Odontogenic tumours in Nigeria: A multicentre study of 582 cases and review of the literature

BACKGROUND: The objective of this study was to classify the various types of odontogenic tumours (OTs) using the newly updated 2017 world health organization (WHO) histological typing and to analyze the prevalence of these tumours among Nigerians as well as to compare the results obtained with reports from world-wide studies. MATERIAL AND METHODS: The records of four major tertiary hospitals in Nigeria were reviewed over a 12-year (2004-2015) period. Lesions diagnosed as odontogenic tumours were classified into four groups according to the 2017 WHO histological typing. Data which consisted of age, sex and site were analyzed using SPSS for Window (version 20.0; SPSS Inc., Chicago, IL) and frequency tables were computed. RESULTS: A total of 582 OTs were recorded and reviewed, benign OTs were 573 (98.5%) cases and malignant OTs were 9 (1.5%) cases. Of the benign OTs, the epithelial OTs were the commonest (500; 86%) while the benign mixed OTs were the least frequent (21; 3.6%). The mean age was 30±14 years (age range of 3–77years) and the peak age was in the third decade (197; 33.8%) of life. There was slight male gender and strong mandibular site predilection. Ameloblastoma, was the most frequent OT and it accounted for 75.5% of the OTs, followed by adenomatoid odontogenic tumour (8.1%) and odontogenic myxoma (7.2%). Malignant OTs accounted for 1.5% of the OTs. CONCLUSIONS: OTs show a geographic variation with tendency for prevalence of the epithelial OTs in Africa. Ameloblastoma has a high prevalence among Nigerians and is the most common OTs in Africa. Prevalence of odontoma is relatively low in developing African countries like Nigeria when compared to the prevalence in developed countries. Key words:Odontogenic tumours, WHO classification, Nigerians.