Behnam Mirzakouchaki; Shirin Shahrbaf; S. Naghinejad Ahmadi
Abstract
Background and aim: Adjusting the retention of orthodontic appliances and the patient’s comfort are important factors for the efficacy of orthodontic treatment using removable appliances. The aim of the present study was to introduce a new technique for adjusting Adams clasp, which is the most ...
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Background and aim: Adjusting the retention of orthodontic appliances and the patient’s comfort are important factors for the efficacy of orthodontic treatment using removable appliances. The aim of the present study was to introduce a new technique for adjusting Adams clasp, which is the most important component involved in the retention of removable appliances, to provide greater retention and patient comfort. Materials and methods: The subjects in the present study consisted of 45 patients referring to the Department of Orthodontics. Four removable maxillary plates were fabricated for each patient. One plate was adjusted from the area of both Adams clasps at overhead areas in the conventional technique. In the three remaining plates, the Adams clasp was bent in the middle area of the bridge under three vertical angles of 8, 15 and 20 degrees. The plates were placed in each patient’s mouth and the retention, overbite change and patient pain scores were determined. Results: The adjustment under a vertical bend of 15° in the middle area of the bridge resulted in maximum retention, followed by 8°, 20° and zero degree (the conventional technique). There were no significantly differences in the mean overbite change values between the four study groups. In addition, mean pain scores did not exhibit significant differences between the four study groups. Conclusion: By creating a bend of 15° in the vertical direction in the bridge area of Adams clasp, the tip of the overheads moved 2 mm toward each other based on trigonometry principles, resulting in maximum retention without increasing patient discomfort.
Seyed Mohammadreza Safavi; Mehdi Ravadgar; Fatemeh Mashhadiabbas; D. Sharifi; Alireza Akbarzadeh Baghban
Abstract
Background and aims: To evaluate the frequency of ankylosis, loss of pulp vitality and external root resorption after intentional root contact with mini-screw.Methods: Sixty maxillary and mandibular second, third, and fourth premolars teeth of five mature beagle dogs were randomly assigned into three ...
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Background and aims: To evaluate the frequency of ankylosis, loss of pulp vitality and external root resorption after intentional root contact with mini-screw.Methods: Sixty maxillary and mandibular second, third, and fourth premolars teeth of five mature beagle dogs were randomly assigned into three experimental groups. Premolars teeth at group I, received a mini-screw (6-mm length, 1.5mm diameter, self drilling) which was removed immediately after contact with the root. Group II consisted of teeth that received mini-screw and the screw left in situ for 15 weeks. In group III once contact was made with mini-screw, the teeth were shifted away from the screw with brackets and Titanium closed coil spring tightened to another bonded orthodontic brackets on the neighbor teeth. Group IV was the control group. The specimens were decalcified, stained and evaluated histologically to determine the presence/absence of root resorption, ankylosis and tooth vitality.Results: There were no signs of ankylosis, root resorption, moderate to severe inflammation or necrosis within the pulp in any experimental group.Conclusions: Ankylosis, pulp necrosis and sever root resorption are not common clinical outcomes when mini-screw contacts the root. Repair after contact with mini-screw depends on the severity of invasion. More severe invasion needs further time necessary for repair.
Shahrzad Tamasoki; Amirfarhang Miresmaeili; Masome BasamTabar; S. Fazlollahi; Mojgan Akbarzadeh
Abstract
Background and aim: The etiology of CL/P is thought to be multifactorial with both genetic and environmental factors. Methylentetrahydrofolatereductuse (MTHFR), an important enzyme in folic acid metabolism with C677T polymorphism is one of the most controversial enzyme in CL/P. Our aim was comparison ...
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Background and aim: The etiology of CL/P is thought to be multifactorial with both genetic and environmental factors. Methylentetrahydrofolatereductuse (MTHFR), an important enzyme in folic acid metabolism with C677T polymorphism is one of the most controversial enzyme in CL/P. Our aim was comparison of MTHFR C677T polymorphism in non syndromic CL/P patients with their healthy relatives.Materials and methods: We examined 50 consecutive CL/P patients and 150 their relatives (father, mother and sibling). Blood samples of all cases were collected. DNA extracted using Millers salting out method, and then C677T of MTHFR gene was evaluated by PCR. The results were analysis by Mc-Nemar test with spss19. Results: The frequency of genotype in patients compared with their mother (p= 0.282), father (p= 0.423) and sibling (p=0.607) and we didn’t find significant different between them. Also there was no significant difference between patient’s allele frequency when compared with their mother (p=1.000), father (p=0.405) and sibling (p= 0.804).
Conclusion: In this case-control study, patient’s parents and sibling were used as controls. Frequency of normal allele C677T(C) was higher than altered allele (T) in patients and control groups. We did not find any relation between NSCL/P and C677T polymorphism however; conflicting results have been achieved in different studies.
M. Saharkhizan; Farzad Mojarad; S. Salimonnafs
Abstract
Background and aim: The aim of the present study was to determine the timing of eruption of permanent teeth and assess its association with the height and weight in 12-year-old female students in Hamadan (2004). Materials and method: This descriptive/cross-sectional study was conducted from September ...
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Background and aim: The aim of the present study was to determine the timing of eruption of permanent teeth and assess its association with the height and weight in 12-year-old female students in Hamadan (2004). Materials and method: This descriptive/cross-sectional study was conducted from September 2003 to April 2004. 1000 healthy female students were consecutively selected from 9 different secondary schools in Hamadan. Each student’s data was recorded in the relevant questionnaire. Measuring their height, weight and date of birth were also obtained. The height was measured in centimeter, using wall-mounted ruler on the child’s head with their back and knees completely straight, and their feet together. The weight was measured in kilogram using a commercial digital scale after removal of the shoes only. The date of birth was obtained from the school records. The dental examination was carried out using a tongue depressor under natural light for the selected child. The mean and standard deviation of tooth eruption time was estimated for all of the girls. Bivariate analysis was used to assess any significant association between tooth eruption time and demographic variables. Pearson and partial correlations were used to determine the significant relationship between tooth eruption times with height/weight.Results: Generally, the means of height and weight of the subjects were 152 cm and 43.3 kg, respectively. The mean number of erupted teeth was 25.35. In partial correlation analysis, mean tooth eruption times were positively, but not significantly associated with height while controlling for weight, On the other hand, mean tooth eruption times were positively associated with weight while controlling for height. The correlation coefficients between height and weight and the number of erupted teeth were 0.321 and 0.25, respectively, indicating a weak correlation but significant at a level of 0.01.Conclusions: It can be concluded that girls with a higher height and weight compared to their peers had more erupted teeth. Although the height and of weight the girls did not show any significant influence on the tooth eruption times.
Zohreh Hedayati; Abdolaziz Haghnegahdar; Ashkan Bagheri
Abstract
Background and Aim: Age estimation may be needed to plan treatment procedures in pedodontic, and orthodontics. Third molar is the last and most variable tooth to develop and may be used for age estimation in adulthood. The purpose of this study was to investigate relationship between chronological age ...
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Background and Aim: Age estimation may be needed to plan treatment procedures in pedodontic, and orthodontics. Third molar is the last and most variable tooth to develop and may be used for age estimation in adulthood. The purpose of this study was to investigate relationship between chronological age and developmental stages of the mandibular third molar in a population of south Iran.Method: The Demirjian’s classification system was used to evaluate the developmental status of the mandibular third molars on the 500 panoramic radiographs of orthodontic patients. The age range of patients was 12 to 20 years. Mean and Standard deviations of Chronological age for each developmental stages were calculated. One-way ANOVA and post-hoc Tuckey HSD test were used to compare the mean age and developmental stages of molar teeth. The age differences in the developmental stages between the genders was assessed. Correlation between calcification stages of the third molars and age was determined.Results: Crown calcification was completed at the mean age of 13.8 years, and root formation without apex closure was observed at the mean age of 17.5 years. At a mean age of 18.4 years apex closure was occurred. Males were advanced in the most of stages of calcification. A strong correlation between developmental stages of the lower third molars and chronological age was found in both genders.Conclusion: The present investigation could provide reference data for third molar development in our population. Developmental stages of mandibular third molars showed a strong correlation with age. The lower third molars developed earlier in males than females.
Ahmad Sodagar; E. Sanaeie; Tahereh HosseinZadehNik; sedigheh SheikhZadeh
Abstract
Background and aim: With the hypothesis that there is an interrelation between the cephalometric characteristics and difference in the arch widths, the aim of this study was to evaluate the relationship between the dental and skeletal features.Materials and methods: Lateral cephalograms and dental casts ...
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Background and aim: With the hypothesis that there is an interrelation between the cephalometric characteristics and difference in the arch widths, the aim of this study was to evaluate the relationship between the dental and skeletal features.Materials and methods: Lateral cephalograms and dental casts of 42 untreated cl II div 1 patients with excessive vertical growth were evaluated for arch widths and cephalometric parameters. Student t -test was used to evaluate the difference of variables with normal distributions and Mann-Whitney as the nonparametric equivalent of t-test.Results: Maxillary arch width in class II div1 subjects is narrower than normal groups in both genders and mandibular arch width is the same as normal group in females and smaller in males. In females, a moderate to high relationship was seen between cephalometric parameters and arch widths.Conclusion: The existence of relationship between craniofacial dimensions and arch widths should be mentioned in treatment planning to prevent unwanted side effects and relapse.
Saeid Sadeghian; Meysam Mahabadi; H. Saadat Hosseini; B. Sabagh
Abstract
Background and aim: Laser ablation as an alternative method for etching porcelain has been proposed. However,previous studies have reported contrasting results. This study is designed to investigate techniques that could obtain maximum bond strength and also modes of their fracture.Materials and method: ...
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Background and aim: Laser ablation as an alternative method for etching porcelain has been proposed. However,previous studies have reported contrasting results. This study is designed to investigate techniques that could obtain maximum bond strength and also modes of their fracture.Materials and method: Fifty samples of porcelain fused to metal according to surface preparation were divided into five groups: 1.HF acid(9.6%) 2. HF acid+ silane 3. Co2 laser (2w, 30 s) 4. Co2 laser+silane 5.removing the glazed layer with diamond bur (controls). After bonding orthodontic brackets and thermocycling process, the shear bond strength (SBS) measured with Instron. Results analyzed by one way ANOVA and Least Significant Difference (p < 0.001). pattern of debonding was investigated with light microscope and results were analyzed by Kruskall wallis and Mann-whitney (p < 0.001).Results: results showed bond strength of Co2 laser (2 w) was clinically high although it was lower than HF acid samples, with better mode of fracture.Conclusion: HF acid in combination with silane showed the highest shear bond strength value while irradiation of grouped pulse Co2 laser for 30 s in combination with silane could be an alternative for HF acid etching.
Hossein Aghili; M.H Toode Zaeim; Mahdjoube Goldani moghadam; M.K. Jafari; A. Hedayati Fard; K. Guya
Abstract
Background and aim: The aim of this study was determining the prevalence of malocclusion amongst the male adolescents of Yazd province and comparing the results with that of other provinces of Iran. Materials and methods: The sample of this epidemiologic study consisted of 1980 male students with ...
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Background and aim: The aim of this study was determining the prevalence of malocclusion amongst the male adolescents of Yazd province and comparing the results with that of other provinces of Iran. Materials and methods: The sample of this epidemiologic study consisted of 1980 male students with age range of 14-17. The prevalence of class I, II, and III malocclusion according to the Angle’s classification was determined. Prevalence of Overbite, overjet, crowding and posterior crossbite was evaluated as well.Results: The prevalence of class I, II, and III malocclusion was 50.7, 19.5, and 16.6 percent respectively and normal occlusion was observed in 13.2% of cases. 47 percent of cases had normal overbite. Increased, reduced and edge to edge overbite was seen in 24, 11.9, and 13.1 percent respectively, and 4% had anterior open bite. Overjet was positive in 74.4% and negative in 12.4% of individuals. Prevalence of crowding and posterior crossbite was 40.5% and 10.5% respectively.
Conclusion: Class I malocclusion was the most common occlusal relationship in all of investigations done in different geographic districts of Iran. Clinical significance: Determining malocclusion prevalence in each population is prerequisite of making macro policy in health care systems, this study provides information about prevalence of malocclusion in Yazd province and comparing it with that of other geographical districts of Iran.
