New WHO odontogenic tumor classification: impact on prevalence in a population

Abstract

Objectives:This study approaches the history of reclassifications and redefinitions around the odontogenic keratocyst (OK), as proposed by the World Health Organization (WHO), and aims to understand the impact of those changes on the prevalence and epidemiology of odontogenic tumors (OTs).Methodology:Cases of OTs diagnosed in an Oral Pathology service between January 1996 and December 2016 were reviewed. Demographic data of patients such as age, gender and site of lesions were retrieved from their respective records.Results:Within the studied period, 7,805 microscopic reports were elaborated and 200 (2.56%) of these were diagnosed as OTs. Out of these 200, between 1996 and 2005, prior to the 2005 WHO classification, there were 41 (20.5%) OTs cases, being odontoma the most frequent (23; 56.09%), followed by ameloblastoma (8; 19.51%) and myxoma (03; 7.31%). Between 2006 and 2016, after the previous 2005 WHO classification there were 159 (79.5%) OTs, being odontogenic keratocystic tumor (KCOT) the most frequent (68; 42.76%), followed by odontoma (39; 24.52%) and ameloblastoma (21; 13.20%).Conclusions:As of today, the most recent WHO classification to be followed brings KCOT back to the cyst category, which will impact on the prevalence and epidemiology of OTs; thus, this study was able to identify a considerable increase (287.80%) in the prevalence of OTs when the 2005 WHO classification was utilized. Despite being an important academic exercise, classifying odontogenic lesions and determining whether to place the odontogenic keratocyst in a cyst or tumor category is crucial to establish the correct diagnosis and treatment to follow, whether by oral medicine or oral surgery specialist, or by the general practitioner.

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

“…Taking into account the differing nature of odontogenic cysts and tumours, several consensus meetings have tried to produce a more systematic classification of these lesions as promoted by the World Health Organization (WHO) in 1971( 4 ). Since then, other WHO meetings have revised the classifications of these lesions in 1992, 2005 and 2017 ( 6 ). One of the biggest changes in classification was reported in the 3rd edition of the Odontogenic Tumour Classification in 2005, where odontogenic keratocysts were considered neoplasm tumours, and referred to as keratocystic odontogenic tumours (KOT).…”

“…One of the biggest changes in classification was reported in the 3rd edition of the Odontogenic Tumour Classification in 2005, where odontogenic keratocysts were considered neoplasm tumours, and referred to as keratocystic odontogenic tumours (KOT). This was to take into account the behaviour of the lesion, histopathology, genetic factors and its tendency for being an aggressive and recurrent lesion ( 6 ). However, the controversy over odontogenic tumour classifications continued.…”

Remoção parcial de odontoma complexo de grandes dimensões em mandíbula

“…12 Antes da classificação de tumores odontogênicos da OMS em 2017, estudos demonstraram divergências, embora relatem maior prevalência do ameloblastoma e ceratocisto odontogênico (antigo tumor odontogênico ceratocístico). 13,14 A variabilidade de tumores mais comuns pode se dar pela diferença no envio das amostras de lesões para análise histopatológica, pelo acesso limitado de alguns países ao serviço ou pelo fato de que, muitas vezes, o odontoma é tratado sem registro ou envio para confirmação histológica.…”

Új terápiás lehetőségek odontomák kezelésében

“…A WHO legutóbbi klasszifikációja szerint az odontomák mesenchymalis és epithelialis elemeket (fog eredetű kemény-és lágyszöveteket) vegyesen tartalmazó be nignus daganatok, melyek két típusát különböztetjük meg: a compound és complex odontomát [5]. Az elváltozás az egyik leggyakoribb odontogén daganat, megjelenési aránya a két nem esetén nem mutat eltérést [2,3]. Eredetük ismeretlen, a fogcsíra genetikai eltérése, illetve külső környezeti tényezők, például traumák játszhatnak szerepet a kialakulásukban.…”

“…Eredetük ismeretlen, a fogcsíra genetikai eltérése, illetve külső környezeti tényezők, például traumák játszhatnak szerepet a kialakulásukban. A genetikai háttér szerepe mellett szól, hogy örökletes szindrómák részeként, például Gardner-, Hermann-, Gorlin-Goltz-szindróma esetén is megfigyelhető jelenlétük [3,14]. A compound odontoma leggyakoribb előfordulási helye a maxilla frontalis régiója, megjelenése kisméretű fogak halmazára hasonlít, ez a gyakoribb elváltozás.…”