Classification Of Odontogenic Tumors Research Articles

Adenoid Ameloblastoma Shares Clinicopathologic, Immunohistochemical, and Molecular Features With Dentinogenic Ghost Cell Tumor: A Comparative Analysis.

The updated classification of odontogenic tumors by the World Health Organization (WHO) has included adenoid ameloblastoma (AA) as a distinct entity. However, distinguishing between AA and dentinogenic ghost cell tumor (DGCT) can still be challenging due to their significant morphologic similarities. In this study, we aimed to compare the clinicopathologic, immunohistochemical, and molecular characteristics of AA and DGCT to aid in their differentiation and to shed light on their pathologic mechanisms. Thirteen cases of AA and 14 cases of DGCT (15 samples) were analyzed, along with 11 cases of adenomatoid odontogenic tumor (AOT) and 18 cases of conventional ameloblastoma (AM) for comparative purposes. The study found that AA and DGCT shared a similar long-term prognosis. Immunohistochemically, all cytokeratins detected, except CK8/18, were not statistically significant in differentiating AA and DGCT, while there was a statistically significant difference in the immunophenotype of CK7 and CK10/13 between AA and AM. Nuclear β-catenin accumulation were detected in all cases of AA and DGCT, while AOTs and AMs exhibited cytoplasmic β-catenin. Molecularly, CTNNB1 hotspot mutations were found in only 1 case of AA (1/13), but not found in the other 3 types of tumors. BRAF p.V600E mutation was positive in 2/13 (15%) AA, 1/15 (7%) DGCT, and 2/11 (18%) AOT cases. In comparison, conventional AM was positive for BRAF p.V600E mutation in 94% (17/18) of cases, while KRAS mutations were detected in 63% (7/11) of AOT cases. The study suggests that the so-called AA is a rare benign tumor that exhibits clinical, immunohistochemical, and molecular features similar to DGCTs. Based on these findings, AA should not be categorized as a standalone entity solely based on the presence of whorls/morules and cribriform/duct-like structures. Further studies are needed to investigate the pathologic mechanisms of these tumors and to identify potential therapeutic targets.

Adenoid ameloblastoma with dentinoid: A rare hybrid odontogenic tumor.

Adenoid ameloblastoma with dentinoid (AAD) is a hybrid odontogenic tumor comprising histopathological presentation of ameloblastoma (AM) and adenomatoid odontogenic tumor (AOT) along with extracellular dentinoid material. A 35-year-old female reported an asymptomatic swelling in the left mandibular posterior region. Histopathological examination revealed composite features of AM with AOT along with dentinoid material, which stained positively with Van Gieson and trichrome stains. The present case report serves to add further to the modicum of literature reports pertaining to AAD, which may gain recognition as a distinct entity in future World Health Organization (WHO) classification of odontogenic tumors.

Giant ossifying fibroma of the mandible treated with en bloc resection and reconstruction plate placement in pediatric patient: case report and literature review

Ossifying Fibroma is a benign fibro-osseous tumor, but osteolytic and invasive, as well as being a rare lesion. It manifests itself more frequently in the mandible than in the upper jaw, being located preferably in the molar (52%) or premolar (25%) region. It is most commonly diagnosed in women (5:1) between the 3rd and 4th decades of life. It is related to other pathologies such as bone dysplasia, florid cement-osseous dysplasia, among others. This lesion was called a tumor by the World Health Organization (WHO) in 1992 in its classification of Odontogenic tumors, because its possible etiopathogenesis is due to periodontal ligament cells. In 2003, the WHO called it a single entity, classified like a bone tumor. The following case that is presented is about a pediatric patient with a diagnosis of Ossifying Fibroma in the mandibular area of large size, which was treated surgically with an en bloc resection of the affected area due to the great extension of the lesion and the compromised tissue. and literature review.

Molecular diagnostics in odontogenic tumors.

Odontogenic tumors (OTs) are rare, with an estimated incidence rate of less than 0.5cases per 100,000 per year. The causes of OTs remain unclear. Nonetheless, the majority of OTs seem to arise de novo, without an apparent causative factor. Although the etiopathogenesis of most OTs remains unclear, there have been some recent advances in understanding the genetic basis relating to specific histologies and clinical features. Molecular analyses performed by different techniques, including Sanger sequencing, next-generation sequencing, and allele-specific PCR, have uncovered mutations in genes related to the oncogenic MAPK/ERK signaling pathway. Genetic mutations in these pathway genes have been reported in epithelial and mixed OTs, in addition to odontogenic carcinomas and sarcomas. Notably, B‑RAF proto-oncogene serine/threonine kinase (BRAF) and KRAS proto-oncogene GTPase (KRAS) pathogenic mutations have been reported in ahigh proportion of ameloblastoma and ameloblastoma-related tumors and adenomatoid odontogenic tumors, respectively. To discuss how molecular profiling aids in diagnostic classification of odontogenic tumors. Molecular profiling of odontogenic tumors helps to identify patients for neoadjuvant therapies and reduces postoperative morbidity.

Prevalence and Epidemiological Profile of Ameloblastoma in India: A Systematic Review and Meta-Analyses.

Ameloblastoma is regarded as the second most prevalent odontogenic tumor in the light of its prevalence, clinical characteristics, greater incidence of tumor recurrence, and therapeutic challenges. The aim of this systematic review was to establish the prevalence of ameloblastoma in the Indian subcontinent and to establish a national epidemiologic profile for these lesions. A systematic review was undertaken based on the PRISMA guidelines in search of epidemiologic studies concerning odontogenic tumors and ameloblastoma that are listed by PubMed, EBSCO, and Google Scholar embracing the period from January 2010 to December 2021, to evaluate the prevalence rate in India. A total of 277 publications were retrieved, of which 27 articles were selected, based on the World Health Organization classification of odontogenic tumors. The affected individuals were on average in the third decade of life, with a higher male predominance. The majority of the tumors were multilocular radiolucencies in the posterior mandible, with follicular and plexiform histopathological features. The most common type of malignant lesion is ameloblastic carcinoma. Over 60% of follicular ameloblastoma recurred more frequently than the other types of ameloblastoma. The systematic study indicates a slight male predisposition to ameloblastoma, with a peak incidence in the third decade of life and the mandible as the preferred anatomical site. The solid/multicystic ameloblastoma is the most prevalent histopathologic pattern. More epidemiological research on the prevalence rate of ameloblastoma is required, particularly in India, in an effort to accurately determine the national epidemiological profile of ameloblastoma.

RETROSPECTIVE AND RECLASSIFICATION STUDY OF ODONTOGENIC TUMORS: A 40-YEAR ANALYSIS IN A REFERENCE SERVICE

<h3>Objectives</h3> In 2017 the World Health Organization (WHO) reported a new classification of odontogenic tumors (OTs). The epidemiologic effect of these changes has not been observed in the literature. The aim was a retrospective and reclassification analysis of OT diagnosed in a reference service. The prevalence and description of the main characteristics of these tumors were assessed according to the new classification. <h3>Study Design</h3> Records of 20,348 biopsies over a 40-year period were analyzed. Demographic data and clinical and radiographic characteristics of each lesion were assessed. Final diagnoses were reclassified according to WHO updates. Inconclusive exams will be reassessed in the future. <h3>Results</h3> In the sample, 322 lesions were diagnosed as OT, representing 1.58% of all diagnoses. Considering inclusion criteria, 226 samples were reevaluated. The most frequent tumors were odontoma (45.6%), ameloblastoma (31.4%), and myxoma (5.3%). Inconclusive diagnoses accounted for 11.5%, and 4.4% of the sample were reclassified. The predominant population was young and female, and the mandible was most frequent localization. <h3>Conclusions</h3> In comparison with previous studies, there was a significant reduction in the prevalence of OT and a change in the hierarchy of occurrence within the group, thus confirming the significant effect of the reclassification.

Management of a multicystic ameloblastoma: About a conservative and multidusciplinary approach

Ameloblastoma is a benign odontogenic tumor of epithelial origin, it represents 1% of all tumors and cysts of the jaws. It is located in the mandible in 80% of cases and in the maxilla in 20% of cases. The WHO, in its classification of odontogenic tumors in 2017 divides ameloblastoma into 3 groups: unicystic ameloblastoma, peripheral ameloblastoma and conventional (or multicystic) ameloblastoma. The histological types of the latter include: the follicular and the plexiform. The surgical management of these tumors represents a real challenge for the surgeon, who wants to be as conservative as possible. The treatment of ameloblastoma is surgical, enucleation, curettage or interruptive resection are applicable depending on the size and the type of lesion. The objective of this article is to report the diagnostic and therapeutic attitude towards a mandibular plexiform ameloblastoma in a young 29-years-old patient treated in the oral surgery department of the dental consultation and treatment center of Casablanca

Exudative Benign Cementoblastoma with Radiographic Rarities- A Case Report with Review of Literature

Cementoblastoma is a rare benign odontogenic neoplasm of mesenchymal origin. The benign cementoblastoma was previously classified as one of the cementoma neoplasias by the World Health Organization’s classification of odontogenic tumours. The benign cementoblastoma in 2005 has been added to the list of odontogenic tumours that involve “mesenchyme and/or odontogenic ectomesenchyme, with or without odontogenic epithelium”. It accounts for around 0.69-8% of all odontogenic tumours. The lesion usually is asymptomatic and slow growing causing cortical plate expansion of both buccal and lingual plates. Cementoblastoma has male predilection, commonly seen involving mandibular first molar diagnosed in early age. There are very few incidents of an infected cementoblastoma in the literature. Radiological examinations can reveal a blend of radiolucent and radiopaque mass presenting a wheel spoke pattern. The histopathological results for both cementoblastoma and osteoblastoma are comparable. The relationship of the lesion with the tooth is the distinguishing element. Hereby, authors present a case of infected cementoblastoma in a 51-year-old female patient involving impacted mandibular second molar, clinically aggressive with unique radiologic features. Cementoblastoma is usually an incidental finding while the present case was associated with an impacted tooth and was symptomatic with infection. The uniqueness of this case was the complete involvement of the root structure and the cyst like expansion of the lesion instead of the usual thin radiolucent rim. Also, the lesion was infected with no dental caries associated with the tooth.

Frequency of Odontogenic Tumors: A Single Center Study of 1089 Cases in Japan and Literature Review

Several attempts have been made to classify odontogenic tumors; however, the need for a uniform international classification system led the World Health Organization (WHO) to present a classification of odontogenic tumors in 1971. We aimed to evaluate the number and types of odontogenic tumors examined at the Tokyo Dental College Hospital in Japan to determine the frequency and types of odontogenic tumors, based on the 2017 WHO classification system, as this information has not been reported previously in Japan. We also compared the results of our evaluation with those reported in previous studies. We conducted a clinicopathological evaluation of odontogenic tumors examined at the Tokyo Dental College Hospital between 1975 and 2020. This included an analysis of 1089 cases (malignant, n = 10, 0.9%; benign, n = 1079, 99.1%) based on the 2017 World Health Organization Classification of Head and Neck Tumors. We identified 483 (44.3%), 487 (44.7%), and 109 (10.0%) benign epithelial odontogenic, mixed odontogenic, and mesenchymal tumors, respectively. The most common tumor types were odontoma (42.5%) and ameloblastoma (41.9%). Of the 1089 cases, 585 (53.7%) and 504 (46.3%) were male and female patients, respectively. Ameloblastoma and ameloblastic fibroma occurred more commonly in male patients, whereas odontogenic fibroma and cemento-ossifying fibroma affected female patients primarily. The age at diagnosis ranged from three to 87 (mean, 29.05) years. In 319 (29.3%) patients, the age at diagnosis ranged from 10 to 19years. Ameloblastoma and odontoma were the most common tumor types among patients in their 20s and those aged 10-19years, respectively. In 737 (67.7%) and 726 (66.7%) patients, the tumors were located in the mandible and posterior region, respectively. Ameloblastoma was particularly prevalent in the posterior mandible. Odontogenic tumors are rare lesions and appear to show a definite geographic variation.

Biphasic clear cell odontogenic carcinoma: An aggressive metastatic neoplasm

AbstractIntroductionThe recent classification of odontogenic tumours includes the entities clear cell odontogenic carcinoma (CCOC) and clear cell ameloblastoma (CCAM) under the unifying name CCOC. The lack of ameloblastic differentiation in many cases of CCOC, its more aggressive behaviour and unique molecular profile suggest a distinct entity which merits its own standing in the classification of odontogenic carcinomas.Case reportA 53‐year‐old male presented with excessive hyperplastic tissue in the anterior maxilla. Microscopic examination disclosed a biphasic clear cell neoplasm with nests of polygonal clear cells, surrounded by intensely eosinophilic flattened cells. The tumour cells were immunoreactive for MNF 116, CK 14, CK 19, CK 5 and EMA. The proliferation index, Ki67, was low and its expression, similar to the basal‐cell‐specific cytokeratins (CK 14 and CK5), was confined to the peripheral cells. Molecular studies confirmed EWSR1 gene rearrangements. An anterior maxillectomy was performed, supplemented with radiotherapy. Three years after resection, multiple metastatic bodies were detected in the lung and the patient passed away 1 year later.ConclusionThis case further supports the notion that CCOC with biphasic histomorphology appears to have a high mortality rate, and it may be wise to treat and monitor these patients more aggressively.

Modern aspects of clinical, radiological and computed tomographic diagnostics of odontogenic cysts and the results of their treatment

There are many classifications of jaw cystic formations. The most perfect is the International histological classification of odontogenic tumors, cystic lesions of the jaws and tumor-like processes, approved by WHO in 1971. According to WHO, the group of epithelial cysts includes both developing ones, including odontogenic (primordial or keratocyst, gingival, erupting, follicular) and non-ontogenic origin (nasopalatine duct, globular-maxillary, nasolabial or so-called naso-alveolar), and inflammatory (radicular) tumor-like formations.

Surgical conservative approach of odontogenic keratocyst tumor of the jaws.

Objective Odontogenic keratocyst (OKC) can be classified as an oral lesion representing the third most common cyst of the jaws characterized by a high rate of recurrence. OKC was accepted as a neoplastic lesion in the 2005 WHO classification and it was called keratocystic odontogenic tumor (KCOT). However, in the 2017 classification of odontogenic tumors, OKC was moved back into the cyst category. This study aims to evaluate clinically, radiographically and through the histological examination the healing of a patient with OKC who underwent surgery with a marsupialization approach. Design An 83-year-old female patient, presented deformation of the right hemi-mandibular region and paresthesia of the right hemi-labium, during intraoral examination it was possible to detect an eggshell crackle on palpation of the anterior edentulous mandible, moreover, the patient reported a growth of the lesion over time that prevented her from using the removable prosthesis. Methods At the OPT it was possible to appreciate a unilocular area that extended from the parasymphyseal region to the right hemi-mandible. The CT scan showed massive erosion that only partially spared the lower cortex and involvement of the mental foramen. Results Checks following surgery show healing also confirmed by instrumental check-ups. Conclusions Surely this study offers a valid alternative to more invasive and debilitating surgical treatments.

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

IntroductionThe 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. ObjectivesThis 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. MethodsThis 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. ResultsA 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. ConclusionsThe 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.

Critical assessment of the latest classification of jaw cysts proposed by the World Health Organization (2017)

BackgroundThe fourth edition of the World Health Organization Classification of Head and Neck Tumors was published in January 2017, and includes a classification of odontogenic tumors and odontogenic cysts. The present review assesses the changes made in this new classification in relation to odontogenic and non-odontogenic jaw cysts. Material and MethodsAn electronic search was conducted in the Cochrane Library, PubMed-MEDLINE and Scopus databases using the search terms: “odontogenic cyst” “WHO classification” “update”. Studies written in English and published between January 2005 and April 2020 with a high level of scientific evidence were included, while studies not published in English, epidemiological studies, and studies with a low level of scientific evidence were excluded. ResultsThe initial search identified 311 articles, and after the deletion of duplicates, 7 studies were selected for full-text assessment. After excluding two studies that failed to provide relevant information and had a low level of scientific evidence, 5 articles were finally included and stratified according to their level of scientific evidence based on the SORT (Strength of Recommendation Taxonomy) criteria. ConclusionsThe incorporation of odontogenic and non-odontogenic cysts to the head and neck tumors classification underscores the recognition of the WHO of these important disorders of the jaws. Based on the current evidence, there is controversy as to whether odontogenic keratocysts should be regarded as cystic lesions or as neoplasms, though there is no such controversy in relation to calcifying odontogenic cysts. On the other hand, orthokeratinized odontogenic cysts have been included in the classification as a single entity differentiated from odontogenic keratocysts, while residual cysts have been removed from the classification. Key words:Odontogenic cyst, WHO classification, pseudocyst.

World Health Organization Classification of Odontogenic Tumors and Imaging Approach of Jaw Lesions.

Tumors of the jaws represent a heterogeneous group of lesions that are classified histologically in the World Health Organization Classification of Odontogenic Tumors (2017). This article provides an update of the current nomenclature. The main role of imaging is to describe the precise location and extent of these lesions. Although characterization of imaging is often difficult due to overlapping characteristics, imaging is helpful to define which lesions should be referred for histologic examination and subsequent treatment planning. Location and density are the cardinal criteria for potential characterization on imaging. Radiologically, lesions may be radiolucent, radiopaque, or of mixed density. Additional criteria include lesion demarcation, morphology, cortical breakthrough, periosteal reaction, and adjacent soft tissue changes. Final lesion characterization is only definitive after interdisciplinary discussion and radiopathologic correlation. Correct diagnosis is obtained by a combination of the patient's age, lesion location, and clinical and radiologic presentation. It is important that all physicians use a uniform nomenclature.

New World Health Organization classification of odontogenic tumours: impact on the prevalence of odontogenic tumours and analysis of 1231 cases from Turkey.

The aims of this study were to describe the frequency of odontogenic tumours (OT) based on the World Health Organization (WHO) 4th edition of Head and Neck Tumours in Turkey, to compare the results with other regions and to assess the frequency changes of OT worldwide after the new WHO classification. OT were selected from the pathology department's files between 1971-2018. In a total of 1231 OT, 1215 (98.7%) were benign, whereas malignant OT were only 16 cases (1.3%). The three most common tumours were ameloblastoma (n=366, 29.7%), odontoma (n=335, 27.2% both complex and compound types), and odontogenic myxoma (n=190, 15.4%), respectively. After the 2017 classification, the decrease of OT frequency was found among 20%-42% in the selected epidemiological series because of re-classification of some lesions. The pattern of incidence in the Turkish population is similar to that in other populations. However, there are some differences in the frequency of the tumour types. It is obvious that the relative frequency of odontogenic tumours worldwide will change based on the new classification. It should be kept in mind that this is not a real decrease of OT cases. These marked changes in the frequency and prevalence of OT is just related to reclassification of some entities.

CEOT Variants or Entities: Time for a Rethink? A Case Series with Review of the Literature

The first detailed description of calcifying epithelial odontogenic tumor (CEOT) are ascribed to Jens Pindborg, but this tumor was described some years previously. Subsequently, CEOT was included in the 1971 WHO classification of odontogenic tumors and a since then number of variants have been described, which have added confusion to the diagnostic criteria. We aimed to survey the literature on the variants of CEOT, in parallel with a review of our single institution experience of CEOTs. Cases identified were collated, including available clinical, radiological and histological information and then reviewed, taking into account changes in the understanding and classifications of odontogenic tumors since initial diagnosis. We identified 26 cases from 1975 to 2017 for which histological material was available. Of these, only 13 (50%) showed the “classic” histological appearance, whilst two cases were identified as recognized variants. In 11 cases, other diagnoses or a differential diagnosis were preferred, with no agreed diagnosis in four of these. The proliferation fraction (Ki67) in the 10 cases tested was 2.1% ± 0.18. These findings illustrate the diagnostic challenges in this group of tumors and highlight the gaps in knowledge. Techniques, such as EWSR1 gene cytogenetic analysis, may be helpful in cases with clear cells. However, in other areas of controversy, including the non-calcifying and Langerhans cell rich variants, further investigation, perhaps utilizing sequencing technologies may be needed to refine the classification. Owing to the relative rarity of these lesions it would be beneficial if future work could be pursued as an international collaboration.

A CLINICO-RADIOLOGICAL PRESENTATION OF ADENOMATOID ODONTOGENIC TUMOR OF MAXILA –A CASE REPORT

Adenomatoid Odontogenic Tumour (AOT) is odontogenic epithelial tumour, also known as pseudoadenoameloblastoma/adenoameloblastoma, which was described by Dreibaldt in 1907 [1]. The term “Adenomatoid odontogenic tumour” was proposed by Philipsen et al [2] indicating that it was not a variant of ameloblastoma. In the World Health Organization classification of odontogenic tumours established in 1971, AOT was mentioned as a mixed odontogenic neoplasm, an epithelial tumour with an inductive effect on the odontogenic mesenchyme [3].It represents 3–7% of all odontogenic tumours largely limited to younger patients and striking tendency to occur in anterior maxilla, and over 750 examples have been reported in the literature [4]. This case report presents a case of an Adenomatoid Odontogenic Tumour in the left maxillary anterior region which was diagnosed using radiographs and removed by surgical excision. KEYWORDS: Adenomatoid Odontogenic Tumor; Maxilla; Odontogenic tumor; Mixed radio opacity

140 Ameloblastom Olgusunun Klinik ve Histolojik Analizi: Histolojik Varyantların Değerlendirilmesi

Objektive: The objective of this study is to evaluate the clinical and demographic features of ameloblastoma cases of a pathology center with a detailed examination of the histopathological properties of the subtypes and variants. Material and Methods: The clinical and radiological data and histologic slides of ameloblastoma cases diagnosed and treated between 2005 and 2017 were retrieved from the archives. Histopathological features of previously diagnosed cases were re-evaluated and re-classification of all cases was performed in accordance with the World Health Organization (WHO) classification of odontogenic tumors. The significance of the relationship between radiological appearance (multiocularity/unilocularity) and final histological diagnosis (solid/unicystic) was evaluated with statistical analysis. Results: There were a total of a hundred and forty cases of ameloblastoma. A hundred and twenty (85.7%) cases were diagnosed as solid type. Sixteen (11.4%) cases were diagnosed as unilocular ameloblastoma. Three cases showed admixed histopathological characteristics. There was a significant relationship between radiological appearance and histological diagnosis (p=0.005). All recurrent luminal unicystic ameloblastomas were re-diagnosed as mural subtype in the histopathological examination. Conclusion: The presence of rare variants should be diagnosed correctly with a thorough histopathological examination to contribute to the prognosis. The radiographic appearance of the tumor is correlated with the histological subtype. In the examination of recurrent unicystic cases, the surgical specimen should be entirely inspected to indicate mural ameloblastic invasions.

Analyses of odontogenic tumours: the most recent classification proposed by the World Health Organization (2017).

Background The fourth edition of the ‘’WHO Classification of Head and Neck Tumours’’ was published in January 2017 and includes a classification of odontogenic tumours. This review aims to examine the changes made in this new classification in comparison with the previous classification of 2005. Material and Methods An electronic search was conducted in the PubMed, Scopus and Cochrane databases with the keywords “odontogenic tumor”, “WHO classification” and “update”. Studies published from January 2009 to April 2019 with a high level of scientific evidence were included, but studies not published in English, epidemiological studies and studies with a low level of evidence were excluded. Results The initial search found 457 articles and after eliminating duplicates, 8 studies were selected for full-text assessment. After excluding 3 epidemiological studies, 5 articles were finally included. These studies were stratified by their level of scientific evidence using SORT criteria (Strength of Recommendation Taxonomy). Conclusions The new odontogenic tumour list has been simplified with the objective of improving its role as an international guide for diagnosis. Some changes have been possible thanks to the application of immunohistochemistry and molecular genetic techniques that allow better characterization of certain tumours. Further clinicopathological and molecular studies are needed so that this new classification can be consolidated and/or amended. Key words:Odontogenic tumour, WHO classification, update.