Odontogenic Tumours: A Clinicopathologic Appraisal of Cases seen in a Nigerian Tertiary Hospital using 2017 WHO Classification.

Background: Odontogenic tumours (OT) are a group of diverse lesions seen in the maxillofacial region. They are categorized according to their tissues of origin as; epithelial, mesenchymal or mixed tumours.

Objectives: The aim of this study is to present the proportion of odontogenic tumours seen in Lagos University Teaching Hospital using the 2017 WHO classification.

Methods: Data from cases of OT histologically diagnosed from January 2006 to December 2016 were collected from records of the Oral and Maxillofacial Surgery and Oral and Maxillofacial Pathology Departments. Information on age, sex, site of occurrence and histologic diagnosis were recorded. After reconfirmation of diagnosis, cases were categorized according to the latest World Health Organization (WHO) classification for OT. Ethical approval was obtained and data was analyzed using SPSS software for Windows (version 22: SPSS, Chicago IL).

Results: A total of 232 odontogenic tumours were diagnosed during the period of study, 227(97.8%) cases were benign OT and 82.8% occurred in the mandible. The mean age ± SD of patients was 32.1±13.8 years and the age range from 2-73 years. OT was slightly more common in females (119) with an almost equal male-to-female ratio of 1:1.1. Most of the patients were in the 21-30 year age group and ameloblastoma 148(63.8%) was the most common OT. The histological types of odontogenic tumours and the age group of patients were significantly associated with the site of occurrence of tumours (P=0.000* and P=0.037* respectively).

Conclusion: Epithelial odontogenic tumours are still by far the most common odontogenic tumours.