MyMedR

Oral biopsy turnaround time: 20-year experience of the Department of Oral Pathology, Oral Medicine and Periodontology, Faculty of Dentistry, University of Malaya

Siar CH, Tan BH

J Oral Sci, 2000 Dec;42(4):205-10.

PMID: 11269378

The turnaround time (TAT) for oral biopsies received for histological examination by the Department of Oral Pathology, Oral Medicine and Periodontology, Faculty of Dentistry, University of Malaya, for the years 1978, 1988 and 1998 was evaluated. For the three years studied, TATs for 61, 233 and 463 specimens were retrospectively analysed. Testing intervals, that is, from the dates the surgeons procured the specimens, the laboratories accessioned them and until the pathologists signed off the diagnoses, were used to calculate TAT. The performance level of the respective pathologists, the growth of tissue diagnostic services and the possible variables that influence TAT were also evaluated. As prompt diagnosis means prompt treatment, which in turn has a bearing on prognosis, the TAT pertinent to oral malignant tumors was emphasized. The mean TAT, its mode and median fell significantly in 1998 compared with the previous 2 years; it was lower for soft tissue than for hard tissue specimens, and lower for malignant, than for non-malignant specimens. The progression of tissue diagnostic services is up to a satisfactory level, as 88.89 % of biopsies could render diagnoses within a fair period of time in 1998.

Nasofacial zygomycosis

Ng KH, Chin CS, Jalleh RD, Siar CH, Ngui CH, Singaram SP

Oral Surg. Oral Med. Oral Pathol., 1991 Dec;72(6):685-8.

PMID: 1812451

Zygomycosis is an uncommon polymorphic fungal disease. One clinical subtype, nasofacial zygomycosis, is caused by infectious exposure to the organism Conidiobolus coronatus. A case affecting the nose and lips of a 42-year-old Malay man is reported here. The clinicopathologic features and management of this disease are described, and its differential diagnosis is discussed.

Fulltext Differential expression of stem cell-like proteins in normal, hyperplastic and dysplastic oral epithelium

Barakat SM, Siar CH

J Appl Oral Sci, 2015 Jan-Feb;23(1):79-86.

PMID: 25760270 DOI: 10.1590/1678-775720140245

The identification of stem cells (SC) remains challenging. In the human oral mucosal epithelium, these cells are believed to be in the basal layer (stem cell niche), but their exact location is unclear. The aim of this study was to examine the dysplastic oral epithelium for these SC-like proteins in order to assess their diagnostic value as biomarkers complementing the histological grading of dysplasia.

The prevalence of tongue lesions in Malaysian dental outpatients from the Klang Valley area

Koay CL, Lim JA, Siar CH

Oral Dis, 2011 Mar;17(2):210-6.

PMID: 20796228 DOI: 10.1111/j.1601-0825.2010.01724.x

OBJECTIVES: To determine the prevalence of tongue lesions in Malaysian dental outpatients from the Klang Valley area.
SUBJECTS AND METHODS: A cross sectional study was conducted on 600 Malaysian outpatients (257 men, 343 women, mean age, 37.7 years) attending the Primary Dental Care Unit at the Faculty of Dentistry, University of Malaya. Demographic and medical data were recorded for all respondents.
RESULTS: One hundred eighty-one patients (30.2%) (81 men, 100 women, mean age 42.0 years) were diagnosed with at least one tongue lesion (n = 207) at the time of examination. Of these, 24 patients (4%) had two or more tongue lesions present synchronously. Seven different lesions were diagnosed: fissured tongue (13.8%), crenated tongue (7.8%), pigmented tongue (6.2%), geographic tongue (2.2%), ankyloglossia (1.7%), hairy tongue (1.0%) and median rhomboid glossitis (0.2%). Their racial prevalences were Malays (n = 65, 10.8%), Indians (n = 62, 10.3%), Chinese (n = 53, 8.8%) and other race (n = 1, 0.2%). A significant relationship was observed between crenated tongue and race; between four types of tongue lesions (fissured tongue, geographic tongue, crenated tongue and pigmented tongue) and age; and between fissured tongue and gender (P

Neoplasia/dysplasia surveillance of oral lichen planus in Malaysia: a preliminary study using topography maps

Lim JS, Tang SP, Siar CH

Asian Pac J Cancer Prev, 2009;10(6):1071-4.

PMID: 20192586

BACKGROUND: Conventional methods for writing case notes detailing the progress of oral lichen planus (OLP), a precancerous condition that requires long-term surveillance, is both time-consuming and tedious for the busy clinician.

OBJECTIVES: To design and perform a simple surveillance on OLP patients based on colour-coded topography mouth maps (TMM).

MATERIALS AND METHODS: Three colour-coded TMM were employed: red for OLP in high risk oral mucosal sites, yellow for cases showing improvement and green for asymptomatic lesions at each recall visit. In this preliminary study, these were applied on 30 histologically confirmed OLP individuals attending the Oral Medicine Clinic at the Department of Oral Pathology, Oral Medicine and Periodontology, Faculty of Dentistry, University of Malaya. The sites and extent of OLP lesions were charted on either red, yellow or green TMM based on defined criteria. This surveillance evaluated OLP in relation to patientandapos;s age, race, gender, underlying systemic conditions, oral habits, initial onset of OLP, oral manifestations and presence/absence of clinically suspicious areas.

RESULTS: Study sample comprised 4 (13.3%) Malays, 9 (30.0%) Chinese and 17 (56.7%) Indians. Most OLP patients belong to the green TMM (n= 14, 46.6%) group followed by red (n= 11, 36.7%) and yellow (n= 5, 16.7%) groups. Of the 11 cases with red TMM, rebiopsy was performed on 4 cases but no dysplasia was detected. Any local confounding factors namely periodontal disease or faulty dental restorations were managed accordingly.

CONCLUSIONS: TMM is simple to use and aided the clinicians in terms of time saving and patient management. Hence, follow-up of OLP patients can be carried out more efficiently and appropriately. TMM can be used for surveillance of other oral precancerous lesions and conditions.

Cannon's disease: clinical and diagnostic implications: a case report

Ram S, Siar CH

Dent Update, 2004 Nov;31(9):557-9.

PMID: 15612463

Cannon's disease or white sponge naevus is a relatively rare genetically determined skin disorder. It is inherited as an autosomal dominant trait that displays a high degree of penetrance and expressivity. This article describes cases of Cannon's disease in a mother and her son.

Chemiluminescence as a diagnostic aid in the detection of oral cancer and potentially malignant epithelial lesions

Ram S, Siar CH

Int J Oral Maxillofac Surg, 2005 Jul;34(5):521-7.

PMID: 16053872

Chemiluminescence was evaluated as a diagnostic aid in the detection of oral cancer and potentially malignant epithelial lesions (PMELs) by comparing it against 1% tolonium chloride mouth rinse. Forty-six clinically identified lesions [14 primary squamous cell carcinoma (SCC), 26 PMELs and 6 benign lesions] and five cases of normal oral mucosa from 40 subjects (inclusive of 10 previously treated SCC cases) were examined with a commercial chemiluminescent kit (Vizilite) and tolonium chloride. Biopsy and histological verification of 31 lesions disclosed 14 SCC (45.2%), 10 epithelial dysplasias (32.3%), 5 lichen planus (16.1%) and 2 benign lesions (6.4%). For the remaining 15 lesions, a biopsy was not performed owing to patient's lack of consent or ill-health. The five cases of normal oral mucosa which tested negative for both tools were also not biopsied for ethical reasons. Sensitivity for Vizilite and tolonium chloride was 100% and 70.3%, respectively; and specificity was 14.2% for Vizilite and 25% for tolonium chloride. Their accuracy was 80.6% and 64.5%, respectively. Current findings suggest that chemiluminescence is a more reliable diagnostic tool than tolonium chloride in the detection of oral cancer and PMELs, and for follow-up of patients treated for the same.

Cellular protrusions--lamellipodia, filopodia, invadopodia and podosomes--and their roles in progression of orofacial tumours: current understanding

Alblazi KM, Siar CH

Asian Pac J Cancer Prev, 2015;16(6):2187-91.

PMID: 25824735

BACKGROUND: Protrusive structures formed by migrating and invading cells are termed lamellipodia, filopodia, invadopodia and podosomes. Lamellipodia and filopodia appear on the leading edges of migrating cells and function to command the direction of the migrating cells. Invadopodia and podosomes are special F-actin-rich matrix-degrading structures that arise on the ventral surface of the cell membrane. Invadopodia are found in a variety of carcinomatous cells including squamous cell carcinoma of head and neck region whereas podosomes are found in normal highly motile cells of mesenchymal and myelomonocytic lineage. Invadopodia-associated protein markers consisted of 129 proteins belonging to different functional classes including WASP, NWASP, cortactin, Src kinase, Arp 2/3 complex, MT1-MMP and F-actin. To date, our current understanding on the role(s) of these regulators of actin dynamics in tumors of the orofacial region indicates that upregulation of these proteins promotes invasion and metastasis in oral squamous cell carcinoma, is associated with poor/worst prognostic outcome in laryngeal cancers, contributes to the persistent growth and metastasis characteristics of salivary gland adenoid cystic carcinoma, is a significant predictor of increased cancer risk in oral mucosal premalignant lesions and enhances local invasiveness in jawbone ameloblastomas.

Odontogenic keratocyst with dentinoid formation

Ng KH, Siar CH

Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 2003 May;95(5):601-6.

PMID: 12738952

Although rare, hard tissue deposits, namely dystrophic calcifications and cartilage, have been reported to occur in the connective tissue wall of the odontogenic keratocyst. However, dentinoid formation has not been previously documented. A case involving the left mandibular premolar-molar region in a 37-year-old Malay male is described here along with a brief review on the reported prevalence of hard tissue deposits in the odontogenic keratocyst. Differential diagnosis of this case from other dentinoid-forming odontogenic cysts and tumors-notably calcifying odontogenic cyst, odontoma, ameloblastic fibro-odontoma, central odontogenic fibroma and adenomatoid odontogenic tumor that may present with dentin/dentinoid formation-is discussed.

Morphometric analysis of epithelial components and dentinoid formation in non-neoplastic calcifying odontogenic cyst

Ng KH, Siar CH

J Nihon Univ Sch Dent, 1995 Sep;37(3):156-62.

PMID: 7490609

Calcifying odontogenic cysts (COCs) represent a group of lesions that may be broadly classified into two main entities: cysts and neoplasms. In the present study 30 non-neoplastic cystic COCs were examined by a quantitative histological method in an attempt to calibrate the relative distribution of the type of epithelial lining, intensity of ghost cell formation and the amount of dentinoid present. The results showed that there are two main types of cystic COC: an odontoma-producing type and a non-odontoma-producing variant. Morphologically, tooth-like structures were a valid distinguishing feature, while morphometrically the odontoma-producing variant showed a greater amount of luminal and mural dentinoid as well as luminal ghost cells. Demographic analysis also revealed that the odontoma-producing COC occurred in younger patients and showed an even sex distribution, whereas the non-odontoma-producing type was seen in older patients and showed a predilection for females. Both subtypes were more prevalent in the Chinese population and occurred preferentially in the maxilla.

Review of oral histoplasmosis in Malaysians

Ng KH, Siar CH

Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 1996 Mar;81(3):303-7.

PMID: 8653464

We reviewed biopsy records for 37 cases of oral histoplasmosis for patient characteristics, clinical features, and histopathologic findings. These represented cases diagnosed in the Division of Stomatology, Institute for Medical Research, Kuala Lumpur between July 1967 and October 1994. All were male patients who ranged in age from 11 to 79 years (mean age, 56.7 years). There were 40.6% Malays, 37.8% Chinese, 18.9% Indians, and 2.7% other races. Five patients with mouth lesions as the initial presenting lesions were proven to be cases of disseminated histoplasmosis. In the remaining cases apart from the biopsy-proven oral histoplasmosis lesions, the extent of the disease elsewhere was unknown. The majority of these lesions involved the gingiva, tongue, and palate in decreasing order of frequency. The most frequent presenting symptom was oral mucosal ulceration. Squamous cell carcinoma and tuberculosis were the two most common clinical differential diagnoses. Our present findings compare favorably with published reports from other regions.

Desmoplastic variant of ameloblastoma in Malaysians

Ng KH, Siar CH

Br J Oral Maxillofac Surg, 1993 Oct;31(5):299-303.

PMID: 8218083

Seventeen cases are reported of desmoplastic variant of ameloblastoma of the jaws observed during the years 1967-1991. There were 12 females and 5 males, and these consisted of 7 Chinese, 6 Malays, 2 Indians, 1 Sikh and 1 Kadazan. Their ages at diagnosis ranged from 21-60 years with a mean of 36.6 years. There were 10 mandibular and 7 maxillary tumours. Of these, 14 cases involved the anterior segment with extension to the premolar region in 5 cases. 60% of cases were radiologically suggestive of fibro-osseous lesions. The main mode of treatment was resection and 1 case presented with recurrence. The findings of this study were compared with those of previous reports.

Calcifying fibroblastic granuloma. A case report

Taiyeb Ali TB, Siar CH

J N Z Soc Periodontol, 1997.

PMID: 9522721

Cemento-ossifying fibroma with mandibular fracture. Case report in a young patient

Ong AH, Siar CH

Aust Dent J, 1998 Aug;43(4):229-33.

PMID: 9775467

The cemento-ossifying fibroma is classified as an osteogenic neoplasm of the jaws. It commonly presents as a progressively growing lesion that can attain an enormous size with resultant deformity if left untreated. A case of a large cemento-ossifying fibroma involving the left mandible is described in a 15 year old male patient. The clinical, radiographic and histological features as well as surgical findings are presented. The treatment of choice of this lesion is also emphasized. Two years after surgery, there was no evidence of recurrence and the transosseous wire used to immobilize the fracture was found to be completely buried in the jaw bone.

Florid cemento-osseous dysplasia in a young Chinese man. Case report

Ong ST, Siar CH

Aust Dent J, 1997 Dec;42(6):404-8.

PMID: 9470284

Florid cemento-osseous dysplasia refers to a group of fibro-osseous lesions which are exuberant, multiquadrant and arise from the tooth-bearing area of the jaws. It is classically described as a condition occurring almost exclusively in middle-aged black women. A case of florid cemento-osseous dysplasia occurring in a young Chinese male is reported which was rare in regard to race and sex. This 20 year old Chinese man presented with huge symmetrical bony lesions in all four quadrants of the jaws. Clinical presentation, radiological findings and histological features of the excised specimens are described. Treatment of the lesions was unusual. Curettage was first done with minimal benefit and it was followed by mandibular recontouring to improve facial appearance. The outcome of these procedures will be discussed.

A clinicopathologic study of odontomas: Malaysian findings

Ng KH, Siar CH

J Nihon Univ Sch Dent, 1997 Dec;39(4):171-5.

PMID: 9476429

This report reviews the clinicopathologic characteristics of 104 cases of odontomas diagnosed in the Division of Stomatology, Institute for Medical Research, Kuala Lumpur, over a 29-year period (1967-1995). The results showed no real predilection in terms of sex (M:F ratio, 1:1), race (45.2% Malays, 40.4% Chinese, 10.6% Indians and 3.8% other races) or site (maxilla:mandible ratio, 1: 1.04) distribution. The mean age at presentation was 24.8 years and the age range was 3-74 years. There were 102 intraosseous and 2 extraosseous odontomas. Swelling was the most common presenting complaint. The majority of cases (81.9%) were clinically diagnosed as odontomas. The treatment of choice was surgical enucleation. Compound (43.3%) and complex (35.5%) odontomas were the two most common histological types encountered. The present findings correlate favorably with reported studies from other geographic areas.

A clinicopathological and immunohistochemical study of the calcifying epithelial odontogenic tumour (Pindborg tumour) in Malaysians

Ng KH, Siar CH

J Laryngol Otol, 1996 Aug;110(8):757-62.

PMID: 8869610

We reviewed the clinicopathological characteristics of 13 cases of calcifying epithelial odontogenic tumour (CEOT) (Pindborg tumour) diagnosed in the Division on Stomatology, Institute for Medical Research, Kuala Lumpur, over a 29-year period. There were eight female and five male patients. These consisted of eight (61.5 per cent) Malays, three (23.1 per cent) Chinese, one (7.7 per cent) Indian and one (7.7 per cent) Melanau. Their ages at presentation ranged from 19-61 years (mean age, 31.8 years). There were 12 central and one peripheral CEOT. Of these, 76.9 per cent of cases were located in the maxilla, the remaining in the mandible. The commonest clinical diagnosis was a dentigerous cyst (66.7 per cent). Enucleation was the main mode of treatment. Histologically, sheets and strands of polyhedral epithelial cells containing eosinophilic, homogeneous globules with Liesegang rings were observed. One case also showed extensive calcification and clear cell differentiation. Immunohistochemistry revealed a variable keratin staining of the CEOT epithelium, confirming its heterogeneity.

Peripheral ameloblastoma with clear cell differentiation

Ng KH, Siar CH

Oral Surg. Oral Med. Oral Pathol., 1990 Aug;70(2):210-3.

PMID: 2290651

This report details a case of mandibular peripheral ameloblastoma having a clear cell component. The latter consisted of ovoid cells with vacuolated or clear cytoplasm and vesicular or pyknotic nuclei that may be disposed as discrete clusters or show direct transition from typical acanthomatous areas. Comparison of this lesion with other odontogenic and nonodontogenic tumors that contain clear cells is discussed in the context of the differential diagnosis.

High-grade malignant mucoepidermoid tumour of tongue. A case report

Ng KH, Siar CH

Singapore Dent J, 1989 Dec;14(1):42-5.

PMID: 2487475

Mucoepidermoid tumours of the minor salivary glands of the tongue are rarely encountered. A case of a high-grade malignant type is reported here. Merits of subdivision of the mucoepidermoid tumour on the basis of its malignant potential are outlined, and variations of histological presentation of the present tumour at its primary and nodal sites are discussed.

Fulltext Teeth in osteogenesis imperfecta: a light microscopic study

Siar CH

Med J Malaysia, 1986 Jun;41(2):161-5.

PMID: 3821613

The light microscopic features of the dentine in three teeth from two cases of osteogenesis imperfecta (OJ) are presented. Results show that teeth in OJ distinctively have a more uniform and tubular mantle dentine, and a characteristic laminated circumpulpal dentine formed by distorted incremental bands alternating with parallel rows of interglobular dentine and interrupted by comet-shaped vascular canals. The study indicated that in the absence of overt OJ features, the changes in dentine alone are sufficiently characteristic to establish such a diagnosis.

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