moderate swelling (60%), and 6 had severe swelling (30%); 10 had mild pain (50%); 6 had moderate pain (30%), and 4 had severe pain (20%). On the second day after surgery, a mild temperature elevation (38.0°C-39.0°C) was noted in 8 patients (40%) treated with the Caldwell-Luc procedure and 1 patient (5%) treated with saline irrigation.Conclusion: Sinus irrigation following large odontogenic cyst surgery involving the maxillary sinus can serve as an alternative to standard CDL and has the advantages of fewer complications, reduced trauma, restoration of the mucosa and more satisfactory results.

Context: Odontogenic cysts are among the most common lesions to affect the oral and maxillofacial region. Cysts are capable of causing significant bony disfigurement, tooth displacement and pathological fractures. Several surgical approaches exist for the management of larger cysts of the jaws. These include enucleation, marsupialization and decompression. Aims: 1. Analysis of histopathologic findings in odontogenic cysts before and after decompression 2. Analysis of Ki-67 expression in odontogenic jaw cysts before and after decompression. Settings and Design: Decompression technique was used for the treatment of 10 cases of odontogenic cysts in the study. Incisional biopsies of cystic lining (pretreatment) and corresponding excisional biopsies (posttreatment) were received for histopathologic and immunohistochemical examination. Subjects and Methods: Hematoxylin and eosin stain was used for histopathologic findings, and Ki-67 was used for immunohistochemical findings using antibody Ki-67 in fresh tissue samples. Results: Overall, radicular cysts, dentigerous cysts, and sialo-odontogenic cyst contained fewer Ki-67 + cells than odontogenic keratocysts. The average scores were found to be 2.2 and 1 for before and after decompression, respectively. A statistically significant difference was observed between the two groups. The two-tailed P value was found to be

The inflammatory follicular cysts are cystic lesions associated with non-erupted permanent teeth and involve devitalized deciduous teeth. Products resulting from the necrotic pulp of deciduous teeth stimulate crown hood growth of successor permanent tooth radiographically shown as a unilocular, radiolucent area, associated with an impacted permanent crown. Treatment based on cyst decompression and maintenance of the deciduous tooth is a conservative approach to space maintenance. This case report describes the diagnosis, treatment, and post-surgery follow-up after 5 years of an extensive inflammatory follicular cyst in the mandible, in the region of tooth 75, with marsupialization being the method of treatment and emphasizing the importance of clinical and radiographic follow-up. How to cite this article: de Oliveira GAA, Limongi MC, Garcia HS, et al. Success in Conservative Treatment of an Inflammatory Follicular Cyst: A 5-year Follow-up. Int J Clin Pediatr Dent 2021;14(2):327–330.

The purpose of this study was to compare the histopathologic findings of pre- and post-active decompression of odontogenic keratocyst and to establish if such findings were consistent. A retrospective case series from a group of patients diagnosed with odontogenic keratocyst who underwent active decompression and distraction sugosteogenesis followed by final enucleation was designed and implemented. The dependent variable was changed in histologic diagnosis, as evaluated by an oral and maxillofacial pathologist. Other variables included age, gender, anatomic location of the lesion, and time elapsed from initial biopsy to final enucleation. Six patients diagnosed with odontogenic keratocyst who underwent active decompression followed by enucleation and curettage were studied. The mean age was 45.6 years (range, 16 to 74) 83.33% were males, 16.66 females. Lesions were located in the mandible in 83.33% of cases and in the maxilla in 16.66% of cases. Post-active decompression histologic examination at the time of definitive enucleation was consistent with the initial diagnosis in 83.33% of cases. The histopathological diagnosis at the time of definitive treatment by enucleation and curettage is consistent with the pre-active decompression diagnosis.

Background Aberrant expression of stem cell markers has been observed in several types of neoplasms. This trait attributes to the acquired stem-like property of tumor cells and can impact patient prognosis. The objective of this study was to comparatively analyze the expression and significance of SOX2 and OCT4 in various types of odontogenic cysts and tumors. Methods Fifty-five cases of odontogenic cysts and tumors, including 15 ameloblastomas (AM), 5 adenomatoid odontogenic tumors (AOT), 5 ameloblastic fibromas (AF), 5 calcifying odontogenic cysts (COC), 10 dentigerous cysts (DC) and 15 odontogenic keratocysts (OKC) were investigated for the expression of SOX2 and OCT4 immunohistochemically. Results Most OKCs (86.7 %) and all AFs expressed SOX2 in more than 50 % of epithelial cells. Its immunoreactivity was moderate-to-strong in all epithelial cell types in both lesions. In contrast, SOX2 expression was undetectable in AOTs and limited to the ameloblast-like cells in a minority of AM and COC cases. Most DCs showed positive staining in less than 25 % of cystic epithelium. Significantly greater SOX2 expression was noted in OKC compared with DC or AM, and in AF compared with COC or AOT. OCT4 rarely expressed in odontogenic lesions with the immunoreactivity being mild and present exclusively in OKCs. Conclusions SOX2 is differentially expressed in odontogenic cysts and tumors. This could be related to their diverse cells of origin or stages of histogenesis. The overexpression of SOX2 and OCT4 in OKC indicates the acquired stem-like property. Future studies should investigate whether the overexpression of OCT4 and SOX2 contributes to the aggressive behaviors of the tumors.

Diagnostic and treatment plans in cystic jawbone tumors are often difficult to address. The etiopathogenic links involved in cell-matrix differentiation disorders are complex. Quantification of the inflammatory process in the evolution of cystic odontogenic lesions highlights a particular reactivity of the host, especially age-dependent and the endodontic-periodontal space interrelation, drawing attention to the difficulties of etiopathogenic, evolution, prognostic and treatment of these lesions. Difficulties in histopathological (HP) diagnosis are reported by the lack of morphofunctional integration of dental tissues, both topographically and evolutionarily, especially when odontogenic epithelial remains in the cystic wall, reactive bone condition, appearance and condition of the reactive epithelium are overlooked. In this study, we developed an interdisciplinary approach for the dynamics of tissue morphology found in the walls of maxillary cysts. Failure to recognize the tissues that form the cystic lesion leads to misinterpretations of pathology and to the wrong classification in the group of maxillary cysts. We analyzed by different techniques 564 biopsy fragments from maxillary cystic lesions, most of which are clinically classified as inflammatory or odontogenic ones. From our experience, we reevaluated the lesions with cystic changes and completed the diagnosis in 10-12% of cases. The most common maxillary cystic lesion encountered by us was the root cyst, an inflammatory dental cyst, which has been over diagnosed clinically, radiologically and histopathologically. Recognition and selection of embryonic remnants from odontogenesis is crucial for the HP diagnosis of maxillary cysts, allowing the clinician to monitor treatment or to develop evolutionary-prognostic perspectives of odontogenic cystic lesions.

The aim of this study was to identify all clinical, radiological, histopathological, and immunohistochemical features associated with recurrence of odontogenic keratocysts (OKCs) in the literature and formulate a recurrence risk stratification based on these findings. A search was performed in PubMed/Medline, Scopus, Web of Science, Google Scholar and Cochrane databases for clinical and laboratory studies reporting on clinico-pathological features that led to OKC recurrences for the period 2000 to 2020. Twenty-three studies were identified and analyzed qualitatively. A total of 2064 OKCs were included of which 439 OKCs were recurrent with a mean follow-up period of 46.7 months. Significantly associated parameters with OKC recurrence included age (variable age categories), large (>4 cm), multilocular lesions with cortical perforation, association with dentition, presence of daughter cysts, and epithelial budding. Immunohistochemical markers including high Ki67 index and AgNOR count were also implicated. A recurrence risk stratification was formulated based on these findings. Although the level of evidence from the included studies was low, there was considerable evidence that the clinico-pathological parameters identified were linked with higher OKC recurrence. The surgeon, radiologist, and pathologist should aim to identify these features when making a diagnosis so as to determine the appropriate management regime and prevent recurrences.

The solid variant of odontogenic keratocyst (SOKC) is an extremely rare odontogenic lesion, which remains poorly defined even in the 2017 World Health Organization odontogenic tumour classification. It is difficult to distinguish between SOKC and so called keratoameloblastoma (KAB), both rare lesions that have similarities in clinical, histological and biological characteristics. Here, we report clinicopathological data and results of molecular analysis of nine cases with a literature review. First, they were compared to previously reported cases of SOKC and/or KAB, and many overlaps were found in clinical and pathological characteristics. Second, we performed PCR analysis for BRAF V600E mutation. Although ameloblastoma-like epithelia were often encountered, none exhibited BRAF V600E mutation, which has been reported to occur frequently in ameloblastomas but not in odontogenic keratocysts (OKCs). One of two cases of SOKC in the present series from which fresh frozen tissue specimens were available was found to harbour PTCH1 mutations, indicating that these were more likely to be a subtype of OKC. Moreover, we also examined the differences between SOKC and primary intraosseous carcinoma (PIOC) with regard to the expression of cytokeratins (pan-CK, CK5/6, CK7, CK8/18, CK10, CK14 and CK19), p53 and Ki-67. The proportions of p53-and Ki-67-positive cells were significantly higher in PIOC than in SOKC. These findings suggest that immunostaining for p53 and Ki-67 would be useful to differentiate between SOKC and PIOC. We also conducted a review of SOKC and KAB cases reported in the English language literature.

Objective We aimed to assess which metabolic pathways would be implicated in the phenotypic changes of the epithelial lining of odontogenic keratocyst after marsupialization, comparing pre- and post-marsupialized lesions with adjacent oral mucosa. Materials and methods Eighteen formalin-fixed and paraffin-embedded tissues from six subjects were divided into three paired groups: odontogenic keratocyst pre (n=6) and post marsupialization (n=6), and adjacent oral mucosa (n=6). The metabolic pathways found in these groups were obtained by high-performance liquid chromatography-mass spectrometry-based untargeted metabolomics performed. Results Through putative metabolite annotation followed by pathway enrichment and predictive analysis with automated algorithms (Mummichog and Gene Set Enrichment Analysis), we found differences in many cellular processes that may be involved in inflammation, oxidative stress response, keratinocyte-basal membrane attachment, differentiation, and proliferation functions, all relevant to odontogenic keratocyst pathobiology and the phenotype acquired after marsupialization. Conclusion Our study was able to identify several metabolic pathways potentially involved in the metaplastic changes induced by marsupialization of odontogenic keratocysts. An improved comprehension of this process could pave the way for the development of targeted therapies.

Calcifying odontogenic cysts (COC) and adenomatoid odontogenic tumors (AOT) have similar radiographic findings. We examined the radiographic and computed tomography (CT) images of patients histologically diagnosed with COC or AOT and identified their characteristic findings. The subjects included 12 patients histologically diagnosed with COC or AOT (one female and five males per group), who underwent CT at our hospital between Nov 1998 and Jun 2019. The location of the lesion, impacted tooth, bone expansion, root resorption, tooth migration, calcified body, and presence or absence of a high-intensity zone in the marginal area of the lesion were examined. In patients with COC, five patients with COC exhibited bone expansion toward the buccal side. The lesion encompassing the crown was attached to the cement-enamel junction and contained a radiopaque lesion with a calcified body. In 6 patients with COC, irregularly shaped calcified bodies were observed with small tooth-like structures. In patients with AOT, all six patients with AOT exhibited bone expansion toward the buccal and lingual sides. The lesion encompasses a part of the tooth root or the entire tooth. Punctate calcification was observed within the lesion and the marginal area in three patients, and a high-intensity zone was observed in the marginal area of the lesion in two patients. We report imaging findings that may be characteristic of COC and AOT, suggesting that CT findings may be useful for differentiating between COC and AOT.

OBJECTIVE The aim of this study is to present and discuss the salient clinicopathological features, differential diagnosis and epithelial immunohistochemical profile of three additional cases of peripheral odontogenic keratocyst (POKC) and to present a review of the literature. POKC is a locally aggressive odontogenic lesion. The peripheral variant of the odontogenic keratocyst is rare and more frequently located in anterior gingiva. MATERIAL AND METHODS We present the clinicopathological features of 3 new cases of POKC (2 women and 1 man; age range: 14-74 years). Immunohistochemical study included CK7, CK14, CK19 and Ki-67, and a systematic review of the literature was performed in PubMed, Scopus and Web of Science databases. RESULTS All cases were located in the anterior gingiva (2 in maxilla and 1 mandible), and none corresponded to Gorlin-Goltz syndrome. High expression of CK14 was seen in all cases, with CK19 and CK7 been only focally positive. The expression of Ki-67 was located in the basal and parabasal cells in all cases. CONCLUSIONS POKC is a rare gingival lesion that seems to originate from remnants of dental lamina or from the basal cells of the gingival epithelium and present a similar histopathology as compared to intraosseous OKC.

Purpose The differentiation of the ameloblastoma and odontogenic keratocyst directly affects the formulation of surgical plans, while the results of differential diagnosis by imaging alone are not satisfactory. This paper aimed to propose an algorithm based on convolutional neural networks (CNN) structure to significantly improve the classification accuracy of these two tumors. Methods A total of 420 digital panoramic radiographs provided by 401 patients were acquired from the Shanghai Ninth People’s Hospital. Each of them was cropped to a patch as a region of interest by radiologists. Furthermore, inverse logarithm transformation and histogram equalization were employed to increase the contrast of the region of interest (ROI). To alleviate overfitting, random rotation and flip transform as data augmentation algorithms were adopted to the training dataset. We provided a CNN structure based on a transfer learning algorithm, which consists of two branches in parallel. The output of the network is a two-dimensional vector representing the predicted scores of ameloblastoma and odontogenic keratocyst, respectively. Results The proposed network achieved an accuracy of 90.36% (AUC = 0.946), while sensitivity and specificity were 92.88% and 87.80%, respectively. Two other networks named VGG-19 and ResNet-50 and a network trained from scratch were also used in the experiment, which achieved accuracy of 80.72%, 78.31%, and 69.88%, respectively. Conclusions We proposed an algorithm that significantly improves the differential diagnosis accuracy of ameloblastoma and odontogenic keratocyst and has the utility to provide a reliable recommendation to the oral maxillofacial specialists before surgery.

Ki-67 is a marker of cell proliferation, used as an important diagnostic marker in the pathologic differentiation of various lesions. It is also relevant for developing targeted molecular therapies. We carried out a systematic review to assess the Ki-67 labeling index (LI) in odontogenic cysts and tumors. Databases were searched, including PubMed (MEDLINE), Scopus, CINHAL, PsycoInfo, the Cochrane Library, and Proquest. The meta-analysis was carried out based on the data of 608 lesions. When a 5% cut-off point was set, ki-67 LI of all benign odontogenic tumors dropped below this point. All the malignant tumors demonstrated an LI of over 15.3%; a significantly higher Ki-67 LI in malignant odontogenic lesions (17.59±2.80) was observed. Among benign tumors, the largest and the smallest Ki-67 LIs were seen in ameloblastoma (4.39±0.47) and adenomatoid odontogenic tumor (0.91±1.71). The mean values of Ki-67 LI in tumors and cysts were 4.23 (0.38) and 1.04 (0.07), respectively. Among odontogenic cysts, the highest Ki-67 LI was found in odontogenic keratocyst (OKC) (3.58±0.51), and the lowest in the radicular cyst (1.29±0.62%). Ki-67 LIs in all odontogenic cysts were

Ghost cell odontogenic carcinoma (GCOC) is a rare malignant neoplasm characterized by the presence of ghostcells. It is considered to originate from either a calcifying odontogenic cyst (COC) or a dentinogenic ghost cell tumor(DGCT). Its clinical and radiographic characteristics are non-specific, including slow growth, locally aggressivebehavior, and eventual metastasis. This case report describes a 43-year-old Thai man with plain radiographs and cone-beam computed tomographic images revealing a unilocular radiolucency with non-corticated borders surrounding an impacted left canine associated with radiopaque foci around the cusp tip. Based on the microscopic findings, the lesion was diagnosed as GCOC. Partial maxillectomy of the right maxilla was performed, and radiotherapy was administered. An obturator was made to support masticatory functions Three years later, the lesion showed complete boneremodeling and no signs of recurrence, and long-term follow-up was done regularly.

Background: Impacted teeth are commonly asymptomatic and not associated with any pathologic lesions for years. Any change in the size of the follicle associated with impacted teeth may result in odontogenic cysts or tumors. CBCT plays an important role in determining the radiographic features of a lesion and therefore, is very helpful for accurate diagnosis and treatment planning. Objective: This study aims to evaluate radiolucent lesions associated with impacted teeth in terms of age and sex distribution, localization, and comparison with the pathological diagnosis. Methods: In this retrospective study, out of 6758 CBCT images, 400 images revealing radiolucent lesions were detected. The study included only 190 cases (regarding 180 patients) which had a matching histopathological evaluation. Data related to the age and sex of the patients, localization of the lesions, and their comparison with the pathological diagnosis were recorded and analyzed. Results: The most encountered lesions were dentigerous cysts (60%) and odontogenic keratocysts (26.3%). Males were the most affected (63.3%). Most of the lesions were found in the left and right posterior mandible and mostly (66.8 %) associated with third molars. Out of 123 radiological diagnoses of dentigerous cyst cases, histopathological diagnoses confirmed 108 cases. Regarding odontogenic keratocyst, histopathological diagnosis confirmed 40 cases out of 48. Conclusion: Radiological diagnoses of the lesions mostly match with their pathological diagnosis unless their characteristics are changed due to infection. CBCT, as a technique enabling detailed imaging of the involved dental structures, is a helpful instrument for differential diagnosis.

Objectives: To determine the role and efficacy of fine needle aspiration cytology (FNAC) and cell block in diagnosis of jaw lesions and compare the agreement between FNAC and cell block to predict the diagnosis. Method: The sample comprised 51 cases, including 12 odontogenic keratocysts (OKCs), 8 ameloblastomas, 22 radicular cysts, 7 dentigerous cysts, and 1 each of intraosseous mucoepidermoid carcinoma (MEC) and adenomatoid odontogenic tumor (AOT). FNAC samples remaining after hematoxylin and eosin (H&E)-stained cytosmear diagnosis were centrifuged at 3,000 rpm for 10 min. The supernatant was discarded and sediment mixed with 2–3 mL alcohol and filtered. To this, 10% formalin was added, filtered, taken for routine processing, and stained with H&E. The result of FNAC smear and cell block was compared with histopathological diagnosis. Results: On cytological examination of the smears, 7 OKCs and 22 radicular cysts were diagnosed, whereas ameloblastomas, AOT, intraosseous MEC, and dentigerous cysts were not. This gave an agreement of 56.8% with the biopsy reports. Cell block sections stained with H&E of 12 OKCs, 22 radicular cysts, 1 MEC, and 3 cases of ameloblastoma offered a diagnosis in accordance with the biopsies giving an agreement of 74.5%, while dentigerous cyst and AOT failed to do so. In comparison with FNAC, additionally 5 cases of OKC and 1 of MEC could be detected, and in ameloblastoma, out of 8 cases, only 3 yielded a concordant diagnosis through the cell block technique. Conclusion: In comparison with FNAC, the architectural pattern and the morphology of the cells were better preserved by the cell block technique. This substantiates that cell block could be used as an ancillary technique to aid in definitive diagnosis of head and neck swellings.

Background The aim of this study was to investigate the clinicopathologic features of primary intraosseous squamous cell carcinoma arising from an odontogenic keratocyst (PIOSCC ex OKC) and comprehensively improve the understanding of this disease. Material and Methods We retrospectively investigated five cases of PIOSCC ex OKC at Peking University School and Hospital of Stomatology. We also conducted a systematic review of studies on PIOSCC ex OKC by using online databases from their inception until February 2020. Results In our series of five cases, all lesions were located in the mandible. Three cases (60%) showed recurrent OKCs and two cases (40%) showed primary OKCs. During the follow-up period, one patient died of local relapse. No patients developed metastasis. On the basis of our literature survey, we selected 22 articles reporting 29 patients with PIOSCC ex OKC. Seven of these patients (24.1%) showed local recurrence, three patients (10.3%) developed cervical metastasis, three patients (10.3%) developed distant metastasis (in the pleura in one case and in the lung in two cases), and seven patients died from the disease during the follow-up period. The disease-specific 5-year survival rate in the study group was 53.2%. Through univariate and multivariate analysis, local recurrence was identified as the only significant independent prognostic factor for survival (P < 0.05). Conclusions The results suggest that PIOSCC ex OKC is a rare intermediate-grade malignancy. Although elective neck dissection is typically unnecessary, adequate therapy should be applied to achieve the lowest local recurrence rate possible to ensure a favorable survival rate. Key words:Primary intraosseous squamous cell carcinoma, odontogenic keratocyst, prognosis.

Background Odontogenic cysts and tumours of the jaws represent one of the most prevalent groups of oral-maxillofacial lesions. We aimed to evaluate the clinical and pathological characteristics of a cohort of odontogenic cysts (OC) and odontogenic tumours (OT) of the jaws in a Portuguese population. Material and Methods This observational retrospective study analysed patients diagnosed with either an OC or OT of the jaws at a central hospital of Oporto, Portugal, between 1988 and 2006. Data collected from patients’ files included demographic, clinical, radiological and histopathological information. Recurrence was evaluated using univariate and multivariate analysis. Results The sample consisted of 397 patients, 231 males (58.2%) and 166 females (41.8%), with a mean-age of 36.7±17 years. Twenty-seven patients (6.8%) presented with more than one lesion providing a total of 433 lesions. There were 396 (91.5%) OC, mostly represented by radicular cysts (n=257;59.4%), dentigerous cysts (n=79;18.2%), or odontogenic keratocysts (n=50;11.5%). There were 37 (8.5%) OT, mostly represented by ameloblastomas (n=16;3.7%), and odontomas (n=9;2.1%). The most common initial clinical manifestation was swelling (n=224;51.7%). Recurrence was observed in 30 cases (6.9%), mostly in ameloblastomas (n=6;37.5%) and odontogenic keratocysts (n=12;24%). In the multivariate analysis the diagnosis classification of the lesion was the only independent and significant variable related with the recurrence (P=0.04). Conclusions Radicular cysts were the most commonly occurring type of OC and ameloblastomas the most commonly occurring OT. Amelobastomas and odontogenic keratocysts were the lesions with the highest rates of recurrence. This large sample provides useful information about the frequency profile and characteristics of OC and OT over a period of 18 years, allowing valuable comparison with data from other countries. Key words:Odontogenic cysts and tumours, radicular cyst, dentigerous cyst, odontogenic keratocyst, ameloblastoma, recurrence.

Odontogenic keratocysts (OKCs) are aggressive lesions that have been variously classified as neoplasms or cysts according to the World Health Organisation (WHO). They can be challenging to surgically remove and the cysts can exhibit locally aggressive behaviour if incompletely excised. We describe a case of recurrent OKC invading the orbit requiring multidisciplinary approach for extended surgical excision, and review the current literature regarding this condition.

Background This study aimed to search for scientific evidence concerning the accuracy of computer-assisted analysis for diagnosing odontogenic cysts. Material and Methods A systematic review was conducted according to the PRISMA statements and considering eleven databases, including the grey literature. Protocol was registered in PROSPERO (CRD 42020189349). The PECO strategy was used to define the eligibility criteria and only studies involving diagnostic accuracy were included. Their risk of bias was investigated using the Joanna Briggs Institute Critical Appraisal tool. Results Out of 437 identified citations, five papers, published between 2006 and 2019, fulfilled the criteria and were included in this systematic review. A total of 5,264 images from 508 lesions, classified as radicular cyst, odontogenic keratocyst, lateral periodontal cyst, glandular odontogenic cyst, or dentigerous cyst, were analyzed. All selected articles scored low risk of bias. In three studies, the best performances were achieved when the two subtypes of odontogenic keratocysts (solitary or syndromic) were pooled together, the case-wise analysis showing a success rate of 100% for odontogenic keratocysts and radicular cysts, in one of them. In two studies, the dentigerous cyst was associated with the majority of misclassifications, and its omission from the dataset improved significantly the classification rates. Conclusions The overall evaluation showed all studies presented high accuracy rates of computer-aided systems in classifying odontogenic cysts in digital images of histological tissue sections. However, due to the heterogeneity of the studies, a meta-analysis evaluating the outcomes of interest was not performed and a pragmatic recommendation about their use is not possible. Key words:Computer-assisted diagnosis, computer-assisted image analysis, computer-assisted image processing, odontogenic cysts, keratocysts, radicular cysts.

Nonmineralized cysts and cyst-like lesions that frequently occur in the mandible include ameloblastomas, odontogenic keratocysts, and dentigerous cysts. They have specific features of well-demarcated, unilocular, and radiolucent lesions that are often associated with tooth impaction. Although it rarely occurs, these cysts can become extremely large. Furthermore, cyst enlargement causes additional symptoms that can challenge the success of tooth recovery through orthodontic treatment. This clinical report presents the successful eruption of 2 impacted molars in a large dentigerous cyst treated with marsupialization and orthodontic traction using an orthodontic miniplate anchorage over a 4-year treatment period.

Background/Aim: The aim of this study was to evaluate and compare the imaging characteristics of common, radiolucent, unilocular, intraosseous lesions of the jaws using both panoramic radiography and cone beam computed tomography (CBCT); also, to evaluate sufficiency of panoramic radiography in determining characteristic features of jaw lesions. Material and Methods: Retrospectively selected images of 57 patients with histopathology results were evaluated by two oral radiologists. The lesions were assessed based on shape, location, borders, relationship with the mandibular canal, presence of destruction of cortical bone, and expansion of cortical bone, and presence of an unerupted tooth related to the lesion. In addition, the widest areas of the lesions were measured. A total of 9 (15.8%) odontogenic keratocysts, 9 (15.8%) apical granulomas, 24 (42.1%) radicular cysts, 12 (21.0%) dentigerous cysts and 3 (5.2%) central giant cell granulomas in 57 patients (20 women, 37 men) with a mean age of 36.93 ± 17.96 years were included. Fifty-seven CBCT and 56 panoramic images of these patients were evaluated. Results: Twenty-nine (50.8%) lesions were in the mandible and 28 (49.2%) in the maxilla. A statistically significant difference was determined for the areas in CBCT images (p=0.007). Conclusions: Panoramic radiography is not as successful as CBCT in demonstrating some characteristics of the lesions, such as expansion and destruction. The area measurements may be beneficial in establishing the differential diagnosis of the lesion.

Decompression of the odontogenic keratocyst has been a long-standing treatment modality in the armamentarium of oral-maxillofacial surgeons. Many different types of effective decompression tubes have been described in the literature. They reduce the size of the cystic lesion by decreasing the intraluminal pressure, induce histologic structural changes in the epithelial lining of the cyst, and allow for bone deposition to occur from the periphery of the cystic cavity. However, many of these have pitfalls including tube dislodgement, traumatization of the oral mucosa, and mucosal overgrowth. We describe a novel technique using an indwelling voice prosthesis (Inhealth Technologies, Carpinteria, CA) to decompress odontogenic keratocysts. We found that our method provides effective decompression using appropriate-length prostheses fit to the cyst dimensions. It provides improved comfort in patients, with less mucosal irritation or overgrowth, improved ease of irrigation, and improved retention that often does not require sutures.

Objectives The aim of this study was to evaluate diffusion-weighted imaging (DWI) in comparison with morphologic magnetic resonance imaging (MRI) in differentiating among odontogenic keratocyst (OKC), unicystic ameloblastoma (UAB), and dentigerous cyst (DC). Study Design Contrast-enhanced MRI, including DWI, was performed on 27 patients with the 3 lesions. Signal intensity characteristics were evaluated on T1- and T2-weighted MRI. The apparent diffusion coefficient (ADC) cutoff value to most effectively differentiate among the 3 lesions was calculated with receiver operating characteristic analysis. Results In total, 17 OKCs, 5 UABs, and 5 DCs were diagnosed histologically. There were no significant differences among them in signal intensity on T1- or T2-weighted images (P ≥ .13). On DWI, 14 of 17 OKCs showed restricted diffusion with a mean ADC value of 0.954 × 10-3 mm2/s. All 5 UABs and all 5 DCs exhibited facilitated diffusion with ADC values ≥ 2.150 × 10-3 mm2/s. The ADC cutoff to differentiate OKCs from UABs was 2.137 × 10-3 mm2/s (P = .01); UABs from DCs was 2.422 × 10-3 mm2/s (P = .03); and OKCs from DCs was 2.347 × 10-3 mm2/s (P = .01). Conclusions Addition of diffusion-weighted sequences to MRI jaw protocols can assist in the characterization of OKCs, UABs, and DCs.

Objective To describe our strategy for the management of odontogenic cysts involving the maxillary sinus, and to define the role of transnasal endoscopic sinus surgery in the treatment algorithm. Methods A retrospective study was conducted. Included were all consecutive patients with odontogenic cysts involving the maxillary sinus who were treated in a single medical center between 2011 and 2019. Their medical records were reviewed for demographic data, preoperative presentation, surgical approach, final pathology, and postoperative course. Odontogenic cysts were classified as small or large according to maxillary sinus extension within or beyond the alveolar recess, respectively. Results A total of 30 patients with odontogenic cysts involving the maxillary sinus were treated by a team of maxillofacial and endoscopic sinus surgeons during the study period. There were 11 cases of dentigerous cysts, 11 radicular cysts, seven odontogenic keratocysts (OKCs), and one glandular cyst. Sixteen cases were managed by transnasal endoscopic sinus surgery alone and 14 were managed by a combined intraoral and endoscopic sinus surgery approach. A total of 22 patients had large cysts and total resection was achieved in 20 of them. There was one case of OKC recurrence during an average follow-up of 31 months. No major complications were recorded. Conclusions The endoscopic approach can serve as an alternative to the transalveolar or lateral window approach. The endoscopic approach is associated with low morbidity and low recurrence rates.

The aim of the present study was to evaluate the 5-year recurrence-free survival and prognostic factors of odontogenic keratocyst (OKC) from a single-center retrospective cohort in the northeastern region of Brazil. Forty cases of OKC comprised the study population. In the cohort analyzed, 18 (45%) cases were recurrent OKCs and 22 (55%) were non-recurrent OKCs. Recurrence-free survival was defined as the period from the release of the histopathological report to the occurrence of relapse or last visit to the service. Comparison of the clinicopathological variables between primary and recurrent OKC lesions revealed no differences in the frequency of epithelial thickness, presence of satellite cysts and cystic spaces, presence of an inflammatory infiltrate, locularity, and lesion borders. The frequency of symptoms was practically the same even after recurrence. Satellite cysts were more frequent in the group of recurrent lesions (n = 9, p = 0.002) and the presence of an inflammatory infiltrate was also significantly associated with recurrent lesions (n = 15, p = 0.006). Previous decompression or marsupialization was associated with recurrence of the lesion (p = 0.010). In conclusion, the most significant prognostic factors were previous decompression or marsupialization, as well as, morphological parameters associated with the recurrence cases were the presence of an inflammatory infiltrate and satellites cysts. The risk of recurrence is low but continues due to the particularities of epithelial proliferation in OKC.

Cripto-1 also known as teratoma-derived growth factor 1 (TDGF-1) belongs to the EGF-CFC family of growth factor-like molecules. Cripto-1 is involved with embryonic development and not expressed in adult tissue, but some tumours are accompanied by reactivation. The aim of this study was to evaluate the immunohistochemical expression of Cripto-1 in most common odontogenic cysts and tumours. Thirty ameloblastomas, 30 keratocysts, 30 dentigerous cysts and two ameloblastic carcinomas were evaluated using the polymeric immunoperoxidase technique. Immunohistochemical expressions were analysed by the IRS (immunoreactive score). Statistical analyses were performed by the Kruskal–Wallis and Mann–Whitney tests (p ≤ 0.05). Age ranged from 9 to 75 years old, with a prevalence of females (n = 49/53.3%). The mandible was the most affected anatomical site (n = 69/75.0%). Cripto-1 immunoexpression was observed in all ameloblastoma, keratocyst and ameloblastic carcinoma cases, although nine dentigerous cyst cases (30%) were negative. Expression scores were higher in ameloblastoma, keratocyst and ameloblastic carcinoma cases (median ranging from 8 to 11) when compared with dentigerous cyst cases (median of 2), with a statistically significant difference (p

Objective: This study was undertaken to investigate the prevalence of intraosseous jaw lesions among pediatrics (0–15 years of age) in a rural health-care center of Maharashtra and to determine the most common types of lesions and their distribution according to gender and anatomical site involved. Study Design: Histopathological data were collected from a database of lesions classified as intraosseous jaw lesions dated between January 1, 2005, and December 31, 2015, from the archives of the Department of Oral and Maxillofacial Surgery, Rural Dental College, Maharashtra, India. All the cases of jaw cysts and tumors among children under 16 years of age group were segregated and scrutinized further under the headings of type of pathologies, anatomical locations where they are most commonly seen, and the age/gender most pertinent to these pathologies. Results: The present study revealed that 114/3896 jaw lesions were pediatric jaw pathologies, of which odontogenic cysts were 67/114 and jaw tumors were 47/114. Among the cysts, 70% were developmental cysts and 30% were inflammatory cysts. The majority (71.6%) of the jaw cysts were found in the mixed dentition phase (7–15 years). Among the jaw tumors, 55% of them were categorized under odontogenic tumors and 45% were under fibro-osseous lesions. Similar to intraosseous jaw cysts, tumors of jaws were more prevalent under the age of mixed dentition, which was found to be 87%. Male predominance was seen and the overall male:female ratio was calculated as 1:0.52 and 1:0.5 for cysts and tumors, respectively. Mandibular posterior segment was found to be the most commonly encountered anatomical site in both the groups of cases. Conclusion: A large number of cases were recorded, which led us to a path of interrogation through which the reason for increased incidence was extracted, and it was agreed that though the pathogenesis remains the same in every individual, routine health checkups and early diagnosis may reduce the incidence and aggressiveness of pathologies, respectively, which was lacking at the rural area.

Odontogenic keratocysts (OKCs) are developmental cysts of the jaws that require proper diagnosis due to their potential for local aggressive growth and recurrences. OKCs have a typical parakeratotic epithelium demonstrating transepithelial cytokeratin 17 (CK17) and basal bcl2 staining on immunohistochemistry (IHC), which distinguishes them from other common jaw cysts. Secondary to inflammation, the epithelial lining may be altered and loses the typical IHC phenotype. The aim of the present study was to analyse a series of consecutive jaw cysts for their expression of CK17 and bcl2 and assess how these IHC stains may help in their diagnosis. All cysts were retrospectively assessed for available clinical, radiological and pathological findings and diagnoses were revised whenever needed. 85 cysts from 72 patients were collected from two departments. The series had 21 OKCs, the remaining non-OKCs included radicular/residual, dentigerous, paradental, lateral periodontal, botryoid odontogenic cysts. OKCs with typical epithelium showed the typical IHC phenotype, which was generally lost in inflammation-associated altered epithelium. Contrarily to earlier descriptions, a wide variety of CK17 positivity was seen in the majority of non-OKCs, including focal transepithelial staining. Basal bcl2 staining was also seen in 16 non-OKCs. These stainings were never as strong in intensity as seen in OKCs. One case was histopathologically identified as OKC due to focally maintained IHC profile. CK17 and bcl2 IHC may help in the diagnosis of OKCs, but must be interpreted with caution and is not a yes or no tool in the diagnostic puzzle. Electronic supplementary material The online version of this article (10.1007/s12253-020-00866-4) contains supplementary material, which is available to authorized users.

OBJECTIVE To characterize clinical, radiographic, and histologic features of canine furcation cysts (CFCs) in dogs and to propose possible mechanisms of CFC development. ANIMALS 20 client-owned dogs with CFCs biopsied between January 1, 2013, and December 31, 2017. PROCEDURES Medical records of the Center for Comparative Oral and Maxillofacial Pathology at the University of Wisconsin-Madison were retrospectively searched to identify records of dogs that had surgical biopsy specimens of mandibular or maxillary cavitary lesions diagnosed as odontogenic cysts and that met additional inclusion criteria. Biopsy sample submission records, medical records, clinical and radiographic images, and histologic samples were reviewed. Clinical, radiographic, and histologic features were evaluated. RESULTS Mean body weight and age of affected dogs were 23.5 kg (51.7 lb) and 8.2 years, respectively. All 20 dogs had a unilateral cyst, with the right (n = 13) or left (7) maxillary fourth premolar tooth affected and viable in all dogs. A predominant clinical sign was a fluctuant swelling of the buccal gingiva and mucosa overlying the CFC, and enucleation of the cyst lining, with or without extraction of the affected tooth, resolved the lesion in most dogs. CONCLUSIONS AND CLINICAL RELEVANCE Our findings indicated that CFC is an odontogenic cyst of uncertain etiopathogenesis and that complete evaluation of the clinical, radiographic, and histologic features of the lesion in affected patients is necessary to distinguish a CFC from other odontogenic cysts and tumors in dogs. Defining CFCs in terms of characteristic features permits accurate diagnosis and appropriate treatment of these previously unclassifiable odontogenic cysts in dogs.

Objectives Kinesiology tape (KT) creates a pulling force on the skin, thus improving blood and lymph flow by alleviating hemorrhage and congestion of lymphatic fluid. The authors hypothesized that the use of KT could be beneficial for the management of complications after head and neck surgery and designed this study to evaluate the effects of KT on swelling, pain, and trismus after enucleation of mandibular dentigerous cysts with third molar extraction. Materials and methods Forty patients who underwent enucleation of a dentigerous cyst with extraction of the mandibular third molar were selected. The patients were randomized into two groups (n=20 each): a KT group, where KT was applied after surgery in addition to basic postoperative care, and a control group, where patients received basic postoperative care without KT application. Swelling, pain, and trismus were evaluated before surgery (T0) and on postoperative days 1 (T1), 2 (T2), and 3 (T3). Cyst volume, gauze weight for assessing bleeding, and operation time were recorded. Results There was a significant difference between the two groups in the change in swelling up to T1 and the change in swelling between T1 and T2. The maximum swelling in the KT group was significantly less than that in the No-KT group and maximum swelling appeared faster in the KT group than in the No-KT group. Both groups showed a mild pain response but there was no significant difference between the two groups. There was no significant difference on interincisal distance change between the two groups. There were no correlations between cyst volume, bleeding, operation time, and maximum swelling. Conclusion KT can effectively manage facial swelling after oral and maxillofacial surgeries such as cyst enucleation and third molar extraction, thus improving postoperative patient satisfaction levels and quality of life.

Objectives: Odontogenic keratocyst (OKC) and ameloblastoma are slowly growing and locally invasive tumors with high recurrence rate. The aim of this study was to investigate the clinicopathologic features of recurrent ameloblastoma and OKC cases, and evaluate outcomes of our treatments in terms of recurrence. Material and Methods: A total of 23 patients with confirmed recurrent ameloblastoma or OKC and treated in our clinic within eleven years period were reviewed retrospectively. Results: Eleven recurrent OKC cases and twelve recurrent ameloblastoma cases were included. Most recurrences occurred within five years after the initial treatment (69.6%). Enucleation had the highest recurrence rate among the first treatments (18/23). All recurrences were located in the mandible, with one exception (22/23). All recurrent OKCs were multilocular. Different histopathologic subtypes of ameloblastoma were seen in our study, follicular ameloblastoma was the most common (8/12). The mean diameter of the lesions was 4.3 cm (ranging from 2 cm to 7 cm). Statically significant relation was found between location and diameter of lesion and year of recurrence onset (p=0.004; p=0.026). We performed radical treatments in these cases (ten patients underwent marginal resections, and thirteen patients underwent segmental resection), and no recurrence was observed during the follow-up period. Conclusion: Previous inadequate surgical procedures were the most important cause of recurrence. Marginal or segmental resection with safety margins is the best method to treat recurrences of OKC or ameloblastoma cases. Resumen Objetivo: Los keratoquistes odontogénicos (KQO) y ameloblastomas son tumores invasivos de lento crecimiento local con una alta tasa de recurrencia. El propósito de este estudio fue investigar las características clínico patológicas de los casos de ameloblastoma y KQO recurrentes y evaluar los resultados de tratamientos en término de recurrencia. Materiales y Métodos: Un total de 23 pacientes con casos confirmados de ameloblastomas o KQO recurrentes tratados en nuestra clínica en un período de once años fueron incluidos. Resultados: Once casos de KQO recurrentes y doce ameloblastomas recurrentes fueron incluidos. La mayoría de las recurrencias ocurrieron en los primeros 5 años posteriores al tratamiento inicial (69.6%). La enucleación mostró la tasa de recurrencia más alta entre los tratamientos iniciales (18/23). Todas las recurrencias se presentaron en la mandíbula excepto por un caso (22/23). Todos los KQO fueron multiloculares. Distintos subtipos histológicos del ameloblastoma fueron detectados en el estudio y el ameloblastoma folicular fue el más común (8/12). El diámetro promedio de las lesiones fue de 4.3cm en un rango de 2cm a 7cm. Una relación estadísticamente significativa se encontró entre la ubicación y el diámetro de la lesión y el tiempo de aparición de la recurrencia (p=0.004; p=0.026). Se realizaron tratamientos radicales en los siguientes casos, diez pacientes tuvieron resecciones marginales y trece pacientes resección segmental; no se observaron recurrencias en el período de seguimiento. Conclusión: Procedimientos previos inadecuados fueron la causa más relevante de recurrencia. Resección marginal o segmental con márgenes de seguridad son el mejor método para tratar casos de ameloblastoma y KQO recurrentes.

Odontogenic cysts and tumors are heterogeneous lesions, originating from elements or remnants of the odontogenic apparatus. Although the majority of these lesions are benign and never undergo malignant transformation, rare malignant tumors may arise de novo or from benign precursors. The molecular basis of these lesions is still poorly understood. This article summarizes and discusses studies using small, medium, and large-scale and/or "-omic" techniques to describe the molecular characteristics of benign and malignant odontogenic lesions and briefly debates strategies to increase the use of "-omic" and multi-omic approaches or integrative analyses in the research of these lesions. A comprehensive understanding of the molecular aspects of odontogenic lesions by using large-scale approaches will enable us to refine the classification of this heterogeneous group of disorders and provide more accurate biomarkers for precise diagnosis, prognosis, and development of molecular tools in the management of patients with these conditions.

We present the frequency of cases of isolated odontogenic keratocysts submitted to microscopic examination at 10 Brazilian referral centres in Oral and Maxillofacial Pathology. In a retrospective (1953-2017) analysis, data on clinicoradiographic features and treatment of these lesions were collected and analysed descriptively. Among the 258,867 cases retrieved, 2,497 (0.96%) were isolated odontogenic keratocysts. In summary, an overview of individuals affected with isolated odontogenic keratocysts is reported herein. This lesion showed predilection for the posterior mandible of young adult men.

Objective. Traditional enucleation of large mandibular odontogenic cysts is an invasive method, which might be associated with several complications. The purpose of this study was to evaluate the clinical outcome of endoscope-assisted enucleation of large mandibular cysts. Study Design. Fifty-seven patients with large mandibular odontogenic cysts were enrolled in this study. Patients were divided into 2 groups as follows: (1) 25 patients who were treated with traditional enucleation and (2) 32 who underwent endoscope-assisted enucleation. Allogeneic bone grafting was applied in all cases. Results. All patients successfully underwent the operation. The follow-up period ranged from 16 to 28 months. Recurrence was found in 2 patients (8%) in the traditional enucleation group; no recurrence was observed in patients in the endoscope-assisted enucleation group. Permanent mandibular nerve palsy was found in 2 patients in the traditional enucleation group; only 2 cases of temporary mandibular nerve palsy were observed in the endoscope-assisted enucleation group. Conclusions. Endoscope-assisted enucleation of large mandibular odontogenic cysts proved to be an effective treatment method, providing complete enucleation of the cystic lesion while preserving surrounding tissue.

Objectives: This study aimed to determine the discrimination power of apparent diffusion coefficient (ADC) for cystic lesions in the jaw using MRI. Methods: We selected 127 cystic lesions, comprising dentigerous cysts (DCs), odontogenic keratocysts (OKCs), and unicystic ameloblastomas (UABs), from our MRI database examined by 3T MRI, including diffusion-weighted imaging sequences, and we reviewed their imaging characteristics. We attempted to discriminate the three types of lesions by ADC values with receiver operator characteristic analysis; however, satisfactory results were not obtained for differentiation between DC and OKC. Therefore, we performed a decision tree analysis. Results: The imaging characteristics of the lesions were significantly different according to Fisher’s exact test, except for differences in sex. The ADC values statistically discriminated the lesions of DC and UAB, OKC and UAB, but not DC and OKC. Thus, differentiation was performed by a decision tree for DC and OKC by evaluating the following points: the attached tooth condition, signal intensity on the T1 weighted image (T1SI), ADC value, and the cyst site. However, cases showing hypo- or isointense T1SI with an ADC value under 1.168 × 10–3 mm2/s were difficult to differentiate. Conclusion: The ADC value helped distinguish UAB from both DC and OKC, but not DC from OKC. However, the decision tree based on ADC value, tooth contact status, and T1SI helped differentiate DC and OKC to some extent.

The objective of the present study was to assess the epidemiology including demographic variables, diagnostic features, and the management of odontogenic keratocyst (OKCs) at several European departments of maxillofacial and oral surgery. This study is based on a systematic computer-assisted database that allowed the recording of data from treated OKCs. The following data were recorded for each patient: gender, age, voluptuary habits, comorbidities, site, size, radiographic features, treatment of OKCs, length of hospital stay, complications, recurrence, management and complications of eventual recurrence. A total of 405 patients, 249 male and 156 female, with 415 OKCs (407 sporadic and 8 syndromic lesions) were included in the study: 320 lesions were found in the mandible, whereas 95 were found in the maxilla. In the mandible, the most frequently involved subsite was the angle, whereas in the maxilla it was the molar region. The most frequently performed treatment option was enucleation plus curettage/peripheral ostectomy in 204 OKCs (recurrence rate, 9%). Decompression without residual cystectomy (recurrence rate, 66%), marsupialization with residual enucleation with the use of Carnoy's solution (recurrence rate, 50%), decompression with residual cystectomy (recurrence rate, 43%), and simple enucleation (recurrence rate, 24%) were the treatment options with the highest recurrence rates. An appropriate management of odontogenic keratocysts should be individualized, taking into consideration clinical and radiological findings, as well as patients’ age and comorbidities.

Cysts of the jaws are not rare, among them the radicular cyst being the most common. It is an inflammatory type of odontogenic cyst forming as a consequence of a long-standing sequel of pulpal necrosis. In contrast to its usual location of occurrence (ie, the maxilla), herewith we report a case of successful management of a 45 year old female patient with a large radiolucent lesion in the left mandibular posterior region with a mandibular ramus extension. The pathology which was strongly presenting as a developmental variety of odontogenic cyst radiographically, was diagnosed as a radicular cyst after histopathological confirmation. To the authors best of knowledge radicular cyst extending into the mandibular ramus is extremely rare and has never been reported previously.