Classification of odontogenic cysts and tumors - Antecedents

Multiple odontogenic keratocysts in a patient with Lowe syndrome: a first case report and literature review

Lowe syndrome (LS) is a rare disease (1:500,000) with X-linked recessive inheritance involving the kidneys, eyes, and nervous system. A Mexican 25-year-old male patient presented for diagnosis of multiple radiolucent lesions observed on routine radiographic examination. General aspects revealed cognitive delay, eye alterations, and kidney involvement, which support the diagnosis of LS. Radiolucent well-delimited lesions were observed in both mandibular angle and symphysis. Under general anesthesia, incisional biopsy and decompression were performed. Histological aspects led to diagnosing odontogenic keratocyst (OKC) for all lesions. The lesions in the right and left mandibular angles were decompressed, and the symphyseal lesion was enucleated. A 2-month follow-up shows the bone healing process. There are few reports detailing oral findings in LS. Here, we reported the first case of multiple OKC in a patient with LS. In addition, we performed a literature review on odontogenic lesions in patients affected by LS.

Immunohistochemical expression of SOX2 in OKC and ameloblastoma: A comparative study

Introduction

Odontogenic, non-inflammatory maxillofacial cysts and tumours vary greatly in their ability to grow and cause local tissue destruction. Despite their common embryologic origin, the biologic mechanisms responsible for this diverse array of clinical behaviour are largely unknown. Unfortunately, even with accurate tissue diagnosis and appropriate surgical management, these tumours have relatively high recurrence rates. While this may be related to surgical technique, it may also be due to intrinsic tumour biology. SOX2 is differentially expressed in odontogenic cysts and tumours, which has an impact over patient prognosis. This could be related to their diverse cells of origin or stages of histogenesis. SOX2 is expressed in OKC and ameloblastoma, and in this study, we look forward to find altered levels and intensity of SOX2 in the above-mentioned lesions.

Aim and Objectives

To profile the expression of SOX2 in odontogenic keratocyst (OKC) and ameloblastomaTo compare the intensity of these lesions, analyse their intrinsic feature and predict their recurrence.

Material and Methods

Histopathologically diagnosed cases of OKC and ameloblastoma will be selected (n = 40). Paraffin-embedded, formalin-fixed sections of these lesions will be stained for SOX2 marker using a standard immunohistochemical technique. Positive control will be taken as oral squamous cell carcinoma and negative control will be taken as normal oral mucosa.

Results

A comparison between the stained cell types in odontogenic keratocyst and ameloblastoma revealed statistically significant differences. The immunoreactivity scores of SOX2 were analysed in both groups. The results indicated that 45% of OKC cases exhibited strongly positive reactivity, while 65% of ameloblastoma cases were negative. Statistical analysis demonstrated highly significant differences in the frequency of SOX2 expression between the two groups, with a higher frequency of negative expression in ameloblastoma.

Conclusion

Stem cell markers have been observed in these lesions, suggesting the acquisition of stem-like properties by tumour cells, which can affect patient prognosis. Specifically, the marker SOX2 shows differential expression in odontogenic cysts and tumours. High expression of SOX2 in OKC indicates the presence of stem cells with significant self-renewal and proliferative properties, potentially signifying neoplastic behaviour. In contrast, weak or absent expression of SOX2 in ameloblastoma suggests different molecular pathways involved in its neoplastic behaviour.

Expression of anti - Apoptotic survivin in odontogenic keratocyst, adenomatoid odontogenic tumor and ameloblastoma

Background

The process of odontogenesis is complex involving epithelial-mesenchymal interactions, along with the molecular signalling pathways triggering the initiating process. The triggering factors and cells precisely involved in the pathogenesis of odontogenic cysts and tumors are unknown. There is a vast array of biomarkers used to stain different sites, thereby helpful in diagnosing and evaluating the prognosis of these cysts and tumors. In the following study, Anti Apoptotic survivin expression patterns were assessed quantitatively in 48 samples (12 each) of Reduced Enamel Epithelium, Adenomatoid Odontogenic Tumor, Odontogenic Keratocyst and Ameloblastoma.

Aim

The Aim of this study is to assess the anti-apoptotic survivin expression in Reduced Enamel Epithelium, Adenomatoid odontogenic tumour, Odontogenic Keratocyst and Ameloblastoma.

Materials and Methods

The present study is carried out with 12 samples in each group. Routine hematoxylin and eosin staining was performed for confirmatory diagnosis. Later Immunohistochemistry was performed using survivin antibody. Survivin protein expression was analyzed using the parameters like location, intensity, percentage of cells positivity with survivin protein and extent of staining. With the help of Olympus BX 43 microscope, with ProgRes microscope camera, the 48 slides obtained were examined. The region of interest was selected in each slide and number of cells positively stained was counted. Data was analyzed using SPSS software version 23. Descriptive for scale data, results were analysed by using ANOVA with Chi-square test for intergroup comparison.

Results

The results showed significant P value <0.05. Expression of survivin was highest in Ameloblastoma, followed by Odontogenic keratocyst, Adenomatoid odontogenic tumor, and Reduced Enamel Epithelium.

Conclusion

Survivin was involved in the inhibition of apoptosis as well as the detailed understanding of the biological behaviour of odontogenic cysts and tumours, thereby increasing therapeutic approaches.

Artificial Intelligence and Machine Learning for Automated Cephalometric Landmark Identification: A Meta-Analysis Previewed by a Systematic Review

Digital dentistry has become an integral part of our practice today, with artificial intelligence (AI) playing the predominant role. The present systematic review was intended to detect the accuracy of landmarks identified cephalometrically using machine learning and artificial intelligence and compare the same with the manual tracing (MT) group. According to the PRISMA-DTA guidelines, a scoping evaluation of the articles was performed. Electronic databases like Doaj, PubMed, Scopus, Google Scholar, and Embase from January 2001 to November 2022 were searched. Inclusion and exclusion criteria were applied, and 13 articles were studied in detail. Six full-text articles were further excluded (three articles did not provide a comparison between manual tracing and AI for cephalometric landmark detection, and three full-text articles were systematic reviews and meta-analyses). Finally, seven articles were found appropriate to be included in this review. The outcome of this systematic review has led to the conclusion that AI, when employed for cephalometric landmark detection, has shown extremely positive and promising results as compared to manual tracing.

Comparative evaluation of podoplanin in odontogenic cysts and tumours to determine their proliferative potential-An immunohistochemical study

Context

Odontogenic cysts and tumours are a wide array of complex pathological entities ranging from mild indolent to aggressive detrimental in nature, which occur as a result of anomalous alterations in normal odontogenesis. Hence, these odontogenic lesions need to be evaluated extensively by using potential immunohistochemical markers.

Aim

To evaluate and compare the expression of podoplanin, a lymphoendothelial IHC marker in odontogenic cysts and odontogenic tumours to determine their proliferative potential.

Settings and Design

All the study samples were retrieved from the archives of the Department of Oral Pathology and Microbiology, PIDS&RC, Hyderabad. The study samples were selected as per the standard histopathological diagnostic criteria and subjected for IHC analysis using podoplanin.

Method and Materials

Seventy paraffin-embedded tissue specimens of OKC, OOC, dentigerous cyst (DC) and ameloblastoma (AM) include study sample, which were stained with podoplanin IHC marker and staining properties were evaluated. All the cases were categorized as high, moderate, weak or negatively reactive on the basis of the composite scoring.

Statistical Analysis Used

Statistical analysis was done using SPSS version 14, and then results were compared by ANOVA post hoc test and Kruskal Wallis Test.

Results

In the comparison of composite scores of OKCs and AM, there was no significant statistical difference.

Conclusion

The present study contributes to the significant association of podoplanin expression with cellular proliferation, cystic expansion and local invasiveness of odontogenic cysts and tumours through cytoskeletal reorganization and cell migration.

Machine learning and orthodontics, current trends and the future opportunities: A scoping review

INTRODUCTION

In recent years, artificial intelligence (AI) has been applied in various ways in medicine and dentistry. Advancements in AI technology show promising results in the practice of orthodontics. This scoping review aimed to investigate the effectiveness of AI-based models employed in orthodontic landmark detection, diagnosis, and treatment planning.

METHODS

A precise search of electronic databases was conducted, including PubMed, Google Scholar, Scopus, and Embase (English publications from January 2010 to July 2020). Quality Assessment and Diagnostic Accuracy Tool 2 (QUADAS-2) was used to assess the quality of the articles included in this review.

RESULTS

After applying inclusion and exclusion criteria, 49 articles were included in the final review. AI technology has achieved state-of-the-art results in various orthodontic applications, including automated landmark detection on lateral cephalograms and photography images, cervical vertebra maturation degree determination, skeletal classification, orthodontic tooth extraction decisions, predicting the need for orthodontic treatment or orthognathic surgery, and facial attractiveness. Most of the AI models used in these applications are based on artificial neural networks.

CONCLUSIONS

AI can help orthodontists save time and provide accuracy comparable to the trained dentists in diagnostic assessments and prognostic predictions. These systems aim to boost performance and enhance the quality of care in orthodontics. However, based on current studies, the most promising application was cephalometry landmark detection, skeletal classification, and decision making on tooth extractions.

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.

Multiple odontogenic keratocysts in Ehlers-Danlos syndrome: a rare case report

BACKGROUND

An odontogenic keratocyst is a lesion characterized by aggressive and infiltrative growth. The lesion is characterized by the existence of satellite microcysts (microtumours) and frequent recurrence (up to 30%). Ehlers-Danlos syndrome is a condition in which collagen production or its post-translational modifications are affected. Defects in connective tissues cause symptoms, which range from mild joint hypermobility to life-threatening complications.

CASE PRESENTATION

We present an extremely rare case of an 11-year old girl with Ehlers-Danlos syndrome and coexistence of multiple odontogenic keratocysts.

CONCLUSIONS

This case shows mainly atypical or rare association between multiple odontogenic keratocysts and Ehlers-Danlos syndrome.

Impact of changing classification systems on prevalence and frequency distribution of odontogenic tumors in tertiary care center of Nagpur

INTRODUCTION

The classification of odontogenic tumors has been revised from time to time in order to provide unified terminology. This reclassification had considerable impact on their prevalence and frequency distribution.

OBJECTIVES

This study was aimed to emphasize impact of changing classification systems on prevalence and relative frequency of odontogenic tumors. The secondary objective was to analyze demographics of various histological types of odontogenic tumors in comparison to published literature. Review of Indian studies (1992-2020) elaborating frequency of odontogenic tumors is summarized in the end.

METHODS

This was a hospital-based retrospective study wherein case files of odontogenic tumors diagnosed from 1990 to 2019 period were retrieved. The classification system used originally at the time of diagnosis was retained and prevalence of odontogenic tumors in three different periods (1990-2004, 2005-2016 and 2017-2019) was compared. Further, prevalence, frequency distribution and demographics of all these tumors (1990-2019) were analyzed using latest World Health Organization 2017 classification.

RESULTS

A total of 345 odontogenic tumors was diagnosed as per World Health Organization 2017 system of classification from 1990 to 2019. 96.81% tumors were benign and 3.81% constituted malignant odontogenic tumors. However, there was marked increase in prevalence of odontogenic tumors in 2005-2016 (6.2%) period as compared to 1990-2004 (3.87%) and 2017-2019 (3.47%). Ameloblastoma remained the most common tumor in three different periods, whereas keratocystic odontogenic tumor became second commonest tumor in 2005-2016 as compared to odontoma in 1990-2004 and adenomatoid odontogenic tumor in 2017-2019.

CONCLUSIONS

The continuous evolving systems of classification may partly be responsible for inconsistency in odontogenic tumors, with inclusion of keratocystic odontogenic tumor,and has marked impact on prevalence and frequency distribution of odontogenic tumors. The geographical variations in demographics of odontogenic tumors might reflect genetic and environment influence; however it requires elucidation by further studies.

Comparison of cytokeratin expressions among orthokeratinized odontogenic cysts, epidermoid cysts and odontogenic keratocysts: An immunohistochemical study

Background:

Orthokeratinized odontogenic cysts are keratinizing jaw cysts and due their association with impacted teeth and keratinaceous content, they resemble odontogenic keratocysts but differ in regards to biological behaviour, being less aggressive. To unravel the nature of OOCs, as they resemble epidermoid cysts histologically and due to their developmental resemblances to OKCs, this study was conducted.

Aim and Objective:

To compare the cytokeratin expressions of CK 10 and CK 19 among orthokeratinized odontogenic keratocysts, epidermoid cysts and odontogenic keratocysts by immunohistochemical study.

Materials and Methods:

30 cases of all three cysts were collected, 10 cases in each of these cysts (OOCs, EDCs and OKCs) were incubated with CK 10 and CK 19 markers respectively. IHC staining was performed and assessed all layers of epithelium. All the data were analyzed using SPSS software, P values were obtained by the Chi-square test and Fisher's test.

Results:

The expression pattern of CK10 showed 100% positive in both OOCs and EDCs with significant difference in OKCs. CK19 expression, between EDCs and OKCs was significant but between OOCs & EDCs and OOCs & OKCs was found to be statistically insignificant.

Conclusion:

CK 10 expressions in both OOCs and EDCs were near identical both in terms of expression and patterns of expression in surface and spinous layers. OOCs may not be distinguished from EDCs both histologically and with CK 10 expression. CK19 expression between OOCs & EDCs and OOCs & OKCs was statistically insignificant. Thus, based upon CK 19 expression, no significant differences were found between OOCs & EDCs and OOCs & OKCs, implying that OOCs resemble both EDCs and OKCs.

Clinico-pathological correlations of odontogenic tumors: Some critical observations based on a 20 year institutional study and a comprehensive review of literature

Context

Odontogenic tumors (OTs) represent a rare subset of pathologies of the oral and maxillofacial region. The classification of OTs has undergone several changes over the years due to a lack of uniform international identification criteria. The histomorphological similarity and the many variations in behavioral patterns elaborated by these lesions warrant research.

Aims

Using the update from the fourth edition of the World Health Organisation Classification of Head and Neck Tumors (2017), this dental institution carried out an epidemiological study on OTs in the state of Goa (India) and compared the data obtained with similar studies on OTs done within India.

Materials and Methods

The clinical and pathological data of OTs from August 1996 to December 2016 was retrieved from the oral and maxillofacial pathology department archives, belonging to the lone dental college and hospital in the state of Goa, India. Demographic data such as frequency, age, gender, and site along with pathological subtype was analysed.

Statistical Analysis Used

Descriptive analysis (i.e. frequency of age, gender, and location), Chi-Square Test and Fischer Exact test.

Results

The relative frequency of OTs was 2.61% of all oral biopsied specimens. The most common OT encountered was ameloblastoma (57.9%). The posterior aspect of the mandible was the most favored site (77.2%). The frequency of OTs decreased after the fourth decade. An overall marginal male predilection (55%) was seen.

Conclusions

This study contributes to the establishment of a comprehensive loco-regional epidemiological database on OTs in India, aiding research on their aetio-pathogenesis and diagnosis.

Clinical Outline of Oral Diseases

Oral diseases are pathologic conditions that affect oral and maxillofacial tissues. Dental caries and periodontal diseases are the most common forms of oral diseases, but there are a wide variety of diseases that can occur in oral and maxillofacial tissues. These oral diseases range from metabolic, inflammatory, infectious, neoplastic, autoimmune, developmental, to idiopathic origin. Numerous oral conditions have overlapping clinical signs and symptoms, which make the diagnosis and management challenging for the dentist. However, a comprehensive understanding of clinical behavior will help in differentiating the various oral diseases and will provide a logical pathway to formulating a diagnosis.

Stem Cell Markers SOX-2 and OCT-4 Enable to Resolve the Diagnostic Dilemma between Ameloblastic Carcinoma and Aggressive Solid Multicystic Ameloblastoma

Background

Ameloblastic carcinoma (ACA) is a malignant neoplasm with overlapping histopathological features of benign aggressive solid multicystic ameloblastoma (SMA). This often leads to misdiagnosis with direct implication on the management protocol. The need of the hour is to adopt reliable tissue biomarkers to differentiate these lesions accurately that will help to implement an appropriate treatment modality. Few studies to differentiate ACA and SMA in literature with a limitation of a single marker and lack of availability of cases have prompted us to undertake this study. Thereby, this study is aimed at resolving the diagnostic dilemma in differentiating ACA and aggressive SMA using SOX-2, OCT-4 and CD44.

Materials and Methods

Tissue samples involved 40 archival cases of histopathologically confirmed cases of ACA (n = 20) and SMA (n = 20). The sections were subjected to immunohistochemical staining using antibodies to SOX-2, OCT-4 and CD44. Nuclear staining for SOX-2 and OCT-4 and membranous reactivity for CD44 was considered positive.

Results

The expression of SOX-2 and OCT-4 in ACA was statistically significant when compared to SMA (P < 0.001). CD44 showed an insignificant statistical value of <0.077 in differentiating ACA and SMA. SOX-2 and OCT-4 expression in ACA showed a significant correlation coefficient of 0.616 at P < 0.004.

Conclusions

SOX-2 and OCT-4 could serve as independent novel markers in resolving the diagnostic dilemma between ACA and aggressive SMA.

Rare case of bilateral complex odontoma associated with mandibular bicuspids

Among oral pathologic lesions, odontomas are the most common odontogenic tumor of the jaws and generally asymptomatic. They are mostly diagnosed as a result of routine radiographic investigation. In this report, we describe a very rare occurrence of bilateral complex odontoma in the region of the mandibular second premolar. Conservative surgical procedure was planned, and removal of the odontomas was carried out through the socket after extraction of the deciduous second molars, and the diagnosis was confirmed with a histopathological study.