Epidemiologic panorama of dental occlusion

The purpose of this study was to explore the possible significant sex difference in occlusion, provide information about the occlusal variation among Egyptians, and present an epidemiologic panorama of dental occlusion among different ethnic world populations. The hypothesis was that the occlusal variation is not independent of sex. A sample of 501 female and male adult subjects was studied. Normal occlusion, Angle's classification of malocclusion, and the Dewey-Anderson modifications for typifications were recorded. Chi-square tests were used. The results obtained from this study indicate that a significant sex difference in occlusion exists for normal occlusion, Angle Class I, and Angle Class III. Further, considering an anterior crossbite as the sole indicator of an Angle Class III malocclusion is erroneous; an anterior crossbite may exist in other classes, and Angle Class III type 1 (edge-to-edge) is more prevalent than either Class III type 2 (normal anterior overbite) or type 3 (anterior crossbite). Although numerically different, occlusal variation follows a universal general distributional pattern for most world populations. Some speculations are presented for clinical implications and for research suggestions.     

Epidemiologic oral health survey of Argentine children

Abstract An epidemiologic oral health survey of 2279 children aged 7–8 and 12–13 was carried out in eight different regions of Argentina using methods and criteria recommended by the WHO. The children examined lived in rural or urban areas and were of Caucasian or Amerindian extraction. Periodontal status showed that 75% of this population had soft deposits, while calculus and gingivitis increased with age. Calculus: 0.4 at 7 yr to 16.1 at 13: gingivitis: 2.7% at 7 yr to 27.2% at 13. At age 8, the mean number of DMF per child was 3.9. The percentage of caries-free children with permanent dentition dropped from 60% at age 7 to 32% at age 13. In Amerindian children, all these parameters were higher. Both the mean DMF and DMF per child were substantially lower in natural fluoride areas than in non-fluoride areas. Data from this first nationwide epidemiologic study in this country provide baseline data for further investigations. According to the data obtained in this study, Argentine regions may be classified as high, medium or low risk areas, although a lack of adequate dental care was found in all regions. With these risk priorities as a guideline, we propose an initial strategy consisting of a carefully planned and selective program of primary dental health care.     

Improving Dental Epidemiologic Data Collection with Computers

A computerized dental data recording system (DDRS) was developed for the New England Elder Dental Study to improve data quality and increase field staff efficiency. The DDRS displays video screens similar to traditional paper forms to record data on coronal and root caries, dentate and denture status, subacute bacterial endocarditis screening, gingival bleeding, calculus, and periodontal attachment level. DDRS provides facilities for date and exam-component time tracking, on-line contextual comments, random record retrieval, editing, data backup, and data output in various data formats. This study compared the DDRS with a paper-form system for data entry accuracy. Dental caries and periodontal disease measurement data from 38 subjects were recorded on paper forms and independently entered using DDRS. The DDRS identified 150 illogical data errors, 39 inconsistent data errors, 7 invalid data and 34 miscellaneous data errors. Four technicians with field experience using both paper forms and DDRS reported time savings using DDRS in the field. DDRS has the potential for additional time savings by minimizing the time for data coding, cleaning, and management. Results demonstrate that DDRS could improve the quality of oral epidemiologic data by mandating strict adherence to protocols, preventing errors, and increasing field efficiency.     

口腔癌相关危险因素的流行病学调查分析

目的:进行口腔癌相关危险因素的流行病学调查,为口腔癌的预防提供依据。方法:采用流行病学问卷调查方法,在国内8个城市进行多中心大样本病例-对照研究。调查内容主要包括个人基本情况、全身疾病和口腔疾病史、口腔卫生习惯、吸烟与被动吸烟、饮用水及常用的饮料情况、运动及劳动情况、家族史等7个方面。采用SAS 8.2软件包对数据进行t检验或χ2检验,采用Logistic回归分析各因素与罹患口腔癌的关系。结果:经常参加运动、饮用牛奶、饮用水处理、高血压、口腔白斑、不良修复体、吸烟史、戒烟史、吸有过滤嘴烟等在病例组和对照组之间有显著差异(P<0.05)。吸烟时间越长、吸烟量越大,危险度越高(OR分别为3.57、4.78)。运动、饮用牛奶及饮用水处理可降低口腔癌的危险(OR分别为0.48,0.48和0.53)。结论:吸烟是口腔癌发生的重要因素,吸过滤嘴烟不能降低口腔癌的发生;运动、饮用牛奶及饮用水处理可降低口腔癌的发生。     

牙龈癌的流行病学危险因素研究

目的：研究牙龈癌发病的流行病学危险因素,为牙龈癌的有效预防提供依据。方法：收集2007-2011年某医院口腔科就医的78例牙龈癌病人,以医院所在社区的156例人群作为对照。收集研究对象的流行病学相关资料。采用SPSS18.0进行Logistic回归分析。结果：非条件Logistic回归分析结果显示,与牙龈癌有关的流行病学危险因素包括年龄、吸烟、饮酒、高血糖、低收入家庭、家族肿瘤史（OR分别为1.064,3.826,2.932,2.067,5.218,2.617）。定期进行口腔护理、经常饮用经处理的水可以降低患牙龈癌的风险（OR分别为0.443,0.288）。结论：年龄较大、吸烟饮酒、高血糖、低收入家庭、家族肿瘤史等是患牙龈癌的危险因素,定期进行口腔护理、经常饮用经处理的水可以降低患牙龈癌的风险。     

526例下颌骨髁状突骨折临床病例回顾性研究

目的:探讨下颌骨髁状突骨折的发生特点。方法:通过对526例髁状突骨折病案资料的调查,对髁状突骨折的发生年龄、性别、致伤原因、骨折类型、合併伤、治疗及后遗症进行分析?峁?髁状突骨折好发于20~30岁;男性多于女性,交通事故伤(47.97%)为主要致伤原因;髁状突骨折60.59%发生在髁颈部;49.62%合并颏部骨折;儿童髁状突骨折69.85%采用保守治疗,高位(囊内)骨折69.52%摘除骨折断端;3.23%继发关节强直。结论:髁状突骨折好发于髁颈部,髁状突矢状骨折及髁颈部骨折伴骨折断端和关节盘移位严重的骨折处理不当易发生关节强直。     

1693名颌面创伤患者临床病例回顾性研究

对第四军医大学口腔医院1986-1995年10年间1693名颌面创伤住院患者进行了临床流行病学回顾性研究。颌面创伤患者人数占住院总人数的16%，并呈逐年递增趋势；男女比例为6：1，20-30岁为发病高峰年龄，交通事故在致伤原因中占47%，居地首位，颌面损伤以多发性骨折为主，人均骨折部位数为1.7个，在颌面骨骼中，下颌骨骨折最常见，其次是颧骨和上颌骨，颅脑伤是颌面骨折最常见的合并伤，面中部较面下部骨折更易造成颅脑损伤。     

Investigations towards nano-hybrid resin-based composites

Objective

Clinical data indicate an increased trend in material fracture as reason for failure in composite restorations, questioning whether modern resin-based composites (RBCs) are able to fulfil the rising aesthetical demands and to provide at the same time a sufficient mechanical stability also in larger cavities. Nano-hybrid RBCs are promoted as materials with improved mechanical properties. The aim of this study was to analyse differences in mechanical properties within and between modern flowable and non-flowable nano-hybrid and micro-hybrid RBCs by measuring mechanical properties at macro- and micro-scale.

Methods

Thirty-four RBCs with traditional and new monomer formulation or photo-polymerization initiator technology—15 nano-hybrid, nine micro-hybrid and ten flowable—were therefore considered. Flexural strength, flexural modulus (E_flexural), indentation modulus, Vickers hardness (HV) and creep were measured after the samples had been stored in water for 24 h at 37°C. Differences within the materials as well as within material categories were statistically analysed using one-way ANOVA with Tukey HSD post hoc test (α?=?0.05) as well as partial eta-square statistics.

Results

The category of micro- and nano-hybrid RBCs performed in all properties superior compared to the flowable RBCs. The former two categories differ significantly only with regard to three parameters, with nano-hybrid RBCs showing higher HV respectively lower E_flexural and filler weight. The micro-mechanical parameters proved to be more sensitive to differences in filler amount and RBCs type than the macro-mechanical properties.

Clinical relevance

Only few differences were found between nano-hybrid and micro-hybrid RBCs as a material category and thus, from laboratory tests, no clear advantages in the mechanical stability in stress-bearing areas of nano-hybrid RBCs are expected clinically. Similar is valid for materials with new monomer formulation or photo-polymerization initiator technology. However, several of the measured nano-hybrid RBCs showed consistently higher mechanical properties than the mean values of the micro-hybrid RBCs.     

Investigations of stomatologic lighting equipment

12 types of stomatologic lighting equipment were investigated with regard to their specific luminous intensity. The examination of the thermal radiation of the lighting equipment included subjective evaluations. Conclusions were drawn in order to improve the lighting.     

髁突骨折498例临床分析

目的:对本院1984-2003年20a间498名髁突骨折患者进行临床流行病学回顾性研究。方法:研究20年 间498名髁突骨折患者年龄、性别、致伤原因、骨折特点以及合并损伤情况。结果:髁突骨折男性多于女性,发病 年龄高峰为21-30岁,原因以交通事故居多,占47.99％。髁突颈部是最常见骨折部位,骨折片成角移位达56. 03％,下颌骨颏部是伴发髁突骨折最常见的部位。结论:髁突骨折中男性好发,交通事故是首要原因,髁突颈部最 易发生骨折。     

Epidemiologic study of joined primary teeth in Finnish children

The frequency of geminated and fused primary teeth was studied in a sample of 1141 Finnish children aged 3-4 years. The prevalence was 0.7%. All the joined teeth were found in the anterior area of the mouth. In seven cases the diagnosis was a fusion of two separate teeth, and in one case it was a gemination of a single tooth. A correlation between joined teeth in primary dentition and numerical variations of teeth in permanent dentition was noted in three cases.