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Biomedical subjects

S H Wei

Publications and source records attributed to S H Wei.

At least 109 records · Page 6Linked to original sources
PubMed1989

Fluoride retention following topical application of a new APF foam.

The oral retention of fluoride (F) following the topical application of a newly developed APF foam was compared with a conventional APF gel. Twenty adults aged 16-26 years participated in the study. Ten of the subjects received the F foam and gel treatments, on separate occasions, with a saliva ejector while another 10 subjects received the same treatment without saliva ejector. Approximately 4 g of the gel, and 0.9 g foam, were dispensed for each treatment. The amounts of fluoride applied, recovered from the mouths, and retained in the mouth were calculated for each treatment.

Acidulated Phosphate Fluoride↗
PubMed1988

Intersex differences in craniocervical morphology and posture in southern Chinese and British Caucasians.

The aim of this study was to compare intersex differences in the angular relationships of the head, the cervical column, and the true vertical in natural head posture (the "postural variables") for unselected samples of southern Chinese (n = 240) and British Caucasian (n = 80) 12-year-old children in Hong Kong. For both samples the cervical spine was angulated significantly more forwardly in the females (P less than or equal to 0.001) and the head held higher relative to the spine. Cervical lordosis was also greater in the females and the cervical column of greater relative length. Our findings are in agreement with comparable data previously reported for a northern Finnish population.

Asian People↗
PubMed1988

The reproducibility of natural head posture: a methodological study.

Current clinical interest in natural head posture (NHP) derives from studies correlating NHP to craniofacial morphology, future growth trends, and to respiratory needs. It has also been argued that NHP is the logical reference and orientation position for craniofacial analysis and the publication of illustrations. The individual or group is presented as they naturally appear in life. Hence, lateral cephalometric radiographs recorded routinely in NHP would be more meaningful for the clinician. Underpinning all these potential clinical benefits is the incompletely answered question of the clinical reproducibility of NHP. In this study a natural head posture, the orthoposition, was defined and standardized for clinical use. The effects of ear posts, an external source of eye reference (a wall mirror), sex and time were evaluated in relation to the reproducibility of recording lateral cephalometric radiographs in this natural head posture. The sample comprised 217 randomly selected 12-year-old Chinese children in Hong Kong. Boys looked up more when changing from the self-balance position to the mirror eye reference position (mean change 2 degrees, P less than or equal to 0.001). No other significant male-versus-female differences were detected. NHP reproducibility was better with a mirror (with mirror, method error = 1.9 degrees, without mirror, method error = 2.7 degrees). No significant differences in reproducibility were detected between NHP recordings taken with and without ear posts. However, without ear posts the radiographs tended to be of poor quality. The reproducibility of same-day repeat radiographs recorded with ear posts and with a mirror (after 4 to 10 minutes and 1 to 2 hours) was 1.9 degrees.(ABSTRACT TRUNCATED AT 250 WORDS)

Cephalometry↗
PubMed1988

A summary five-factor cephalometric analysis based on natural head posture and the true horizontal.

A simple and clinically practical five-factor cephalometric summary analysis is described that is based on the true horizontal and natural head posture. Special reference is made to the AB/horizontal angle as an improved method for the assessment of the sagittal skeletal pattern. A Class I clinical normal range of 12 degrees to 18 degrees was established. In comparison to analyses based on conventional intracranial reference planes, the new methods are more valid in two important respects: (1) the true horizontal reference plane displays less variance when the head is observed in natural posture; (2) the new methods better describe the dentoskeletal and profile features as they appear in life. Hence, they are more clinically meaningful. Data from a large cephalometric population study were used selectively to illustrate the benefits of the new methods. Previous conventional cephalometric analyses of the Chinese male had shown the average pattern to be skeletal Class II, with retrognathic mandible, when compared to the Caucasian male. However, when observed in natural head posture and using the methods based on the true horizontal, the true life skeletal pattern has been shown to be Class III. Analysis of individual subjects produced differing interpretations of craniofacial form, depending upon whether the conventional intracranial planes were used as reference or the true horizontal. It was concluded that conventional methods may result in significant errors in analysis, diagnosis, and treatment. The new methods produce valid supplementary data.

Asian People↗
PubMed1988

Orthodontic treatment of the primary dentition.

Five patients were treated for corrections of problems in the primary dentition. Anterior and posterior crossbite, deep overbite malocclusion, and overbite malocclusion were treated with simple removable orthodontic appliances. Early orthodontic treatment for these patients helped resolve any functional problems that could interfere with later growth and development, such as health and function of the TMJ complex.

Activator Appliances↗
PubMed1986

Needs and implementation of preventive dentistry in China.

Based on a literature review and recent surveys, the needs and implementation of preventive dentistry in China have been estimated. The average DMFT of 12- and 15-yr-old schoolchildren in Beijing were 1.61 and 2.11 respectively. The caries prevalence was higher in the coastal cities in the south. The caries rate was also higher in urban areas than in rural areas. There were some controversies in the results of fluoridation studies with one study reporting as high as 47.2% of the children to be afflicted with enamel fluorosis. The community periodontal disease status and treatment needs index (CPTNI) showed that 93% of the 12-yr-olds had bleeding, 98% had calculus and 15% had shallow pockets, with 100% of the children needing prophylaxis. There was a high prevalence of dental malocclusion with 54% of schoolchildren with dental anomalies, of whom 36% needed treatment. Much emphasis had been placed on oral pathology, oral medicine and maxillofacial surgery in the curriculum of Stomatology in Chinese dental schools.

Adolescent↗
PubMed1986

The dental caries status and dental treatment patterns of 12-year-old children in Hong Kong.

A randomly selected sample of 662 12-year-old Hong Kong children, 529 of whom were Southern Chinese and 133 non-Chinese, was clinically examined for dental caries. The DMFT values were 2.76 and 1.66 for the Chinese and non-Chinese children, respectively. The D component for the Chinese children was 2.12, while for the non-Chinese children it was only 0.45. Approximately 24.0% of the Chinese children had attended the dentist because they were in pain. Only 3.8% of the Chinese children had sought orthodontic or preventive treatment, compared with 24.0% of the non-Chinese children. Although these findings indicate the caries experience to be well below the FDI/WHO global goal for the year 2000, there is a great need to increase the level of dental awareness among Chinese children.

Child↗
PubMed1986

Developmental defects of enamel: a study of 12-year-olds in Hong Kong.

The prevalence of enamel defects in Hong Kong was determined using a randomly selected group of 12-year-olds (N = 1,069). The most common defects were enamel opacities, which occurred in 99.6% of the Chinese children, with 63.4% of them having more than 20 teeth affected. Almost 17% of the Chinese children had disfiguring enamel discoloration, but only one of the non-Chinese children had this defect. The high prevalence of enamel defects may be related to the high frequency of use of tetracycline, metabolic disturbances, and a greater-than-optimal intake of dietary fluoride.

Child↗