24 research outputs found
Incisal Morphology of Southern Chinese
Aim: To investigate the dental morphology of incisors of the Southern Chinese and compare these with studies in different populations.
Materials and Methods: The dental morphology of study casts of an unselected sample from a 12 year old Hong Kong Oral Health Survey of 12 year old children (n=459; 295 boys and 164 girls) were studied.
Results: The moderate types of shovel-shaped central incisors were prevalent in the Southern Chinese, whereas the pronounced type of shovel-shaped incisors were more prevalent in the Taiwan Chinese.
Conclusion: The Southern Chinese shows a lesser degree of shoveling than the other Chinese populations.published_or_final_versio
Incisal Morphology of Southern Chinese
Aim: To investigate the dental morphology of incisors of the Southern Chinese and compare these with studies in different populations.
Materials and Methods: The dental morphology of study casts of an unselected sample from a 12 year old Hong Kong Oral Health Survey of 12 year old children (n=459; 295 boys and 164 girls) were studied.
Results: The moderate types of shovel-shaped central incisors were prevalent in the Southern Chinese, whereas the pronounced type of shovel-shaped incisors were more prevalent in the Taiwan Chinese.
Conclusion: The Southern Chinese shows a lesser degree of shoveling than the other Chinese populations.published_or_final_versio
Incisor winging in Chinese
Aim: To investigate the incisor wingings of the Southern Chinese and compare these with studies in different populations.
Materials and Methods: The maxillary and mandibular incisor alignment in study casts of an unselected sample from a 12 year old Hong Kong Oral Health Survey of 12 year old children (n=459; 295 boys and 164 girls) were studied.
Results: The prevalence of bilateral winging in the maxillary arch was 9% for males and 10% for females respectively. The prevalence of bilateral winging of the mandibular incisors was higher than the maxillary central incisors, at a prevalence of 22% for both sexes. Bilateral counter-winging of the central incisors was rare.
Conclusion: The prevalence of bilateral winging or mesio-palatal rotation of upper central incisors was between low and intermediate in the Southern Chinese. On the contrary, the prevalence of counter-winging was low.published_or_final_versio
Molar cusps in Southern Chinese
Aim: To investigate the number of molar cusps of the Southern Chinese and compare these with studies in different populations.
Materials and Methods: The number of molar cusps of study casts of an unselected sample from a 12 year old Hong Kong Oral Health Survey of 12 year old children (n=459; 295 boys and 164 girls) were studied.
Results: For upper first molars, 5-cusp molars were the most prevalent in males (39%) while 4-cusp molars were the most prevalent in females (39%). For lower first molars, 5-cusp molars were the most prevalent in both sexes (63%-72%). For lower second molars, 5-cusp molars were the most prevalent in both sexes (43%-53%).
Conclusion: Different from traditionally described, the Southern Chinese has more 5-cusp lower second molars than the 4- cusp ones.published_or_final_versio
Risk Factors of Household Transmission of Pandemic (H1N1) 2009 among Patients Treated with Antivirals: A Prospective Study at a Primary Clinic in Japan
Background: Household transmission of influenza can affect the daily lives of patients and their families and be a trigger for community transmission, thus it is necessary to take precautions to prevent household transmission. We aimed to determine the risks of household transmission of pandemic (H1N1) 2009 influenza virus from an index patient who visited a primary clinic and was treated with antiviral drugs. Methods: We followed up all the patients who were diagnosed with influenza A by rapid diagnostic test with a questionnaire or interview from July 2009 to April 2010. Secondary cases were defined as patients visiting the clinic or other clinics and being positive for influenza A by rapid diagnostic test within 7 days of onset of an index patient. Logistic regression analysis was used to explore the association between household transmission and the studied variables. Results: We recruited 591 index patients and 1629 household contacts. The crude secondary attack rate was 7.3 % [95% confidence interval (CI): 6.1–8.7]. Age of index patients (0–6 years old: odds ratio 2.56; 95 % CI: 1.31–4.01; 7–12 years old: 2.44, 1.31–3.72; 30–39 years old 3.88; 2.09–5.21; 40 years old or more 2.76; 1.17–4.53) and number of household members with five or more (3.09, 2.11–4.07), medication started 48 hours from the onset of fever (2.38, 1.17–3.87) were significantly associated with household transmission. Conclusions: Household transmission was associated with index patients aged #12 years old and adults 30 years wit
Dental metric standards for sex estimation in archaeological populations from Iran
Sex estimation of skeletal remains is one of the major components of forensic
identification of unknown individuals. Teeth are a potential source of information on
sex and are often recovered in archaeological or forensic contexts due to their post-mortem
longevity. Currently there is limited data on dental sexual dimorphism of
archaeological populations from Iran. This dissertation represents the first study to
provide a dental sex estimation method for Iron Age populations.
The current study was conducted on the skeletal remains of 143 adults from two Iron
Age populations in close temporal and geographic proximity in the Solduz Valley
(West Azerbaijan Province of Iran). 2D and 3D cervical mesiodistal and buccolingual
and root volume measurements of maxillary and mandibular teeth were used to
investigate the degree of sexual dimorphism in permanent dentition and to assess their
applicability in sex estimation. In total 1327, 457, and 480 anterior and posterior teeth
were used to collect 2D cervical, 3D cervical, and root volume measurements
respectively. 2D cervical measurements were taken using Hillson-Fitzgerald dental
calliper and 3D measurements were collected using CT images provided by Open
Research Scan Archive (ORSA) - Penn Museum. 3D models of the teeth were created
using manual segmentation in the Amira 6.01 software package. Since tooth density
largely differs from crown to apex, root segmentation required two threshold levels:
the segmentation of the root from the jaw and the segmentation of the crown from the
root. Thresholds used for root segmentation were calculated using the half maximum
height protocol of Spoor et al. (1993) for each skull, and thresholds used for crown
segmentation were set visually for each tooth separately. Data was analysed using
discriminant function analysis and posterior probabilities were calculated for all
produced formulae where sex was previously assessed from morphological features of
pelvis and skull. Bootstrapping was used to account for small sample sizes in the
analysis. Statistical analysis was carried out using SPSS 23. The percentage of sexual
dimorphism was also used to quantify the amount of sexual dimorphism in the sample.
The results showed that incisors and canines were the most sexually dimorphic teeth,
providing percentages of correct sex classification between 80% and 100% depending
on the measurement used. Root volume measurement was shown to be the most
sexually dimorphic variable providing an accuracy of over 90% in all functions.
The present study provided the first dental metric standards for sex estimation using
odontometric data in Iranian archaeological populations. Dental measurements,
particularly root volume measurements, were found to be of value for sex assessment
and the method presented here could be a useful tool for establishing accurate
demographic data from skeletal remains of the Iron Age from Iran
Tooth dimensions of Southern Chinese
Teeth in casts of a random sample from the Hong Kong Oral Health Survey of 12-year-old children (n=459; 295 boys and 164 girls) were measured in the mesiodistal, buccolingual, and clinical crown height dimensions. Sexual dimorphism was evident in all tooth types in nearly all tooth dimensions, with the exception of the mesiodistal dimension of mandibular central incisors. The Chinese male tooth dimensions were larger than in females in nearly all characters. The measurements were compared with other human groups. Results showed that the Southern Chinese had larger tooth dimensions than the Japanese and than the White Americans. Hence it is important to have data concerning a relevant human group for purposes of clinical diagnosis and planning of treatment. These data may also be useful in forensic dentistry. © 2007 Elsevier GmbH. All rights reserved.link_to_subscribed_fulltex
Tanaka-Johnston mixed dentition analysis for southern Chinese in Hong Kong
Objective: To compare the prediction of unerupted permanent canine and premolar size of a comparable sample size of southern Chinese population with that of the study of Tanaka and Johnston. Materials and Methods: Teeth on study casts of an unselected sample from a 12-year-old Hong Kong Oral Health Survey of 12-year-old children (n = 459; 295 males and 164 females) were measured in the mesiodistal dimension. A Chinese mixed dentition analysis based on the Tanaka and Johnston method was constructed with linear regression equations for prediction of the mesiodistal widths of unerupted canines and premolars. Results: Sexual dimorphism was evident between southern Chinese males and females in incisors, canines, and premolars in the mesiodistal dimension. Conclusions: To predict the space (in mm) required for alignment of unerupted canine and premolars in southern Chinese children, halve the sum of the mesiodistal dimensions of the four mandibular incisors and add the respective constants for males (upper, 11.5; lower, 10.5) or females (upper, 11.0; lower, 10.0). © 2006 by The EH Angle Education and Research Foundation, Inc.link_to_subscribed_fulltex