Browsing by Author "Opperman, Johan Frank"

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    A study to determine the forensic quality of records and record keeping by dentists in the greater Cape Town area
    (University of the Western Cape, 2018) Opperman, Johan Frank; Phillips, Vincent
    South African dentists have a legal and ethical obligation to maintain complete and comprehensive dental records. In addition to the legal and ethical requirements, dental records are also important in the case of medico-legal issues, quality assurance processes and forensic purposes. Valuable forensic evidence contained in dental records are used in the identification of victims of mass disasters, personal victim identification e.g. in severely decomposed or skeletonized remains where DNA or other biometric data are not available. The victim identification process is highly dependent on complete, legible and accurate dental records. A review of the literature however shows that dental record keeping practices are sub-optimal worldwide. There is a paucity of studies in South Africa regards to dental record keeping practices. The aim of this study was to assess the record keeping practices of a sample of private practicing dentists in Cape Town and surrounding towns, for forensic dental purposes. Knowledge and awareness regards to forensic odontology as well as adherence to the guidelines prescribed by the Health Professional Council of South Africa were also assessed. This was a cross-sectional descriptive study, employing a researcher-administered questionnaire and a dental checklist for forensic valuable items in the dental file. The results were entered in a MS Excel spreadsheet and statistically analysed using IMB SPSS Statistics. This study concluded that most of the dental records kept by Cape Town dentists are near to optimal and would be helpful during forensic odontology investigations. However, shortcomings in record keeping practices exists which may compromise the forensic accuracy of their dental records. The study also shows a significant difference in dental record keeping practices by dentists practicing in lower income areas in Cape Town, compared to those practicing in economic affluent areas. The dentists in this study adhered to most of the guidelines prescribed by the Health Professional Council of South Africa however, important medico-legal information was missing from most dental records. This study hopes to contribute to future comprehensive studies in the broader South Africa to determine the validity of dental records for forensic odontology purposes.
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    Impact of thyroid dysfunction on clinical outcome in head and neck cancer: a systematic review and meta-analysis
    (BioMed Central Ltd, 2025) Roberts, Tina S.; Opperman, Johan Frank; Sandeepa N.C.
    Background: The influence of thyroid dysfunction on the clinical outcomes of head and neck cancer (HNC) patients remains an area of ongoing investigation, with previous studies yielding variable results. Treatments for HNC, particularly radiotherapy, frequently impact thyroid function. This meta-analysis aimed to synthesize the available evidence on the association between thyroid status (dysfunction vs. euthyroid) and survival outcomes in HNC patients. Methods: A systematic review and meta-analysis were conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Medline, Web of Science, Cochrane Library, Embase and Scopus were searched (January 2000-October 2024) for studies comparing survival outcomes (primarily Overall Survival) in adult HNC patients with thyroid dysfunction versus euthyroid patients. Two reviewers independently selected studies and extracted relevant data. The risk of bias for included studies was assessed using the Newcastle-Ottawa Scale (NOS) for cohort studies and the Cochrane Risk of Bias 2 (RoB2) tool for randomized controlled trials. Hazard ratios (HRs) with 95% confidence intervals (CIs) comparing survival were pooled using both fixed-effect (common-effect) and random-effects (REML) models. Heterogeneity across studies was assessed using the I² statistic and Cochran’s Q test. Statistical analyses were performed using R with the meta package. Results: Six studies met the inclusion criteria for systematic review. Four of these studies, encompassing 671 participants, reported sufficient data (Hazard Ratios for Overall Survival) for meta-analysis. The fixed-effect model yielded a pooled HR of 0.99 (95% CI: 0.98, 1.00; p = 0.0013). However, significant heterogeneity was observed (I² = 81.5%, p = 0.0010). Consequently, the random-effects model, deemed more appropriate, yielded a pooled HR of 1.45 (95% CI: 0.66, 3.19; p = 0.3601), indicating no statistically significant association between thyroid status and overall survival in HNC patients. The estimated between-study variance (τ²) was 0.53. Conclusion: This meta-analysis revealed substantial heterogeneity among studies investigating the impact of thyroid status on HNC survival. When accounting for this heterogeneity using a random-effects model, no significant association was found. The findings highlight the need for further research with larger sample sizes, standardized definitions of thyroid dysfunction, consistent reporting of adjusted effect estimates, and exploration of heterogeneity sources. Trial registration: CRD42024535167.