Pathologic jaw lesions associated with impacted teeth

The aim of this study was to evaluate the histopathologic diagnoses and radiographic characteristics of lesions associated with impacted teeth. In this retrospective study, 2624 biopsy reports were assessed. If the report was a record of a pericoronal lesion, the age and sex of the patient and the location, microscopic diagnosis, radiographic features, and size of the lesion were recorded. The Pearson chi-square, Kruskal-Wallis, and Fisher exact tests were used for statistical analysis. In total, 189 patients (7.2%) had lesions associated with impacted teeth. The mean (SD) age of affected patients was 25.91 (14.38) years, and 51.9% of patients with pericoronal lesions were male. The most common lesion sites were the posterior region of the maxilla (43.3%) and the posterior region of the mandible (38.0%). Dentigerous cysts (DCs) constituted 64.6% of the lesions, and odontogenic keratocysts (OKCs) represented 18.5%. Radiographs were available in 153 cases, and most lesions were radiolucent (96.1%), had well-defined outlines (99.3%), and were unilocular (87.6%). Lesions larger than 2.0 cm were 5.5 times more likely than smaller lesions to be diagnosed as non-DC lesions (P = 0.001; Kruskal-Wallis test). Although most of the lesions associated with impacted teeth were DCs, there were other lesions with aggressive behavior, such as OKCs, ameloblastomas, and glandular odontogenic cysts, which require more extensive treatment. Lesions that were 2.0 cm or greater showed a higher probability of being non-DC lesions.

Histopathological spectrum of primordial odontogenic tumor with co-existing dentigerous cyst: 1st reported case of the world with a proposed 'updated diagnostic criteria'

BACKGROUND

POT is a relatively newly described benign odontogenic tumor with very few cases registered to date. We present the 1st case of Primordial odontogenic tumor (POT) from Sub-Saharan Africa with unique clinicopathological features; also, this is the first case to report POT's existence as a Hybrid Odontogenic lesion (HOL), with a pertinent review of the literature.

CASE PRESENTATION

This was a 17-year-old patient who presented with slow-growing, painless posterior mandibular swelling. The imaging revealed a well-defined, unilocular, expansile, lytic lesion with internal calcific foci surrounding an impacted #36, indicating a calcifying odontogenic cyst. The incisional biopsy revealed the presence of POT. The tumor was excised along with the involved tooth.

CONCLUSION

POT is predominantly a non-aggressive and mostly affects the pediatric population. Hence, clinicians must be updated on all the aspects of this tumor to diagnose it appropriately and avoid any undue over-or under-treatment.

Evaluation of cyst treatment technique, cyst type, size differences and healing by fractal analysis

AIM

The aim of the study was to evaluate the trabeculation increase of treated mandibular cysts.

MATERIAL AND METHOD

The study included 26 female and 33 male patients (age mean: 38,4 years) with cysts larger than 3 cm in the posterior region of the mandible who were admitted to the same center. Two groups in treatment technique: marsupialization (n = 29) and enucleation (n = 30). Four groups in cyst types: dentigerous cyst (n = 21), keratocyst (n = 19), radicular cyst (n = 15) and residual cyst (n = 4). Cyst size was divided into two categories: smaller than 5.5 cm (n = 31) and larger than 5.5 cm (n = 28). Panoramic radiographs (PR) of the patients were analyzed at the beginning, 6. month and 12. month.

RESULT

At the end of the treatment, there was no statistically significant difference in terms of Fractal Analysis (FA) between patients treated with marsupialization and enucleation, but considering that the cysts in the marsupialization group were larger in size, a faster increase in FA was observed in the marsupialization group. When the cysts were grouped according to their size, it was observed that healing tissues in cysts smaller than 5.5 cm reached normal FA values faster, while healing in the middle of cysts larger than 5.5 cm took more time.

CONCLUSIONS

FA is a reproducible and reliable method. In large cysts, marsupialization results in a faster recovery, but FA values at the end of treatment are similar to the enucleation group. Cysts larger than 5.5 cm show a more rapid increase in Fractal Dimension (FD). The centre of the cysts is the area that heals the latest. Studies with larger sample sizes are needed to evaluate the difference in healing between cyst types.

CLINICAL TRIAL NUMBER

Clinical trial number: Not applicable.

Does YAP influence cell proliferation and apoptosis in benign epithelial odontogenic lesions?

OBJECTIVE

To analyze the immunohistochemical expression of YAP and its correlation with markers involved in cell proliferation and apoptosis in benign epithelial odontogenic lesions.

STUDY DESIGN

The sample consisted of 95 cases of odontogenic lesions (25 dentigerous cysts, 30 non-syndromic odontogenic keratocysts, 30 conventional ameloblastomas, and 10 unicystic ameloblastomas) and 10 dental follicles used as normal odontogenic tissue. The histological sections were submitted to immunohistochemistry with YAP, cyclin D1, Ki-67, and Bcl-2 antibodies. Immunoexpression was analyzed qualitatively and quantitatively using an adapted method. The collected data were analyzed descriptively and statistically (p ≤ 0.05).

RESULTS

The highest YAP expression was observed in odontogenic keratocysts, followed by unicystic ameloblastomas and conventional ameloblastomas, which exhibited moderate immunoreactivity predominantly in peripheral cells. Furthermore, significant differences in YAP immunoexpression were observed between the groups analyzed, with significant positive correlations between YAP and cyclin D1 in dentigerous cysts and unicystic ameloblastomas and between YAP and Ki-67 in unicystic ameloblastomas (p < 0.05). However, there were no statistically significant correlations between YAP and Bcl-2 immunoexpression in the groups studied.

CONCLUSION

YAP may influence epithelial cell proliferation in odontogenic cysts and tumors, suggesting its possible participation in the progression of the odontogenic lesions studied.

Proteomic profile of tissue-derived extracellular vesicles from benign odontogenic lesions

BACKGROUND

Benign odontogenic lesions (BOLs) can cause severe jaw bone defects and compromise the quality of life of patients. Extracellular vesicles (EVs) are well-established and versatile players in mediating pathophysiological events. EVs in the interstitial space (tissue-derived EVs or Ti-EVs) possess higher specificity and sensitivity in disease-related biomarker discovery. However, the role of Ti-EV-loaded proteins in mediating the development of BOLs has remained untapped. Herein, we aim to explore the contribution of Ti-EV-loaded proteins to the development of BOLs.

METHODS

Samples were obtained from 3 with dental follicle, 3 with dentigerous cyst (DC), 7 with odontogenic keratocyst (OKC), and 3 patients with ameloblastoma (AM). Tissue-derived EVs were then extracted, purified, and validated using ultracentrifugation, transmission electron microscopy, and western blotting. Proteins from Ti-EVs were analyzed using LC-ESI tandem mass spectroscopy and differentially expressed proteins were screened, which was then validated by immunohistochemistry and immunofluorescence assays.

RESULTS

The protein profile of Ti-EVs in each group was mapped by LC-MS analysis. The top 10 abundant proteins in BOL-derived Ti-EVs were COL6A3, COL6A1, ALB, HIST1H4A, HBB, ACTB, HIST1H2BD, ANXA2, COL6A2 and FBN1. Additionally, unique proteins in the Ti-EVs from various lesions were identified. Moreover, focal adhesion kinase (FAK) and myeloid differentiation primary response 88 (MyD88) showed higher expressions in Ti-EVs derived from OKC and AM, which were confirmed by immunohistochemistry and immunofluorescence staining.

CONCLUSIONS

Ti-EVs containing FAK and MyD88 might be related to the development of OKC and AM, which can be potential therapeutic targets.

Management of a dentigerous cyst; a ten-year clinicopathological study

BACKGROUND

Dentigerous cysts, deemed of developmental origin, are benign odontogenic cysts characterized by a gradual growth rate. Their occurrence is twice as prevalent in men compared to women. These cysts are recognized as the most frequent developmental cysts affecting the jaws, with a typical manifestation in individuals aged 20 to 40, while infrequently identified in young children. Notably, dentigerous cysts have the potential to attain significant dimensions, resulting in painless enlargement of the jaw and subsequent deformation.

OBJECTIVES

To assess the clinicopathological features and management of ten years of experience with dentigerous cysts.

METHODS

A challenging cases were reported from reviewed records of the patients who were treated by the surgical intervention of various dentigerous cysts throughout the period of ten years, 2012-2022 and only histologically confirmed cases were selected, at Ramadi Teaching Hospital in addition to Rashid, Razi, Zuhur Private Hospitals and private clinics in Iraq.

RESULTS

76 patients were included in this clinicopathological research. The highest age group affected was ≤ 18 years (68.4%), 54% were male, the mandible was more affected (63.1%) than the maxilla (36.9%). Marsupialization was applied to 30.3% of the cases, while enucleation was carried out in 69.7%.

CONCLUSIONS

The significance of meticulous examination of radiographs and the consequences associated with undetected and untreated ailments is affirmed by this case study. A comprehensive understanding of oral pathology serves as a valuable resource for dentists, facilitating accurate diagnosis, appropriate referrals, and the provision of anticipatory guidance to patients striving to achieve optimal oral health across various age groups.

CITED1 expression in odontogenic cysts

BACKGROUND

Originating from odontogenic tissue, Odontogenic cysts are pathological cavities lined with epithelial cells and surrounded by fibrous connective tissue. This study investigated expression of CITED1 protein in different types of odontogenic cysts.

MATERIAL AND METHOD

40 keratocysts, 40 radicular cysts, and 40 dentigerous cysts were excised and processed for routine paraffin wax embedding protocol. Macroscopic and panoramic radiographies images were used for diagnosis. Demographical properties and dental parameters were recorded. Cystic tissues were stained with hematoxylin-eosin dye and CITED1 antibody. Semi-quantitative analysis was performed for immune staining. The protein-protein interaction network, hub gene detection and KEGG analysis were conducted using Cytoscape software.

RESULT

Odontogenic keratocysts was imaged with 6-8 layered epithelial cells and fibrous cyst walls with inflammatory cells. Radicular cysts had stratified squamous epithelium with varying thickness, ciliated cells, and Rushton hyaline bodies. Dentigerous cysts presented hyperplastic non-keratinized epithelium, fibrous tissue, rete ridges, and inflammatory cells. CITED1 immunoexpression was highest in odontogenic keratocysts, followed by radicular cysts, and lowest in dentigerous cysts. Nuclear and cytoplasmic CITED1 expression was significantly elevated in odontogenic keratocysts compared to radicular and dentigerous cysts. The top five targets of CITED1 were identified, primarily showing enrichment in hormone and cancer related pathways.

CONCLUSIONS

Positive CITED1 expression in all three types of odontogenic cysts suggest a potential role for CITED1 in the pathogenesis of odontogenic cysts, particularly in keratocysts. Further investigations are needed to elucidate the exact mechanisms underlying the differential expression of CITED1 and its implications for the development and progression of odontogenic cysts.

Three-dimensional evaluation of dentigerous cysts in the Turkish subpopulation

BACKGROUND

To investigate the radiological and demographic features, types, distribution, and treatment methods of dentigerous cysts (DC).

METHODS

Panoramic radiographs and cone beam computed tomography (CBCT) images of patients diagnosed with DC based on biopsy results between January 2020 and December 2023 were examined. In patients from different age groups, the numbers, types and locations, and radiological features of DCs, associated changes in surrounding tissues, and treatment methods used were reviewed.

RESULTS

Among 95 patients with DC (66 males, 29 females), sex and age distributions were comparable between those with a single cyst (n = 86) and those with two cysts (n = 9). Of 104 DCs, 44 were central, 38 were lateral, and 22 were circumferential. DC types were not significantly affected by sex, age group, or anatomical location. Circumferential DCs often caused displacement of the mandibular canal inferiorly. While enucleation was preferred for the treatment of central DCs, circumferential DCs were treated with marsupialization.

CONCLUSIONS

In this study, which is the first to evaluate the DC types on CBCT images, the central type was the most common. Circumferential DCs were mostly treated with marsupialization. CBCT imaging can assist in determining DC types, and may provide guidance for treatment planning.

Surgical management of dentigerous cyst arises from ectopic tooth: A report of three consecutive cases and literature review

BACKGROUND

Dentigerous cysts are slow-growing, asymptomatic lesions that typically form around the crowns of impacted teeth. They are not detected until they start to harm the tissues around the teeth.

AIM

The present study aimed to describe surgical techniques for treating dentigerous cysts associated with ectopic teeth.

CASES

Three patients with dentigerous cysts associated with ectopic teeth, their surgical approaches, and the supporting literature are presented herein. In two cases, the surgical technique used was intra-oral, and in one case was extra-oral. Under general anesthesia, dentigerous cyst enucleation and ectopic tooth removal were carried out.

DISCUSSION

In the present study, the ectopic tooth cases were all linked to dentigerous cysts. Enucleation or marsupialization treatments could be used to treat dentigerous cysts. Enucleation with the removal of the impacted tooth is the preferred treatment for dentigerous cysts.

CONCLUSION

To perform minimally invasive surgery, the position of the ectopic teeth, the accessibility of the surgical site, the degree of bone reduction, and the simplicity of instrumentation should all be considered.

Diagnosis of common intraosseous lesions of the dentomaxillofacial region by chemometry-assisted FT-IR spectroscopy in dental tissue samples

PURPOSES

This study aimed to determine the differential diagnosis of three intraosseous lesions (odontogenic keratocyst (OKC), central giant cell granuloma (CGCG), and dentigerous cyst (DC)) of the dentomaxillofacial region with very similar radiological and clinical features by using chemometrics assisted FT-IR (Fourier transform infrared) spectroscopy in tissue samples.

METHODS

Tissue samples (exposed to formaldehyde for a similar time) of 20-micron thickness belonging to 19 intraosseous lesions diagnosed histopathologically were obtained from the pathology laboratory. The samples were analyzed by FT-IR spectroscopic method using the 400-4000 cm-1 wavenumber range, and the obtained spectra of the samples were evaluated using the orthogonal partial least squares discriminant analysis (OPLS-DA) algorithm.

RESULTS

The intraosseous lesions with different histopathological diagnoses were accurately and precisely clustered with different FT-IR bands corresponding to the main molecular vibrations, especially the phosphodiester region, of the tissue components using the proposed model with 3 latent variables.

CONCLUSIONS

The model showed high sensitivity and specificity. The present study is the first to report the elucidation of clear spectral differences between similar lesions in the maxillofacial region. In the future, the FT-IR method may be used in the non-destructive classification of similar lesions in the maxillofacial region as an alternative to histopathological evaluation.

Cysts of the jaws: A multicentre study

OBJECTIVES

To determine the relative frequency, demographic and pathologic profiles of patients diagnosed with cysts of the jaws.

MATERIALS AND METHODS

Biopsy records of the participating institutions from 2000 to 2020 were reviewed for lesions diagnosed in the cyst category. Demographic data, the location of the cysts and pathologic diagnoses were collected. Data were analyzed by appropriate statistics using IBM SPSS software version 28.0.

RESULTS

From 148,353 accessioned cases, 25,628 cases (17.28%) were diagnosed in the cyst category. Mean age of the patients ± SD = 42.62 ± 19.36 years. Paediatric patients (aged ≤ 16 years) accounted for 9.63%, while geriatric patients (aged ≥ 65) comprised 14.22% of all the patients. The male-to-female ratio was 1.27:1. The majority of the lesions were encountered in the mandible. The most prevalent cyst was radicular cyst followed by dentigerous cyst and odontogenic keratocyst. In the paediatric group, dentigerous cyst was the most prevalent, whereas in the geriatric group, radicular cyst was the most common.

CONCLUSIONS

In general, the results of this study are in accordance with previous studies. This study provides an invaluable database for clinicians when formulating clinical differential diagnoses as well as for pathologists in rendering the final diagnosis.

Dentigerous cysts suspected the other odontogenic lesions on panoramic radiography and CT

Dentigerous cysts are known as the second most common type of cyst in the jaws. The cyst is one of the lesions occurred frequently in the posterior body of the mandible and is often related to the unerupted third molar and forms around the crown of the unerupted tooth attaching at the cementoenamel junction. Such characteristic appearances are the diagnostic points differentiating from ameloblastoma or odontogenic keratocyst. However, it would be hard for us to diagnose it as a dentigerous cyst if the lesion does not show its typical appearance. We experienced two cases of dentigerous cysts which did not form around the crown of the unerupted tooth on radiologically. Both cysts were relatively large and resorbed adjacent teeth roots. Therefore, an ameloblastoma or an odontogenic keratocyst was suspected rather than a dentigerous cyst as the imaging diagnosis. The biopsy revealed that the lesion was a "dentigerous cyst" in one of the cases and "developmental cyst with inflammation" in another case. After the excision, the histopathological diagnosis was a dentigerous cyst with inflammation in both cases. This report shows the two cases of dentigerous cysts focusing on panoramic radiography and CT images. Also, we discuss the differential diagnosis by reconsidering those diagnostic points.

Assessment of MUC5AC and MUC2 Immunoexpression in Glandular Odontogenic Cysts, Dentigerous Cysts, and Mucoepidermoid Carcinomas

Glandular odontogenic cysts (GOCs) and dentigerous cysts may show mucous metaplasia. Central mucoepidermoid carcinoma is very rare and mostly associated with dental cysts. It is hypothesized that odontogenic cysts showing mucus differentiation in their lining, have a propensity to transform into MEC. The present study is the first attempt to explore the relationship between odontogenic cysts [GOCs and dentigerous cysts with mucus metaplasia (DCMM)] and MEC by evaluating immunoexpression of MUC5AC and MUC2. Immunoexpression of MUC5AC and MUC2 was evaluated semiquantitatively in GOCs (20 cases), DCMMs (20 cases), and MECs (20 cases). The percentage of positive cells, intensity, and localization of immunoexpression were assessed for each marker in all cases. Of GOCs, DCMMs, and MECs cases, 85%, 70%, and 80%, respectively, were immunopositive for MUC5AC. Strong cytoplasmic immunoreactivity for MUC5AC was noted, particularly in mucous cells present diffusely within MECs. However, the immunoreactivity was limited to the epithelial lining of GOCs and DCMMs. Most of the MECs (60%) showed more than 25% positivity for MUC5AC, followed by GOCs, and the least in DMMCs. Mild cytoplasmic and nuclear positivity of MUC2 was noted only in epithelial lining cells of 70% GOCs and 45% DCMMs. Whereas, 55% of MECs displayed moderate to strong cytoplasmic and membranous immunopositivity for MUC2 exclusively within mucous cells. As MECs showed strong MUC5AC immunoreactivity in mucous cells, immunoexpression of MUC5AC in odontogenic cysts with mucus cells can possibly explain the pathogenesis of MEC from cysts. However, the variable expression of MUC2 did not give any strong evidence regarding its role as a marker.

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

AIM

Cyst formation of the jaws is frequently accompanied by the proliferation of odontogenic epithelial cells located in the periodontal ligament (PDL), which consists of heterozygous cells and includes the most fibroblasts. The lining epithelium of radicular cyst, an odontogenic cyst of inflammatory origin, is derived from the proliferation of the remnants of the Hertwig epithelial root sheath (odontogenic epithelial cell rests of Malassez; ERMs) in the PDL. ERMs are maintained at a lower proliferative state under physiological conditions, but the regulatory mechanisms underlying the inflammation-dependent enhanced-proliferative capabilities of ERMs are not fully understood. The aim of this study was to evaluate the effects of cytokine pathway association between TGF-β signalling and IL-1β signalling on the regulation of odontogenic epithelial cell proliferation using radicular cyst pathological specimens and odontogenic epithelial cell lines.

METHODOLOGY

Immunofluorescence analyses were performed to clarify the expression levels of Smad2/3 and Ki-67 in ERMs of 8-week-old mouse molar specimens. In radicular cyst (n = 52) and dentigerous cysts (n = 6) specimens from human patients, the expression of p65 (a main subunit of NF-κB), Smad2/3 and Ki-67 were investigated using immunohistochemical analyses. Odontogenic epithelial cells and PDL fibroblastic cells were co-cultured with or without an inhibitor or siRNAs. Odontogenic epithelial cells were cultured with or without TGF-β1 and IL-1β. The proliferative capabilities and Smad2 phosphorylation levels of odontogenic epithelial cells were examined.

RESULTS

Immunohistochemically, Smad2/3-positivity was increased, and p65-positivity and Ki-67-positivity were decreased both in ERMs and in the epithelial cells in dentigerous cysts, a non-inflammatory developmental cyst. In contrast, p65-positive cells, along with the expression of Ki-67, were increased and Smad2/3-positive cells were decreased in the lining epithelia of radicular cysts. Co-culture experiments with odontogenic epithelial cells and PDL fibroblastic cells revealed that PDL cells-derived TGF-β1/2 and their downstream signalling suppressed odontogenic epithelial cell proliferation. Moreover, TGF-β1 stimulation induced Smad2 phosphorylation and suppressed odontogenic epithelial cell proliferation, while IL-1β stimulation reversed these phenotypes through p65 transactivation.

CONCLUSIONS

These results suggest that IL-1β-p65 signalling promotes odontogenic epithelial cell proliferation through suppressing TGF-β-Smad2 signalling, which would be involved in the pathogenesis of radicular cysts.

The Effect of Decompression on Histologic Diagnoses of Cystic Jaw Lesions

AIM

The aim of this study is to investigate if and how decompression alters histopathologic diagnoses of cystic jaw lesions.

METHODS

A retrospective study was conducted on patients with a histologic diagnosis of an odontogenic cystic lesion that was surgically treated with decompression followed by a definitive surgery. The correlation between variables including age, gender, location of the lesion, decompression time and the change in histopathologic diagnosis following decompression was analyzed.

RESULTS

Thirty-nine patients were included in the study. The mean decompression time was 7.87 ± 3.43 months. Post-decompression histologic examination at time of definitive surgery was consistent with the initial biopsy diagnosis in 83.33% (5 of 6) of odontogenic keratocysts (OKCs), 94.11% (16 of 17) of radicular cysts, 100% of dentigerous cysts, and 100% of residual cysts. The change in histopathologic diagnosis of the cystic lesions was not found to be statistically correlated with the study variables.

CONCLUSIONS

Histopathologic diagnoses of odontogenic cystic lesions predominantly remain unchanged after decompression. A treatment protocol based on the initial diagnosis may be appropriate for odontogenic cystic lesions that are considered for decompression before definitive surgery.

Identification of ferroptosis-related proteins in ameloblastoma based on proteomics analysis

PURPOSE

We used proteomic sequencing and experimental verification to identify the potential ferroptosis-related proteins in ameloblastoma.

METHODS

Samples of ameloblastoma (n = 14) and normal gingival tissues (n = 5) were collected for proteomic sequencing to identify differentially expressed proteins (DEPs) in ameloblastoma. Ferroptosis-related genes were downloaded from FerrDb V2, which were then compared with DEPs to obtain ferroptosis-related DEPs (FR-DEPs). A functional enrichment analysis was performed, and a protein-protein interaction network was built. The hub proteins were screened using the Cytoscape software, and potential drugs targeting them were retrieved from the DrugBank database. A hub protein was selected for immunohistochemical validation, and its expression was assessed in ameloblastomas, odontogenic keratocysts, dentigerous cysts, and normal gingival tissues. The primary ameloblastoma cells were cultured to explore the effect of the protein on the migratory properties of the tumour cells.

RESULTS

A total of 58 FR-DEPs were screened, and six hub proteins were identified: mTOR, NFE2L2, PRKCA, STAT3, EGFR, and CDH1. Immunohistochemical analysis showed that mTOR expression was upregulated in ameloblastomas compared with that in odontogenic keratocysts, dentigerous cysts, and normal gingival tissues. p-mTOR was highly expressed in ameloblastomas, with a positivity rate of 83.3%. In addition, rapamycin, an inhibitor of mTOR, can inhibit the migratory capacity of primary cultured ameloblastoma cells.

CONCLUSION

Our results revealed the ferroptosis-related proteins in ameloblastomas and their underlying biological processes. Additionally, mTOR was overexpressed and was found to be associated with the aggressiveness of ameloblastomas, which may be a potential target for future treatments.

Pediatric Oral Pathology: Odontogenic Cysts

Cysts encountered in the head and neck typically arise from epithelium that would normally be programmed to form teeth or tooth-supporting structures (odontogenic epithelium). These cysts come with a confusing array of similar-sounding names and histopathologic features that are sometimes shared between conditions. Here we describe and contrast the relatively-common lesions: hyperplastic dental follicle, dentigerous cyst, radicular cyst, buccal bifurcation cyst, odontogenic keratocyst, glandular odontogenic cyst, and the less-common gingival cyst of the new-born and thyroglossal duct cyst. The goal of this review is to help clarify and simplify these lesions for the general pathologist, pediatric pathologist, and surgeon.

Differential expression of PEA3 in odontogenic cysts and tumors

BACKGROUND

PEA3 transcription factor has been identified as a downstream target of the MAPK and PI3K pathways, and PEA3 overexpression has been observed in a variety of tumor types. We aimed to evaluate PEA3 expression in odontogenic cysts and tumors and compare the expression among odontogenic lesions. In addition, the correlations between PEA3 expression and clinicopathological characteristics of conventional ameloblastoma and unicystic ameloblastoma were investigated.

METHODS

This study was performed on 165 samples of odontogenic cysts and tumors including 20 dentigerous cysts, 20 odontogenic keratocysts, 16 adenomatoid odontogenic tumors, 5 ameloblastic fibromas, 45 unicystic ameloblastomas, and 59 conventional ameloblastomas. The sections were immunohistochemically stained with mouse monoclonal anti-PEA3 antibody and PEA3 expression was evaluated as the immunoreactive score.

RESULTS

PEA3 expression was absent in all dentigerous cysts (DCs) and odontogenic keratocysts, while all adenomatoid odontogenic tumors showed either no (75%) or low (25%) expression of PEA3. Most of the ameloblastic fibromas (60%) displayed no PEA3 expression. A high expression of PEA3 was observed in a substantial number of unicystic ameloblastomas (48.9%) and conventional ameloblastomas (49.2%) in our study. PEA3 expression in DCs, odontogenic keratocysts and adenomatoid odontogenic tumors were significantly different from that in conventional ameloblastomas and that in unicystic ameloblastomas (p < 0.05). The expression of PEA3 was significantly different in the age groups of unicystic ameloblastomas and histological subtypes of conventional ameloblastomas (p < 0.05).

CONCLUSION

PEA3 overexpression is predominant in unicystic ameloblastomas and conventional ameloblastomas compared to other odontogenic lesions, indicating a pivotal role of PEA3 as a downstream effector of MAPK pathway in these two odontogenic lesions.

Comprehensive cornified envelope protein profile of odontogenic keratocysts clarifies the characteristics of non-keratinized oral epithelium

BACKGROUND

Odontogenic keratocysts constitute 10%-20% of odontogenic cysts and exhibit a distinctive corrugated parakeratinized lining epithelium. Considering that cornified envelope formation is an important phenomenon during keratinocyte differentiation, this study aimed to clarify the characteristics of cornified envelope formation in odontogenic keratocysts.

METHODS

We investigated the cellular distribution of cornified envelope-related proteins (transglutaminases and their substrates), as well as the upstream regulatory protein c-Fos, by immunohistochemical analysis of the lining epithelium of 20 odontogenic keratocysts. We examined the corresponding mRNA levels by quantitative polymerase chain reaction. Ten dentigerous cysts served as control non-keratinized cysts.

RESULTS

The distributions of transglutaminase and their substrates except loricrin and small protein-rich protein 1a significantly differed between odontogenic keratocysts and dentigerous cysts. There was no significant difference in c-Fos expression between odontogenic keratocysts and dentigerous cysts. The mRNA levels of transglutaminases and their substrates were significantly higher in odontogenic keratocysts than in dentigerous cysts. However, c-Fos mRNA levels did not significantly differ between groups.

CONCLUSION

Surprisingly, the overall appearance of cornified envelope-related proteins of odontogenic keratocysts was consistent with the characteristics of non-keratinized oral mucosa identified in previous studies. These findings indicate that the contribution of cornified envelope-related molecules in odontogenic keratocysts is similar to that in non-keratinized oral epithelium, rather than keratinized oral epithelium, suggesting that odontogenic keratocysts are not genuine keratinized cysts. The upregulation of cornified envelope-related genes in odontogenic epithelium could be an important pathognomonic event during odontogenic keratocyst development.

Immunoexpression of CXCL12 and CXCR4 in Radicular Cysts, Dentigerous Cysts, and Odontogenic Keratocysts

The aim of this study was to evaluate the immunoexpression of chemokine CXCL12 and its receptor CXCR4 in radicular cysts (RCs), dentigerous cysts (DCs), and odontogenic keratocysts (OKCs), and to correlate the findings with morphologic parameters of RCs (inflammatory infiltrate and cystic epithelium). Twenty RCs, 20 DCs, and 20 OKCs were submitted to immunohistochemistry. The percentages of cytoplasmic (CXCL12 and CXCR4) and nuclear (CXCR4) staining in epithelial and fibrous capsule cells were determined. RCs and DCs exhibited higher epithelial expression of CXCL12 than OKCs ( P <0.05). The expression of CXCL12 in the fibrous capsule was higher in DCs than in RCs and OKCs ( P <0.05). Higher cytoplasmic expression of CXCR4 was observed in the epithelial lining and fibrous capsule of RCs and DCs compared with OKCs ( P <0.05). In the fibrous capsule, DCs exhibited higher nuclear expression of CXCR4 than OKCs ( P <0.05). No significant differences in the immunoexpression of CXCL12 or CXCR4 were observed according to the morphologic parameters of RCs ( P >0.05). Strong positive correlations were found between cytoplasmic and nuclear expression of CXCR4 in the epithelial lining of RCs and DCs and in the fibrous capsule of all groups ( P <0.05). The results suggest the participation of CXCL12 and CXCR4 in the pathogenesis of RCs, DCs, and OKCs. These proteins may be particularly relevant for the development of odontogenic cysts with less aggressive biological behavior, irrespective of their nature (inflammatory or developmental). In RCs, the expression of CXCL12 and CXCR4 may not be related to the intensity of the inflammatory infiltrate or the status of cystic epithelium.

Giant follicular cyst with maxillary sinus and pterygomaxillary space extension

BACKGROUND

Dentigerous, follicular, cysts are developmental odontogenic cysts of reduced adamantine epithelium origin, associated with an impacted tooth. They are the second most frequent cystic pathology after inflammatory cysts. Although the frequency of dentigerous cysts associated with upper third molars is far lower than the mandibular ones, their complications are nothing but ordinary. Most of the times asymptomatic, being discovered during routine x-ray examinations, maxillary follicular cysts can grow to important size, altering the position of adjacent teeth, producing osteolysis of the nearby bone structures, as well as infectious complications, antral and orbital pathology.

CASE REPORT

The present manuscript describes the clinical, radiological, pathological and therapeutical aspects of a giant follicular cyst with antral and pterygomaxillary extension, associated with an impacted upper third molar.

CONCLUSION

The most efficient treatment of maxillary follicular cysts consists in the surgical removal of the lesion along with the involved tooth. Complete excision is mandatory to prevent recurrence. Extension into adjacent structures might complicate the surgery Preoperative evaluation and rigorous planning are essential, especially in large-sized lesions. Pathological examination is outmost importance in order to exclude aggressive transformations.

KEY WORDS

Dentigerous follicular cyst, Maxillary sinus extension, Pterygomaxillary space.

Transmigrated and Impacted Upper 2nd Premolar Associated with Dentigerous Cyst

A male patient about 45 years old came to my private clinic "The Dental Aid", Dhanmondi, Dhaka, Bangladesh last year (February 2016) with the complaint of pain at right palatal premolar region. On clinical examination we found the absence of upper left 2nd premolar from the series of dentition but on the right side premolars are present. The oral mucosa was intact and normal in color. There was no caries, dental pocket or any other pathology in the teeth of both jaws. On palpation we found soft area on the right palatal side at the premolar area. We took intraoral peri-apical radiograph and found impacted left 2nd premolar whose crown was encircled by radiolucent area at the palatal side. Here, we present a rare case of transmigrated and impacted left 2nd maxillary premolar associated with dentigerous cyst. The cyst was successfully treated under general anaesthesia by enucleation along with extraction of the involved maxillary transposed and impacted left second premolar.

A Bag of Marbles: A Fascinating Compound Odontoma of the Maxilla

Odontomas are the most common odontogenic tumors, typically diagnosed during the first two decades of life. 1 The purpose of this paper was to report an interesting case of an eight-year-old Caucasian boy who presented with an asymptomatic, progressive, firm swelling of the right maxilla with no eruption of the permanent maxillary right lateral incisor. Radiographic investigation revealed a mixed radiolucent and radiopaque lesion measuring 28 by 24 by 17 mm with a corticated border causing expansion and thinning of the buccal cortical plate. This large bag-of-marbles-like appearance representing odontoids was impeding his adult teeth from erupting; hence, complete surgical removal under general anesthesia was the treatment of choice. Removal of the lesion resulted in an unexpected loss of the embedded permanent maxillary right lateral incisor. Histopathological investigations gave a diagnosis of compound odontoma; due to their low growth potential, recurrence after removal is not expected.

Metachronous ameloblastic fibro-odontoma and dentigerous cyst in the posterior mandible

An ameloblastic fibro-odontoma (AFO) is a rare mixed odontogenic tumor with histologic features of an ameloblastic fibroma in conjunction with the presence of dentin and enamel. It usually appears as a well-circumscribed radiolucency with radiopaque foci and slow growth and is commonly seen in children and young adults. A 13-year-old boy presented with an asymptomatic swelling in the posterior right region of the mandible and the right ascending ramus. The clinical, imaging, and histopathologic findings confirmed the diagnosis of an AFO. After 8 months, a radiolucent lesion involving the unerupted mandibular left third molar was observed; a final diagnosis of a dentigerous cyst (DC) was established for this lesion. Although coincidental events, metachronous odontogenic lesions suggest a possible common genetic origin, since both can be caused by related cellular signaling pathways. Complete enucleation is recommended for both AFOs and DCs; rates of recurrence are low.

Endoscopic modified medial maxillectomy for odontogenic cysts and tumours

BACKGROUND

Odontogenic maxillary cysts and tumours originate from the tooth root and have traditionally been treated through an intraoral approach. Here, we report the efficacy and utility of endoscopic modified medial maxillectomy (EMMM) for the treatment of odontogenic maxillary cysts and a tumour.

METHODOLOGY

We undertook EMMM under general anaesthesia in six patients: four had radicular cysts, one had a dentigerous cyst, and one had a keratocystic odontogenic tumour.

RESULTS

The cysts and tumours were completely excised and the inferior turbinate and nasolacrimal duct were preserved in all patients. There were no peri- or postoperative complications, and no incidences of recurrence.

CONCLUSION

Endoscopic modified medial maxillectomy appears to be an effective and safe technique for treating odontogenic cysts and tumours.