Optimal time to definitive enucleation of large cysts following marsupialization: a single center, retrospective study

OBJECTIVES

Optimal time to enucleation following marsupialization of large odontogenic mandibular cysts is undefined. We aim to assess volume reduction throughout follow-up, to indicate optimal time to enucleation. Secondary objectives include the identification of factors influencing cyst reduction.

STUDY DESIGN

We retrospectively enrolled 15 patients with mandibular cysts of different histological types treated with marsupialization at our center between 2018-2022. Cyst volume was assessed with cone-beam computed tomography (CBCT) and a semi-automatic segmentation algorithm, at baseline and between 6-8 months post marsupialization.

RESULTS

The overall mean cyst volume reduction percent (VR%) was 57.7% or 0.2% per day. VR% at 8 months was significantly higher than those assessed at 6-7 months (67.1% vs 47.1%, p=0.003). Time to CBCT was the only independent variable influencing cyst VR%.

CONCLUSION

Our study proves that the optimal time to enucleation for mandibular cyst is 8 months, independent of histological cyst type, patient age, baseline cyst volume and the number of pre-operative residual bone walls.

Bone Trabecular Pattern Analysis in Odontogenic Cysts Using Cone Beam Computed Tomography: A Clinical Retrospective Study

Introduction The cysts of the maxillofacial region account for one of the most common pathologies of the head and neck region after the mucosal pathologies. Radiography provides an essential clue in early diagnosis and triaging, but it continues further as it is used to evaluate the post-treatment outcome. However, manual analysis is prone to errors. In this scenario, fractal analysis (FA) in radiographs uses mathematical methods to analyse the changes in grey scales in a given radiographic image. FA in odontogenic cysts is used to characterise their complexity, uncover hidden patterns, monitor treatment response, and potentially provide prognostic information. This paper aimed to assess the fractal characteristics of the radicular cyst (RC), dentigerous cyst (DC), and odontogenic keratocyst (OKC) using cone beam computed tomography (CBCT). The objective was to calculate fractal dimension (FD) values expressed in each of these cysts, which could prove to be a radiological adjunct in diagnosing the above cysts. Materials and methods As this is a retrospective study, the archives of CBCT images from June 2021 to December 2023 were obtained from patients diagnosed and confirmed with a histopathological diagnosis with RC, DC, and OKC. The FA was performed using Image J Software (Ver 1.51, National Institute of Health Bethesda, Fiji). The cortical and cancellous bones were segmented using thresholding techniques and converted to binary images. The mean FD of the three planes was then compared to establish the distinctive fractal characteristic for the specific odontogenic cysts. A one-way ANOVA was performed using the Statistical Product and Service Solutions (SPSS) (version 23.0; IBM SPSS Statistics for Windows, Armonk, NY) to determine the difference between FD values of RC, DC, and OKC with a significance level less than 0.05. Results The FD values of DC, RC, and OKC were 1.33 ± 0.17, 1.08 ± 0.16, and 1.65 ± 0.12, respectively. The results indicated that OKC had higher FD values than DC and RC, which means that OKC had lesser bone destruction compared to DC and RC. Inferential statistics showed that the one-way ANOVA was used to compare the means of the three groups of FD data. When calculated for the three groups, the F-statistic value was at 7.29, which yielded a P value of 0.03, making it statistically significant for a 95% confidence interval (p<0.05). Conclusion Our CBCT study on bone trabecular pattern analysis using FD and FA in odontogenic cysts reveals distinct alterations in bone parameters among different cyst types. The probability of higher FD values in OKC is because of lesser cortical bone destruction in OKC compared to the other cyst types. These findings have potential implications for diagnosing, treating, and prognosticating odontogenic cysts.

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.

Central Mucoepidermoid Carcinoma in the Mandible Mimicking Dentigerous Cyst: A Report of a Rare Case

Mucoepidermoid carcinoma is a rare neoplasm of the salivary gland of which the intraosseous variety is commonly observed with a female predilection and the affected side is more commonly in the mandible. It is usually perceived as an asymptomatic swelling that increases in volume over a few months to a year. They more frequently present as a cortical bulging and are mostly discovered as an accidental finding in a routine radiograph as a well-defined unilocular or multilocular radiolucency resembling an odontogenic cyst. The most widely accepted treatment is radical surgical resection due to its recurrence or metastatic nature. The current case is quite unusual developing in the posterior jaw as a result of an impacted third molar in a 22-year-old female patient.

Actinomycosis of periodontium, mimicking gingival enlargement - A case report and its management

Gingival abscess is a localized, acute inflammatory lesion which is caused by various factors that include microbial plaque infection, foreign body impaction, and trauma. Management includes a simple incision and draining of the purulent exudate along with systemic antibiotics in most of the cases. This article reports a case of a 16-year-old female patient, with a chief complaint of painful and swollen gums in her lower right front tooth region of the jaw along with fever for the past 5 days. Emergency treatment of abscess drainage was done on day 1. On 5th day of review, the case presented with persistent signs of gingival inflammation in relation to 43 to 41. Considering the provisional diagnosis as dentigerous cyst with persistent gingival abscess, definitive treatment was performed by transalveolar extraction of the impacted canine and debridement of the osseous lesion. The histologic analysis of the lesion exhibited foci of eosinophilic coagulum-like areas with epicentric and radiating filamentous appearance at the periphery, which is suggestive of an inflamed dentigerous cyst with actinomycosis infection of periodontium.

Coexistence of a Nasopalatine Duct Cyst and Radicular Cyst: A Unique Clinical Presentation

This study discusses a case of coexistence of two distinct cysts, a nasopalatine duct cyst (NPDC) and a radicular cyst, within the anterior region of the maxilla. NPDC is a prevalent non-odontogenic developmental cyst, while radicular cysts are commonly found in odontogenic inflammatory cysts. The clinical and radiographic characteristics of these cysts are explored, emphasizing the importance of accurate diagnosis and treatment planning. In this case, a 51-year-old male patient presented with swelling and pain in the maxillary anterior region. Radiographic examinations revealed a heart-shaped radiolucent lesion extending from tooth 13 to 23, associated with the NPDC, and a separate radicular cyst. Surgical enucleation and tooth extraction were performed as the treatment of choice. This unique case underscores the significance of meticulous radiographic assessment to detect multiple cystic lesions within the same area.

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.

Cholesterol Granuloma in the Maxillary Sinus: A Rare Presentation Associated With an Odontogenic Cyst

Cholesterol granuloma is a histopathological finding characterized by a mass of connective tissue and granulation tissue. It is primarily observed in the middle ear, mastoid process, or paranasal sinuses, with rare occurrences in the dental odontogenic region. A dentigerous cyst encloses the crown of an unerupted tooth by expanding its follicle and attaches to the neck of the tooth. Here, we report a 63-year-old female who presented to the dental clinic complaining of an ill-fitted denture. A panoramic radiograph showed a well-defined radiolucent lesion in the upper left maxillary sinus with an impacted third molar. Computed tomography revealed loss of the anterior and lateral sinus walls. The cyst was enucleated surgically. The final diagnosis was confirmed by histopathological examination, which revealed focal areas of cholesterol clefts in the cystic wall of the dentigerous cyst.

Adjunctive Plasma Rich in Growth Factors in the Treatment of Osteomyelitis and Large Odontogenic Cysts Prior to Successful Implant Rehabilitation: Case Report

Osteomyelitis of the jaws presents a clinical challenge to conventional treatment, often requiring multiple surgical interventions resulting in significant deformity and presenting significant problems to satisfactory rehabilitation. While benign odontogenic cysts, such as the radicular cyst, are generally predictably treated, they can cause significant localized bone destruction and thus can present significant problems in satisfactory rehabilitation. In this case report, patients were treated combining conventionally appropriate surgical debridement and oral antibiotics with adjunctive plasma rich in growth factors (PRGF). Patients showed a complete soft tissue and osseous regeneration to their pre-pathologic state, with successful implant rehabilitation. PRGF appears to be highly successful in minimizing or eliminating osseous deformities normally associated with conventional treatment of osteomyelitis of the jaw and treatment of large odontogenic cysts. Future trials must be performed to confirm these results in comparison to controls using conventional treatment alone.

Modified Carnoy's Versus Carnoy's Solution in the Management of Odontogenic Keratocysts-A Single Center Experience

To date, few studies have been conducted to test the effectiveness of Carnoy's (CS) versus modified Carnoy's (MC) solution for preventing the recurrence of odontogenic keratocysts, which are potentially aggressive lesions. To evaluate the efficacy of MC application, we conducted a retrospective cohort study over an 18-year period, from October 2004 to October 2022, in 122 patients treated surgically with adjunctive chemical cautery, with either CS (n = 73; median age: 30 years) or MC (n = 49; median age: 42 years), by a single surgeon. The primary outcome variables were observed recurrence and interval to recurrence. Independent variables were demographics, location, clinical presentation at baseline, adjacent tooth extraction, and bone grafting. Males predominated in both groups. No statistically significant differences were observed between the two arms in terms of recurrences in particular months, with six patients (8.2%) in the CS arm and 5 (10.2%) in the MC arm. Of the 11 recurrences, 10 were observed within the first 2 years post-surgery, with only one occurring in the 7th year of follow-up. Thus, when used as adjunctive therapy, the application of MC has an efficiency comparable to that of CS for lowering the recurrence rate of odontogenic keratocysts.

Frequency and Demographic Profile of Odontogenic Cysts in Riyadh, Saudi Arabia: Retrospective Multicenter Study

Odontogenic cysts (OCs) are etiologically diverse conditions with a shared origin in the jaws. Unfortunately, there is a scarcity of published data regarding OC frequency, treatment, and follow-up information in Saudi Arabia, especially from tertiary centers.

OBJECTIVES

The study aims to assess the relative frequency, clinicopathological features, treatment, and follow-up of OCs in three tertiary medical centers.

METHODS AND MATERIAL

OCs were identified from King Abdulaziz Medical City, King Fahad Medical City, and Prince Sultan Military Medical City from January 2010 to December 2021.

RESULTS

Three hundred and seventy-two cases of OCs were identified from the archive of three medical centers in Riyadh; one hundred and forty-nine (40%) cases were retrieved from Prince Sultan Military Medical City. The mean age of all OCs was 32 years (range 2-90), with 225 (60.4%) cases occurring in males. There was an almost equal distribution of OCs between the maxilla (47.0%) and the mandible (53.0%). The apical radicular cyst (ARC) accounted for half of the cases, followed by dentigerous cyst (DC) (29.3%) and odontogenic keratocyst (OKC) (14.2%). Enucleation was the most common treatment modality (52.8%), followed by excision (35.0%). Thirteen cases showed recurrence: one ARC, four DCs, and eight OKCs.

CONCLUSION

This is the first large multicenter study of OCs in Riyadh, Saudi Arabia. All three centers showed that ARC was the most common, followed by DC and OKC.

Marsupialisation of 12 odontogenic cysts in Boxer dogs: Retrospective case series

Marsupialisation of odontogenic cysts is a minimally invasive treatment method used in human dentistry. Marsupialisation decompresses the cyst and promotes remodeling of alveolar bone and shrinkage of the cyst. In this retrospective study we look at the effectiveness of marsupialisation at reducing the size of odontogenic cysts in dogs. The case series consists of six Boxer dogs with 12 odontogenic cysts. Each case underwent a high resolution CT scan prior to treatment and at follow-up. Each CT scan was reviewed, the volume of each cyst calculated using manual segmentation and the reduction in cyst volume calculated. There was a marked reduction in cystic volume of 66.6% over a mean of 138 days. This shows that the use of marsupialisation effective method of reducing cyst volume.

Correlation of amyloid and ameloblast-associated proteins to odontogenic cysts and tumors: A cross-sectional study

Background and Aims

Odontogenic cysts and tumors often form hard and soft structures that resemble odontogenesis. It is well known that amyloid is produced in Pindborg tumors; however, it is still debatable whether it is also formed in other odontogenic tumors and cysts. This study aimed to detect the presence of amyloid in different odontogenic cysts and tumors in correlation to matrix proteins secreted during enamel formation; namely amelogenin and odontogenic ameloblast-associated protein.

Methods

This study included formalin fixed paraffin embedded tissue blocks of 106 different types of odontogenic cysts and tumors. Congo red and thioflavin T were performed to confirm the presence of amyloid; immunohistochemistry was used to detect amelogenin and odontogenic ameloblast-associated protein.

Results

Amyloid was detected in pindborg tumors (conventional), adenomatoid odontogenic tumors, odontogenic fibroma (Amyloid variant), follicular solid and unicystic ameloblastomas, radicular cysts, dentigerous cysts, dentinogenic ghost cell odontogenic tumor, ameloblastic fibroma, calcifying odontogenic cyst, and primordial Odontogenic tumor. Amelogenin was detected in 95.3% of the cases, while odontogenic ameloblast-associated protein was detected in 93.4% of the cases. The association between odontogenic ameloblast-associated protein and amyloid was highly significant at p < 0.01. However, there was no significant relationship between amelogenin and amyloid p > 0.05.

Conclusion

Although pindborg tumor is the bonafide example of amyloid deposition in odontogenic tumors, this study concluded that amyloid may be deposited in traces to massive amounts in various odontogenic cysts and tumors, and it is significantly linked to odontogenic ameloblast-associated protein but not amelogenin matrix protein, since all amyloid cases were odontogenic ameloblast associated protein positive.

The molecular basis of odontogenic cysts and tumours

The advances in molecular technologies have allowed a better understanding of the molecular basis of odontogenic cysts and tumours. PTCH1 mutations have been reported in a high proportion of odontogenic keratocyst. BRAF p.V600E are recurrent in ameloblastoma and KRAS p.G12V/R in adenomatoid odontogenic tumour, dysregulating the MAPK/ERK pathway. Notably, BRAF p.V600E is also detected in ameloblastic carcinoma, but at a lower frequency than in its benign counterpart ameloblastoma. Recently, adenoid ameloblastoma has been shown to be BRAF wild-type and to harbour CTNNB1 (β-catenin gene) mutations, further suggesting that it is not an ameloblastoma subtype. CTNNB1 mutations also occur in other ghost-cell-containing tumours, including calcifying odontogenic cysts, dentinogenic ghost cell tumours and odontogenic carcinoma with dentinoid, but the link between CTNNB1 mutations and ghost cell formation in these lesions remains unclear. Regarding mixed tumours, BRAF p.V600E has been reported in a subset of ameloblastic fibromas, ameloblastic-fibrodentinomas and fibro-odontomas, in addition to ameloblastic fibrosarcoma. Such mutation-positivity in a subset of samples can be helpful in differentiating some of these lesions from odontoma, which is BRAF-wild-type. Recently, FOS rearrangements have been reported in cementoblastoma, supporting its relationship with osteoblastoma. Collectively, the identification of recurrent mutations in these aforementioned lesions has helped to clarify their molecular basis and to better understand the interrelationships between some tumours, but none of these genetic abnormalities is diagnostic. Since the functional effect of pathogenic mutations is context and tissue-dependent, a clear role for the reported mutations in odontogenic cysts and tumours in their pathogenesis remains to be elucidated.

Efficacy of calcium sulfate dihydrate as a bone graft substitute in odontogenic cystic defects of jaws following enucleation: A clinical study

Background

The treatment of osseous bone defects created following enucleation of a cyst is an arduous challenge. Autogenous bone grafts despite being the gold standard have various drawbacks such as donor site morbidity, limited availability of bone graft, and increased operative time. Hence, there are various bone grafts which are being investigated which could overcome the limitations of autografts. Thus, this study was conducted to evaluate the efficacy of calcium sulfate (CS), a bone graft substitute, for spontaneous bone regeneration of cystic defects.

Objectives

The purpose of this study is to evaluate bone formation in odontogenic cystic defects following enucleation and reconstruction with bone graft substitute by three-dimensional radiographic and clinical evaluation.

Methodology

A total of twenty patients diagnosed with odontogenic cysts were randomly divided into two groups, out of which the study group had undergone enucleation with bone grafting (tobramycin-impregnated CS dihydrate) and the control group had undergone enucleation without bone grafting. The patients were evaluated clinically and radiographically at the 1st, 3rd, 6th, and 12th months postoperatively.

Results

There was no bone formation observed at 1 month postoperative in both the groups. There was a statistically significant higher bone defect reduction observed radiologically on orthopantomogram and computed tomography scan in the study group than the control group at the 3rd, 6th, and 12th months postoperative. The rate of reduction in cystic volume of the study group at the 12th month was 94.4% and in the control group was 37.16%.

Conclusion

Immediate grafting of cystic cavity can avoid complications such as pathological fracture due to less bone support, delayed healing, etc., The utilization of a graft with a property of inducing rapid bone formation should be taken into consideration. The use of CS as a grafting material accelerated the rate of bone regeneration in the cystic defects, with minimal complications.

Combined conservative treatment of a recurrent mandibular keratocyst by enucleation, diode laser, 5-Fluorouracil and dental implants: a case report with 18 years-follow up

In 2017, the World Health Organization classified the odontogenic keratocyst as a developmental odontogenic cyst. The posterior parts of the mandible, especially the angle and the ramus, are the most involved sites. Due to their high recurrence rate, keratocysts are managed surgically with careful complete excision. Additionally, chemical solutions such as Carnoy's solution, modified Carnoy's solution, and 5-Fluorouracil have been associated with surgical treatment. Diode lasers generate diverse wavelengths that have photothermal and photochemical special properties and could have some effects on the lining epithelium remnants of the cyst. In this paper, we discuss a case of mandibular recurrent odontogenic keratocyst treated with 5-Fluorouracil topical application after enucleation and diode laser application with 18 years follow-up and teeth replacement with dental implant. 5-Fluorouracil and diode laser have been found to be very effective in the treatment of keratocysts.

Immunohistochemical analysis of SHH, SMO and GLI-1 proteins in epithelial odontogenic lesions

The present study analyzed the expression of proteins involved in the sonic hedgehog signaling pathway (SHH, SMO, and GLI-1) in benign epithelial odontogenic lesions (odontogenic keratocyst - OKC, ameloblastoma - AB, and adenomatoid odontogenic tumor - AOT) in order to identify the role of these proteins in the pathogenesis of these lesions. The sample consisted of 20 OKCs, 20 ABs, and 10 AOTs. The Kruskal-Wallis, Mann-Whitney U, and Spearman's (r) tests were used for statistical analysis, with the level of significance set at 5% (p < 0.05). The membrane/cytoplasmic expression of SHH was significantly higher in AB compared to AOT (p = 0.022) and OKC (p = 0.02). No differences were found in the membrane/cytoplasmic expression of SMO between the lesions studied. Regarding GLI-1, significant differences were observed at the nuclear level for AB and OKC compared to AOT (p < 0.0001). In addition, significant positive correlations were found between cytoplasmic and nuclear GLI-1 in AB (r = 0.482; p = 0.031) and OKC (r = 0.865; p < 0.0001), and between membrane/cytoplasmic SMO and cytoplasmic GLI-1 in AOT (r = 0.667; p = 0.035) and OKC (r = 0.535; p = 0.015). The results of this study confirm the participation of the sonic hedgehog signaling pathway in the pathogenesis of the lesions studied. Overexpression of SHH in ABs and nuclear expression of GLI-1 in ABs and OKCs indicate that these proteins contribute to the more aggressive behavior of these two lesions when compared to AOT.

Oral and Maxillofacial Surgeon's Perspective on Gorlin-Goltz Syndrome - A Report of Two Cases

Rationale

Gorlin-Goltz syndrome (GGS) is an autosomal dominant disorder and is associated with multisystem involvement, multiple cysts, neoplasms and other developmental anomalies. The purpose of the study was to highlight the incidental findings of GGS and to lay emphasis on its early diagnosis.

Patient Concerns

Two patients complaining of pain, swelling and at times pus discharge from the oral cavity were reported with a coincidental finding of odontogenic keratocysts and positive family history.

Diagnosis

Upon thorough examination, a diagnosis of GGS was made.

Treatment

The patients were managed by enucleation and chemical cauterisation using Carnoy's solution and were maintained on follow-up semi-annually.

Outcomes

Both patients showed no signs of recurrence post six months follow-up.

Lessons

The role of an oral and maxillofacial surgeon is of utmost importance in the early diagnosis of this syndrome to render good quality of life to these patients.

Glandular odontogenic cysts: a collaborative investigation of 22 cases and proteins related to invasiveness

BACKGROUND

A glandular odontogenic cyst has an intriguing, aggressive behaviour whose mechanisms have not yet been clarified.

OBJECTIVE

To conduct a collaborative cross-sectional study on the clinical, demographic, microscopic, and immunohistochemical characteristics of glandular odontogenic cysts, emphasizing the histopathological characteristics and expression of proteins related to invasiveness.

METHODS

Twenty-two cases of glandular odontogenic cyst from three oral and maxillofacial pathology services in Brazil were selected from 1988 to 2018. Clinical and demographic data were collected. Histopathological features were evaluated in detail. Sixteen cases of glandular odontogenic cyst were also submitted to immunohistochemistry to detect MT1-MMP, TKS4, TKS5, and cortactin, the key regulators of invadopodia formation.

RESULTS

GOCs were primarily seen in men over 40 years of age, in the posterior mandible and the anterior maxilla as a unilocular, radiolucent lesion. All cases presented hobnail cells, clear cells, and variable thickness of the lining epithelium, three of the ten key histopathological parameters to be evaluated in glandular odontogenic cysts. Immunohistochemistry revealed a greater expression of the studied proteins in the glandular odontogenic cysts than in the controls (p <0.0001).

CONCLUSION

Overexpression of proteins that regulate cell invasiveness was identified, and the present study's findings suggest that invadopodia activity is a possible mechanism used by glandular odontogenic cysts to promote local invasion, which could partly explain its intriguing biological behaviour.

Histopathologic and immunohistochemical findings of odontogenic jaw cysts treated by decompression technique

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 decompression2. 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 <0.0001. The confidence interval was found to be 95%.

Conclusions

The proliferative activity evaluated by Ki-67 marker was greater in predecompression epithelial lining compared to postdecompression. Our study infers that proliferative rate of the cystic epithelial lining is significantly diminished after decompression.

Dentigerous cyst in a young child: a case report

Dentigerous cysts are one of the most common developmental types of odontogenic cysts occurring in the oral cavity and often manifest as incidental findings on dental radiographs and/or as asymptomatic swellings. These cysts develop from remnants of reduced enamel epithelium around the crown of an unerupted or impacted tooth, attached at the level of the cementoenamel junction. Most are considered developmental. However, in young clients they may be inflammatory in origin, the result of caries in the primary dentition. This short communication highlights a case of an asymptomatic dentigerous cyst identified in a 4-year-old child and subsequent enucleation under general anesthesia. A thorough clinical and radiographic assessment of the oral cavity in pediatric clients merits a review of dentigerous cysts by the dental hygienist.

Maxillary dentigerous cyst showing squamous odontogenic tumor-like proliferation: surgical approach and literature review

Squamous odontogenic tumor (SOT) is a rare benign neoplasm of the jaw that likely arises from remnants of the dental lamina. It is a slow-growing lesion, with a radiolucent appearance in the central variant. Microscopically, SOT shows islands of squamous epithelium supported by fibrous stroma. In rare cases, squamous odontogenic tumor-like proliferation (SOT-LP) can be observed arising from odontogenic cysts (SOT-LPOC). Herein, we describe the case of a 42-year-old man who presented with discreet bleeding in the maxillary gingiva. Imaging revealed a well-defined, ovoid-shaped lesion with sclerotic margins involving tooth #18 in the intraosseous location. Fine needle aspiration supported the cystic nature of the lesion. After surgery, microscopy revealed a dentigerous cyst showing SOT-LP features. There was no recurrence after a 3-year follow-up. To the best of our knowledge, this is the first report of a dentigerous cyst showing SOT-LP features in the maxilla. Such cysts should be identified to avoid misdiagnosis, with the finding having therapeutic and prognostic implications.

Novel recurrence risk stratification of odontogenic keratocysts: A systematic review

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.

Immunohistochemical evaluation of myofibroblasts in odontogenic keratocyst, dentigerous cyst and different clinical variants of ameloblastoma: A comparative study

BACKGROUND

Odontogenic cysts and tumors exhibit varying degrees of aggressiveness in their biological behavior. Odontogenic keratocyst (OKC), dentigerous cyst (DC), ameloblastoma are most common odontogenic cysts and tumors to occur in the oral cavity. Myofibroblasts (MFs) in the connective tissue stroma participate in the matrix degradation process by secreting matrix metalloproteinase 2, transforming growth factor beta1 and may contribute to variation in their biological behavior. Its activity is identified by alpha-smooth muscle actin (α-SMA) marker. With this background, the present study aims to evaluate the frequency of MFs using α-SMA to determine the biological behavior of OKC, DC, and different clinical variants of ameloblastoma.

MATERIALS AND METHODS

A retrospective study was carried out with total of 60 samples which include 10 cases each of OKC, DC, 30 cases of different clinical variants of ameloblastomas and 10 normal mucosa taken as controls. All are stained immunohistochemically using α-SMA and were analyzed for the same. Comparison between more than 2 groups done by one way analysis of variance test with the level of significance of P ≤ 0.0001, i.e., <0.05.

RESULTS

Statistically significant difference in the mean number of MFs observed between certain groups, with higher mean number in solid ameloblastoma (SA) (32.45) followed by OKC (28.79), unicystic ameloblastoma (24.53), desmoplastic ameloblastoma (7.44), and DC (1.72).

CONCLUSION

Higher frequency of MFs noticed in SA, OKC which are key cells for connective tissue remodeling by interacting with epithelial cells and other connective tissue cells to facilitate progression of cysts and tumors thereby contributing to their biological behavior.

Retrospective evaluation of cone-beam computed tomography findings of odontogenic cysts in children and adolescents

Background

Odontogenic cysts develop from the epithelium of dental structures and generally grow slowly. In children and adolescents, cysts usually grow faster than adults and require much knowledge for diagnoses and treatments.

Aims

This study aimed to determine the diagnosis and treatment of odontogenic cysts in different age groups by evaluating the type of lesions, age, gender, and anatomical distribution of odontogenic cysts seen in children and adolescents by cone-beam computed tomography.

Materials and Methods

A total of 42 odontogenic cysts (radicular, dentigerous cyst, and odontogenic keratocyst) were determined in children and adolescents aged 7-18 years. Cone-beam computed tomography images of odontogenic cysts were analyzed in terms of types, age, sex, anatomical location, height, width, depth, scalloped borders, lesion shapes, tooth displacement, root resorption, and association with an unerupted tooth.

Results

There was a significant correlation between odontogenic cyst types and age groups, scalloped borders, lesion shape, tooth displacement, root resorption, and association with an unerupted tooth.

Conclusion

When odontogenic cysts seen in children and adolescents are examined with cone-beam computed tomography, the radicular cyst was the most common form and was predominated in the 13-18 years age group and in boys. Differences in terms of scalloped borders, lesion shape, tooth displacement, root resorption, and association with unerupted teeth were noticed. The knowledge of the distribution and properties of odontogenic cysts in pediatric patients will help diagnose the lesions during clinical and radiological examinations and make appropriate treatment planning.

Prevalence of odontogenic cysts and its associated factors in South Indian population

Background:

Odontogenic cysts (OCs) constitute a major part of oral pathological lesions, but little is known about their distribution patterns in various populations.

Aims:

The aim was to determine the prevalence and factors associated with the cases of histopathologically diagnosed OCs that report to our institution and to analyze the factors associated with the presence of OCs and to study the biologic behavior of different types of cysts.

Materials and Methods:

A cross-sectional study was performed on 596 oral and maxillofacial specimens during 2013–2017. Out of these, the cases which were histopathologically proven as OCs were separated and data were collected and analyzed regarding the age, gender, primary symptom, site, radiographic feature, histopathologic diagnosis, treatment given, recurrences and associated conditions if any.

Results:

Of the 596 cases included in the study, 67 (11.2%) had a histopathological diagnosis of OCs. 41 cases were inflammatory cysts and 26 developmental cysts. 28 cases (41.8%) were reported as periapical cysts, 10 cases (14.9%) were odontogenic keratocysts (OKCs), 9 cases (13.4%) were dentigerous cysts, 8 cases (11.9%) were inflamed cyst wall, 5 cases (7.5%) each of residual cyst and developmental OCs and one case (1.5%) each of orthokeratinized OC and calcifying OC.

Conclusion:

This study showed that the prevalence of OCs was similar to other reported studies. Periapical cysts were the most common cysts reported, followed by OKCs showing that the latter were more frequent than dentigerous cysts.

The significance of recurrent odontogenic keratocysts in bone grafts

A comprehensive literature review identified 10 reported cases of recurrent odontogenic keratocysts (OKCs) in bone grafts. Seven of them were sufficiently documented for further analysis. All except one of the patients had a long history of repeated recurrences. They were all approached via an extraoral route, avoiding a mucosal perforation, when the bone graft was placed after a segmental resection. In three cases, this was also true for the primary treatment. The origin of the recurrences is considered to be the oral mucosa, almost certainly involving the proliferation of epithelial islands or microcysts that were close to the original OKC. A plea is made to avoid segmental or marginal resections for this lesion and to pay attention to possible epithelial islands/microcysts in the overlying attached mucosa in the case where marsupialization is preferred.

Whole Exome Sequencing of SMO, BRAF, PTCH1 and GNAS in Odontogenic Diseases

BACKGROUND/AIM

Odontogenic diseases are diagnosed based on clinical course, imaging, and histopathology. However, a definitive diagnosis is not always possible.

PATIENTS AND METHODS

We analyzed whole exons of SMO, BRAF, PTCH1 and GNAS using next-generation sequencing (NGS) in 18 patients.

RESULTS

Of the 6 patients with ameloblastoma, 2 patients had the same missense mutation in BRAF, and 1 patient with peripheral ameloblastoma had a missense mutation in PTCH1. Of the 7 patients with odontogenic keratocyst, 4 patients had a missense mutation in PTCH1, 2 patients had missense mutations in BRAF, and 1 patient had a missense mutation in SMO. The patient with odontoma had missense mutations in SMO, BRAF and PTCH1. One patient with cement-osseous dysplasia had missense mutations in SMO and PTCH1. The patient with adenomatoid odontogenic tumor had missense mutations in SMO.

CONCLUSION

Whole exome sequencing of the above genes by NGS would be useful for the differential diagnosis of odontogenic diseases.

Expression of stem cell markers in stroma of odontogenic cysts and tumors

BACKGROUND

The stroma of odontogenic cysts/tumors may confer them differential biological behavior. We aimed to investigate the immunoexpression of stem cell markers (Nanog, SOX2, Oct4, and CD34) in the stroma of odontogenic cysts and tumors. CD34 was investigated exclusively as a marker for stromal fibroblast/fibrocyte cells (CD34 + SFCs). CD34 + SFCs were also investigated ultrastructurally.

METHODS

Ten cases each of primary odontogenic keratocyst (OKC), recurrent OKC, dentigerous cyst, ameloblastoma, unicystic ameloblastoma, odontogenic myxoma, and 7 syndromic OKC were included. Results were represented as the mean score (%) of positive cells/field for each marker for each study group. For CD34 + SFCs, results are presented as the mean number of cells/field for each type of lesion. Kruskal-Wallis and Spearman's correlation statistical tests were used; significance was set at P < .05.

RESULTS

All markers except Oct4 were expressed by stromal cells in all lesions. Expression of SOX2 was significantly higher in tumors than in cysts (P < .05). CD34 + SFCs were more frequent in cysts than in tumors. Ultrastructurally, CD34 + SFCs were identified for the first time in odontogenic lesions and showed characteristic bipolar/dendritic morphology.

CONCLUSION

Among examined stromal stem cell markers, only SOX2 distinguished tumors from cysts. CD34 + SFCs may also contribute to the biological behavior of odontogenic lesions.

Studying the multiple faces of nevoid basal-cell carcinoma syndrome: A case series

Nevoid basal-cell carcinoma syndrome (NBCCS) or Gorlin–Goltz syndrome is an autosomal dominant-inherited condition that exhibits high penetrance and variable expressivity; however, this disorder can arise spontaneously. In 1960, Gorlin and Goltz described the syndrome as a condition, comprising the principle triad of multiple basal cell carcinoma, odontogenic keratocysts, and skeletal anomalies. The diagnostic findings of NBCCS in four patients were studied and compared with other reports in the Indian population. Early diagnosis of this syndrome is important for counseling of patients to prevent the life-long complications of this syndrome which includes the malignancy, oro-maxillofacial deformation, and destruction; this may be reduced if the diagnosis and treatment are made feasible at the earliest.

Proliferative and anti-apoptotic indices of unicystic ameloblastoma, odontogenic keratocyst, dentigerous cyst and radicular cyst

Objective:

The aim of this study is to compare the proliferative capacity and antiapoptotic capacity of unicystic ameloblastoma (UA), odontogenic keratocyst (OKC), dentigerous cyst (DC) and radicular cyst (RC) by assessing the Ki-67 labeling index (LI) and Bcl-2 LI, respectively.

Materials and Methods:

Formalin-fixed, paraffin-embedded tissue blocks of twenty-three histopathologically diagnosed UAs, 6 OKCs, 8 DCs and 10 RCs were selected from the archival specimens. Five micrometer thick sections of tissue blocks of the lesions were processed for immunohistochemical staining with Ki-67 and Bcl-2. The Ki-67 LI and Bcl-2 LI were determined for the cases with a positive reaction.

Results:

Ki-67 expression was seen in 6 (26.1%) cases of UA, 4 (66.7%) OKC, 1 (12.5%) DC and 1 (10.0%) RC. There was a statistically significant difference between the mean Ki-67 LI of UA and OKC (P = 0.024). Bcl-2 expression was seen in 16 (69.6%) UA, 5 (83.3%) OKC, 5 (62.5%) DC and 5 (50.0%) RC. The mean Bcl-2 LI of UA was significantly higher than that of DC (P = 0.048). Furthermore, cases of OKC had significantly higher mean Bcl-2 LI compared to DC (P = 0.026) and RC (P = 0.049).

Conclusion:

This study suggests that the Ki-67 LI may help in differentiating OKC from UA. The Bcl-2 LI may be useful in differentiating UA from DCs, and differentiating OKC from DC and RC.

Concurrent Occurrence of Odontogenic Keratocyst and Lateral Periodontal Cyst in the Mandible

Clinical presentation of odontogenic keratocyst (OKC) along with other pathologies of the jaw such as ameloblastoma, and ossifying fibroma is well documented. However, the simultaneous occurrence of OKC with lateral periodontal cyst (LPC) is very rare. We present a clinical scenario where there was concurrent presentation of OKC with LPC.

Deep Learning for Automated Detection of Cyst and Tumors of the Jaw in Panoramic Radiographs

Patients with odontogenic cysts and tumors may have to undergo serious surgery unless the lesion is properly detected at the early stage. The purpose of this study is to evaluate the diagnostic performance of the real-time object detecting deep convolutional neural network You Only Look Once (YOLO) v2—a deep learning algorithm that can both detect and classify an object at the same time—on panoramic radiographs. In this study, 1602 lesions on panoramic radiographs taken from 2010 to 2019 at Yonsei University Dental Hospital were selected as a database. Images were classified and labeled into four categories: dentigerous cysts, odontogenic keratocyst, ameloblastoma, and no lesion. Comparative analysis among three groups (YOLO, oral and maxillofacial surgeons, and general practitioners) was done in terms of precision, recall, accuracy, and F1 score. While YOLO ranked highest among the three groups (precision = 0.707, recall = 0.680), the performance differences between the machine and clinicians were statistically insignificant. The results of this study indicate the usefulness of auto-detecting convolutional networks in certain pathology detection and thus morbidity prevention in the field of oral and maxillofacial surgery.

Pericoronal follicles revealing unsuspected odontogenic cysts and inflammatory lesions: A retrospective microscopy study

Aim

This study aimed to analyze the prevalence of diseases related to pericoronal follicles, and assess the rate of concordance between clinical and histopathological diagnoses.

Methods

Histologically, we analyzed 1,298 tissue samples surrounding the crowns of teeth that were diagnosed clinically as pericoronal follicles. In addition, we determined associations among histopathological diagnosis, patients' age and sex, tissue site, presence of nests of odontogenic epithelium, presence of reduced enamel epithelium, and presence of diffuse inflammation.

Results

Odontogenic pathologies were present in 35% of the samples, and rate of concordance between clinical and histopathological diagnoses was 0.54. Probability of developing odontogenic pathologies was high in the mandibular molars (odds ratio: 2.13) and in the tissues with odontogenic epithelial remnants (odds ratio: 1.2), reduced enamel epithelium (odds ratio: 1.3), and diffuse inflammation. (odds ratio: 10.5).

Conclusions

The findings of this study highlight the clinical relevance of histopathological examination of the pericoronal tissue in unerupted and partially erupted teeth for early diagnosis of pathologies because this study demonstrated the odontogenic cysts and inflammatory lesions in tissues clinically diagnosed as pericoronal follicles.

844例牙源性角化囊肿的临床病理学分析

OBJECTIVE

To investigate the clinicopathologic features and prognostic factors in odontogenic keratocyst (OKC), and to provide new reference for clinic treatment and management of these patients.

METHODS

Clinicopathological data of 844 cases initially diagnosed as or associated with OKC at Department of Oral Pathology, Peking University Hospital of Stomatology from 2000 to 2018 were collected. The cases were divided into 4 groups: sporadic OKCs (intraosseous, cystic lesion irrelevant to nevoid basal cell carcinoma syndrome), syndromic OKCs, solid OKCs and peripheral OKCs. The patients were follow-up for 6 to 216 months and the factors that might relate to recurrence were analyzed.

RESULTS

There were 805 cases (95.4%) of sporadic OKCs, 32 cases (3.8%) of syndromic OKCs, 3 cases of solid OKCs and 4 cases of peripheral OKCs. The main age of sporadic OKCs was 36.03 years with the peak at the second and third decades. Ratio of male and female was 1.27:1. The predilection site was the molar and ramus area of mandibular (56.2%). In the study, 428 cases (71.2%) were unilocular in radiography while 28.8% were multilocular. The recurrent rate of enucleation with the follow-up was 20.1% (118/588) while most of them occurred in 1-3 years after surgery. The recurrent rate of multilocular patients (39.0%) was significantly higher than that of the unilocular. Enucleation after marsupialization (43 cases) or enucleation only (545 cases) showed no difference in recurrence (P>0.05). The syndromic OKCs was younger (main 20.97) and preferred to be multiple compared with sporadic OKCs (30/32, 93.7%). The predilection site was also molar and ramus area of mandibular (41.7%). Age and gender distribution of multiple cases had no significant difference with those in sporadic OKCs. More daughter cysts and epithelial islands were seen (56.3% and 17.9%). Furthermore, the recurrent rate was significantly higher than that of the sporadic OKCs (13/29, 44.9%). But there was no evidence of recurrent-related factors. The age of solid and peripheral OKCs, averaged at 45.00 and 65.75 years, were older than others. Four of peripheral OKCs showed no recurrence after enucleation.

CONCLUSION

The recurrence rate of sporadic OKCs after enucleation is 20.1%. The multilocular lesions prefer to be recurrent. There is no significant difference of recurrence with enucleation only or enucleation after marsupialization. Compared with sporadic OKCs, the syndromic patients are younger and easier to be multiple. It tends to be recurrent frequently and rapidly. There are no related factors about recurrence of syndromic patients. The clinicians should considerate comprehensively and make an individual management of therapy and follow-up. Solid and peripheral OKCs are rare and older.

A Brazilian multicentre study of 2,497 isolated cases of odontogenic keratocysts

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.

Retrospective 3D analysis of bone regeneration after cystectomy of odontogenic cysts

BACKGROUND/OBJECTIVE

In this retrospective study, we aimed to investigate a new 3D evaluation method for evaluating bone regeneration after cystectomy of odontogenic cysts.

METHODS

The study included 26 patients who underwent cystectomies between 2012 and 2017 and had received either fillings or non-fillings with autologous iliac crest. Bony regeneration was analyzed using 3D imaging software and comparing identical regions of interest (ROIs) that were determined by exact overlays of the postoperative cone beam computer tomography (CBCT) or computer tomography (CT) images. Outcome measures, including volume changes according to the defect size and configuration, patient age, the entity and distribution of the cysts, were collected.

RESULTS

Twenty-six patients (5 women and 21 men) had 30 defects, including nine keratocysts, seven radicular cysts and 14 dentigerous cysts. A total of 73% of the defects were in the mandible. The mean 3D follow-up time was 12 months. According to the 3D evaluation of bony regeneration, the defect size and configuration showed no significant differences between the groups (filled or non-filled with 15 defects per group).

CONCLUSIONS

By establishing a standardized 3D method for evaluating bone regeneration, healing can be better monitored and evaluated.

A 10-year reflection

Objectives

To determine the prevalence of odontogenic cysts and tumors along with age range, sex distribution, site of presentation and also to identify the most common type of odontogenic cyst and tumor among the population of coastal Karnataka over a 10-year period.

Methods

Data was collected from patient records and histologically diagnosed cases of odontogenic cysts and tumors. The age, gender of patients, as well as the site of lesion was recorded.

Results

A total of 167 cases were retrieved. Among them, 125 cases were diagnosed as odontogenic cysts and 42 cases were odontogenic tumors. Radicular cyst was the most frequently diagnosed cyst and unicystic ameloblastoma was the most frequently diagnosed tumor. A strong predilection for males was observed for both the odontogenic cysts and odontogenic tumors. Odontogenic cysts were more commonly seen in individuals in the age range 21–41 years, while odontogenic tumors were frequently seen in individuals in the age range 1–20 years.

Conclusion

This study provides an epidemiological profile of odontogenic cysts and odontogenic tumors among a rural population of coastal Karnataka. There is a notable variation in demographic profile of odontogenic cysts and odontogenic tumors in this population when compared with other populations.

p16INK4a as a proliferation marker unrelated to HPV expression in odontogenic cysts and tumors

INTRODUCTION

p16INK4a is a tumor suppressor protein that retards cell cycle progression from G1 to S phase. Prior studies have evaluated p16INK4a expression in odontogenic keratocyst and ameloblastoma, but data regarding other odontogenic cysts and tumors have been sparse.

METHODS

With IRB approval, cases from the following entities were identified from archives of the UF Oral Pathology Biopsy Service (2005-2015): benign incidental odontogenic rest, dentigerous cyst, lateral periodontal cyst, calcifying odontogenic cyst, glandular odontogenic cyst, odontogenic keratocyst, orthokeratinized odontogenic cyst, adenomatoid odontogenic tumor, calcifying epithelial odontogenic tumor, and ameloblastoma. All cases were submitted for p16INK4a immunohistochemical testing.

RESULTS

Results were scored as follows: nuclear and cytoplasmic staining of <5% cells (score 0), 5%-25% (score 1), 25%-50% (score 2), >50% (score 3). No significant difference in p16INK4a staining was noted between odontogenic cysts and the listed odontogenic tumors (chi-square, P = .540). When comparing lesions with higher recurrence rates (over 25% as reported in the literature) versus lesions with low recurrence rates (under 25%), higher recurrence correlated to significantly higher p16INK4a positivity (chi-square, P = .001). Follow-up testing was performed on 18 cases with "2" or "3" p16INK4a expression scores for high-risk HPV strains through HPV in situ hybridization (ISH) messenger RNA testing with no cases exhibiting a positive result.

CONCLUSION

This study exhibits an association between increased p16INK4a positivity and odontogenic lesions with higher recurrence rates and highlights the role of p16INK4a as a progression marker unrelated to HPV expression in this group of pathologic entities.

Diagnosis of cystic lesions using panoramic and cone beam computed tomographic images based on deep learning neural network

OBJECTIVES

The aim of the current study was to evaluate the detection and diagnosis of three types of odontogenic cystic lesions (OCLs)-odontogenic keratocysts, dentigerous cysts, and periapical cysts-using dental panoramic radiography and cone beam computed tomographic (CBCT) images based on a deep convolutional neural network (CNN).

METHODS

The GoogLeNet Inception-v3 architecture was used to enhance the overall performance of the detection and diagnosis of OCLs based on transfer learning. Diagnostic indices (area under the ROC curve [AUC], sensitivity, specificity, and confusion matrix with and without normalization) were calculated and compared between pretrained models using panoramic and CBCT images.

RESULTS

The pretrained model using CBCT images showed good diagnostic performance (AUC = 0.914, sensitivity = 96.1%, specificity = 77.1%), which was significantly greater than that achieved by other models using panoramic images (AUC = 0.847, sensitivity = 88.2%, specificity = 77.0%) (p = .014).

CONCLUSIONS

This study demonstrated that panoramic and CBCT image datasets, comprising three types of odontogenic OCLs, are effectively detected and diagnosed based on the deep CNN architecture. In particular, we found that the deep CNN architecture trained with CBCT images achieved higher diagnostic performance than that trained with panoramic images.

Primary intraosseous carcinoma of the maxilla arising from an odontogenic keratocyst: a case report and review of the literature

A 47-year-old man was referred for treatment of a painful lesion of 5 months' duration located on the left side of the maxilla. A small perforation in the buccal cortex was observed during the intraoral examination. Cone beam computed tomography (CBCT) showed an extensive, well-delimited radiolucent lesion extending from the alveolar ridge to the nasal cavity. An incisional biopsy was performed, and a cystic lesion consistent with an odontogenic keratocyst (OKC) was observed microscopically. The initial treatment option was decompression to be followed by enucleation. However, 3 months after decompression of the lesion, the patient returned because there was a significant increase in the size of the perforation. A destructive lytic lesion that involved the left side of the maxilla and crossed the midline was evident in the CBCT. The examination of a second incisional biopsy specimen showed epithelial neoplasia comprising islands and projections toward the surface. There was abundant keratin deposition, resulting in the formation of pearls and plugs. A diagnosis of primary intraosseous carcinoma arising from an OKC was confirmed, and the patient underwent a maxillectomy. After 1 year of follow-up, there were no signs of recurrence.

Angiogenesis in odontogenic keratocyst and dentigerous cyst: Evaluation of JunB and VEGF expression

BACKGROUND

Nowadays, different clinical behaviors of odontogenic cysts, little information about their biological agents, importance of diagnosis, and early diagnosis of these lesions have encouraged the researchers to conduct new studies. JunB acts as a regulator of vascular endothelial growth factor (VEGF) protein production and affects vessel proliferation and tissue angiogenesis. Hence, this study was conducted to compare angiogenesis through VEGF and JunB expression in odontogenic keratocysts (OKCs) and dentigerous cysts (DCs).

MATERIALS AND METHODS

A total of 25 paraffin blocks of OKCs and 25 DCs were included in this experimental descriptive cross-sectional study, and immunohistochemical expression of VEGF and JunB was evaluated. Percentage and score of expression were recorded for each sample, and independent t-test, Mann-Whitney U, and Spearman statistical tests were run to analyze the data. The statistical significance level was set at <0.05.

RESULTS

From 50 studied samples, 39.6% belonged to women and 60.4% belonged to men, with mean age of 34.2 ± 1.7 years. The mean percentages of JunB expression were 52.88 ± 17.35 and 74.6 ± 18.55 for DC and OKC samples, respectively. This expression was significantly higher in OKC than DC, and it had significantly higher scores as well (P = P = 0.0001 and 0.00033, respectively). The means of VEGF were 20.2% ±11.86 and 52.6% ±19.98 in DC and OKC samples, respectively. The mean VEGF expression was significantly higher in OKC than DC (P = 0.045), and it had significantly higher scores, too (P = 0.000). Furthermore, there was a significant correlation between VEGF and JunB expression in the studied samples (r_s = 0.3 and P = 0.005).

CONCLUSION

Based on the results of this study, it seems evaluation of angiogenesis through JunB expression can be helpful in the prediction of more aggressive behavior in pathologic lesions such as OKC.

Gorlin-Goltz syndrome

BACKGROUND

Gorlin-Goltz syndrome is an autosomal dominant inherited disorder characterized by a predisposition to various cancers. Clinicopathological findings of syndrome are very diverse and many symptoms begin to manifest in a certain period of life.

CASE

The authors describe a case report of a man who, at the age of 34 years, presented to a dermatologist with multiple tumor lesions of the skin. The lesions started to develop when he was 30 years old and thereafter increased in number. Histology revealed superficial, superficial-nodular and nodular basal cell carcinomas. A total of 11 basal cell carcinomas were surgically removed and microscopically investigated. The others were treated locally with imiquimod cream and cryotherapy. In addition, he was found to have multiple odontogenic keratocysts in the jaw and mandible, as well as supernumerary and retinated teeth. Stomatologic and maxillofacial surgery interventions were performed. Further clinical and imaging examinations confirmed macrocephaly, hypertelorism, calcification of falx cerebri, and abnormalities of the cervical vertebrae. The spectrum of pathological findings met the diagnostic criteria of Gorlin-Goltz syndrome.

CONCLUSION

Although Gorlin-Goltz syndrome is very rare in routine practice, it usually represents a serious disease with multiple organ system involvement. From a prognostic point of view, early diagnosis with adequate therapy is critical. If a diagnosis is confirmed, lifetime dispensary care with interdisciplinary medical cooperation is necessary. The authors would like to thank all physicians who participated in the diagnostics and therapy of the presented patient. The authors declare they have no potential confl icts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Submitted: 30. 8. 2018 Accepted: 8. 1. 2019.

Bevacizumab or fibronectin gene editing inhibits the osteoclastogenic effects of fibroblasts derived from human radicular cysts

Fibronectin (FN) is a main component of extracellular matrix (ECM) in most adult tissues. Under pathological conditions, particularly inflammation, wound healing and tumors, an alternatively spliced exon extra domain A (EDA) is included in the FN protein (EDA⁺FN), which facilitates cellular proliferation, motility, and aggressiveness in different lesions. In this study we investigated the effects of EDA⁺FN on bone destruction in human radicular cysts and explored the possibility of editing FN gene or blocking the related paracrine signaling pathway to inhibit the osteoclastogenesis. The specimens of radicular cysts were obtained from 20 patients. We showed that the vessel density was positively associated with both the lesion size (R = 0.49, P = 0.001) and EDA⁺FN staining (R = 0.26, P = 0.022) in the specimens. We isolated fibroblasts from surgical specimens, and used the CRISPR/Cas system to knockout the EDA exon, or used IST-9 antibody and bevacizumab to block EDA⁺FN and VEGF, respectively. Compared to control fibroblasts, the fibroblasts from radicular cysts exhibited significantly more Trap⁺MNCs, the relative expression level of VEGF was positively associated with both the ratio of EDA⁺FN/total FN (R = 0.271, P = 0.019) and with the number of Trap⁺MNCs (R = 0.331, P = 0.008). The knockout of the EDA exon significantly decreased VEGF expression in the fibroblasts derived from radicular cysts, leading to significantly decreased osteoclastogenesis; similar results were observed using bevacizumab to block VEGF, but block of EDA⁺FN with IST-9 antibody had no effect. Furthermore, the inhibitory effects of gene editing on Trap⁺MNC development were restored by exogenous VEGF. These results suggest that EDA⁺FN facilitates osteoclastogenesis in the fibrous capsule of radicular cysts, through a mechanism mediated by VEGF via an autocrine effect on the fibroblasts. Bevacizumab inhibits osteoclastogenesis in radicular cysts as effectively as the exclusion of the EDA exon by gene editing.

The World Health Organization classification of odontogenic and maxillofacial bone tumors: An appraisal

Classification is the process of grouping similar entities under one category for the ease of their comprehension and better handling. Medical classification dates back to the days of William Farr who is credited with the development of a nosology, which later served as the forerunner for the modern-day disease classification by ICD. The WHO system of classification is a time-honoured system that has prevailed from decades together and is under constant evolution. The classification of odontogenic tumours was first formulated by Pierre Paul Broca and has undergone several transformations over years. Though the earlier classifications and their modifications by several authors and even by the WHO appeared to be fitting for their time, the latest edition of WHO classification of odontogenic and maxillofacial bone tumours neither seems to be complete nor perfect, even at the present context. It is unfortunate that even with the advancement of molecular biology, the present WHO classification on Odontogenic and Maxillofacial bone tumours, fails to serve as a 'reference standard' in the true sense of the term. This article highlights the limitations of the current classification with constructive criticism that may help in further improvement.

Tetrad presentation of non-syndromic odontogenic keratocyst: An uphill diagnostic and therapeutic challenge

Odontogenic keratocyst (OKC), in the last decade sceptically referred to as keratocystic odontogenic tumor (KCOT), is known for its subclinical extensive growth potential and significant rate of recurrences. Odontogenic keratocyst, being the third most common cystic lesion (10-20%) of the maxillofacial region, is often recognized as a sporadic lesion and is well-documented in the literature. Multiple presentation of these cysts over a lifetime is relatively uncommon and is usually seen in conjunction with nevoid basal cell carcinoma syndrome (NBCC), orofacial digital syndrome, Noonan syndrome, Ehlers-Danlos syndrome, Simpson-Golabi-Behmel syndrome, or other syndromes. The 'two-hit' hypothesis postulated by Knudson best explains this anomaly, wherein multiple OKCs associated with the syndromes arise as a consequence of the allelic loss in the patched (PTCH) gene, mapped to the long arm of chromosome 9q22.3-q31. A partial expression of the gene may result in multiple OKCs (5%) without any related syndromes. Though concurrent occurrence of non-syndromic multiple OKCs is a rare phenomenon, a handful of cases have been documented over the past few years. Adding to this, we report a case of multiple OKCs occurring synchronously and bilaterally in all 4 quadrants in non-syndromic, otherwise healthy persons, which could indicate a shift in trend.

Assessment of cell block technique in head and neck pathology diagnoses: A preliminary study

OBJECTIVE

The head and neck region is a composite site made of multiple tissue components. These tissues when affected by disease or pathology present with an array of changes in the tissue architecture and pattern. It is essential to visualize the cellular details and tissue patterns for accurate diagnosis and treatment planning. Aspiration cytology primarily makes use of the cellular details for diagnosing lesions of the head and neck. Despite the promising results, its use is still limited in certain cases of the head and neck. The reason implicated could be the indiscernible appearance of cells in the absence of tissue integrity. In this regard, cell blocks are known to facilitate the visualization of the cytomorphological as well as the tissue arrangement patterns. Thus, the present study was designed to evaluate the role of cell block cytology in the diagnosis of various lesions of the head and neck.

METHODS

Odontogenic lesions, epithelial carcinomas and connective tissue pathology of the head and neck origin were included in the study (n = 45). Aspiration cytology smears and cell block diagnosis were compared with tissue biopsy diagnosis for determining their sensitivity (%) and diagnostic efficacy.

RESULTS

Cell blocks showed distinct preservation of the architectural pattern. In case of fluid-filled lesions, the contents were preserved and correlated with the tissue biopsy results. The results of cell blocks were similar to that of tissue biopsy in majority of the cases (95.56%).

CONCLUSION

We recommend using cell blocks as a part of routine laboratory practice for all head-neck cases.

[Endoscopic surgery in the treatment of patients with extensive odontogenic cysts]

The aim of the study was the assessment of effectiveness of endoscopic techniques in the treatment of extensive odontogenic cysts. Endosurgery for diagnostic and therapeutic purposes was used in 67 patients with odontogenic cysts of the jaws: 23 follicular cysts, 19 radicular cysts, 6 residual cysts, and 19 keratokists. The results prove that the developed methods of endovideosurgery of odontogenic cysts have low invasiveness, provide an optimal healing of bone tissue and reduce postoperative complications.