A multi-centre evaluation of malignant odontogenic tumours in Nigeria.

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.

A geographical analysis of ethnic distribution of jaw ameloblastoma in Nigerians.

INTRODUCTION: Ameloblastoma is the most common odontogenic tumour in Nigeria. A definite geographic variation has been observed in the frequency of odontogenic tumors from different parts of the world. However, there is no study on the regional variations in Nigeria. Hence, this study was designed to document the ethnic and geographical distribution of jaw ameloblastoma in Nigeria. METHODS: Archival data on ameloblastoma from 10 health facilities were obtained. Global Moran's I detected geographic clustering in its distribution while Local Getis Ord indicated the location of ameloblastoma clusters. Chi-square tested associations between variables at 0.05 level of significance. RESULTS: A total of 1,246 ameloblastoma cases were recorded in Nigeria. Besides substantial state variations, a South-North gradient was noticed in its distribution. Significant positive spatial autocorrelation was observed in the three major groups while ameloblastoma hotspots were found in the SouthWestern and Northwestern Nigeria. The Igbos had a higher prevalence of ameloblastoma outside their home region than within. CONCLUSION: The study hypothesized that the geographical distribution of ameloblastoma in Nigeria is the result of all or one of the following: the country's tropical climate, migration patterns and health seeking behavior. Hopefully, these claims should lead to further enquiry on the underlying causes.

Descriptive epidemiology of salivary gland neoplasms in Nigeria: An AOPRC multicenter tertiary hospital study.

OBJECTIVES: Accurate diagnosis of salivary gland neoplasms (SGN) in many centers in Africa is limited by poor diagnostic resources and ancillary services. Hence, we have carried out a multicenter epidemiological study to understand the true burden of SGN in Nigeria. METHOD: In this descriptive cross-sectional study, we have deployed resources available to members of the African Oral Pathology Consortium (AOPRC) to examine the burden of salivary gland lesions in Nigeria, using a multicenter approach. Data from seven major tertiary health institutions in northern, western, and southern Nigeria were generated using a standardized data extraction format and analyzed using the Epi-info software (Version 7.0, Atlanta, USA). RESULT: Of the 497 cases examined across the seven centers, we observed that SGN occurred more in females than males. Overall, pleomorphic salivary adenoma (PA) was found to be the most common. PA was found to be the commonest benign SGN while adenocystic carcinoma (ADCC) was the commonest malignant SGN. Regional variations were observed for age group, diagnosis, and gender distribution. Significant statistical differences were found between males and females for malignant SGNs (p-value=0.037). CONCLUSION: We found regional variation in the pattern of distribution of SGN in Nigeria. This is the largest multicenter study of SGN in Nigeria, and our findings are robust and representative of the epidemiology of this neoplasm in Nigeria.

Concordance between clinical and histopathologic diagnosis and an audit of oral histopathology service at a Nigerian tertiary hospital.

INTRODUCTION: Although histopathological diagnosis remains the gold standard; good clinical impression is potentially a key diagnostic tool in rural resource-limited settings. Thus, good concordance between clinical impression and histopathological diagnosis is thus a very crucial diagnostic oral pathology tool in low- and middle-income countries (LMICs). METHODS: This retrospective study was performed at the Oral pathology and Oral diagnoses units of Obafemi Awolowo University Teaching Hospital Complex (OAUTHC), Osun state. Clinicopathological reports of all biopsies between the period of 2008-2017 were retrieved and analyzed. Descriptive analysis of data was done using Stata 14. Frequency of oral lesions and rates of accurate clinical diagnoses were evaluated for lesional sites and clinician's qualification/specialization. RESULTS: In 592 biopsied cases, the mean age was 36.1years with higher female predilection (54.4%). Odontogenic tumors (OTs) were the most prevalent category of lesions (25.3%, n=149), followed by reactive lesions (12%, n=71). Absolute concordance was recorded for 54.6% (k=0.5) of the cases; with highest concordance observed in fibro-osseous lesions (65.6%, k=0.43), and least in pulp/periapical lesions (3.5%). Concordance was higher in females (59.5%, k=0.53) than males (48.3%, k=0.44). Oral medicine specialists had the highest concordance index (62.5%, k=0.59). CONCLUSION: The findings in this research indicate that, on a general note, the degree of concordance between clinical and histopathological diagnosis is poor. Hence, improvement in diagnostic skills (irrespective of clinical specialty) is important to improve treatment outcomes, particularly in LMICs. Continuous personnel training and utilization of advanced diagnostic techniques can potentially help bridge the diagnostic gaps.

Review of 109 cases of primary malignant orofacial lesions seen at a Nigerian Tertiary Hospital.

BACKGROUND: Orofacial malignancy is a growing health issue common in developing regions of the world. Presentation patterns are myriad with geographic variations. Advanced stage owing to late presentation constitutes a significant public health burden. The site and type of the lesions are valuable in diagnosis and patient management. AIM: This study aims to review cases of primary orofacial malignancies at the OAUTHC Dental Hospital. OBJECTIVES: The objective of the study was to determine the prevalence of histologically diagnosed orofacial malignancies, the relative frequencies, types and site of distribution. MATERIALS AND METHODS: Records of patients with orofacial malignancies at the OAUTHC, Dental Hospital over a period of 10 years (January 2008-December 2017) were reviewed, demographic data (age, gender and site), history of tobacco use were retrieved and entered into a pro forma. The data obtained were analysed with STATA 11. Statistical significance was set at P < 0.05. RESULTS: Of 375, 109 cases of neoplasms seen were primary malignant tumours, with prevalence rate of 29.1%. There were 71 (65.1%) males and 38 (34.9%) females (male:female ratio of 1.87:1), mean age (48.7 ± 19.3 years) and range (4-94 years). Affected sites were mandible (41, 37.6%), maxilla (39, 35.8%), palate (17, 15.6%) and others. Lesions were mainly squamous cell carcinomas (SCC: 46, 42.2%), salivary gland adenocarcinomas (SGAs, 25, 22.9%) including 8 (32%) cases of adenoid cystic carcinoma (ACC). Others were odontogenic carcinoma (18, 16.5%) and lymphoma (8, 7.3%). Most specimen analysed were hard tissues (n = 63, 57.8%). Thirty-four (73.9%) cases of SCC and 66 (60.6%) cases of primary malignancies were in the 5th-9th decades of life. This was statistically significant at P = 0.000. CONCLUSION: SCC was more prevalent than salivary and odontogenic carcinomas. ACC and mucoepidermoid carcinoma were two most common SGAs. Metastatic tumours to the jaws are rare.

Ameloblastic carcinoma: a clinicopathologic analysis of cases seen in a Nigerian Teaching Hospital and review of literature.

INTRODUCTION: Ameloblastic carcinoma is a rare malignant odontogenic neoplasm that exhibits histological features of ameloblastoma in combination with cytological atypia. It may arise de novo or secondarily through malignant de-differentiation of pre-existing ameloblastoma or odontogenic cyst. Secondary ameloblastic carcinomas often results from repeated surgical intervention, which is a mainstay of odontogenic tumor management in resource limited settings. To date, relatively few cases of ameloblastic carcinomas have been reported and many cases have been misdiagnosed as ameloblastoma. This is due to its wide range of clinicopathological feature which range from indolent to aggressive. It may present as an aggressive ulcerated mass or as a simple cystic lesion; hence, it often challenging to delineate from its benign counterpart, ameloblastoma. METHODS: this study reviewed the clinicopathological data on 157 cases of odontogenic tumors diagnosed over a 10 years period from the pathology archive of the Oral Pathology Unit of Obafemi Awolowo University Teaching Hospital Complex (OAUTHC), Ile-Ife, Nigeria. RESULTS: of all these cases, we identified that 64.9% were Ameloblastomas, while 8.3% were ameloblastic carcinomas. Primary subtypes of ameloblastic carcinoma constituted 23.08%, while 69.23% of the cases were of the secondary subtype. We also found that the secondary subtype of ameloblastic carcinomas showed a higher mean duration value of 7.7 years. Most lesions were found in posterior mandible and presented with ulceration, perforation and ill-defined borders radiographically. CONCLUSION: this study is among the few that have documented higher frequency of secondary ameloblastic carcinoma in the scientific literature.

A multi-centre evaluation of oral cancer in Southern and Western Nigeria: an African oral pathology research consortium initiative.

INTRODUCTION: Oral cancer is a leading cause of cancer deaths among African populations. Lack of standard cancer registries and under-reporting has inaccurately depicted its magnitude in Nigeria. Development of multi-centre collaborative oral pathology networks such as the African Oral Pathology Research Consortium (AOPRC) facilitates skill and expertise exchange and fosters a robust and systematic investigation of oral diseases across Africa. METHODS: In this descriptive cross-sectional study, we have leveraged the auspices of the AOPRC to examine the burden of oral cancer in Nigeria, using a multi-centre approach. Data from 4 major tertiary health institutions in Western and Southern Nigeria was generated using a standardized data extraction format and analysed using the SPSS data analysis software (version 20.0; SPSS Inc. Chicago, IL). RESULTS: Of the 162 cases examined across the 4 centres, we observed that oral squamous cell carcinomas (OSCC) occurred mostly in the 6th and 7th decades of life and maxillary were more frequent than mandibular OSCC lesions. Regional variations were observed both for location, age group and gender distribution. Significant regional differences was found between poorly, moderately and well differentiated OSCC (p value = 0.0071). CONCLUSION: A multi-centre collaborative oral pathology research approach is an effective way to achieve better insight into the patterns and distribution of various oral diseases in men of African descent. The wider outlook for AOPRC is to employ similar approaches to drive intensive oral pathology research targeted at addressing the current morbidity and mortality of various oral diseases across Africa.

A retrospective review of 61 cases of adenomatoid odontogenic tumour seen in five tertiary health facilities in Nigeria.

INTRODUCTION: Adenomatoid odontogenic tumor (AOT) is a benign lesion originating from the dental lamina or its remnants. It is a relatively uncommon neoplasm representing about 3% of all odontogenic tumors. The aim of this study was to examine the clinical and radiological characteristics of AOTs in five major tertiary centres in Nigeria. METHODS: Archival hospital-based data stores of five tertiary health facilities in Nigeria were accessed. Case files and biopsy records were retrieved to obtain relevant information. Data was collected according to a proforma for standardization and entered into and analysed using SPSS for Windows (version 20.0; SPSS Inc. Chicago, IL). RESULTS: 61 (4.5%) cases of AOT were documented. The age range was 8-46 years with a mean age of 20.4±9.9 years. Male: Female ratio was 1:1.3. The anterior maxilla had 34 (55.8%) cases and the anterior mandible had 20 (32.8%) cases. 40 (65.6%) follicular cases, 20 (32.8%) extra-follicular cases and 1(1.6%) extra-osseous case were found. 31 cases (61.1%) were associated with impacted teeth and the upper canine was involved in 19 (57.6%) cases. CONCLUSION: This study showed AOT to be more common in the maxilla, more in females, most often associated with impacted canines, however, the suggestion of AOT being a "Two third tumour" was not observed in this study.

A retrospective study of 21 cases of malignant odontogenic tumours from two tertiary health centres in Nigeria.

INTRODUCTION: Malignant odontogenic tumours (MOTs) are relatively rare tumours and only few cases have been reported in the sub-Sahara African literature. The aim of this study was to describe the demographic distribution of malignant odontogenic tumours in two tertiary health centres based on the current WHO 2005 classification scheme. METHODS: We reviewed 21 malignant odontogenic tumours out of a total of 374 odontogenic tumours from two Tertiary Health Centres. Information regarding histology, location, patients age and gender for MOTs were analysed using SPSS for Windows (version 20.0; SPSS Inc. Chicago, IL). RESULTS: Twenty one (5.6%) MOTs out of a total of 374 odontogenic tumours were seen from the two institutions over the study period. The median age for MOTs was 42.0 (± 19.0) years (range = 16-66 years). The male: female ratio was 2.5:1 and 85.7% occurred in the mandible. Ameloblastic carcinoma (AC) with 13 (61.9%) cases was the most common MOT. AC had a mean age of 37.5 (± 11.9) years. AC had a mandible: maxilla ratio of 5.5:1 with majority (84.6%) occurring in the posterior mandible. CONCLUSION: This study showed that MOTs are rare lesions. AC was the most common MOT and majority of MOTs occurred in the posterior mandible of male patients. The study helps to better elucidate the demography of MOTs in sub-Sahara Africans.

Facial fracture management in northwest Nigeria.

BACKGROUND: Facial fracture is gradually become a public health problem in our community due to the attendant morbidity and mortality. Hence, the aim of this study was to determine the pattern of facial fracture in Dental and Maxillofacial Surgery Department of Usmanu Danfodiyo University Teaching Hospital. This cross-sectional study was undertaken to provide information regarding gender, age, etiology, and diagnosis of patients with maxillofacial fractures. MATERIALS AND METHODS: A 1-year review of patients diagnosed and treated for facial fractures in Usmanu Danfodiyo University Teaching Hospital between January 2011 and December 2011. The diagnosis was based on radiographic data and clinical examination. The main analysis outcome measures were etiology, age, gender, site, and treatment. Data were organized and presented by means of descriptive statistics and Pearson's Chi-square test. The level of significance adopted was 5%. RESULTS: A total of 40 patients were treated in this period. Over 95% were male, 81% were caused by road traffic crash (RTC) and 86.4% were in the 21-30 years group. Most patients (52%) had mandibular fractures, and the most common site was the body. Most patients with midfacial fractures had fractures of the zygomaticomaxillary region (36%), while fractures of the parasymphyseal region were more common in the mandible 156 (31%). The most common treatment for jaw fractures was mandibulomaxillary fixation (MMF). Stable zygomatic complex fractures were reduced (elevated) intraorally, and unstable ones were supported by antral packs. CONCLUSIONS: This study highlights facial fractures secondary to RTC as a serious public health problem in our environment. Preventive strategies remain the cheapest way to reduce direct and indirect costs of the sequelae of RTC. It also bring to the fore the necessity to shift to open reduction and internal fixation (ORIF) of fractures.