Research Articles (Maxillo-Facial and Oral Surgery)

Permanent URI for this collectionhttp://hdl.handle.net/2263/2686

For inquiries regarding this collection or items in the collection, please contact : Suzy Nyakale
Tel.: +27 12 319 2905

Browse

Now showing 1 - 20 of 90

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.
Pattern and management of maxillofacial trauma in selected trauma units across Africa : a prospective pilot study
(Springer, 2024-12) Mabongo, Mzubanzi; Parkins, Grace E.; Aladelusi, Timothy; Abdullahi, Mohammed Adam Sheikh; Ngamo, Felicite Ngounou; Ayo-Yusuf, Imade J.; Blankson, Paa-Kwesi; Nokaneng, Emmy N.; Mfolo, Tshepiso; Boamah, Matthew O.
INTRODUCTION : Trauma to the facial region could lead to considerable social, psychological and economic consequences. With the African region being a major contributor to global trauma events, we set out to describe the epidemiology and management of maxillofacial trauma in selected trauma units across Africa. MATERIALS AND METHODS : This was a six-month prospective multicentre study carried out during March—September 2021.The study involved five major hospitals across the African continent. The patterns of maxillofacial injuries were recorded and patients managed according to local standardized operating protocols. Treatment delays and postoperative complications were recorded at review. Data analysis included descriptive statistics and regression analysis (p < 0.05). P FINDINGS : A total of 195 patients were included in the study. The age range of patients was 1–87 years, with a mean age of 32.4 (SD = ± 16.1). The study population consisted of 43 (22.1%) females, accounting for a Male:Female ratio of 3.5:1. Lacerations were the most common soft tissue injuries observed, while the prevalence of upper-, mid-, and lower- third fractures were 5.1%, 33.8%, and 19.5% respectively. There was loss of consciousness in 27.2%. Road crashes were the predominant aetiology of injuries, while 33.8% had concomitant injuries. About 38.3% of participants experienced treatment delays. Compared to employed patients, unemployed patients had significantly higher odds of experiencing treatment delays (OR = 3.76; 95%CI: 1.62 – 8.73). CONCLUSION : With the overwhelming contribution of road crashes, measures to ensure road safety are needed to significantly reduce maxillofacial injuries in the African region, while also reducing socioeconomic inequality to timely treatment.
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.
Investigation of mandibular second molar root and canal morphology in a Black South African population using cone-beam computed tomography and two classification systems
(Nihon University School of Dentistry, 2023) Buchanan, Glynn Dale; Gamieldien, Mohamed Yasin; Fabris-Rotelli, Inger Nicolette; Van Schoor, Albert-Neels; Uys, Andre
PURPOSE : To investigate the root and canal morphology of mandibular second molars, including anatomical variations, in a Black South African population using two classification systems. METHODS : Cone-beam computed tomography images of 386 teeth were evaluated. The number of roots and canal configurations were categorized using the classifications of Vertucci (with modifications by Sert and Bayirli) and Ahmed et al. (including the modified Melton classification). Relationships between variables were assessed using Fisher’s exact test (P < 0.05). RESULTS : Mandibular second molars were predominantly two-rooted (91.7%). The majority of teeth had three canals including Type IV mesial (41.2%) and Type I (75.1%) distal (Ahmed et al. configuration: 2MDM M2 D1). Three or more canals were present in almost one-fifth of mesial (n = 72/386, 18.6%) and a small number of distal (n = 21/386, 5.4%) roots. Males displayed additional canals more frequently in the distal root (P = 0.02). C-shaped anatomy was found in 5.7%. Among the C-shapes, the most common was Melton’s Type III in the coronal (50%), middle (81%) and apical (72%) thirds. CONCLUSION : In this population, mandibular second molar teeth exhibited diverse morphology, which would have clinical significance for endodontic practitioners. The Ahmed et al. classification provided a better description than the Vertucci classification.
A cone-beam computed tomography study of canalis sinuosus and its accessory canals in a South African population
(Springer, 2024-07) Beckenstrater, Michael A.; Gamieldien, Mohamed Yasin; Smit, Chane; Buchanan, Glynn Dale
OBJECTIVES : Canalis sinuosus (CS) is a clinically relevant structure in the anterior maxilla. The present study aimed to determine the prevalence and distribution of CS and its accessory canals (ACs) in the South African population and describe its anatomical variations. METHODS : In total, 500 cone-beam computed tomography (CBCT) scans of the anterior maxilla were assessed for prevalence, sidedness, diameter, and distribution of CS. The frequency, number, diameter, configuration, and point of termination of ACs were also recorded. Statistical analysis was performed using analysis of variance, Kruskal–Wallis, chi-squared, and Fisher Exact tests with P < 0.05. RESULTS : CS was present in most cases (99.6%), and commonly occurred bilaterally (98.8%). The mean diameter of CS was 1.08 mm (range: 0.50 mm–2.39 mm). Sex, population group, and age had no significant effect on the prevalence or sidedness of CS. Additionally, 535 ACs were observed in 58.8% of the sample, with 42.9% of ACs found bilaterally and 57.1% unilaterally. The mean diameter of the ACs was 0.86 mm on the left and 0.87 mm on the right (range; 0.50 mm–1.52 mm). The majority of ACs maintained a straight vertical configuration (72.3%). ACs most commonly terminated in the anterior palatal region of the maxilla (57.2%). No significant differences were found in any groups mentioned (P > 0.05). CONCLUSIONS : A high prevalence of CS as well as ACs were observed in the sample population. Due to their clinical significance, surgical planning with the aid of high quality CBCT scans of the anterior maxilla is advisable.
The Risk of orofacial cleft lip/palate due to maternal ambient air pollution exposure : a call for further research in South Africa
(Ubiquity Press, 2023) Wright, Caradee Yael; Kapwata, Thandi; Wernecke, Bianca; Malherbe, Helen L.; Butow, Kurt-W.; Naidoo, Natasha; Garland, Rebecca M.; De Lange, Anzel; Gareth E., Murray
BACKGROUND: Despite being underreported, orofacial cleft lip/palate (CLP) remains in the top five of South Africa’s most common congenital disorders. Maternal air pollution exposure has been associated with CLP in neonates. South Africa has high air pollution levels due to domestic burning practices, coal-fired power plants, mining, industry, and traffic pollution, among other sources. We investigated air pollutant levels in geographic locations of CLP cases. METHODS: : In a retrospective case series study (2006–2020) from a combined dataset by a Gauteng surgeon and South African Operation Smile, the maternal address at pregnancy was obtained for 2,515 CLP cases. Data from the South African Air Quality Information System was used to calculate annual averages of particulate matter (PM) concentrations of particles < 10 µm (PM10) and < 2.5 µm (PM2.5). Correlation analysis determined the relationship between average PM2.5/PM10 concentrations and CLP birth prevalence. Hotspot analysis was done using the Average Nearest Neighbor tool in ArcGIS. RESULTS: Correlation analysis showed an increasing trend of CLP birth prevalence to PM10 (CC = 0.61, 95% CI = 0.38–0.77, p < 0.001) and PM2.5 (CC = 0.63, 95% CI = 0.42–0.77, p < 0.001). Hot spot analysis revealed that areas with higher concentrations of PM10 and PM2.5 had a higher proclivity for maternal residence (z-score = –68.2, p < 0.001). CLP birth prevalence hotspot clusters were identified in district municipalities in the provinces of Gauteng, Limpopo, North-West, Mpumalanga, and Free State. KwaZulu-Natal and Eastern Cape had lower PM10 and PM2.5 concentrations and were cold spot clusters. CONCLUSIONS: Maternal exposure to air pollution is known to impact the fetal environment and increase CLP risk. We discovered enough evidence of an effect to warrant further investigation. We advocate for a concerted effort by the government, physicians, researchers, non-government organizations working with CLP patients, and others to collect quality data on all maternal information and pollutant levels in all provinces of South Africa. Collaboration and data sharing for additional research will help us better understand the impact of air pollution on CLP in South Africa.
A study of mandibular premolar root and canal morphology in a Black South African population using cone-beam computed tomography and two classification systems
(Nihon University School of Dentistry, 2022) Buchanan, Glynn Dale; Gamieldien, Mohamed Yasin; Fabris-Rotelli, Inger Nicolette; Van Schoor, Albert-Neels; Uys, Andre; glynn.buchanan@up.ac.za
PURPOSE : An investigation of the configurations of mandibular premolar roots and canals in a population of Black South Africans. METHODS : Cone-beam computed tomography analysis of 772 mandibular premolars was performed, and the premolars were classified according to the systems proposed by Vertucci and Ahmed et al. Root number, canal morphology, age, and sex were recorded. Fisher’s exact test was used to determine relationships based on age and sex (P < 0.05). RESULTS : Single roots were seen in the majority of mandibular premolars (97.1%). Single canal configurations (i.e., Vertucci Type 1/Ahmed et al. 1MP1) were observed in 48.5% of first and 81.3% of second mandibular premolars. Mandibular first premolars demonstrated multiple canals in more than half of the sample (51.5%), and C-shaped morphology in more than one-tenth (11.1%). A relationship between sex and the presence of radicular grooves was demonstrated (P = 0.049), males being more likely to demonstrate this feature (P = 0.051). Multiple canals in mandibular first premolars also showed a relationship with sex (P = 0.005), a male predilection being evident (P = 0.007). The Ahmed et al. system proved superior to the Vertucci classification for reporting complex configurations and anatomical variations, although a greater number of unique categories were created. CONCLUSION : Diverse mandibular premolar root and canal morphology was observed in the studied population. Clinicians must be aware of common morphological features as well as possible anatomical variations in mandibular premolars, as failure to treat complete root canal systems may negatively impact endodontic treatment outcomes.
Root and canal morphology of the permanent anterior dentition in a Black South African population using cone-beam computed tomography and two classification systems
(Nihon University School of Dentistry, 2022-10) Buchanan, Glynn Dale; Gamieldien, Mohamed Yasin; Fabris-Rotelli, Inger Nicolette; Van Schoor, Albert-Neels; Uys, Andre; glynn.buchanan@up.ac.za
PURPOSE : This study investigated the root and canal morphology of the permanent anterior dentition in a Black South African population. METHODS : In total 2,343 permanent anterior teeth were evaluated using cone-beam computed tomography images and described according to the Vertucci and Ahmed et al. classifications. Demographic information, root number and internal canal morphology were recorded. Age and sex associations were made using Fisher’s exact test (P < 0.05). RESULTS : All anterior teeth were single-rooted (100%). The most frequent configuration in maxillary anteriors was a single canal (Vertucci Type I/1MXA1). In mandibular anteriors, single canal configurations (Type I/1MDA1) predominated, however 36.6% of mandibular central and 33.9% of lateral incisors displayed two canals. Older subjects (>40 years) demonstrated single canals more than younger subjects (P = 0.0004). Females displayed variations more compared to males (P = 0.002). The two classifications were found to be comparable for evaluation of permanent anterior teeth. Complex configurations were better described using the newer system. CONCLUSION : The permanent anterior teeth of this population exhibited exclusively single roots and diverse internal characteristics. Clinicians should be aware of anatomical variations, particularly in mandibular incisors, as these may result in adverse endodontic outcomes if not taken into consideration by the treating practitioner.
AI and precision oncology in clinical cancer genomics : from prevention to targeted cancer therapies-an outcomes based patient care
(Elsevier, 2022) Dlamini, Zodwa; Skepu, Amanda; Kim, Namkug; Mkhabele, Mahlori; Khanyile, Richard; Molefi, Thulo; Mbatha, Sikhumbuzo; Setlai, Botle; Mulaudzi, Thanyani Victor; Mabongo, Mzubanzi; Bida, Nndweleni Meshack; Kgoebane-Maseko, Minah; Mathabe, Kgomotso; Lockhat, Zarina I.; Kgokolo, C.M.; Chauke-Malinga, Nkhensani; Ramagaga, Serwalo; Hull, Rodney; zodwa.dlamini@up.ac.za
Precision medicine is the personalization of medicine to suit a specific group of people or even an individual patient, based on genetic or molecular profiling. This can be done using genomic, transcriptomic, epigenomic or proteomic information. Personalized medicine holds great promise, especially in cancer therapy and control, where precision oncology would allow medical practitioners to use this information to optimize the treatment of a patient. Personalized oncology for groups of individuals would also allow for the use of population group specific diagnostic or prognostic biomarkers. Additionally, this information can be used to track the progress of the disease or monitor the response of the patient to treatment. This can be used to establish the molecular basis for drug resistance and allow the targeting of the genes or pathways responsible for drug resistance. Personalized medicine requires the use of large data sets, which must be processed and analysed in order to identify the particular molecular patterns that can inform the decisions required for personalized care. However, the analysis of these large data sets is difficult and time consuming. This is further compounded by the increasing size of these datasets due to technologies such as next generation sequencing (NGS). These difficulties can be met through the use of artificial intelligence (AI) and machine learning (ML). These computational tools use specific neural networks, learning methods, decision making tools and algorithms to construct and improve on models for the analysis of different types of large data sets. These tools can also be used to answer specific questions. Artificial intelligence can also be used to predict the effects of genetic changes on protein structure and therefore function. This review will discuss the current state of the application of AI to omics data, specifically genomic data, and how this is applied to the development of personalized or precision medicine on the treatment of cancer.
Measuring final-year dental students’ ability to remove teeth independently using independence ratios
(Health and Medical Publishing Group, 2022-09) Merbold, Karl-Heinz; Postma, Thomas Corne; corne.postma@up.ac.za
BACKGROUND. Universities are obliged to ensure that dental graduates possess the necessary skills to render safe and effective treatment. Empirical evidence regarding the development of safe and effective independent practice at undergraduate level is unfortunately lacking. OBJECTIVES. To measure final-year students' abilities to correctly perform exodontia (tooth removal/extraction) skills independently, based on the applied postgraduate progressive independence theory. METHODS. Fourteen clinical teachers systematically assessed 13 263 tooth extractions completed by final-year dental students (2014 - 2016). An independence ratio (extractions performed without assistance/total number of extractions) was used as the key performance indicator to provide feedback on the ability to complete procedures independently over time. A customised index was used for controlling the level of difficulty. RESULTS. Final-year students (n=146) achieved independence ratios ranging between 90% and 94% (standard deviation 3.3%) by the end of their clinical training. Logical gradients of increased independence were illustrated with time, as well as variable performance among students. The level of difficulty index scores remained similar within cohorts per year of study. Acceptable assessment differences existed between clinical teachers, which could largely be explained by complex operational circumstances. CONCLUSIONS. As far as we are aware, this is the first study that quantified progressive independence in exodontia for undergraduate students. The measure was sensitive enough to show logical independence gradients and variance among students. Final-year students demonstrated that they could remove >8/10 teeth independently by the time of their graduation. The measure shows promise as a proxy of competence for skills that are often practised. It is recommended that factors that influence these measurements be examined in more detail.
Osteogenic competence and potency of the bone induction principle : inductive substrates that initiate "bone : formation by autoinduction"
(Lippincott Williams and Wilkins, 2022-05) Ripamonti, Ugo; Duarte, Raquel; Ferretti, Carlo; Reddi, A. Hari
The de novo induction of bone has always been a fascinating phenomenon, keeping skeletal reconstructionists and cellular developmental biologists continuously engaged to finally provide a molecular and cellular approach to the induction of bone formation. A significant advancement was made by the purification and cloning of the human recombinant bone morphogenetic proteins, members of the transforming growth factor-β supergene family. Human bone morphogenetic proteins are powerful inducers of bone in animal models including nonhuman primates. Translation in clinical contexts has however, proven to be surprisingly difficult. This review also describes the significant induction of bone formation by the human transforming growth factor-β3 when implanted in heterotopic intramuscular sites of the Chacma baboon Papio ursinus. Large mandibular defects implanted with 250 mg human transforming growth factor-β3 in human patients showed significant osteoinduction; however, the induction of bone was comparatively less than the induction of bone in P ursinus once again highlighting the conundrum of human osteoinduction: is the bone induction principle failing clinical translation?
Root and canal morphology of maxillary second molars in a Black South African subpopulation using cone-beam computed tomography and two classifications
(Wiley, 2023-09) Buchanan, Glynn Dale; Gamieldien, Mohamed Yasin; Fabris-Rotelli, Inger Nicolette; Van Schoor, Albert-Neels; Uys, Andre; glynn.buchanan@up.ac.za
This study investigated the root and canal morphology of maxillary second molars in a Black South African population using high-resolution cone-beam computed tomography. In total, 386 maxillary second molar teeth were evaluated and described according to the classifications of Vertucci (with the additions of Sert and Bayirli), as well as Ahmed et al. Root number, fusions and canal morphology were recorded. Relationships between morphology, sex and age were assessed using Fisher's exact test (p < 0.05). Maxillary second molars were predominantly three-rooted (96.1%), with root fusion observed in 14%. No relationships between sex, age and canal morphology were found. Additional canals were observed in 67.4% of mesiobuccal roots. The Ahmed et al. classification provided a better overall description of the morphology. In this population, maxillary second molar teeth exhibited a diversity of root and canal morphology. Complex variations may render endodontic management more difficult and increase the possibility of missed anatomy.
The conundrum of human osteoinduction : is the bone induction principle failing clinical translation?
(Lippincott, Williams and Wilkins, 2021-06) Ferretti, Carlo; Ripamonti, Ugo
No abstract available.
Audit of the workload in a maxillofacial and oral surgical unit in Johannesburg
(South African Dental Association, 2021-05) Sukha, Kamal; Mabongo, Mzubanzi
INTRODUCTION : Maxillofacial and oral surgical (MFOS) audits are able to provide data to both current and prospective patients regarding the quality of care an institution is capable of providing. The more frequently performed MFOS procedures can be determined and the allocation of funding and resources can therefore be achieved more appropriately. AIMS AND OBJECTIVES : To conduct an audit to evaluate the workload and scope of practice of the MFOS unit of the Charlotte Maxeke Johannesburg Academic Hospital (CMJAH) for the year 2015 by quantifying MFOS conditions and the respective treatment modalities. DESIGN : The study was retrospective and cross-sectional. METHODS : Data was retrieved from the patient logbook of the unit which was then entered into a Microsoft Excel Spreadsheet. Pie graphs and bar charts representing the data were then generated. RESULTS : A total of 1 750 patients were treated in the unit. The male to female ratio was 1.3:1 and the majority of these patients were in their 3rd and 4th age decade. Most patients required a tooth extraction mainly for an impacted 3rd molar. CONCLUSIONS : Dentoalveolar surgery was the most commonly performed procedure followed by the treatment of facial fractures. Pathological and other MFOS conditions were less commonly encountered. The CMJAH MFOS unit treats a high volume of patients according to comparisons with global studies.
A debt repaid? A case of an unusual foreign body found in the nasal cavity
(Wiley, 2021-02) Gamieldien, Mohamed Yasin; Musson, C.G.; Uys, Andre; Buchanan, Glynn Dale
The appearance of nasal foreign bodies is well reported in children but hardly ever seen in adults. These objects are often easily identified and removed. This report documents an unusual case of a bank note lodged in the nasal cavity of an adult male. The foreign body in question presented a significant diagnostic challenge both from a clinical and radiological perspective. Careful review of the case history, as well as clinical and radiographic features, led to appropriate management and avoidance of unnecessary interventions. Clinicians involved in head and neck surgery and radiology should suspect, and be aware of the radiographic appearance, of a wide variety of foreign bodies.
Development of a clinical prediction model for in-hospital mortality from the South African cohort of the African surgical outcomes study
(Springer, 2021-02) Kluyts, Hyla-Louise; Conradie, Wilhelmina; Cloete, Estie; Spijkerman, Sandra; Smith, Oliver; Alli, Ahmed; Koto, Modise Z.; Montwedi, Daniel; Govender, Komalan; Cronje, Larissa; Grobbelaar, Mariette; Omoshoro-Jones, Jones A.; Rorke, Nicolette F.; Anderson, Philip; Torborg, Alexandra; Alphonsus, Christella; Alexandris, Panagiotis; Peter, Aunel Mallier; Singh, Usha; Diedericks, Johan; Mrara, Busisiwe; Reed, Anthony; Davies, Gareth L.; Davids, Jody G.; Van Zyl, Hendrik A.; Govindasamy, Vishendran; Rodseth, Reitze; Matos-Puig, Roel; Bhat, Kajake A.P.; Naidoo, Noel; Roos, John; Jaworska, Magdalena; Steyn, Annemarie; Dippenaar, Johannes Marthinus (Tinus); Pearse, R.M.; Madiba, Thandinkosi; Biccard, Bruce McIure
BACKGROUND : Data on the factors that influence mortality after surgery in South Africa are scarce, and neither these data nor data on risk-adjusted in-hospital mortality after surgery are routinely collected. Predictors related to the context or setting of surgical care delivery may also provide insight into variation in practice. Variation must be addressed when planning for improvement of risk-adjusted outcomes. Our objective was to identify the factors predicting in-hospital mortality after surgery in South Africa from available data. METHODS : A multivariable logistic regression model was developed to identify predictors of 30-day in-hospital mortality in surgical patients in South Africa. Data from the South African contribution to the African Surgical Outcomes Study were used and included 3800 cases from 51 hospitals. A forward stepwise regression technique was then employed to select for possible predictors prior to model specification. Model performance was evaluated by assessing calibration and discrimination. The South African Surgical Outcomes Study cohort was used to validate the model. RESULTS : Variables found to predict 30-day in-hospital mortality were age, American Society of Anesthesiologists Physical Status category, urgent or emergent surgery, major surgery, and gastrointestinal-, head and neck-, thoracic- and neurosurgery. The area under the receiver operating curve or c-statistic was 0.859 (95% confidence interval: 0.827–0.892) for the full model. Calibration, as assessed using a calibration plot, was acceptable. Performance was similar in the validation cohort as compared to the derivation cohort. CONCLUSION : The prediction model did not include factors that can explain how the context of care influences post-operative mortality in South Africa. It does, however, provide a basis for reporting risk-adjusted perioperative mortality rate in the future, and identifies the types of surgery to be prioritised in quality improvement projects at a local or national level.
Genetic drivers of head and neck squamous cell carcinoma : aberrant splicing events, mutational burden, hpv infection and future targets
(MDPI, 2021-03-15) Dlamini, Zodwa; Alaouna, Mohammed; Mbatha, Sikhumbuzo Z.; Bhayat, Ahmed; Mabongo, Mzubanzi; Chatziioannou, Aristotelis; Hull, Rodney; zodwa.dlamini@up.ac.za
Head and neck cancers include cancers that originate from a variety of locations. These include the mouth, nasal cavity, throat, sinuses, and salivary glands. These cancers are the sixth most diagnosed cancers worldwide. Due to the tissues they arise from, they are collectively named head and neck squamous cell carcinomas (HNSCC). The most important risk factors for head and neck cancers are infection with human papillomavirus (HPV), tobacco use and alcohol consumption. The genetic basis behind the development and progression of HNSCC includes aberrant non-coding RNA levels. However, one of the most important differences between healthy tissue and HNSCC tissue is changes in the alternative splicing of genes that play a vital role in processes that can be described as the hallmarks of cancer. These changes in the expression profile of alternately spliced mRNA give rise to various protein isoforms. These protein isoforms, alternate methylation of proteins, and changes in the transcription of non-coding RNAs (ncRNA) can be used as diagnostic or prognostic markers and as targets for the development of new therapeutic agents. This review aims to describe changes in alternative splicing and ncRNA patterns that contribute to the development and progression of HNSCC. It will also review the use of the changes in gene expression as biomarkers or as the basis for the development of new therapies.
Should South Africa train specialist endodontists? A cross-sectional online survey
(Medknow Publications, 2021-09) Buchanan, Glynn Dale; Gamieldien, Mohamed Yasin; Tredoux, Sheree; Vorster, Martin; Warren, Nichola; Van der Vyfer, Peet J.; glynn.buchanan@up.ac.za
INTRODUCTION: Endodontics as an independent dental specialty exists in many regions worldwide, with training programs established in both developed and developing countries. Endodontic specialty training is, however, currently not available in South Africa. This study aimed to determine whether private dental practitioners, who perform clinical endodontic treatment, believed that South Africa should train specialist endodontists. MATERIALS AND METHODS: A cross-sectional, observational study was conducted. An online program was used to generate a survey which was electronically mailed to 3252 South African private dental practitioners. Quantitative and qualitative questions with open-ended responses were used. Topics included the following: demographic information, management/referral strategies regarding difficult endodontic cases, and need for endodontics as an independent dental specialty in South Africa. Data were analyzed using simple descriptive methods. RESULTS: A total of 215 (n = 215/3252) responses were received by the closing date. The overall response rate was 7%. The valid responses of 193 participants were included (n = 193/215). The majority (83%, n = 160/193) of the respondents indicated the opinion that South Africa should train specialist endodontists. The reasons for this opinion were varied. Strategies in place for the management of difficult endodontic cases and existing endodontic referral pathways were additionally identified. CONCLUSION: There is a need to train specialist endodontists in South Africa.
Double gemination or fusion of a permanent mandibular second molar : a case report
(Quintessence Publishing Company, 2021) Buchanan, Glynn Dale; Tredoux, Sheree; Schouwstra, Ciska-Mari; Nel, Chane; Gamieldien, Mohamed Yasin
Gemination and fusion are developmental conditions affecting the shape of teeth in both primary and permanent dentition. A 12-year-old girl presented for clinical assessment and the examination revealed an unusually shaped mandibular right second molar with irreversible pulpitis. Correlation of the intraoral and radiological appearance of this tooth suggested a diagnosis of either double gemination or fusion. The favourable position of the developing third molar supported early extraction of the abnormal second molar. The present report documents the clinical and radiological presentation of a mandibular second molar with an unusual developmental alteration in shape. Well-timed extraction therapy and good communication may reduce the need for unnecessary, complex treatment.
MicroRNA and alternative mRNA splicing events in cancer drug response/resistance : potent therapeutic targets
(MDPI, 2021-12-02) Marima, Rahaba; Francies, Flavia Zita; Hull, Rodney; Molefi, Thulo; Oyomno, Meryl; Khanyile, Richard; Mbatha, Sikhumbuzo Z.; Bates, David Owen; Dlamini, Zodwa; zodwa.dlamini@up.ac.za
Cancer is a multifaceted disease that involves several molecular mechanisms including changes in gene expression. Two important processes altered in cancer that lead to changes in gene expression include altered microRNA (miRNA) expression and aberrant splicing events. MiRNAs are short non-coding RNAs that play a central role in regulating RNA silencing and gene expression. Alternative splicing increases the diversity of the proteome by producing several different spliced mRNAs from a single gene for translation. MiRNA expression and alternative splicing events are rigorously regulated processes. Dysregulation of miRNA and splicing events promote carcinogenesis and drug resistance in cancers including breast, cervical, prostate, colorectal, ovarian and leukemia. Alternative splicing may change the target mRNA 30UTR binding site. This alteration can affect the produced protein and may ultimately affect the drug affinity of target proteins, eventually leading to drug resistance. Drug resistance can be caused by intrinsic and extrinsic factors. The interplay between miRNA and alternative splicing is largely due to splicing resulting in altered 30UTR targeted binding of miRNAs. This can result in the altered targeting of these isoforms and altered drug targets and drug resistance. Furthermore, the increasing prevalence of cancer drug resistance poses a substantial challenge in the management of the disease. Henceforth, molecular alterations have become highly attractive drug targets to reverse the aberrant effects of miRNAs and splicing events that promote malignancy and drug resistance. While the miRNA–mRNA splicing interplay in cancer drug resistance remains largely to be elucidated, this review focuses on miRNA and alternative mRNA splicing (AS) events in breast, cervical, prostate, colorectal and ovarian cancer, as well as leukemia, and the role these events play in drug resistance. MiRNA induced cancer drug resistance; alternative mRNA splicing (AS) in cancer drug resistance; the interplay between AS and miRNA in chemoresistance will be discussed. Despite this great potential, the interplay between aberrant splicing events and miRNA is understudied but holds great potential in deciphering miRNA-mediated drug resistance.

Browse

Recent Submissions