Rahena Akhter

Reasons for Permanent Tooth Extractions in Japan

BACKGROUND There has been no nationwide study in Japan on reasons for extraction of permanent teeth. This survey was aimed to determine the reasons for extraction of permanent teeth in Japan. METHODS Five thousand, one hudred and thirty-one dentists were selected by systematic selection from the 2004 membership directory of the Japan Dental Association. The dentists selected were asked to record the reason for each extraction of permanent teeth during a period of one week from February 1 through 7, 2005. Reasons for tooth extraction were assigned to five groups: caries, fracture of teeth weakened by caries or endodontics, periodontal diseases, orthodontics, and other reasons. RESULTS A total of 2,001 dentists (response rate of 39.1%) returned the questionnaires, and information on 9,115 extracted teeth from 7,499 patients was obtained. The results showed that caries and its sequela (totally 43.3%, 32.7% and 10.6%, respectively) and periodontal disease (41.8%) were the main reasons for teeth extraction. Extraction due to caries or fracture was commonly observed in all age groups over 15 years of age, whereas periodontal disease was predominant in the groups over 45 years of age. CONCLUSIONS Most of the permanent teeth were extracted due to caries and its sequela and periodontal disease. Prevention and care for dental caries for all age groups and periodontal disease for over middle age groups are required.

Correlations of noncarious cervical lesions and occlusal factors determined by using pressure-detecting sheet

OBJECTIVES The purpose of this clinical study was to examine the relationships of v-shaped noncarious cervical lesion (NCCL) formation with occlusal factors. METHODS A total of 159 male self-defense force officials with a mean age of 36.2 years participated in this study. All present teeth were examined for the presence and type of NCCL using the Tooth Wear Index (TWI). The subjects were then interviewed about bruxing and toothbrushing habit. Finally, occlusal force, occlusal contact area and average pressure were measured using a pressure-detecting sheet. Subject-level logistic regression was carried out to assess the associations of factors with presence of v-shaped NCCL teeth. Subjects without v-shaped NCCL were designated as control subjects. RESULTS Totally, 4518 teeth were examined. Seventy-eight subjects (49.1%) had one or more teeth with typical v-shaped NCCL (259 teeth). The number of teeth with v-shaped NCCL of grade 2 (defect less than 1mm in depth) was 195 (4.3%), and the number of teeth with v-shaped NCCL of grade 3 (defect 1-2mm in depth) was 54 (1.2%). The prevalence of teeth with v-shaped NCCL was significantly higher in the maxilla than in the mandible. Most of the NCCL teeth were premolars. There was no significant difference between teeth with NCCL on the right side and those on the left side. Subject-level logistic regression analysis revealed that age (OR=1.11), toothbrushing pressure (400g, OR=2.43) and occlusal contact area (>23.0mm(2), OR=4.15) were associated with the presence of NCCL teeth. CONCLUSIONS It is concluded that aging, toothbrushing pressure and occlusal contact area are associated with the presence of NCCLs.

Presence of dominant negative mutation of TP53 is a risk of early recurrence in oral cancer

Genetic alteration of p53 is a significant determining factor in the carcinogenesis. The loss of function, mutant p53 can possess a dominant negative effect on wild-type p53 and may also exert gain-of-function activity. It is, however, not clear how p53 functional status due to various types of mutation results in outcome of patients with oral cancer. A total of 60 oral SCC samples were subjected to yeast functional assay that screens human p53 function in yeast, and sequencing for determination of p53 mutations. The detected mutants were further investigated for their dominant negative activity using a yeast-based transdominance assay that tests dominant negative activity of a mutant p53 over wild-type p53 by coexpressing the mutant and wild-type p53 in a yeast transcriptional reporter system. p53 mutation was found in 42 out of 60 of which 10 (24%) exhibited dominant negative activity and 32 (76%) without dominant activity (recessive mutation). The remaining 18 (30%) were considered to have wild-type p53. The patients with dominant negative mutation had significantly shorter disease-free survival than patients with no mutation (log-rank test, p<0.001) and those with a recessive mutation (p<0.016). There were slight significant differences in disease-free survival were found between the patients with tumours harbouring a recessive p53 mutation and those with tumours harbouring a wild-type p53 (p<0.038). The presence and absence of a dominant negative p53 mutation may thus provide a predictor of early recurrence in oral SCC patients.

Relationship between folic acid intake and gingival health in non-smoking adults in Japan

OBJECTIVE To assess the relationship between dietary intake of folate and gingival bleeding in non-smoking adults in Japan. MATERIALS AND METHODS Data were obtained from residents who participated in the regional nutrition survey and survey of dental diseases conducted by the administrative office of northernmost prefecture of Japan. Dietitians visited households to collect data on dietary intake. Clinical parameters, including Community Periodontal Index (CPI) and bleeding on probing (BOP), were examined in community centers. Information on smoking habit was obtained from the interview. Then the data from 497 non-smoking adults with 20 teeth or more, aged 18 years or older, were analyzed. The relationship between dietary intake of folic acid and gingival bleeding status was estimated using multivariate analysis. RESULTS Pearsons correlation coefficient showed a significant negative correlation between dietary folate level and bleeding on probing. The negative association between folate level and bleeding on probing remained statistically significant in multiple regression analysis (standardized beta = -0.204, P < 0.001). However, no significant association was found between CPI scores and folate intake level. CONCLUSIONS The results suggest that dietary intake of folic acid, an important indicator of gingival bleeding in adults, may provide an important clinical target for intervention to promote gingival health.

Relationship between periodontal status and physical fitness in an elderly population of nonsmokers in Bangladesh.

ACKNOWLEDGMENTS Conflict of Interest: The editor in chief has reviewed the conflict of interest checklist provided by the authors and has determined that the authors have no financial or any other kind of personal conflicts with this letter. This study was sponsored by the Conselho Nacional de Desenvolvimento Cientı́fico e Tecnológico (CNPq), Brazil (process no. 4708412004-4). Author Contributions: M. Fernanda Lima-Costa: study conceptualization and design, acquisition of subjects and data, analysis and interpretation of data, preparation of manuscript. Sergio V. Peixoto: study conceptualization, analysis, interpretation of data, and preparation of manuscript. Maristela Taufer and Emilio H. Moriguchi: ApoE genotyping and preparation of manuscript. Sponsor’s Role: The sponsor had no influence on the design, methods, subject recruitment, data collection, analysis, or preparation of the letter.