Mehdi Birjandi; Mohammad Salehi-Marzijarani; Seyyed Mohammad Taghi Ayatollahi; Houshang Rashidi; Ali Hosseinzadeh
Volume 23, Issue 3 , July and August 2016, , Pages 468-477
Abstract
Background Oral diseases are common in many communities and dental caries is the most prevalent disease among children and adults. DMFT (Decayed Missed Filled Teeth) is one of the useful indexes in dental epidemiology. This study aimed to investigate caries epidemiology among students and compare several ...
Read More
Background Oral diseases are common in many communities and dental caries is the most prevalent disease among children and adults. DMFT (Decayed Missed Filled Teeth) is one of the useful indexes in dental epidemiology. This study aimed to investigate caries epidemiology among students and compare several modeling of DMFT based on real data.Materials & Methods This cross-sectional study was conducted on school children aged 7-12 years in Khoramabad City, Iran during 2010 to 2011. A total of 920 samples were recruited by multistage random sampling method. Regarding to countable data, right skewness and zero inflated variable of DMFT index, different models such as Poisson regression, negative-binomial regression, and zero-inflated Poisson regression were used for modeling, and the selection of the best model was based on the minimum amount of AIC and BIC. Data analysis was performed using Stata version 12, according to significant level of 5%.Results In this study, 43% of school children were girls and the rest were boys, so that their Mean±SD age and DMFT were 9.02±1.49 years and 1.02±1.35, respectively. A total of 528 (out of 920) children had dental caries. Zero-inflated Poisson regression, comparing with other models, was of the best model for goodness of fit among the fitted models. This model revealed significant relationships between being at risk of dental caries and variables of age, father’s educational level, and presence of microbial plaque (P<0.05). Severity of dental caries intensified significantly as children’s ages increased (P<0.05).Conclusion The best regression method for modeling DMFT among all models in this study was zero-inflated Poisson regression. Age, father’s educational level, and presence of microbial plaque were significantly correlated with children’s dental caries.
Mohammad-Mehdi Yaghoti-Khorasani; Sasha sadat Sajjadi; Sepideh Asar
Volume 22, Issue 5 , November and December 2015, , Pages 724-731
Abstract
Background & Objectives: The first maxillary and mandibular permanent molar teeth are the first teeth that erupt behind primary dentition. So they maybe decayed because of carelessness. Caries of these teeth can extend to the pulphorn and result pulp and periapical diseases. The purpose of this study ...
Read More
Background & Objectives: The first maxillary and mandibular permanent molar teeth are the first teeth that erupt behind primary dentition. So they maybe decayed because of carelessness. Caries of these teeth can extend to the pulphorn and result pulp and periapical diseases. The purpose of this study is to assess the need for first molar root canal therapy in school children of 8 to11years old in Rafsanjan in 2013. Materials & Methods: In this descriptive study, 450 students of 8-11years (210 girls and 240 boys) were selected in Rafsanjan schools in 2013, using a random cluster sampling method. We examined their maxillary and mandibular first molars with a mirror and an explorer.We used SPSS version 17 and Chi-square and Mann-Whitney tests for statistical analysis. P< 0.05 was considered as significant. Results: In 57 students (12.66%) there was an indication for endodontic treatment of the first molars. The need for endodontic therapy was significantly related to the subjects' age (p=0<001), fathers' education level (p=0.046), mother's education level (p=0.005) and father's job (p=0.001). Conclusion: Age, gender, parent's eduction level and job are important and influencing factors in necessity of first molar root canal therapy in 8- to 11-year-old school children.