The Prevalence of EBV and KSHV in Odontogenic Lesions

ObjectivesOdontogenic lesions evolve as a result of altered dental development. This study aimed to evaluate the prevalence and the coinfection of Epstein-Barr virus (EBV) and Kaposi sarcoma–associated herpesvirus (KSHV) in radicular cysts, dentigerous cysts, odontogenic keratocysts, and ameloblastomas.MethodsPolymerase chain reaction (PCR) was used to analyse 66 cases of odontogenic lesions for the presence of EBV-DNA and KSHV-DNA. These lesions were 15 radicular cysts, 16 dentigerous cysts, 18 odontogenic keratocysts, and 17 ameloblastomas.ResultsEBV-DNA was detected in 24 (36.4%) of the studied samples as follows: 6 samples (40.0%) of radicular cysts, 4 (25.0%) of dentigerous cysts, 10 (55.6 %) of odontogenic keratocysts, and 4 (23.5%) of ameloblastomas (P = .168). KSHV-DNA was found in 16 (24.2%) of the studied samples as follows: 1 sample (6.7%) of radicular cysts, 6 (37.5%) of dentigerous cysts, 8 (44.4 %) of odontogenic keratocysts, and 1 (5.9%) of ameloblastomas (P = .001). Additionally, EBV and KSHV were positively correlated in all studied samples (P = .002).ConclusionsBoth EBV and KSHV are found in odontogenic cysts and ameloblastomas. KSHV and EBV are more prevalent in odontogenic keratocysts than in other studied odontogenic lesions. Further, there is a high prevalence of EBV and KSHV coinfection in odontogenic cysts and ameloblastomas.     

Accuracy of computer-aided image analysis in the diagnosis of odontogenic cysts: A systematic review

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.     

An observational retrospective study of odontogenic cyst´s and tumours over an 18-year period in a Portuguese population according to the new WHO Head and Neck Tumour classification

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.     

Frequency of odontogenic cysts and tumors: a systematic review

A systematic review of the literature from 1993 to 2011 was undertaken examining frequency data of the most common odontogenic cysts and tumors. Seven inclusion criteria were met for the paper to be incorporated. In the preliminary search 5231 papers were identified, of these 26 papers met the inclusion criteria. There were 18 297 odontogenic cysts reported. Of these there were 9982 (54.6%) radicular cysts, 3772 (20.6%) dentigerous cysts and 2145 (11.7%) keratocystic odontogenic tumors. With the reclassification of keratocystic odontogenic tumor in 2005 as an odontogenic tumor, there were 8129 odontogenic tumors reported with 3001 (36.9%) ameloblastomas, 1163 (14.3%) keratocystic odontogenic tumors, 533 (6.5%) odontogenic myxomas, 337 (4.1%) adenomatoid odontogenic tumors and 127 (1.6%) ameloblastic fibromas. This systematic review found that odontogenic cysts are 2.25 times more frequent than odontogenic tumors. The most frequent odontogenic cyst and tumor were the radicular cyst and ameloblastoma respectively.     

Evaluation of collagen in connective tissue walls of odontogenic cysts –A histochemical study

J Oral Pathol Med (2011) 40 : 257–262 Background: The purpose of this study was to evaluate the nature of collagen in the connective tissue walls of odontogenic cysts, like the odontogenic keratocyst (OKC), dentigerous cyst and radicular cyst using picrosirius red stained sections. Furthermore, it was intended to assess if the capsular connective tissue can affect the nature of overlying epithelium, thus emphasizing the role of epithelial–mesenchymal interactions in biological behaviour of the cysts. Materials and method: The material for the study included 51 formalin‐fixed paraffin‐embedded tissue blocks (15 odontogenic keratocyst, 15 dentigerous cysts, 15 radicular cysts and four normal mucosa and two dental follicular tissue as controls), retrieved from the Department of Oral Pathology and Microbiology, MCODS, Manipal. Tissue blocks were sectioned at 5‐μm thickness, stained with picrosirius red stain and observed with polarization and light microscopy. Results: Few sections of OKC and dentigerous cyst exhibited greenish‐yellow birefringence in sub‐epithelial region, whereas others showed a yellowish‐orange birefringence under polarization microscopy. Most radicular cysts had yellowish‐orange to orange birefringence. Shift in colour in case OKC and dentigerous cyst was attributed to the presence of inflammation in those sections. These regions also exhibited either a change in phenotype or thickness of overlying epithelium. Conclusion: This technique can be used to study the nature of collagen fibres in odontogenic cyst walls. Further studies with an increased sample size and using various epithelial and mesenchymal markers and ssDNA antibodies should be carried out to confirm the effect of epithelial–mesenchymal interactions on the nature of epithelium of odontogenic cysts.     

Interleukin-1alpha-dependent regulation of matrix metalloproteinase-9(MMP-9) secretion and activation in the epithelial cells of odontogenic jaw cysts

Interleukin-1alpha (IL-1alpha) and matrix metalloproteinase-9 (MMP-9) are thought to be involved in odontogenic cyst expansion. In this study, we investigated the effects of IL-1alpha on the secretion and activation of MMP-9 in odontogenic jaw cysts. An active form of MMP-9 was present in odontogenic keratocyst (6 of 8 cases) fluids more frequently than dentigerous cyst (3 of 10 cases) and radicular cyst (3 of 10 cases) fluids, although proMMP-9 was present in all cyst fluids. Odontogenic keratocyst fragments in explant culture secreted a larger amount of IL-1alpha than dentigerous cyst and radicular cyst fragments in explant culture, and spontaneously secreted both proMMP-9 and an active form of MMP-9. The fragments of dentigerous cysts and radicular cysts secreted a small amount of proMMP-9, but no active form of MMP-9. Exogenously added recombinant human IL-1alpha (rhlL-1alpha) increased the secretion and activation of proMMP-9 in the fragments of dentigerous cysts and radicular cysts. The epithelial cells isolated from odontogenic keratocysts secreted IL-1alpha and proMMP-9 without stimulation. Under the cultivation on a fibronectin-coated dish, rhIL-1alpha increased the secretion of proMMP-9 from the epithelial cells in a dose-dependent manner. Moreover, rhIL-1alpha induced the secretion of proMMP-3 and plasminogen activator urokinase (u-PA) from the epithelial cells, and converted the secreted proMMP-3 to the active form in the presence of plasminogen. The secreted proMMP-9 was also activated in the presence of rhIL-1alpha and plasminogen. Hence, our results suggest that IL-1alpha may up-regulate not only proMMP-9 secretion but also proMMP-9 activation by inducing proMMP-3 and u-PA production in the cyst epithelial cells by autocrine/paracrine regulatory mechanisms.     

Prevalence of developmental odontogenic cysts in children and adolescents with emphasis on dentigerous cyst and odontogenic keratocyst (keratocystic odontogenic tumor)

Objective. To investigate the incidence and prevalence of developmental odontogenic cysts in children and adolescents and compare the features of the two most common types, dentigerous cyst and keratocystic odontogenic tumor (KCOT). Study design. A retrospective review in a series of 369 patients with all histological diagnoses of developmental odontogenic cysts in children (≤12 years) and adolescents (13–18 years) was conducted. Results. Among these, 361 (97.8%) patients were diagnosed as dentigerous cyst (n = 281) and KCOT (n = 80), with the male-to-female ratios of dentigerous cyst and KCOT both being 2:1. The average age of the patients with KCOT was older than that of those with dentigerous cyst (14.7 years vs 11.8 years, p < 0.001). Dentigerous cyst (59.1%) was more common in children, but KCOT (78.8%) was more common in adolescents (p < 0.001). Dentigerous cyst (57.6%) predominantly located on the maxilla, but KCOT (60.3%) predominantly located on the mandible (p = 0.010). Conclusions. Adolescent patients with lesions located on the mandible would favor KCOT over dentigerous cyst. This study aids in better knowledge of the prevalence of developmental odontogenic cysts in a large pediatric population, and shows that a well-supported early diagnosis is indispensable for a more adequate treatment.     

A radiolucent lesion crossing the midline in maxilla: a rare presentation of odontogenic keratocyst in young patient

Odontogenic Keratocyst (OKC) is a developmental non-inflammatory odontogenic cyst which is proposed to be arising from cell rests of dental lamina. Among the jaw cysts OKCs account for third most common following radicular and dentigerous cyst. Most of the studies have stated that posterior part of the mandible is the most common site, but there are inconsistencies regarding the prominent location of OKCs in the maxilla. Very few studies and cases are reported with OKCs crossing maxillary midline. If do occur they are in older individuals. According to WHO reclassification, this cyst is considered as Keratocystic Odontogenic Tumour (KCOT) because of its neoplastic nature. This article describes a rare site of occurrence of this lesion especially in young patient.     

Morphologic analysis of odontogenic cysts with computed tomography

Purpose. The purpose of this study was to analyze the effects of lesion site and epithelial keratinization on the morphologic characteristics of odontogenic cysts and clarify determinate factors for cyst morphology.Material and methods. Computed tomographic images of 92 odontogenic cysts were analyzed: 31 primordial, 31 dentigerous and 30 radicular. Thirty-four cysts were located in the maxilla (6 primordial, 10 dentigerous, and 18 radicular) and 58 in the mandible (25 primordial, 21 dentigerous, and 12 radicular). Histologically, 31 cysts showed epithelial keratinization (18 primordial and 13 dentigerous). No keratinization was seen in radicular cysts. The morphologic features of cysts were assessed by measuring long length parallel to dental arch and short length vertical to it and calculating the long/short ratio. In addition, the computed tomography pattern of the cyst was classified into unilocular, lobulated, and multilocular patterns. Appearance of the sclerotic rim and surrounding cortex were classified into three and four patterns respectively to evaluate the developmental features of the cyst.Results. As a whole, the long length of the primordial cysts was statistically larger than the other two cyst groups and resulted in a larger long/short ratio. Statistical differences of CT pattern were also seen among cyst groups. There was no preference in any cyst group for the appearance of the sclerotic rim and cortex. There were statistical differences between maxilla and mandible in short axis and long/short ratio. The maxillary cysts generally showed round shapes irrespective of their histologic characteristics. A multilocular pattern was more frequent in the keratinized group of mandibular primordial cysts. In dentigerous cysts, a multilocular pattern was seen only in the keratinized group and the long/short ratio was statistically larger; cyst shape was elliptical along the long axis.Conclusion. Our results demonstrated morphologic differences of odontogenic cysts caused by lesion site and keratinization. The dentigerous cyst with predominant keratinization should be included in the primordial cyst (odontogenic keratocyst) group.     

Cytokeratin expression of the odontogenic epithelia in dental follicles and developmental cysts

The patterns of cytokeratin expression in the epithelium of 5 dental follicles, 7 dentigerous cysts, 5 odontogenic keratocysts, 3 nasopalatine cysts and an epidermoid cyst have been studies using a panel of monoclonal antibodies. The epithelium of dental follicles and of developmental odontogenic cysts strongly expressed keratins 5 and 19 and showed weaker expression of keratins typical of stratified non-cornified and of simple epithelia. Staining with mAbs against the latter keratins varied with the degree of epithelial differentiation. Nasopalatine cysts strongly expressed simple epithelial keratins and the epidermoid cyst strongly expressed a marker of cornification. Odontogenic cysts thus appear to differ in their pattern of keratin expression from other oral developmental cysts and all derivatives of odontogenic epithelia appear to share similar basic patterns of cytokeratin expression.     

Range and demographics of odontogenic cysts diagnosed in a UK population over a 30-year period

BACKGROUND: The aim of this study was to determine the range of all histologically diagnosed odontogenic cysts along with age range, sex distribution and site of presentation over a 30-year period. METHODS: All entries for odontogenic cysts occurring during 1975-2004 inclusive were retrieved and analysed for demographic data. RESULTS: A total of 55,446 specimens were received, of these 7121 (12.8%) specimens were diagnosed as odontogenic cysts. Radicular cyst was the most common diagnosis (52.3%), followed by dentigerous cyst (18.1) and odontogenic keratocysts (11.6%). CONCLUSIONS: Our study provides demographic data on a large series of odontogenic cysts in a European population. This is one of the largest series reported to date. Cysts such as the paradental cyst have a predilection for certain ages, sexes and sites. Odontogenic keratocysts and glandular odontogenic cysts have a marked propensity to recur as well as behave aggressively. It is essential that such lesions are detected as early as possible to minimize any necessary surgery.     

Relative incidence of odontogenic tumors and oral and jaw cysts in a Canadian population

The diagnoses of 40,000 consecutively accessioned oral biopsies from the Oral Pathology Diagnostic Service, University of Western Ontario, London, Canada, were reviewed. All odontogenic neoplasms, neoplasm-like lesions (tumors), and true cysts of the oral tissues and jaws were listed. Clinical data were reviewed, and microscopic diagnoses were confirmed for cases in which diagnoses were ambiguous. Records of all cases were examined to identify distant referrals that were not representative of the study population. Of a total of 445 (1.11%) odontogenic tumors, 392 (0.98%) were lesions from patients in the usual local drawing area of the biopsy service; 53 were referred from distant centers. From the local population, odontomas were by far the most common tumor (51.53%) followed by ameloblastomas (13.52%) and peripheral odontogenic fibromas (8.93%). Locally, radicular (periapical) cysts were the most common odontogenic cyst (65.15%) followed by the dentigerous cyst (24.08%) and the odontogenic keratocyst (4.88%). The most common nonodontogenic cyst was the nasopalatine duct cyst that accounted for 73.43% of this subset of cysts. Surprisingly few studies of this type are available, especially for odontogenic tumors. These data are important to assess geographic differences in the incidence of lesions and to allow clinicians to make realistic judgments in counseling patients before biopsy about the probability of diagnosis and risks associated with nonspecific clinical or radiographic lesions.     

Prevalence and distribution of odontogenic cysts in Sicily: 1986-2005

The objective of this study was to assess the prevalence of odontogenic cysts (OCs) in Sicily and evaluate their distribution during a 20-year period. A cross-sectional retrospective study was carried out in 1,310 cysts of the jaw diagnosed in 12,197 individuals, who consecutively attended the Odontostomatologic Clinic of Palermo from 1986 to 2005. 1,273 cysts were classified as odontogenic, whereas only 37 were non-odontogenic. In the former group, the most frequent lesions were radicular cysts (84.5%), followed by dentigerous OCs (11.4%). Inflammatory radicular cysts were observed more in male gender, younger age at diagnosis and anterior maxilla as site of presentation. Unlike dentigerous cysts, the frequency of radicular cysts decreased from 10.4% in 1986-1995 to about 8% in 1996-2005 (P < 0.0001). Inflammatory radicular cysts are the most represented group among OCs in our area with a higher prevalence than that reported in other countries. The decreasing epidemiologic trend with time could be attributed to the possible changes in individual oral health behavior.     

Surgical management of odontogenic cysts involving the maxillary sinus- a retrospective study

ObjectiveTo 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.MethodsA 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.ResultsA 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.ConclusionsThe 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.     

Relation between size of odontogenic jaw cysts and the pressure of fluid within

Intracystic fluid pressure may have a crucial role in the growth of odontogenic jaw cysts. In this study, we investigated the relation between the size of the cyst and the pressure of the fluid within odontogenic keratocysts, dentigerous cysts, and radicular cysts. The radiolucent area of the cyst on a panoramic radiograph was linearly related to the volume in the cavity, and the correlation coefficient (gamma) was 0.70 (n = 25, P < 0.001). Intracystic fluid pressure correlated negatively with the radiolucent area in odontogenic keratocysts (gamma = -0.76, n = 9, P = 0.02), dentigerous cysts (gamma = -0.54, n = 16, P = 0.03), and radicular cysts (gamma = -0.69, n = 10, P = 0.03). The values of [(intracystic fluid pressure (mmHg)) x (radiolucent area (cm(2)))] did not differ significantly among the three types of cyst. Intracystic fluid pressure may therefore be negatively related to the size of all three types of cyst.     

牙源性囊肿上皮增殖活性的研究

目的：研究牙源性角化囊肿,含牙囊肿,根尖囊肿3种主要的牙源性囊肿衬里上皮的细胞增殖活性,方法：应用Ki-67单克隆抗体免疫组化LSAB法对30例牙源性囊肿进行免疫组化染色,结果通过计算机图像分析,计算单位面积衬里上皮内（mm2)阳性细胞数,进行统计学分析,结果：牙源性角化囊肿衬里上皮有较多的Ki-67阳性细胞,明显高于含牙囊肿和根尖囊肿;正常口腔粘膜未见Ki-67阳性表达,结论：Ki-67在不同的牙源性囊肿中表达的差异显示了它们具有不同的增殖和分化过程。     

Cytokeratin expression patterns for distinction of odontogenic keratocysts from dentigerous and radicular cysts

BACKGROUND: The clinical outcome of treatment of odontogenic cysts differs depending on separate entities. Particular clinical relevance must be attached to the distinction between odontogenic keratocysts, which have an evident tendency to recur, and other odontogenic cysts. The aim of this study was to evaluate cytokeratin (CK) expression patterns as an additional tool for characterization of different cysts as the histomorphologic appearance often is not decisive. METHODS: Thirty cases of dentigerous and radicular cysts respectively as well as 15 cases of odontogenic keratocysts were considered. Expression of CK 5/6, 7, 10, 13, 17, 19 and 20 was determined in addition to Ki-67 immunohistochemically. RESULTS: Expression of CK 17 was discernible in 93.3% of the odontogenic keratocysts, but only in 35.0% of dentigerous and radicular cysts under study (P < 0.001). CK 19 could be detected in 48.3% of dentigerous and radicular cysts, whereas odontogenic keratocysts were completely negative (P < 0.002). CONCLUSION: Immunohistochemical detection of CK 17 and 19 seems to be a valuable additional parameter distinguishing between odontogenic keratocysts and other odontogenic--especially dentigerous--cysts which clinically are likely the most significant differential diagnoses in this context. J Oral Pathol Med (2005) 34: 558-64.     

Perlecan-rich epithelial linings as a background of proliferative potentials of keratocystic odontogenic tumor

Background:  The intraepithelial deposit of perlecan, a basement membrane-type heparan sulfate (HS) proteoglycan, has been demonstrated in neoplastic conditions such as salivary gland tumors, odontogenic tumors, and oral carcinoma in situ . Our aim was to determine whether perlecan turnover was enhanced in the lining cells of keratocystic odontogenic tumor (KCOT), which had been recently renamed from odontogenic keratocyst because of its accumulated evidence of neoplasm, as a possible background for neoplastic proliferation.
Methods:  Ten surgical specimens from each of KCOT, dentigerous cyst, and radicular cyst were examined for the expressions of perlecan core protein, HS chains, heparanase, and Ki-67 by immunohistochemistry and in situ hybridization.
Results:  In KCOT, perlecan core protein and HS chains were localized on the cell border from the parabasal to subkeratinized layers of the lining epithelium. Heparanase was localized in a similar fashion to those for perlecan and HS chains but was within the cytoplasm. mRNA signals for perlecan core protein and heparanase were mostly compatible with their protein signals. Ki-67-positive cells were localized mainly in the second basal cell layers with definitely higher labeling indices (approximately 31.3%, second layer). In contrast to KCOT, dentigerous cysts and radicular cysts had no perlecan, HS chains, and heparanase deposition in their linings with extremely lower Ki-67 indices (0.4–0.8%).
Conclusion:  The result suggests that the characteristic intra-lining-epithelial deposit of perlecan in KCOT, which has never been seen in other cystic jaw lesions, is a new evidence supporting the neoplastic nature of KCOT.     

Cyst or Tumor? A systematic review and meta-analysis on the expression of p53 marker in Odontogenic Keratocysts

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 < 0.05 was considered to provide evidence to the effect estimates.Results: The first hit retrieved 126 records. After duplicates removal, there were 84 articles, of which eighteen were assessed for eligibility. Thirteen articles were included in the meta-analysis, showing that OKC's have an estimated difference of 23% (P < 0.003) in the probability to express the p53 over dentigerous cysts, and an estimated difference of 4% (P = 0.28) in the probability to express the p53 over ameloblastomas.OKCs seem to behave more similarly to a tumor rather than an odontogenic cyst regarding its p53 expression and the classification of this lesion into Keratocystic Odontogenic Tumor should be carefully revaluated.     

Immunohistochemical analysis of P53 protein in odontogenic cysts

The p53 is a well-known tumor suppressor gene, the mutations of which are closely related to the decreased differentiation of cells. Findings of studies on immunohistochemical P53 expression in odontogenic cysts are controversial. The present study was carried-out to investigate the immunohistochemical expression of P53 protein in odontogenic cysts. Thirty paraffin blocks of diagnosed odontogenic cysts were processed to determine the immunohistochemical expression of P53 protein. Nine of the 11 odontogenic keratocysts (81.8%) expressed P53, one of three dentigerous cyst cases expressed P53, while none of the 16 radicular cysts expressed P53 protein. The findings of the present work supported the reclassification of OKC as keratocystic odontogenic tumor.