Displaying publications 1 - 20 of 35 in total

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  1. Ghazali N, Bakri MM, Zain RB
    J Oral Pathol Med, 2003 Aug;32(7):383-92.
    PMID: 12846784
    Some oral verrucal lesions may constitute parts of the clinicopathological spectrum of proliferative verrucous leukoplakia (PVL). Because of its idiopathic yet sinister nature, it is possible that PVL may exist in other populations. The aim of this study was to review the clinicopathological features of persistent, multifocal, oral verrucal lesions in Malaysian population.
  2. Goh YC, Siriwardena BSMS, Tilakaratne WM
    J Oral Pathol Med, 2021 Aug 06.
    PMID: 34358362 DOI: 10.1111/jop.13228
    BACKGROUND: Ameloblastoma is an odontogenic tumour exhibiting locally invasive behaviour and high recurrence rate after treatment. Conventional ameloblastoma is reportedly been more aggressive showing infiltrative growth patterns and a tendency for recurrence. This is a retrospective study performed to analyse the relationship between clinicopathological characteristics and treatment modalities in the recurrence of ameloblastoma.

    METHODS: 624 cases of ameloblastoma comprising of 519 non-recurrent ameloblastoma and 105 recurrent ameloblastoma from two main diagnostic centres in Malaysia and Sri Lanka were included. The demographic data, clinical characteristics, histopathological data, treatment modality and episodes of recurrence were extracted and analysed.

    RESULTS: The mean age for recurrent ameloblastoma was 37.23 with a peak occurrence in the third decade of life. Recurrent ameloblastoma was marginally female predominant with male to female ratio of 1:1.3. Mandible was the commonest site for the recurrence with a predilection for more than two segments of left mandible followed by left posterior mandible. Follicular (58.1%) histopathological variant was the most reported type to recur followed by plexiform (17.1%). 49.5% of recurrent cases were treated with conservative approach. 65.7% of recurrent cases demonstrated a single episode of recurrence. Mixed (follicular and plexiform) histopathological variants showed the longest average years (11.5 years) for the single episode of recurrence. Plexiform ameloblastoma treated with conservative approach recurred in the shortest follow-up period. The recurrence of ameloblastoma was significantly associated with age group, sub-site of occurrence and histopathological variants (p<0.05).

    CONCLUSION: This study showed that age, sub-site of occurrence and histopathological variants are significant factors responsible for the recurrence of ameloblastoma.

  3. Yaacob HB, Samaranayake LP
    J Oral Pathol Med, 1989 Apr;18(4):236-9.
    PMID: 2769596
    A postal survey of 730 Malaysian dental practitioners was undertaken to assess their awareness and acceptance of the plasma derived hepatitis B vaccine. Only 32% of the 325 practitioners who responded had been vaccinated, 41% intended to be and 15% categorically refused vaccination. The main reservations about vaccine acceptance were fear of side effects including AIDS, cost of the vaccine and lack of information. Vaccine efficacy was not confirmed by serology in two-thirds of the vaccinees and two-fifths of the respondents were unaware that 5% of the vaccinees do not develop a successful antibody response after vaccination. Seventy-eight percent of dentists believed that their risk of contracting hepatitis B was high or very high while 71% recalled having received needle stick injuries in the 3 yr prior to the survey. Only 13% of respondents were aware of delta hepatitis while 63% were aware of non-A non-B hepatitis. The survey has highlighted the need for dissemination of information on hepatitis B vaccine among dentists in Malayasia.
  4. Diajil AR, Goodson ML
    J Oral Pathol Med, 2023 Jul;52(6):521-527.
    PMID: 37038041 DOI: 10.1111/jop.13432
    BACKGROUND: The ABO and Rh systems are the most commonly used blood-group systems used to classify blood group globally. A number of studies have shown that ABO blood groups may be associated with an increased serum cholesterol levels which in turn may be related to the presence of oral Fordyce spots or granules. Oral Fordyce's granules are ectopic sebaceous glands within the oral cavity and are visible through epithelium. The aim of this study was to assess the relationship between ABO and Rhesus blood groups and the presence of oral Fordyce's granules and serum cholesterols level by gender.

    METHODS: Following ethical approval and informed consent, 124 subjects were recruited into this cross-sectional study. Clinical oral examination assessed the number of Fordyce's granules and blood samples were collected to determine the serum cholesterol and ABO/Rh blood-group systems of individual subjects.

    RESULTS: Blood group AB+ showed the highest mean of oral Fordyce's granules number and serum cholesterol level but this was not statistically significant compared to other blood groups. Female subjects in this study who were AB+ were had significantly higher serum cholesterol levels than males.

    CONCLUSION: This study indicates an association between ABO blood group, serum cholesterol level and mean number of oral Fordyce's granules. A larger sample size in a future study is required to ascertain whether number of Fordyce's granules is an important measure of serum cholesterol, but the study does show that for AB+ individuals, females may have higher serum cholesterol than males.

  5. Kallarakkal TG, Zaini ZM, Ghani WMN, Karen-Ng LP, Siriwardena BSMS, Cheong SC, et al.
    J Oral Pathol Med, 2024 Jan;53(1):53-60.
    PMID: 38081145 DOI: 10.1111/jop.13501
    INTRODUCTION: A major pitfall of many of the established oral epithelial dysplasia (OED) grading criteria is their lack of reproducibility and accuracy to predict malignant transformation. The main objective of this study was to determine whether calibration of practicing oral pathologists on OED grading could improve the reproducibility of the WHO 2017 and the binary OED grading systems.

    METHODS: A nationwide online exercise was carried out to determine the influence of calibration on the reproducibility of the WHO 2017 and the binary OED grading systems.

    RESULTS: A significant improvement was observed in the inter-observer agreement for the WHO 2017 OED grading system (K 0.196 vs. 0.448; Kw 0.357 vs. 0.562) after the calibration exercise. The significant difference (p = 0.027) in the level of agreement between those with five or more years and less than 5 years of experience was no more observed (p = 0.426) after the calibration exercise. The percent agreement for binary grading was significantly higher (91.8%) for buccal mucosal lesions as compared to lesions on the tongue after the calibration exercise.

    CONCLUSION: This study validates the significance of calibration in improving the reproducibility of OED grading. The nationwide exercise resulted in a statistically significant improvement in the inter-observer agreement for the WHO 2017 OED grading system among a large number of oral pathologists. It is highly recommended that similar exercises should be organized periodically by professional bodies responsible for continuing education among oral pathologists to improve the reliability of OED grading for optimal treatment of oral potentially malignant disorders.

  6. Bakri MM, Cannon RD, Holmes AR, Rich AM
    J Oral Pathol Med, 2014 Oct;43(9):704-10.
    PMID: 24931506 DOI: 10.1111/jop.12193
    The aim of this study was to investigate the relationship between expression of Candida albicans alcohol dehydrogenases (ADH) genes in archival formalin-fixed paraffin-embedded (FFPE) samples from biopsies of leukoplakia.
  7. Siar CH, Nakano K, Han PP, Nagatsuka H, Ng KH, Kawakami T
    J Oral Pathol Med, 2010 Aug 1;39(7):552-8.
    PMID: 20337864 DOI: 10.1111/j.1600-0714.2009.00871.x
    In mammals, the Notch gene family encodes four receptors (Notch1-4), and all of them are important for cell fate decisions. Notch signaling pathway plays an essential role in tooth development. The ameloblastoma, a benign odontogenic epithelial neoplasm, histologically recapitulates the enamel organ at bell stage. Notch has been detected in the plexiform and follicular ameloblastoma. Its activity in the desmoplastic ameloblastoma is unknown.
  8. Siar CH, Nagatsuka H, Han PP, Buery RR, Tsujigiwa H, Nakano K, et al.
    J Oral Pathol Med, 2012 Apr;41(4):332-9.
    PMID: 22077561 DOI: 10.1111/j.1600-0714.2011.01104.x
    Canonical and non-canonical Wnt signaling pathways modulate diverse cellular processes during embryogenesis and post-natally. Their deregulations have been implicated in cancer development and progression. Wnt signaling is essential for odontogenesis. The ameloblastoma is an odontogenic epithelial neoplasm of enamel organ origin. Altered expressions of Wnts-1, -2, -5a, and -10a are detected in this tumor. The activity of other Wnt members remains unclarified.
  9. Siar CH, Ng KH
    J Oral Pathol Med, 2014 Jan;43(1):45-52.
    PMID: 23560539 DOI: 10.1111/jop.12065
    Epithelial-to-mesenchymal transition (EMT) via the mechanism of transcription repression is a crucial process for the induction of invasiveness in many human tumors. Ameloblastoma is a benign odontogenic epithelial neoplasm with a locally infiltrative behavior. Twist, an EMT promoter, has been implicated in its invasiveness. The roles of the other transcription factors remain unclarified.
  10. Sinon SH, Rich AM, Parachuru VP, Firth FA, Milne T, Seymour GJ
    J Oral Pathol Med, 2016 Jan;45(1):28-34.
    PMID: 25865410 DOI: 10.1111/jop.12319
    The objective of this study was to investigate the expression of Toll-like receptors (TLR) and TLR-associated signalling pathway genes in oral lichen planus (OLP).
  11. Sathasivam HP, Nayar D, Sloan P, Thomson PJ, Odell EW, Robinson M
    J Oral Pathol Med, 2021 Feb;50(2):200-209.
    PMID: 33151583 DOI: 10.1111/jop.13121
    BACKGROUND: Oral potentially malignant disorders are a clinical conundrum as there are no reliable methods to predict their behaviour. We combine conventional oral epithelial dysplasia grading with DNA ploidy analysis to examine the validity of this approach to risk assessment in a cohort of patients with known clinical outcomes.

    METHODS: Sections from diagnostic biopsies were assessed for oral epithelial dysplasia using the WHO grading system, and DNA ploidy analysis was performed using established methods. Patients reviewed for a minimum of 5 years who did not develop oral squamous cell carcinoma were classified as "non-transforming" cases. Patients that developed oral squamous cell carcinoma ≥ 6 months after the initial diagnostic biopsy were classified as having "malignant transformation."

    RESULTS: Ninety cases were included in the study. Seventy cases yielded informative DNA ploidy results. Of these 70 cases, 31 progressed to cancer. Oral epithelial dysplasia grading and DNA ploidy status were both significantly associated with clinical outcome (P 

  12. Goodson ML, Smith DR, Thomson PJ
    J Oral Pathol Med, 2017 Nov;46(10):896-901.
    PMID: 28833675 DOI: 10.1111/jop.12627
    BACKGROUND: Oral potentially malignant disorders (PMD) harbour unpredictable risk for squamous cell carcinoma development. Current management requires tissue biopsy for histopathology characterisation, dysplasia grading and targeted intervention to "high-risk" lesions, although evidence-based guidelines are limited and diagnoses subjective. This study investigated the use of adjunctive oral brush biopsy techniques during the management of PMD in a UK hospital population.

    METHODS: Retrospective review of a 310 PMD patient cohort presenting to Maxillofacial Surgery in Newcastle upon Tyne with new, single-site lesions between December 2009 and May 2014. Patients underwent Orcellex® brush biopsy and liquid-based cytology examination in addition to conventional biopsy techniques, with management proceeding along established care pathways. Patient demographics, cytology data, most significant histopathology diagnoses and clinical outcome were all documented at the study census date (31.12.15).

    RESULTS: A total of 170 male & 140 female patients (age range 18-91 years), exhibiting primarily leukoplakia (86.5%) at floor of mouth and ventrolateral tongue sites (44.9%), were identified. Management comprised: observation (49.7%), laser surgery (44.9%), antifungal treatment (3.5%) and Head & Neck clinic referral following cancer diagnosis (1.9%). Clinical outcomes were as follows: disease free (51.3%), persistent PMD (42.3%) and malignant transformation (6.4%). Histology and cytology diagnoses strongly correlated (r = .305). Treatment modality, lesion site, histology and cytology diagnoses were the best predictors of clinical outcome.

    CONCLUSIONS: Orcellex® brush cytology provides reliable diagnoses consistent with conventional histopathology and offers less invasive, adjunctive assessment appropriate for long-term monitoring of patients in specialist clinics.

  13. Ahmed H, Paterson I, Aziz SA, Cremona O, Robinson M, Carrozzo M, et al.
    J Oral Pathol Med, 2023 Sep;52(8):710-717.
    PMID: 37339783 DOI: 10.1111/jop.13460
    BACKGROUND: Most oral squamous cell carcinoma patients present with late-stage disease. Early detection of the disease is considered to be the most effective way of improving patient outcomes. Several biomarkers have been identified as indicators of oral cancer development and progression; however, none have been translated into clinical practice. In this study, we have investigated the role of Epsin3, an endocytic adaptor protein, and Notch1, a transmembrane signalling protein, in oral carcinogenesis with a view to explore their potential as biomarkers.

    METHODS: Oral cancer cell lines and a normal oral keratinocyte cell line were used together with tissue samples of normal oral mucosa (n = 21), oral epithelial dysplasia (n = 74) and early stage (Stages I and II) oral squamous cell carcinoma (n = 31). Immunocytochemical staining, immunoblotting and real-time quantitative polymerase chain reaction (PCR) were performed to assess protein as well as gene expression levels.

    RESULTS: The expression levels of Epsin3 and Notch1 mRNA and protein are variable across different oral squamous cell carcinoma derived cell lines. Epsin3 was upregulated in oral epithelial dysplasia and oral squamous cell carcinoma tissues compared with normal epithelium. Overexpression of Epsin3 resulted in a significant reduction of Notch1 expression in oral squamous cell carcinoma. Notch1 was generally downregulated in the dysplasia and oral squamous cell carcinoma samples.

    CONCLUSION: Epsin3 is upregulated in oral epithelial dysplasia and oral squamous cell carcinoma and has the potential to be used as a biomarker for oral epithelial dysplasia. Notch signalling is downregulated in oral squamous cell carcinoma, possibly through an Epsin3-induced de-activation pathway.

  14. Prime SS, Cirillo N, Hassona Y, Lambert DW, Paterson IC, Mellone M, et al.
    J Oral Pathol Med, 2017 Feb;46(2):82-88.
    PMID: 27237745 DOI: 10.1111/jop.12456
    There is now compelling evidence that the tumour stroma plays an important role in the pathogenesis of cancers of epithelial origin. The pre-eminent cell type of the stroma is carcinoma-associated fibroblasts. These cells demonstrate remarkable heterogeneity with activation and senescence being common stress responses. In this review, we summarise the part that these cells play in cancer, particularly oral cancer, and present evidence to show that activation and senescence reflect a unified programme of fibroblast differentiation. We report advances concerning the senescent fibroblast metabolome, mechanisms of gene regulation in these cells and ways in which epithelial cell adhesion is dysregulated by the fibroblast secretome. We suggest that the identification of fibroblast stress responses may be a valuable diagnostic tool in the determination of tumour behaviour and patient outcome. Further, the fact that stromal fibroblasts are a genetically stable diploid cell population suggests that they may be ideal therapeutic targets and early work in this context is encouraging.
  15. Sathasivam HP, Casement J, Bates T, Sloan P, Thomson P, Robinson M, et al.
    J Oral Pathol Med, 2021 Jan;50(1):60-67.
    PMID: 32740996 DOI: 10.1111/jop.13090
    BACKGROUND: A large number of oral squamous cell carcinomas (OSCCs) are believed to be preceded by oral potentially malignant disorders (OPMD) that have an increased likelihood of malignant transformation compared to clinically normal mucosa. This study was performed to identify differentially expressed genes between OPMDs that underwent malignant transformation (MT) and those that did not, termed "non-transforming" (NT) cases.

    METHODS: Total RNA was extracted from formalin-fixed paraffin-embedded tissue biopsies of 20 OPMD cases with known clinical outcomes (10 MT vs. 10 NT). Samples were assessed for quantity, quality and integrity of RNA prior to sequencing. Analysis for differential gene expression between MT and NT was performed using statistical packages in R. Genes were considered to be significantly differentially expressed if the False Discovery Rate corrected P-value was  1.90). Analysis of RNA-Sequencing outputs revealed 41 genes (34 protein-coding; 7 non-coding) that were significantly differentially expressed between MT and NT cases. The log2 fold change for the statistically significant differentially expressed genes ranged from -2.63 to 2.48, with 23 protein-coding genes being downregulated and 11 protein-coding genes being upregulated in MT cases compared to NT cases.

    CONCLUSION: Several candidate genes that may play a role in malignant transformation of OPMD have been identified. Experiments to validate these candidates are underway. It is anticipated that this work will contribute to better understanding of the etiopathogenesis of OPMD and development of novel biomarkers.

  16. Yadav M, Arivananthan M, Chandrashekran A, Tan BS, Hashim BY
    J Oral Pathol Med, 1997 Oct;26(9):393-401.
    PMID: 9385576
    Archival oral tissues comprising 51 squamous cell carcinomas, 18 non-malignant lesions and 7 normal mucosa samples were investigated for human herpesvirus-6 (HHV-6)-encoded antigens and HHV-6 DNA. The virus-specific antigens were detected by an immunohistochemical method using monoclonal antibodies. Two further techniques used for HHV-6 DNA detection included the polymerase chain reaction (PCR) with virus-specific primers and in situ hybridization using digoxigenin-labelled oligonucleotides specific for HHV-6A and HHV-6B genotypes. A high proportion (79-80%) of the squamous cell carcinomas were positive for HHV-6 with the various detection methods. In cases of lichen planus and leukoplakia a high prevalence rate (67-100%) was noted with in situ hybridization and immunohistochemical techniques but a lower proportion (22-33%) was detected with the PCR method. All 7 normal tissues tested were negative for HHV-6. The HHV-6 variant B was found in 60% of the oral carcinoma tissues analysed. The study demonstrates the frequent presence of HHV-6 in neoplastic and non-malignant lesions of the oral cavity. While the role of HHV-6 in oral mucosal tissues remains to be determined, the in vitro tumorigenic potential of the virus suggests a possible role in the etiopathogenesis of oral lesions.
  17. Venkataswamy P, Samudrala Venkatesiah S, Rao RS, Banavar SR, Patil S, Augustine D, et al.
    J Oral Pathol Med, 2020 Dec 01.
    PMID: 33259689 DOI: 10.1111/jop.13144
    BACKGROUND: The prognosis of hyperproliferative skin lesions, such as psoriasis, basal cell carcinoma, and non-melanoma skin cancers, is significantly benefited from the levels of tazarotene-induced gene-1 (TIG3) expression and subsequent treatment with tazarotene. Such observations suggest that TIG3 could be used as a biomarker for apoptosis, differentiation, and proliferation. The current study aimed to evaluate the expression of TIG3 in normal oral mucosa (NOM) and oral squamous cell carcinoma (OSCC) compared with normal skin (NS) and skin squamous cell carcinoma (SSCC) using immunohistochemistry.

    METHODS: Seventeen cases each of SSCC, OSCC, NOM, and NS were evaluated. Each section was immunohistochemically stained with a rabbit polyclonal TIG3 antibody. The entire procedure was blinded and evaluated by 5 observers. Statistical analysis was performed using the chi-square test.

    RESULTS: There was a significant decrease in TIG3 protein expression in OSCC and SSCC compared with that in NOM and NS (P = 0.008). The progressive loss of expression was observed as the grade of both malignancies increased. However, there was no significant difference in the expression among the normal tissue groups and within SCC groups of similar grades.

    CONCLUSION: The present study suggests that the loss of TIG3 is an important event in carcinogenesis. TIG3 acts as a regulator of keratinocyte proliferation and terminal differentiation. Therefore, TIG3 could be a potential biomarker to differentiate aggressive and non-aggressive neoplasms.

  18. Siar CH, Ishak I, Ng KH
    J Oral Pathol Med, 2015 May;44(5):378-85.
    PMID: 25155411 DOI: 10.1111/jop.12247
    The ameloblastoma is a benign but locally aggressive odontogenic neoplasm with a high recurrence rate. While significant progress has been made in our understanding regarding the role of tumoral vasculature relative to the diverse behavioral characteristics of this tumor, no attention has been paid to a distinct subset of blood vessels entrapped within its epithelial compartment. As vascular niches are known to influence tumoral growth, clarification of these vessels is important. The objectives of this study were to investigate the morphologic characteristics of intra-epithelially entrapped blood vessels (IEBVs) in ameloblastoma and to speculate on their relevance.
  19. Siar CH, Rahman ZA, Tsujigiwa H, Mohamed Om Alblazi K, Nagatsuka H, Ng KH
    J Oral Pathol Med, 2016 Sep;45(8):591-8.
    PMID: 26752341 DOI: 10.1111/jop.12417
    BACKGROUND: Cell migration and invasion through interstitial tissues are dependent upon several specialized characteristics of the migratory cell notably generation of proteolytic membranous protrusions or invadopodia. Ameloblastoma is a benign odontogenic epithelial neoplasm with a locally infiltrative behaviour. Cortactin and MMT1-MMP are two invadopodia proteins implicated in its local invasiveness. Other invadopodia regulators, namely N-WASP, WIP and Src kinase remain unclarified. This study addresses their roles in ameloblastoma.

    MATERIALS AND METHOD: Eighty-seven paraffin-embedded ameloblastoma cases (20 unicystic, 47 solid/multicystic, 3 desmoplastic and 17 recurrent) were subjected to immunohistochemistry for expression of cortactin, N-WASP, WIP, Src kinase and F-actin, and findings correlated with clinicopathological parameters.

    RESULTS: Invadopodia proteins (except Src kinase) and F-actin were widely detected in ameloblastoma (cortactin: n = 73/87, 83.9%; N-WASP: n = 59/87; 67.8%; WIP: n = 77/87; 88.5%; and F-actin: n = 87/87, 100%). Protein localization was mainly cytoplasmic and/or membranous, and occasionally nuclear for F-actin. Cortactin, which functions as an actin-scaffolding protein, demonstrated significantly higher expression levels within ameloblastoma tumoral epithelium than in stroma (P < 0.05). N-WASP, which coordinates actin polymerization and invadopodia-mediated extracellular matrix degradation, was overexpressed in the solid/multicystic subtype (P < 0.05). WIP, an upstream regulator of N-WASP, and F-actin were significantly upregulated along the tumour invasive front compared to tumour centres (P < 0.05). Except for males with cortactin overexpression, other clinical parameters (age, ethnicity and anatomical site) showed no significant correlations.

    CONCLUSIONS: Present results suggest that local invasiveness of ameloblastoma is dependent upon the migratory potential of its tumour cells as defined by their distribution of cortactin, N-WASP and WIP in correlation with F-actin cytoskeletal dynamics.

  20. Hedin CA, Axéll T
    J Oral Pathol Med, 1991 Jan;20(1):8-12.
    PMID: 2002444
    At the faculties of dentistry in Chiang Mai, Thailand (CM), and Kuala Lumpur, Malaysia (KL), 234 and 233 consecutive out-patients were interviewed concerning tobacco and chewing habits and examined for the presence of oral melanin pigmentation. Tobacco was regularly used by 32% and 28% of the studied populations in CM and KL. Cigarette smoking was the predominant habit, but the chewing of betel and tea leaves (miang) and the smoking of banana leaf cigars (khi yo) was also registered. The genetically acquired pigmentation dominated. Although nearly all non-tobacco users in the Malay and Indian populations had oral melanin pigmentation, it was found that tobacco smokers had significantly more oral surfaces pigmented than non-tobacco users. Among Thais, the percentage of pigmented individuals was significantly higher among tobacco smokers. It was concluded that tobacco smoking stimulates oral melanocytes to a higher melanin production also in dark-skinned ethnic groups.
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