Research Articles (Oral Pathology and Oral Biology)

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Head and neck rhabdomyosarcoma in pediatric patients : an international collaborative study
(Wiley, 2025-02) Gallagher, Karen Patricia Dominguez; Hunter, Keith D.; Arboleda, Lady Paola Aristizabal; Pedroso, Caique Mariano; Mariz, Bruno Augusto Linhares Almeida; Penafort, Paulo Victor Mendes; De Souza, Lucas Lacerda; Rodrigues-Fernandes, Carla Isabelly; Tager, Elena Maria Jose Roman; Carlos, Roman; Robinson, Liam; Schouwstra, Ciska-Mari; Villanueva-Sanchez, Francisco German; Gomez, Francisco Jose Paz; Gonzalez-Galvan, Maria del Carmen; Martins-de-Barros, Allan Vinicius; De Vasconcelos Carvalho, Marianne; Cavalcante, Roberta Barroso; Turatti, Eveline; Pontes, Helder Antonio Rebelo; Siqueira, Sheila Aparecida Coelho; De Mendonca, Regina Maria Holanda; Innocentini, Lara Maria Alencar Ramos; De Macedo, Leandro Dorigan; Ribeiro-Silva, Alfredo; Abrahao, Aline Correa; Romanach, Mario Jose; Van Heerden, W.F.P. (Willem Francois Petrus); Vargas, Pablo Agustin; Santos-Silva, Alan Roger
BACKGROUND : Rhabdomyosarcoma (RMS), a rare malignant tumor, frequently affects pediatric patients, with 35%–40% occurring in the head and neck. This study analyzes the clinicopathologic profile of pediatric head and neck rhabdomyosarcomas from Brazil, Guatemala, Mexico, and South Africa. METHODS : We reviewed 44 cases from 10 Oral and Maxillofacial Pathology services, conducting immunohistochemical analyses of desmin, myogenin, Myo-D1, and Ki67, with quantification via QuPath software. Cases with ≥ 50% myogenin expression were tested for fusion status using AP2β, NOS-1, and HMGA2. Statistical analyses included the Kruskal–Wallis test for age and marker expression comparisons, Fisher's exact test for categorical variables, Spearman's rank correlation for marker relationships, and multinomial logistic regression to assess fusion status likelihood. RESULTS : Cases were predominantly from Brazil (40.9%), followed by South Africa (27.3%), Guatemala (22.7%), and Mexico (9.1%). Two-thirds of patients were diagnosed in their first decade with no gender predilection. Nonparameningeal sites (45.5%) were more affected than parameningeal (40.9%) and orbital sites. Microscopically, embryonal RMS (77.3%) was most common, followed by alveolar (18.2%) and spindle cell (2.3%) tumors. Immunohistochemistry revealed positivity for myogenic markers, with significant differences in myogenin expression between embryonal and alveolar RMS variants (p < 0.05). Fusion status prediction identified two potential fusion-positive alveolar RMS cases, while all embryonal RMS and one alveolar RMS case appeared fusion-negative. Significant correlation with positive fusion status was found only between AP2β and NOS1 (p < 0.05). CONCLUSION : Although there are slight clinical-demographic variations among pediatric head and neck rhabdomyosarcomas in these regions, identifying fusion status through immunohistochemistry remains a diagnostic challenge.
A radiologic-pathologic study of the histopathologic variants of ameloblastomas and their proliferation indices
(Elsevier, 2024-09) Smit, Chane; Robinson, Liam; Van Heerden, M.B. (Marlene); Meyer, Pieter Willem Adriaan; Ogunsakin, Ropo Ebenezer; Fonseca, Felipe Paiva; Uys, Andre; Van Heerden, Willem Francois Petrus; chane.smit@up.ac.za
OBJECTIVES: This study aimed to analyze the clinicoradiologic features and Ki-67 proliferation indices between the histopathologic variants of ameloblastomas (ABs) for possible associations. STUDY DESIGN: The diagnosis and histopathologic variant were confirmed for all cases by experienced Oral and Maxillofacial Pathologists. Immunohistochemistry for Ki-67 was performed on the most representative formalin-fixed paraffin-embedded tissue block. Demographic, clinical data and radiologic features were analyzed from patient records and available radiographic examinations. The investigators were blinded to the histopathologic variant and proliferation index when the clinicoradiologic features were assessed. RESULTS: The current study included 116 cases of AB in the final sample. The indolent behavior of the unicystic variant was supported by their low proliferation index and slow growth paired with low frequencies of cortical destruction, loss of teeth, root resorption, and encroachment on anatomical structures. In contrast, the comparatively high proliferation index of the plexiform variant correlated with their fast growth and pain. Furthermore, high radiologic frequencies of cortical destruction, loss of teeth, and encroachment of surrounding anatomical structures supported their more aggressive clinical course. CONCLUSION: Statistically significant differences were noted between certain variants and Ki-67, location, borders, locularity, and cortical destruction, providing better insight into their biological behavior.
Radiologic specific growth rate of ameloblastomas : a clinicopathological correlation
(Wiley, 2025-01) Smit, Chane; Robinson, Liam; Van Heerden, Marlene B.; Meyer, Pieter Willem Adriaan; Fonseca, Felipe P.; Van Heerden, Willem Francois Petrus; Uys, Andre; chane.smit@up.ac.za
BACKGROUND : The study aimed to assess the radiologic-specific growth rate of ameloblastomas, evaluating potential associations with demographics, radiologic features, histopathologic variants and proliferation indices. The results of this study will hopefully establish if any clinical or histopathologic features can elude fast-growing ameloblastomas. METHODS : Patients presenting with multiple radiographs before surgical intervention due to various healthcare constraints or patient factors were included in the study. The measurements from each radiograph included the lesion's length, height, width and amount of expansion in these dimensions. Furthermore, the circumference of the lesion was measured in sagittal, coronal and axial planes. The radiologic-specific growth rate was assessed by calculating the difference in measurements from the initial to follow-up radiographs divided by the duration between the visits to calculate the growth rate per year. RESULTS : The specific growth rate was analysed between age groups, histopathologic variants and Ki-67 values, with no statistically significant correlations found in all dimensions measured. A statistically significant faster growth (p = 0.04) was seen in females when measuring the mesial-distal length. When comparing radiologic features, ameloblastomas with loss of border demarcation, severe cortical destruction and tooth displacement demonstrated statistically significant faster growth. CONCLUSION : This study found significant correlations with the growth rate of ameloblastomas, specifically in coronal dimensions, supporting the notion of buccal-lingual growth/expansion for which ameloblastomas are known.
Head and neck myofibroma : a case series of 16 cases and literature review
(Medicina Oral S.L., 2024-11) De Souza, Lucas Lacerda; Fonseca, Felipe Paiva; De Caceres, Cinthia Veronica Bardalez Lopez; Soares, Ciro Dantas; Gurgel, Alberto da Costa; Pontes, Helder Antonio Rebelo; Pontes, Flavia Sirotheau Correa; Paradela, Carolina Almeida; Correia-Neto, Ivan Jose; Kalinin, Yuri; Lopes, Marcio Ajudarte; Santos- Silva, Alan Roger; De Almeida, Oslei Paes; Vargas, Pablo Agustin; Robinson, Liam; Van Heerden, Willem Francois Petrus
BACKGROUND : This study aimed to explore the clinical, histopathologic, and immunohistochemical characteristics of myofibromas (MFs) affecting the head and neck region. MATERIAL AND METHODS : Formalin-fixed paraffin-embedded tissue blocks of patients diagnosed with MFs in the head and neck were retrieved from the archives of three oral and maxillofacial pathology laboratories. Data including clinical, radiographic, microscopic and immunohistochemical findings, treatment employed, and followup status were retrieved from the patient's medical records or pathology reports. RESULTS : Sixteen cases were included in the study. Females were slightly more affected than males. The first and second decades of life were more prevalent. The most common locations were the alveolar ridge and cheek. Although rare, some of the patients were presented with intraosseous lesions. Microscopically, tumors consisted of plump, spindle-shaped myofibroblasts arranged in whorls or fascicles with varying degrees of differentiation. Immunohistochemically, diffuse positivity for vimentin and α-SMA was observed, while Ki-67 mostly showed low immunoreactivity (<5%). Treatment primarily involved complete excision. CONCLUSIONS : MFs in the head and neck region are rare and predominantly affect female patients during the second decade of life. Despite their rarity, central MFs should be considered in the differential diagnosis of intraosseous lesions in infants.
The relevance of taurodontism in forensic dental age estimation
(Elsevier, 2024-09) Timme, Maximilian; Smit, Chane; Robinson, Liam; Bernitz, Herman; Guo, Yu-Cheng; Schmeling, Andreas
Taurodontism is a dental morphological anomaly characterized by enlarged pulp cavities repositioned towards the apical region of the tooth, coupled with shortened root structures. Molars are commonly affected by this alteration. Certain populations exhibit up to 48% prevalences for this dental alteration, underscoring its significance in dental age estimation (DAE). In the field of DAE, an individual’s chronological age is inferred from specific dental features, frequently employed within the forensic context. The effect of taurodontism on the features of DAE is an unanswered issue. The influence of taurodontism on eruption, mineralization, radiographic visibility of root canals, and radiographic visibility of the periodontal ligament space in mandibular third molars- some of the established criteria for DAE as examples-is currently not systematically examined. Some common staging scales for the dental features of DAE cannot technically be applied to taurodontic teeth. Additionally, given the association of taurodontism with syndromes affecting tooth development, caution is warranted in age assessment procedures. Notably, taurodontic teeth may serve as indicators of syndromes influencing skeletal development, further emphasizing the relevance of taurodontism in forensic age assessment. Presumably taurodontic teeth were included in reference data to some extent due to their partially high prevalence in the past, whereby the influence of taurodontism has been statistically absorbed within the overall spread of the features. Future studies should compare the temporal course of these tooth characteristics in affected and unaffected teeth. Subsequent initiatives should focus on raising awareness among forensic dentists regarding taurodontism, necessitating in-depth exploration of the subject.
Advances in nano-delivery of phytochemicals for glioblastoma treatment
(SpringerOpen, 2024-12) Ambele, Melvin Anyasi; Maebele, Lorraine Tshegofatso; Mulaudzi, Thanyani Victor; Kungoane, Tsholofelo; Damane, Botle Precious; melvin.ambele@up.ac.za
Glioblastoma (GBM) is an aggressive brain tumor characterized by cellular and molecular diversity. This diversity presents significant challenges for treatment and leads to poor prognosis. Surgery remains the primary treatment of choice for GBMs, but it often results in tumor recurrence due to complex interactions between GBM cells and the peritumoral brain zone. Phytochemicals have shown promising anticancer activity in in-vitro studies and are being investigated as potential treatments for various cancers, including GBM. However, some phytochemicals have failed to translate their efficacy to pre-clinical studies due to limited penetration into the tumor microenvironment, leading to high toxicity. Thus, combining phytochemicals with nanotechnology has emerged as a promising alternative for treating GBM. This review explores the potential of utilizing specific nanoparticles to deliver known anticancer phytochemicals directly to tumor cells. This method has demonstrated potential in overcoming the challenges of the complex GBM microenvironment, including the tight blood–brain barrier while minimizing damage to healthy brain tissue. Therefore, employing this interdisciplinary approach holds significant promise for developing effective phyto-nanomedicines for GBM and improving patient outcomes.
Probing the effects of retinoblastoma binding protein 6 (RBBP6) knockdown on the sensitivity of cisplatin in cervical cancer cells
(MDPI, 2024-04-02) Mehta, Harshini; Ambele, Melvin Anyasi; Mokgautsi, Ntlotlang; Moela, Pontsho; pontsho.moela@up.ac.za
Cervical cancer is a major cause of death in women despite the advancement of current treatment modalities. The conventional therapeutic agent, cisplatin (CCDP), is the standard treatment for CC; however, resistance often develops due to the cancer’s heterogeneity. Therefore, a detailed elucidation of the specific molecular mechanisms driving CC is crucial for the development of targeted therapeutic strategies. Retinoblastoma binding protein 6 (RBBP6) is a potential biomarker associated with cell proliferation and is upregulated in cervical cancer sites, exhibiting apoptosis and dysregulated p53 expression. Furthermore, RBBP6 has been demonstrated to sensitize cancer cells to radiation and certain chemotherapeutic agents by regulating the Bcl-2 gene, thus suggesting a crosstalk among RBBP6/p53/BCL-2 oncogenic signatures. The present study, therefore, investigated the relationship between cisplatin and RBBP6 expression in CC cells. Herein, we first explored bioinformatics simulations and identified that the RBBP6/p53/BCL-2 signaling pathway is overexpressed and correlated with CC. For further analysis, we explored the Genomics of Drug Sensitivity in Cancer (GDSC) and found that most of the CC cell lines are sensitive to CCDP. To validate these findings, RBBP6 was silenced in HeLa and Vero cells using RNAi technology, followed by measurement of wild-type p53 and Bcl-2 at the mRNA level using qPCR. Cells co-treated with cisplatin and siRBBP6 were subsequently analyzed for apoptosis induction and real-time growth monitoring using flow cytometry and the xCELLigence system, respectively. Cancer cells in the cotreatment group showed a reduction in apoptosis compared to the cisplatin-treated group. Moreover, the real-time growth monitoring revealed a reduced growth rate in RBBP6 knockdown cells treated with cisplatin. Although wild-type p53 remained unchanged in the co-treatment group of cancer cells, Bcl-2 was completely repressed, suggesting that RBBP6 is necessary for sensitizing cervical cancer cells to cisplatin treatment by downregulating Bcl-2. The Vero cell population, which served as a non-cancerous control cell line in this study, remained viable following treatment with both siRBBP6 and cisplatin. Findings from this study suggest that RBBP6 expression promotes cisplatin sensitivity in HeLa cells through Bcl-2 downregulation. Knockdown of RBBP6 limits apoptosis induction and delays cell growth inhibition in response to cisplatin. The knowledge obtained here has the potential to help improve cisplatin efficacy through personalized administration based on the expression profile of RBBP6 among individual patients.
Extensive immunophenotypic sub-population analysis of StemRegenin1 expanded haematopoietic stem/progenitor cells
(BMC, 2024-09) Mellet, Juanita; Hendricks, Candice Laverne; Stivaktas, Voula; Durandt, Chrisna; Ambele, Melvin Anyasi; Pepper, Michael Sean; michael.pepper@up.ac.za
BACKGROUND : Ex vivo haematopoietic stem/progenitor cell (HSPCs) expansion constitutes an important area of research, and has the potential to improve access to umbilical cord blood (UCB) as a source of stem cells for haematopoietic stem cell transplantation (HSCT). The ability to improve stem cell dose and thereby reduce delayed engraftment times, which has plagued the use of UCB as a stem cell source since inception, is a recognised advantage. The extent to which cluster of differentiation (CD)34 sub-populations are affected by expansion with StemRegenin1 (SR1), and whether a particular subtype may account for better engraftment than others, is currently unknown. The purpose of this study was to determine the impact of SR1-induced HSPC expansion on CD34+ immunophenotypic subsets and gene expression profiles. METHODS : UCB-derived CD34+ HSPCs were characterised before (D0) and after expansion (D7) with SR1 using an extensive immunophenotypic panel. In addition, gene expression was assessed and differentially expressed genes were categorised into biological processes. RESULTS : A dose-dependent increase in the number of CD34+ HSPCs was observed with SR1 treatment, and unbiased and extensive HSPC immunophenotyping proved to be a powerful tool in identifying unique sub-populations within the HSPC repertoire. In this regard, we found that SR1 promotes the emergence of HSPC subsets which may aid engraftment post expansion. In addition, we observed that SR1 has a minimal effect on the transcriptome of 7-day expanded CD34+ HSPCs when compared to cells expanded without SR1, with only two genes being downregulated in the former. CONCLUSION : This study revealed that SR1 selects for potentially novel immunophenotypic HSPC subsets post expansion and has a minimal effect on the transcriptome of 7-day expanded HSPCs when compared to vehicle controls. Whether these distinct immunophenotypic sub-populations possess greater engraftment capacity remains to be tested in animal models.
Studying eruption patterns of mandibular third molars for forensic age assessment : introducing current reference data from a population of black South Africans
(Springer, 2024-09) Timme, Maximilian; Viktorov, Jan; Steffens, Laurin; Streeter, Adam; Karch, Andre; Smit, Chane; Robinson, Liam; Bernitz, Herman; Schmeling, Andreas
INTRODUCTION : Evaluation of the eruption of mandibular third molars in orthopantomograms (OPGs) is a method of forensic age assessment. The objective of our study was to provide valid reference data for this trait within a population of black South Africans. The study was guided by the criteria for reference studies in age assessment. MATERIALS AND METHODS : A study population from Pretoria, South Africa comprising 670 OPGs obtained from 338 black females and 332 black males aged between 15.00 and 25.97 years was analysed. All OPGs were performed for medical indication during the period from 2011 to 2022 and were retrospectively evaluated. From the 670 OPGs, a total of 1021 mandibular third molars were evaluated. The assessment of mandibular third molars was conducted using the staging scale presented by Olze et al. in 2012. Two experienced dentists evaluated the OPGs independently of each other. If the two examiners diverged in their assessments, a consensus stage was assigned. RESULTS : As expected, the mean, median and minimal age increased with higher stages for both teeth and both sexes. The minimum age recorded for stage D, indicating complete tooth eruption, was 15.79 years in females and 16.62 years in males. CONCLUSION : As it is the case for previous reference studies in other countries, placing exclusive reliance on the evaluation of mandibular third molar eruption is inadequate for ascertaining the age of majority among Black South Africans. Future studies need to examine if our results are transferable to other countries in Sub-Saharan Africa.
Insights into dental age estimation : introducing multiple regression data from a Black South African population on modified Gustafson's criteria
(Springer, 2025-01) Rudolphi, Fabian; Steffens, Laurin; Shay, Denys; Smit, Chane; Robinson, Liam; Bernitz, Herman; Schmeling, Andreas; Timme, Maximilian
Dental Age Estimation (DAE) is an effective instrument of the rule of law for verifying dubious age claims in living individuals. Once tooth development is complete, only degenerative dental characteristics can be used for this purpose. The influence of ethnicity on these degenerative dental characteristics has not been clarified. Degenerative changes were examined using modified Gustafson’s criteria including secondary dentin formation, cementum apposition, periodontal recession and attrition using the Olze et al. (2012) staging scales. Orthopantomograms of 1882 black South Africans, consisting of 934 females and 948 males, from 12.00 to 40.96 years of chronological age were utilized. Two independent examiners performed the evaluations, with one of the two evaluating all radiographs twice. The relationship between individual characteristics and chronological age was analyzed using multiple regression analysis with chronological age as the dependent variable. The resulting R2 values ranged from 0.22 to 0.35, and the standard error of estimate were between 6.6 and 7.3 years. The correlation with age was consistently lower for females compared to males. The characteristic of cementum apposition emerged as critical in this population, due to a particularly low correlation with age and observer agreements partly in the “slight” range. The formula’s values for the correlation with age were in general below the literature values for other populations. Overall, the limited precision of the age estimation by the formulae presented, especially for females, must be emphasized. The question of whether ethnicity per se exerts an influence on the characteristics in question, or whether the different socio-economic status, which encompasses factors such as nutrition and healthcare, is the determining factor, needs to be assessed in future studies.
Surrogate immunohistochemical markers of proliferation and embryonic stem cells in distinguishing Ameloblastoma from ameloblastic carcinoma
(Springer, 2024-10) Robinson, Liam; Smit, Chane; Van Heerden, M.B. (Marlene); Moolla, Haroon; Afrogheh, Amir H.; Opperman, Johan F.; Ambele, Melvin Anyasi; Van Heerden, Willem Francois Petrus; liam.robinson@up.ac.za
PURPOSE : The current study aimed to investigate the use of surrogate immunohistochemical (IHC) markers of proliferation and stem cells to distinguish ameloblastoma (AB) from ameloblastic carcinoma (AC). METHODS : The study assessed a total of 29 ACs, 6 ABs that transformed into ACs, and a control cohort of 20 ABs. The demographics and clinicopathologic details of the included cases of AC were recorded. The Ki-67 proliferation index was scored through automated methods with the QuPath open-source software platform. For SOX2, OCT4 and Glypican-3 IHC, each case was scored using a proportion of positivity score combined with an intensity score to produce a total score. RESULTS : All cases of AC showed a relatively high median proliferation index of 41.7%, with statistically significant higher scores compared to ABs. ABs that transformed into ACs had similar median proliferation scores to the control cohort of ABs. Most cases of AC showed some degree of SOX2 expression, with 58.6% showing high expression. OCT4 expression was not seen in any case of AC. GPC-3 expression in ACs was limited, with high expression in 17.2% of ACs. Primary ACs showed higher median proliferation scores and degrees of SOX2 and GPC-3 expression than secondary cases. Regarding SOX2, OCT4 and GPC-3 IHC expression, no statistically significant differences existed between the cohort of ABs and ACs. CONCLUSION : Ki-67 IHC as a proliferation marker, particularly when assessed via automated methods, was helpful in distinguishing AC from AB cases. In contrast to other studies, surrogate IHC markers of embryonic stem cells, SOX2, OCT4 and GPC-3, were unreliable in distinguishing the two entities.
Effect of 2-methoxyestradiol on mammary tumor initiation and progression
(Wiley, 2024-04) Peta, Kimberly Thando; Durandt, Chrisna; Van Heerden, Marlene B.; Joubert, Anna Margaretha; Pepper, Michael Sean; Ambele, Melvin Anyasi; melvin.ambele@up.ac.za
BACKGROUND : The anti-cancer agent 2-methoxyestradiol (2-ME) has been shown to have anti-proliferative and anti-angiogenic properties. Previously, the effect of 2-ME on early- and late-stage breast cancer (BC) was investigated in vivo using a transgenic mouse model (FVB/N-Tg(MMTV-PyVT)) of spontaneous mammary carcinoma. Anti-tumor effects were observed in late-stage BC with no effect on early-stage BC. Given the contrasting results obtained from the different BC stages, we have now investigated the effect of 2-ME when administered before the appearance of palpable tumors. METHODS : Each mouse received 100 mg/kg 2-ME on day 30 after birth, twice per week for 28 days, while control mice received vehicle only. Animals were terminated on day 59. Lung and mammary tissue were obtained for immunohistochemical analysis of CD163 and CD3 expression, and histological examination was performed to analyze tumor necrosis. Additionally, blood samples were collected to measure plasma cytokine levels. RESULTS : 2-ME increased tumor mass when compared to the untreated animals (p = .0139). The pro-tumorigenic activity of 2-ME was accompanied by lower CD3+ T-cell numbers in the tumor microenvironment (TME) and high levels of the pro-inflammatory cytokine interleukin (IL)-1β. Conversely, 2-ME-treatment resulted in fewer CD163+ cells detectable in the TME, increased levels of tumor necrosis, increased IL-10 plasma levels, and low IL-6 and IL-27 plasma levels. CONCLUSION : Taken together, these findings suggest that 2-ME promotes early-stage BC development.
Resolution of apical periodontitis-induced mental nerve paresthesia through nonsurgical endodontic retreatment : a case report
(Elsevier, 2023-07) Buchanan, Glynn Dale; Smit, Chane; Gamieldien, Mohamed Yasin; ElSheshtawy, Ahmed S.; glynn.buchanan@up.ac. za
Paresthesia is a potential consequence of unsuccessful root canal treatment. Persistent infection resulting in apical periodontitis may enlarge sufficiently to involve the mental neurovascular bundle. The case presented in this report was referred for endodontic evaluation with a chief complaint of discomfort on mastication and persistent numbness of the lower left lip. Clinical and radiographic evaluation revealed incomplete primary endodontic treatment of the left mandibular second premolar with complex internal anatomy. The untreated root canal system resulted in the progression of apical periodontitis involving the left mental neurovascular bundle as confirmed by cone-beam computed tomography imaging. Nonsurgical root canal retreatment was performed over 2 visits. At the 3-year follow-up visit, the paresthesia had resolved with return of normal sensation. Nonsurgical endodontic retreatment may be sufficient to allow healing of large periapical lesions and resolve complications including paresthesia without the need for surgical intervention.
Clinicoradiologic features of ameloblastomas : a single-centre study of 155 cases
(Wiley, 2024-02) Smit, Chane; Robinson, Liam; Ker-Fox, Jason; Fonseca, Felipe Paiva; Van Heerden, Willem Francois Petrus; Uys, Andre; chane.smit@up.ac.za
BACKGROUND : The purpose of the current study was to report on the clinical presentation and radiologic features of 155 cases of ameloblastoma (AB), representing a detailed, large, single-centre radiologic study. METHODS : Histologically confirmed cases were reviewed over 11 years. Demographic and clinical data were retrieved from the patient's records. Radiologic information was analysed from available radiographs. The radiologic features of ABs were assessed according to the mean age of presentation and the mean duration of the lesion. The distinguishing radiologic features between adults/children and sex were also evaluated. RESULTS : A statistically significant correlation existed between loss of border demarcation and advanced mean age. Multilocular lesions were markedly more common in adults compared to children. Multilocular ABs were associated with increased lesion duration and advanced mean age. Radiologic signs of reactive bony changes associated with the tumour presented at the highest mean duration of all bony effects. Bony expansion and cortical destruction were statistically correlated with lesion duration. Tooth impaction was more common in children. Some mandibular lesions reached a significant size, resulting in impingement of the maxillary sinus, zygoma, orbit and pterygoid plates. CONCLUSION : Due to unfortunate healthcare access constraints, ABs grow to significant sizes and exhibit features not often reported in the literature. The findings of this analysis highlighted the radiologic features of ABs expressed through the mean age and duration of the lesion. This emphasises the significance of timely management of these lesions.
Ameloblastic carcinoma : a systematic review
(Wiley, 2024-03) Robinson, Liam; Abreu, Lucas Guimaraes; Fonseca, Felipe Paiva; Hunter, K.D. (Keith); Ambele, Melvin Anyasi; Van Heerden, Willem Francois Petrus; liam.robinson@up.ac.za
BACKGROUND : Ameloblastic carcinoma (AC) is the most common odontogenic malignancy, constituting approximately 30% of cases in this category. Literature is sparse on malignant odontogenic neoplasms, with a large proportion of current knowledge derived from case reports or small case series. METHODS : A systematic review of case series/case reports of AC was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) Statement guidelines. Demographic and clinical information, including duration of the lesion, location, clinical presentation and radiologic features, were analysed. Additionally, the origin of the lesion (primary/secondary), Ki-67 proliferation index, treatment performed, metastasis, tumour recurrence and prognosis were collected for analysis. RESULTS : A total of 126 studies, including 285 individual cases of AC, were included in this review. Patients presented with a near-equal distribution of painless and painful swellings. ACs presented at a median age of 45 years, with a male-to-female ratio of 1:2. The mandible was most frequently involved, with rare cases extending to involve more than one region, including crossing the midline. Although most lesions presented with poorly-demarcated borders (52.6%), unilocular lesions with well-demarcated borders (47.4%) comprised a substantial number in the sample. The proliferation index was only reported in 27 cases, with a mean score of 42% and a wide range. The probability of tumour recurrence increased, and the survival probability decreased with prolonged follow-up duration. CONCLUSION : This study provides more comprehensive, up-to-date descriptive data on these rare odontogenic malignancies, aiding clinicians and Pathologists with the diagnosis and surgeons in their management of cases.
Mantle cell lymphoma involving the oral and maxillofacial region : a study of 20 cases
(Elsevier, 2023-01) Ribeiro Carvalho, Marcus Vinicius; Rodrigues-Fernandes, Carla Isabelly; Lopez de Caceres, Cinthia Veronica Bardalez; Mesquita, Ricardo Alves; Martins, Manoela Domingues; Jose Roman Tager, Elena Maria; Carlos, Roman; Pires, Fabio Ramoa; Robinson, Liam; Van Heerden, Willem Francois Petrus; Valente, Vitor Bonetti; Caldeira Xavier-Junior, Jose Candido; Bernabe, Daniel Galera; Rebelo Pontes, Helder Antonio; Soares, Ciro Dantas; Melo da Costa, Mauro Henrique; Vargas, Pablo Agustin; Fonseca, Felipe Paiva
OBJECTIVE : To investigate the clinicopathologic features of mantle cell lymphoma (MCL) involving the oral and maxillofacial region. METHODS : The MCL cases were retrieved from the pathosis database of 6 pathology laboratories. Original hematoxylin and eosin slides and immunohistochemical reactions were reviewed for confirmation of the initial diagnosis. Clinical data of the cases were obtained from the patients’ pathosis and/or medical charts. RESULTS : Twenty cases were included in the study, showing a male predominance and a mean age of 66 years. The oral cavity (12 cases) and the oropharynx (5 cases) were the most commonly involved subsites. Most cases presented as asymptomatic swellings, with 2 cases showing bilateral involvement of the palate. The classic histologic variant predominated (12/20 cases). All cases expressed CD20 with nuclear cyclin D1 positivity. SOX11 was seen in 9/13 cases, CD5 in 6/16 cases, Bcl2 in 16/19 cases, CD10 in 2/20 cases, and Bcl6 in 4/16 cases. Ki67 showed a mean proliferation index of 40.6%. The Epstein-Barr virus (EBV) was negative in all cases investigated. Follow-up data was available for 7 patients, with 5 currently alive and 2 deceased. CONCLUSION : Mantle cell lymphoma, albeit rare, may manifest in the oral and maxillofacial region. Its histologic heterogeneity demands a high degree of diagnostic skill from pathologists.
An ulcerative nodule on the dorsal tongue in an 8-year-old boy
(Elsevier, 2023-08) Giraldo-Roldan, Daniela; Fernandes, Diego Tetzner; Louredo, Brendo Vinicius Rodrigues; Penafort, Paulo Victor Mendes; Roza, Ana Luiza Oliveira Correa; Santos-Silva, Alan Roger; Vargas, Pablo Agustin
An otherwise healthy 8-year-old boy was consulted in July 2020, presenting with a 20-day history of a painless tongue growth associated with trauma. According to his parents, the lesion initially appeared as a “blood-filled blister” and had evolved into an ulcerated swelling. Intraoral examination revealed a reddish, sessile nodule with an ulcerated surface in the tongue dorsum's midline.
A pigmented nodule in the buccal mucosa
(Elsevier, 2023-04) Souza, L.L.; Roza, Ana Luiza Oliveira Correa; Leite, Amanda Almeida; Gallagher, Karen Patricia Dominguez; Mariz, Bruno Augusto Linhares Almeida; Santos, Mariana Rates Gonzaga; Santos-Silva, Alan Roger; Vargas, Pablo Agustin
A 59-year-old woman presented with a chief complaint of a 1-year history of a slow-growing painless nodule in the left buccal mucosa. She had no past or familial history of head and neck diseases, although she reported regular tobacco and alcohol consumption. She denied taking any medication at the time of the consultation. Physical examination was unremarkable, but an intraoral examination revealed a submucous nodule located in close relation to the occlusal line of the left buccal mucosa near the mandibular residual roots. The lesion was mobile and firm but slightly compressible on palpation. Clinically, the lesion presented as a well-defined asymptomatic pigmented nodule covered by intact mucosa, measuring approximately 8 mm.
Human examination and artificial intelligence in cephalometric landmark detection—is AI ready to take over?
(Oxford University Press, 2023-09) Indermun, Suvarna; Shaik, Shoayeb; Nyirenda, Clement; Johannes, Keith; Mulder, Riaan
OBJECTIVES : To compare the precision of two cephalometric landmark identification methods, namely a computer-assisted human examination software and an artificial intelligence program, based on South African data. METHODS : This retrospective quantitative cross-sectional analytical study utilized a data set consisting of 409 cephalograms obtained from a South African population. 19 landmarks were identified in each of the 409 cephalograms by the primary researcher using the two programs [(409 cephalograms x 19 landmarks) x 2 methods = 15,542 landmarks)]. Each landmark generated two coordinate values (x, y), making a total of 31,084 landmarks. Euclidean distances between corresponding pairs of observations was calculated. Precision was determined by using the standard deviation and standard error of the mean. RESULTS : The primary researcher acted as the gold-standard and was calibrated prior to data collection. The inter- and intrareliability tests yielded acceptable results. Variations were present in several landmarks between the two approaches; however, they were statistically insignificant. The computer-assisted examination software was very sensitive to several variables. Several incidental findings were also discovered. Attempts were made to draw valid comparisons and conclusions. CONCLUSIONS : There was no significant difference between the two programs regarding the precision of landmark detection. The present study provides a basis to: (1) support the use of automatic landmark detection to be within the range of computer-assisted examination software and (2) determine the learning data required to develop AI systems within an African context.
Fibrodysplasia ossificans progressiva
(Wiley, 2023-11) Smit, Chane; Uys, Andre; andre.uys@up.ac.za
Fibrodysplasia ossificans progressiva is a rare condition with an estimated prevalence of one in two million individuals. The condition is characterized by widespread heterotrophic ossification of skeletal muscles and ligaments. We report the case of an 8-year-old female patient and show the radiological progression of the condition.

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