RESUMEN

OBJECTIVES: To compare the morphological changes and quantitative distribution of lamellar bodies (Lb) (membrane coating granules) in the hamster cheek pouch epithelium with smokeless tobacco (ST). MATERIALS AND METHODS: Archives of experimental material from previously published studies [S. Ashrafi, A. Das, R. Worawongvasu, B. Mehdinejad and J. Waterhouse (1992) Scanning Microscopy6: 183] were utilized. Animals in experimental group received most ST (snuff) in their right pouch, 5 days weekly, for 24 months, while no snuff was given to control group. After 24 months, the epithelial tissues were processed for electron microscopic study. Volume densities of Lb were assessed by morphometry. MAIN OUTCOME MEASURES: Densities of Lb in the two groups, experimental vs control. RESULTS: In the control, Lb extruded their contents into the intercellular spaces of upper granular layers and in between the last granular cell layers and keratin layers to form a permeability barrier. Conversely, in the smokeless tobacco-treated epithelium, the majority of the Lb that were formed remained inside and accumulated within the granular cells, without extruding their contents into the intercellular spaces to form a lipid compound permeability barrier. CONCLUSIONS: Commercial alkaline ST may have contributed to the abnormal accumulation of Lb in the granular cell layer and affected the extrusion process of Lb to form an incomplete permeability barrier in the oral epithelium.

Asunto(s)

RESUMEN

OBJECTIVES: To compare the morphological changes and quantitative distribution of mitochondria in the hamster cheek pouch (HCP) epithelium treated with smokeless tobacco (ST). MATERIALS AND METHODS: Archives of experimental material from previously published studies (Ashrafi et al., 1992) were utilized. Animals in experimental group received moist ST (snuff) in their right pouch, 5 days weekly for 24 months, while no snuff was given to control group. After 24 months, the epithelial tissues were processed for electron microscopy study. Volume densities of mitochondria were assessed by morphometry. MAIN OUTCOME MEASURES: Mitochondrial volume densities in the two groups, experimental vs control. RESULTS: In both control and experimental groups mitochondria were concentrated between the nucleus and basal cell plasma membrane. A decrease in the mean mitochondrial volume density (Vvmit) was observed from the basal layer to the more superficial layers in both groups. The experimental HCP displayed more mitochondria than control, and the granular epithelial cell layer in experimental group showed significantly a higher mean Vvmit than the control group (P = 0.03). It was concluded that greater numbers of mitochondria were retained in ST-treated granular cells of the hyperplastic epithelia than in the normal epithelium.

Asunto(s)

RESUMEN

OBJECTIVES: The purpose of this study was to assess dentists' opinions about oral cancer (OC) prevention and early detection. METHODS: Data were collected by a self-administered mail questionnaire sent to all 398 registered dentists practising along the Texas-Mexico border. RESULTS: The effective response rate to the survey was 40%. While 90% of respondents agreed that oral cancer examinations (OCE) should be provided annually for patients 40 years of age and older, only 59% of respondents believed their OC knowledge was current. While 99% agreed that dentists were qualified to perform OCE, only 54 and 68% respectively, agreed that dental hygienists and physicians were similarly qualified. Dentists who rated their undergraduate OC training favorably (OR = 2.68, 1.23-5.81, P = 0.011), had attended their last oral cancer continuing education (OCCE) course within the past 5 years (OR = 2.46, 1.25-4.86, P = 0.009), and those who performed OCE on all patients 40 years and older (OR = 2.64, 1.32-5.26, P = 0.005), were more likely to agree their OC knowledge was current. CONCLUSIONS: Respondents expressed diverse opinions about OC prevention and early detection. Positive opinion on currency of OC knowledge was associated with performance of OCE. Results indicate a need for OCCE targeting the study population as well as increased emphasis on OC curriculum in dental schools.

Asunto(s)

RESUMEN

Trauma to the teeth is a common reason for emergency room visits among children, with the maxillary anterior teeth being mostly affected. The consequences of dental trauma include disfigurement, speech defects and psychological effects. This is a cross-sectional study comprising 1039 students, with 47% being males and 53% females. Teeth were examined for physical evidence of trauma. The prevalence of incisal fracture was 2.4% with no significant gender difference (2.9% and 2.0% among males and females, respectively). The male to female prevalence ratio was 1.45 to 1.0. The maxillary incisors accounted for 96% of fractured teeth. Among children with traumatized incisors, 86% had one tooth affected, while 14% had two traumatized teeth. The prevalence of incisal trauma was significantly higher among children of low socioeconomic status (chi2=5.86, P=0.02, df=1). Though African American and Hispanic children had higher prevalence than White children, the differences were not statistically significant. The study reports a low prevalence of incisal trauma among Harris County children and a socioeconomic difference. This study recommends further investigation of incisal trauma in this region as well as educational programs to prevent dental trauma.

Asunto(s)

Asunto(s)

RESUMEN

OBJECTIVE: To determine the prevalence and severity of dental caries among school children of St. Vincent and The Grenadines. Also, to establish baseline data on dental caries and determine the extent to which the present oral health care system is meeting dental needs. BASIC RESEARCH DESIGN: National cross-sectional survey utilising the World Health Organization's pathfinder methods. Dental examinations were conducted from October to November 1991 by three trained examiners. PARTICIPANTS: A total of 1648 students, 21% of school children in St. Vincent and The Grenadines, were sampled through multistage systematic sampling. OUTCOME MEASURES: Dental caries was diagnosed clinically according to the World Health Organization's diagnostic criteria. RESULTS: Caries prevalence in the permanent dentition was 69.4%, ranging from 68 to 73% according to gender and geographic location. In the primary dentition caries prevalence was 76.6%. Mean DMFT for the survey population was 2.69, dmft was 3.25, while the DMFT scores for gender and location types varied from 2.39 to 3.25. DMFT at 12 years was 3.25. No difference in caries prevalence was observed between gender in the permanent dentition but prevalence was significantly different in the primary dentition being higher among boys. Prevalence was significantly higher in the urban population relative to the rural population. The decayed component constituted 92% of DMFT and 91% of dmft. CONCLUSION: Moderate caries severity and high levels of untreated decay were found in both primary and permanent teeth. The results emphasise the need for continuous surveillance and for appropriate intervention and prevention programmes.

Asunto(s)

RESUMEN

A national oral health survey of school children was conducted in October through November 1991. The objective was to determine the periodontal status of school children in St. Vincent and The Grenadines (SVG), the pattern and severity of periodontal disease, estimate treatment needs and provide information for health planners. The study had a cross-sectional design, and 1646 schoolchildren representing all school districts were selected via multistage, systematic sampling. Examinations were conducted by three examiners using CPITN probe. Periodontal indicators and treatment needs were determined using the CPITN index. Calculus was the most prevalent condition with values ranging from 26 to 83 percent, bleeding was the least prevalent condition, while children with healthy indicator were intermediate in prevalence. Subjects with healthy indicators ranged from a low of 12 percent among 15-19 year olds, to a high of 51 percent among seven-year-olds. The mean number of healthy sextants varied from three to five, and mean number of sextants with bleeding or calculus varied from one to three. Oral hygiene instruction (OHI) was the most common treatment need, ranging from 49 to 88 percent. The need for prophylaxis was associated with increase in age, with the highest prophylaxis treatment needs of 83 percent, among 15-19 year olds. No significant differences were observed in periodontal status between gender, and also between urban and rural children. A high prevalence of calculus and bleeding was observed among SVG school children. Study recommends initiation of primary prevention programs in form of health promotion and health education.

Asunto(s)