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.
A study was conducted to investigate the relationship between the parents' level of knowledge, and their attitudes to nursing bottle syndrome. Of 284 children aged 2-6 years clinically examined, 153 were diagnosed as having nursing bottle syndrome based on the criterion that at least one upper maxillary incisor was affected by caries. The parents of the 153 affected children were then interviewed by questionnaire. The findings suggested that parents had adequate knowledge and a positive attitude towards maintaining satisfactory dental care for their children. However, these attitudes were not reflected in the dental health of their children. The implications of these findings are discussed.
The lining epithelium of 15 cases of odontogenic keratocyst (OKC) was evaluated immunohistochemically. The peroxidase-antiperoxidase technique was applied to study the distribution of polyclonal keratin and S-100 protein while the indirect method was used to examine monoclonal vimentin and desmin reactivity. Consistent positive keratin staining was revealed in the lining epithelium of all 15 OKCs with additional intense staining in the stratum corneum. None of the cases showed vimentin or desmin reactivity within the lining epithelium elements. One of the 15 cysts studied showed positive S-100 protein staining in the nuclei of the lining epithelial cells. The pertinent literature on the immunophenotyping of the lining epithelium of OKC is reviewed.
A cross-sectional exploratory survey was conducted in six West Malaysian schools involving 762 fifteen- to eighteen-year-old secondary school students. Periodontal health status was assessed using the Community Periodontal Index of Treatment Needs (CPITN), utilizing six index teeth to represent the six sextants of the mouth. The results indicated that 66.8% of the students examined had healthy gingiva (Score 0), 2.6% had bleeding of the gingiva on gentle probing, while 30.6% had calculus on their teeth. In terms of treatment needs, 35.0% of those examined needed oral hygiene education, 34.4%, on the other hand, required scaling. No student was found to require complex treatment. Sex-specific comparison revealed a slightly higher prevalence of calculus formation in male students. In terms of race, the Malays had a higher prevalence of calculus formation than either Chinese or Indians.
Two cases of either peripheral odontogenic fibroma (POF) (WHO type) or peripheral ameloblastoma are reported. Their immunohistochemical characteristics were investigated in an attempt to clarify their histogenesis. The results showed that the epithelial component of this neoplasm tended to retain its distinct odontogenic character and expressed a keratin profile different from that of the overlying oral epithelium from which both cases most probably originated. The connective tissue element of these tumors was vimentin-positive and S-100 protein negative, confirming their mesodermal nature but precluding the possibility of ectomesenchymal derivation. No reactivity for desmin was noted.
The term "choristoma" is used to describe a mass of histologically normal tissue presenting in an aberrant site. A rare case of osseous choristoma of the tongue is presented and the literature is briefly reviewed.
Granular cell ameloblastoma (GCA) is a well recognized variant of follicular ameloblastoma with extensive granular cell change. In contrast, plexiform granular cell odontogenic tumor (PGCOT) is a rare and recently described lesion characterized histologically by a monophasic plexiform pattern of granular cells. In this paper, two cases of an unusual granular cell odontogenic tumor exhibiting combined features of these two entities are described along with their immunohistochemical characteristics. The granular cells of both the GCA and PGCOT areas showed similar patterns of expression for keratin and S-100, which differed from those of typical ameloblastoma. No reactivity for desmin or vimentin was noted. The histomorphologic and immunohistochemical features of these hybrid tumors suggest that the granular cells present have a common origin, most probably the odontogenic epithelium.
Seventeen cases of desmoplastic ameloblastoma were examined immunohistochemically. Immunoperoxidase techniques were applied for detection of keratin, desmin, vimentin and S-100 protein expression in these tumors. The tumor epithelium of desmoplastic ameloblastoma exhibited weak, focal, inconstant keratin staining, weak, variable expression of S-100 protein, desmin immunoreactivity of mild to moderate intensity and vimentin non-reactivity. The pertinent literature on the immunohistochemistry of ameloblastomas is briefly reviewed.
It has been postulated that subjects with high levels of oral sensory perception and motor ability are able to achieve higher standards of oral hygiene even under different dietary regimes. In this study, eleven dental personnel volunteers were started on a low-sucrose diet for one week, followed by a high-sucrose diet for another week, while eleven others followed a reverse-order dietary regime. Oral sensory perception and motor ability were assessed by the oral stereognosis test and a test for oral motor ability. There was a greater trend for subjects to have more plaque on their teeth when they were on the high-sucrose diet, even when normal oral hygiene procedures were taken. There were no significant correlations between the state of oral hygiene and levels of oral sensory perception and motor ability. These results do not support the hypothesis that subjects with high levels of oral sensory perception and motor ability are likely to achieve better oral hygiene.
Histiocytosis X is a rare disorder with no particular predilection for race, age or sex. Since its discovery by Hand in 1893, the etiology has remained unknown, although viruses, bacteria and genetic factors have been implicated. Familial occurrence of this disease is very rare, and only a handful of such cases have been reported. The present study adds further evidence to support the influence of genetic factors in the etiology of histiocytosis X.
Dental composite resins are widely used in dental practice and are continually being developed in order to obtain better products. To gain full benefit from these materials, it is important for the clinician to understand their properties. The following is a review of the more common characteristics of composites in current use.
Levels of serum IgG against Porphyromonas gingivalis cell sonicate were determined in patients with rheumatoid arthritis (RA) (n = 25), rapidly progressive periodontitis (RPP)(n = 25) and adult periodontitis (AP)(n = 15) and controls (HP)(n = 10) utilizing the ELISA technique. Comparison between groups showed no significant differences between the HP and RA groups and also between the RPP and AP groups. The increased levels of IgG in the RPP and AP groups were comparable. Significant differences in IgG levels were noted between HP and RPP (p<0.05) and between HP and AP (p<0.01). The differences between RA and RPP and between RA and AP were highly significant (p<0.0001). Thus it was revealed that the serum levels of IgG against P. gingivalis in RPP and AP patients were elevated, whereas the levels in RA patients were comparable to those in controls.
The study was conducted to determine thiocyanate (SCN-) and hypothiocyanite (OSCN-) concentrations in resting (RWS) and stimulated whole saliva (SWS) and stimulated parotid saliva (SPS) of 20 healthy young adults aged 21-29 y. Samples of saliva were collected at 12:30, immediately before lunch. Resting saliva was collected by expectoration, and stimulated saliva was collected during the uniform chewing of paraffin wax. Parotid secretion was collected using a modified Carlsson-Crittenden cup (Carlsson et al., Am, J. Physiol., 26, 169-177, 1910). SCN- concentration was determined by the ferric nitrate method (Betts et al., J. Am. Chem. Soc., 75, 5721-5727, 1953) whilst OSCN- was assayed using 2-mercaptoethanol as a reducing agent (Pruitt et al., Caries Res., 16, 315-323, 1982). In RWS, SWS and SPS, the mean SCN- concentrations (in mM) were 1.48 +/- 0.59(S.D.), 0.90 +/- 0.56(S.D.) and 1.24 +/- 0.65(S.D.) whilst the mean OSCN- concentrations (in microM) were 31.21 +/- 13.54(S.D.), 24.90 +/- 12.61 and 30.19 +/- 23.35(S.D.) in the respective salivas. The presence of OSCN- in the secretion collected from the parotid gland supported previous findings by Tenovuo and Pruitt (Tenovuo et al., J. Oral Path, ol. 13, 573-584, 1984), who suggested an endogenous glandular (eukaryotic) source of hydrogen peroxide (H2O2), since parotid saliva from healthy glands is devoid of bacteria and leukocytes.
The mean strength that has traditionally been taken as a measurement of the strength of a material does not reflect the true strength, and therefore it cannot be used as a design parameter. This explains why many brittle materials fail at unpredictable stress, either below or above the mean strength. By using Weibull statistics, the prediction and assessment of strength can be made more sensibly. The performance of a material can be predicted by considering a stress at a lower level of failure probability.
Fresh samples of human whole saliva containing approximately 20-40 micrograms protein were analyzed using SDS-polyacrylamide slab gel electrophoresis systems. More than 20 protein bands were revealed by Coomassie Brilliant Blue R 250 staining. Some of the protein bands were shown to be glycoprotein-positive with PAS (periodic acid-Schiff) reagent. The protein bands with alpha-Amylase activity appeared within a molecular weight range of 120,000-180,000, which is 2 to 2.8 times higher than the normal molecular weight reported for alpha-Amylase from parotid saliva, and showed positive staining with PAS reagent. These results show that the alpha-Amylase in whole saliva appears to exist in a macromolecular form which is not dissociated in the presence of sodium dodecyl sulfate (SDS).
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.
Twelve pleomorphic adenomas of minor salivary gland origin were examined for the distribution of S-100 protein, detected using the peroxidase-antiperoxidase (PAP) method. Strong S-100 protein immunoreactivity was noted in areas containing plasmacytoid cells, stellate and spindle cells against a myxochondroid or hyalinous stroma, and solid epithelial areas. Tubular and duct-like structures showed variable stainability. Stromal tissue and normal salivary glands were generally negative for S-100 protein. These findings were compared with those reported elsewhere.
Belief in a golden age has provided mankind with solace in times of despair and with élan during the expansive periods of history. Dreamers imagine the golden age in the remote past, in paradise lost, free from toil and grief. Optimists put their faith in the future and believe that mankind, Prometheus-like, will master the arts of life through power and knowledge. Thus, the golden age means different things to different men, but the very belief in its existence implies the conviction that perfect health and happiness are birthrights of men. Yet, in reality, complete freedom from disease and from struggle is almost incompatible with the process of living.