A genetic and epidemiologic study of periodontal disease in Hawaii

Using a modification of the Ramfjord procedure, 939 individuals aged 14 years or above of six racial groups were examined for periodontal disease to study the effects of genetic and epidemiologic factors with special emphasis on inbreeding and race. Other factors studied included sex, age, years of education, frequency of toothbrushing, smoking, tooth malalignment, and medical history.
Among six racial groups, two distinct clusters were discernible even when relevant concomitant variables including years of education and oral hygiene practice were adjusted for. Caucasians, Japanese, and ≪Others≫ had clearly higher levels of periodontal health status than Hawaiians or part-Hawaiians, Samoans, and Filipinos. The difference in Samoans and Filipinos may be explained in part by cultural and socioeconomic factors associated with their recent immigration to Hawaii. Inbreeding was not related to any indicator of periodontal disease showing inconsistency with the hypothesis of significant role of recessive genes in the etiology of the disease.
Smoking was found to have adverse effect on periodontal health status, whereas no clear-cut association was noted with tooth malalignment. The principal component analysis on eight periodontal disease variables led to the extraction of two major factors, destructive periodontal disease and plaque accumulation.     

A clinical epidemiologic analysis of a sample of 73 supernumerary premolars

BackgroundThe authors conducted a retrospective study to determine the prevalence of supernumerary premolars in sample of patients from Madrid, as well as the possible complications associated with the presence of such supernumerary premolars.MethodsThe study included a data assessment of all patients seeking dental care at a hospital&;apos;s department of oral surgery across four years. The authors studied data from patients who had supernumerary premolars.ResultsThe authors identified supernumerary premolars in the records of 43 patients (0.32 percent) of the total population studied. These patients had 73 hyperdontic premolars (65 mandibular premolars [89 percent] and eight maxillary premolars [11 percent]).ConclusionsSupernumerary premolars usually are diagnosed as a coincidental radiographic finding without an associated pathology. However, the authors found a higher percentage of comorbidity than they initially expected.Clinical ImplicationsMechanical or obstructive pathology was associated with 2.7 percent of the premolars, and enlargement of the follicular sac of more than 3 millimeters was present in 26.0 percent of the sample.     

Spaced dentition. An epidemiologic study

This epidemiologic study deals with the incidence of spaced dentition in 1279 students between the ages of 12 and 18 years. The sample includes only those with a full complement of permanent teeth (third molars were not considered) and with no apparent etiological conditions that might lead to disruption of dental arch continuity. The sample was evenly divided by age and sex. Frequency of spaced dentition was high, occurring in 51.8% of males and in 45.5% of females. Prevalence was less in higher age groups, and the sexual dimorphism that was significant in the 14 YR-16 YR group was not found in the 16 YR-18 YR group. The mean number of spaces per subject was 6 +/- 4.3 for males and 5 +/- 3.7 for females, again displaying diminishing incidence with age and a concomitant absence of the sexual dimorphism in the highest age group. Spaces were found in both arches in 49.5% of the spaced dentitions, and in only the maxillary arch in 34.3%. Incidence of spacing in the mandibular arch alone was only 16.2%. In most subjects the spaces were distributed equally between the two quadrants of each arch. The most common sites and largest space widths in either dental arch were found between cuspids and the first bicuspids and between cuspids and lateral incisors.     

Oral cancer in India: an epidemiologic and clinical review

This article reviews the epidemiologic and clinical aspects of oral cancer in India, where the disease ranks number one among all cancers in male patients and number three among cancers in female patients. Causal association between oral cancer and the chewing of betel quids containing tobacco leaves or stem and other tobacco habits has been extensively studied. But there is need for more in-depth studies on the role of alcohol, diet, and oral hygiene practices in India. The exciting opportunity provided by the well-established oral precancerous lesions for intervention and early detection programs is also discussed. The peak age frequency of occurrence is at least a decade earlier than that described in Western literature. Sex ratio reveals a 2:1 preponderance of male patients. Only 10% to 15% of cases present in localized stages. The poor survival revealed by existing studies is mainly due to the overwhelming proportion of advanced cases. The excellent opportunity for more research and efforts in prevention and control of oral cancer in India is highlighted in this review.     

Alveolar arch dimensions and occlusal traits. An epidemiologic study

A statistical evaluation of dentoalveolar relationships in a cross-section of young Finnish adults, finding little relationship between occlusal anomalies and dimensions of the alveolar arches.     

Comparative epidemiologic study of caries in German and Hungarian adolescents

The aim of the study was to assess the trend of caries prevalence in German and Hungarian population sample. The authors examined 15-16-year-old Hungarian adolescents in Debrecen and Budapest in 1997 (451 persons), then re-examined them in 1999 (377 persons). These data were compared to those of 15-16 and 17-18-year-old adolescents examined in the Eastern part of Germany (Plauen) in 1991 (668 persons) and in 1995 (586 persons). The results showed significant caries reduction in Germany. The DMFT values of 17-18-year-old adolescents were nearly half in Germany (x = 5.2) compared to those of Hungary (x = 9.0). This fact suggests the necessity of introduction of effective preventive programs including salt fluoridation in Hungary.     

Infraocclusion of primary molars: an epidemiologic and familial study

Abstract The prevalence of infraocclusion of primary molars was studied in 1059 Swedish children aged 3–12 years with an even distribution between the age groups. No extractions were performed due to infraocclusion. 94 children (8.9%) showed infraocclusion of primary molars Infraocclusion was found from 3 years of age. The prevalence varied between age groups, with a maximum of 14.3% in 8-and 9-year-old children and a minimum of 1.9% in 12-year-old children 49 children had a single tooth in infraocclusion. The primary mandibular molars were affected more than 10 times as often as the maxillary. The prevalence of infraocclusion of primary mandibular first molars rose to a maximum at 8 years. The prevalence of infraocclusion of the primary mandibular second molar showed a similar patten but with a 1–2-year delay, up to a maximum in 9-year-old children. After this age the mandibular second molar was the tooth most commonly found in infraocclusion. In a study of 138 3–12-year-old siblings of 109 children with infraocclusion the prevalence of infraocclusion was found to be 18.1 %. When compared with the frequency in the total material (8.9%), the difference proved to be significant, supporting the hypothesis that there is a familial tendency in infraocclusion of primary molars. The mode of inheritance is discussed and it is concluded that the most likely explanation is that the condition is inherited on a multifactorial basis.     

Important considerations for designing and reporting epidemiologic and clinical studies in dental traumatology

Abstract – The purpose of this article is to suggest important considerations for epidemiologic and clinical studies in the field of dental traumatology. The article is based on the authors’ experiences from research in this field and editorial board work for the scientific journal Dental Traumatology. Examples are given of issues where development is important. The importance of planning ahead of the study and consulting with experts in other fields is emphasized.     

应用CAD/CAM技术进行个体化下颌骨重建

目的:探讨计算机辅助设计和制造技术(CAD/CAM)应用于下颌骨肿瘤切除术后骨缺损的个体化修复重建。方法:选择面部畸形明显的单侧下颌骨成釉细胞瘤4例,术前行下颌骨螺旋CT扫描,三维重建成像,用CAD/CAM数控技术和镜像技术,制成与患者骨组织完全相同的个体化实体模型,根据模型预弯制重建钛板。手术切除病灶下颌骨,切取髂骨节段,植于重建板的舌侧,固定重建板于正常下颌骨端。结果:CT三维重建影像与实体模型测量数据接近;预弯制钛重建板与下颌骨匹配;手术恢复了下颌骨的连续性和功能,面部外形对称,X线片显示重建的下颌骨高度和厚度适中。结论:CAD/CAM技术为术前设计提供了个体化实体模型,提高了手术的精确性,节省了手术时间,降低了手术并发症。     

A long-term epidemiologic study of the relationship between occlusal factors and mandibular dysfunction in children and adolescents

A longitudinal investigation of changes of signs and symptoms of mandibular dysfunction over four to five years was performed, by means of questionnaires and clinical examination, in 240 children, ages 7, 11, and 15 years at the first examination. The objective of this part of the study was to analyze correlations between some occlusal and other factors, and mandibular dysfunction. Signs and symptoms of mandibular dysfunction increased slightly in both frequency and severity but were judged to be mild in most cases. Several types of occlusal interference were frequently recorded at both examinations. Dental wear increased during the follow-up period, while the results of evaluations of motor activity and psychological traits were relatively constant. There were only a few significant correlations, most of which were weak, between the recorded variables and mandibular dysfunction, and those found were not consistent in all age groups. TMJ sounds were positively correlated with lateral deviation of the mandible between retruded contact and intercuspal position in all age groups. An attempt to analyze the longitudinal relationship of occlusal interference with signs and symptoms of mandibular dysfunction did not reveal any strong correlations. The results are interpreted as supporting the heterogeneous and multifactorial nature of functional disturbances of the masticatory system.     

Comparative study of plaque and gingivitis prevention by AmF/SnF2 and NaF A clinical and microbiological 9-month study

Abstract This comparative clinical 9-month study was designed to examine the efficacy of amine/stannous fluoride (AmF/SnF₂) (Meridol®) and sodium fluoride (NaF I. 150 probands with chronic gingivitis or early signs of periodontitis were divided into? randomised groups. Group 1 was given a NaF toothpaste and an NaF mouthrinse. group 2 AmF/SnF; toothpaste and moulhrinse, and group 3 AmF'SnF; toothpaste and NaF mouthrinse. The probands were examined at intervals (0. 1. 3 and 9 months) under conditions of a clinical double-blind study. The parameters recorded were the plaque index (PII). the approxinal plaque index (API), the gingival index (GI) and the mod. sulcus bleeding index (SBI). The probing depths IPD) were also measured. The composition of the supragingival plaque was evaluated by dark-field microscopy, A highly significant reduction in all clinical parameters was recorded in all 3 groups in the course of the study. The most pronounced reduction in PH. API. SB1 and PD was recorded in group 2. In the group comparison, however, no significant differences were recorded. Microbiological examination revealed a highly significant increase in cocci and a decrease in rods in all 3 groups. There was also a significant reduction in spirochetes. filaments and fusiforms in groups 2 and 3. In group 1, there was a significant fall only in fusiforms and small spirochetes, Overall, no significant difference in clinical parameters was recorded in the group comparison. However, the use of AmF/SnF₂ toothpaste and mouihrinse (group 21 and. to a lesser degree, the combined use of AmF/SnFi toothpaste and NaF mouthrinse display a favorable microbiological effect. The results from the present double-blind study reveal a reduction in gingival inflammation and supragingival plaque accumulation with a positive change in plaque flora in all groups. The reduction in potentially gingivopathogenic bacteria was slightly higher in the amine/stannous fluoride group.