Background Salivary gland tumours (SGT) are a relatively rare group of neoplasms with a wide range of histopathological appearance and clinical features. To date, most of the epidemiological studies on salivary gland tumours are limited for a variety of reason including being out of date, extrapolated from either a single centre or country studies, or investigating either major or minor glands only. Methods This study aimed to mitigate these shortcomings by analysing epidemiological data including demographic, anatomical location and histological diagnoses of SGT from multiple centres across the world. The analysed data included age, gender, location and histological diagnosis from fifteen centres covering the majority of the world health organisation (WHO) geographical regions between 2006 and 2019. Results A total of 5739 cases were analysed including 65% benign and 35% malignant tumours. A slight female predilection (54%) and peak incidence between the fourth and seventh decade for both benign and malignant tumours was observed. The majority (68%) of the SGT presented in major and 32% in the minor glands. The parotid gland was the most common location (70%) for benign and minor glands (47%) for malignant tumours. Pleomorphic adenoma (70%), and Warthin’s tumour (17%), were the most common benign tumours whereas mucoepidermoid carcinoma (26%) and adenoid cystic carcinoma (17%) were the most frequent malignant tumours. Conclusions This multicentre investigation presents the largest cohort study to date analysing salivary gland tumour data from tertiary centres scattered across the globe. These findings should serve as a baseline for future studies evaluating the epidemiological landscape of these tumours.

Introduction odontogenic tumors originate from neoplastic transformation of the remnants of tooth forming apparatus. There are varying degrees of inductive interactions between odontogenic ectomesenchyme and epithelium during odontogenesis, leading to lesions that vary from benign to malignant. Malignant odontogenic tumours (MOTs) are very rare and are classified according to embryonic tissue of origin. Recently, there has been a few changes to the classification of MOTs according to the World Health Organization's (WHO) classification in 2017. This study aims to evaluate and reclassify MOTs, using a multi-centre approach in some major tertiary dental hospitals in Nigeria. Methods this study reviewed the clinicopathological data on 63 cases of MOT diagnosed over 25 years in five major tertiary dental hospitals in Nigeria. All MOT cases were reclassified according to the recent revision to the 2017 WHO classification of odontogenic tumours. Results from a total of 10,446 biopsies of oral and jaw lesions seen at the 5 study centres over the 25-year study period, 2199 (21.05%) cases were found to be odontogenic tumours (OTs), of which 63 were MOT. MOTs constituted 0.60% of the total biopsy cases and 2.86% of OTs. Odontogenic carcinomas presented with a mean age higher than odontogenic sarcomas. According to our 2017 WHO reclassification of MOTs, odontogenic carcinomas, ameloblastic carcinomas and primary intraosseous carcinomas were found to be the top three lesions, respectively. Carcinosarcomas were found to be extremely rare. Conclusion using a multi-centre approach is a robust way to reduce diagnostic challenges associated with rare maxillofacial lesions such as MOTs.

The prevalence values are within the range of values reported in other Nigerian studies but differ widely with values from other ethnic groups from other countries.

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Objective: The accuracy of OraQuick® rapid test in detecting HIV 1 & 2 antibodies in saliva is evaluated against the blood EIA benchmark tests with confirmatory testing, against which OraQuick® accuracy is determined.Method: Paired samples of saliva and blood from 281 Nigerians were tested for HIV antibodies, and compared for sensitivity and specificity. Subjects included in the study were  those who had a complete test, which included saliva test with OraQuick® rapid test, serologic test using conventional Enzyme Immunoassay (EIA), and confirmatory serological test.Result: From the 281 subjects who completed the oral fluid-based OraQuick® tests & EIA with confirmatory tests, 192 were seropositive and 89 seronegative for HIV 1 & 2 antibodies. The  sensitivity (95% CI) of OraQuick® was 98.96% (97.98% to 99.96%) and specificity was 100% thereby comparing favorably with serum EIA with benchmark sensitivity of 100% and specificity (95% CI) of 96.63% (95.61 to 97.56).Conclusion: Saliva based OraQuick® rapid assays for detecting HIV antibodies using oral fluids give accurate sensitivity and specificity results comparable to EIA results with serum samples. They are more acceptable, easier to use and not invasive.