Mesh diagram software programming and norm calculations for Iranian adolescences [Qazvin, Mashhad]

Nowadays, taking lateral cephalograms in natural head position is recommended however, the radiographic norms vary in different populations. Performance of cephalometric analysis has become much easier and more accurate using computer software. The aim of present study was to program software for Mesh analysis and constructing two normal Mesh templates for cities of Qazvin and Mashhad. This was a descriptive study in which the Mesh analysis software was programmed by means of Microsoft visual C++ based on Windows XP using My-SQL as database. The samples were NHP cephalograms from 11 to 13 years old adolescence with normal occlusion including 37 [21 girls and 16 boys] in the city of Qazvin and 65 [32 girls and 33 boys] in the city of Mashhad. The cephalograms were scanned and 4 Mesh templates constructed for each gender in each of two cities using Moorees method. The dimensions of each of the 34 landmarks of each template were statistically compared with each other by means of t- test in both boys and girls, separately. Among girls, 38 measures out of 68 [17 width and 21 height] and in boys 20 measures out of 68 [8 width and 12 height] indicated significant statistical differences between two cities. In addition to sex, age, and the dimensions of SN and N-ANS, the ethnical origin of patients should be considered when dentoskeletal analysis of abnormalities is performed

[Evaluation of load-deflection rate changes of nickel-titanium wire after single clinical application in three different crowdings]

Desired mechanical properties of nickel-titanium wires have resulted in some orthodontists to recycle these wires and apply them repeatedly. The aim of this study was to evaluate load-deflection changes of nickel-titanium wires after single clinical application in three different types of crowding. 80 nickel-titanium wires [Global trade mark] with 0.014 inch diameter were randomly divided into four groups as: control, mild, moderate and severe crowding. Wires were used in patients for a period of 6 +/- 1 weeks Then, load-deflection experiment, using Zwick machine was done. Data were analyzed by Hottelling, Fisher's exact and Duncan tests. Hottelling analysis showed a significant difference between the groups. Fisher's exact test showed that there was a significant difference between forces at 0.5, 1.0, 1.5, 2, 2.5 mm deflection loading and unloading but there was no significant difference in 3 mm loading deflection. This study showed that although single application of nickel-titanium wire [at least for the wire used in this study] for one orthodontic visit causes significant decrease in force levels in different types of crowding, residual force after single clinical application is still enough for repeated clinical application

[Lip position and arch width changes in class I patients after orthodontic treatment with four premolars extracted]

Tooth extraction is one of the most controversial subjects in orthodontics due to its inevitable effects on facial esthetics, and smile characteristics. The aim of this study was to evaluate lip position in relation to S-line and Snpog', Merrifield Z angle, as evaluating well as upper and lower arch widths in canine, premolar, and molar regions following four premolar extraction in class I malocclusion patients. Pre and post lateral cephalograms and dental casts of 47 class one malocclusion patients including 43 girls and four boys with the mean age of 12.7 +/- 1.86, treated by the same practitioner were used in this study. All patients had four first premolar extraction, and orthodontic treatment was performed with 0.22 slot standard edgewise appliance. Convenient improbable sampling was used in this cross sectional study. The distance of the most prominent points of lips from S-line and Sn-Pog', and Z-angle values were measured on lateral cephalograms. Upper and lower arch widths in canine, premolar and molar regions were also measured by a digital caliper on dental casts before and after treatment. To compare the changes, paired t-test with 0.05 significance level was used. Following orthodontic treatment with four premolar extraction, dental arch widths in upper and lower arch increased in canine region [p<0.001], but it was decreased in premolar and molar regions significantly [p<0.001]. It was also observed that, the lips were retracted significantly with reference to S-line and Sn-Pog' [p<0.001], and Z-angle was also increased [p<0.05]. Orthodontic treatment with four first premolar extractions in class one malocclusion patients resulted in: 1. Increase in upper and lower arch width in anterior region, and decrease in posterior region. This means that, first premolars extraction in Class one malocclusions does not increase buccal corridor width, and consequently have no adverse effects on smile esthetics. 2. More posterior position of the lips related to S-line and Sn-Pog' as well as increase in Zangle leading to more straight profiles in patients

Cephalometric norms in 12 old year Mashhad children with normal occlusion

Each group or nation should have its own cephalometric norms to be used in diagnosing and treatment planning of their malocclusions. There was no cephalometric norm available for Mashhad children and we had to use other nations' norms available in textbooks. The aim of this study was to determine the cephalometric norms of Mashhad children with normal occlusion to be used in diagnosis and treatment planning of orthodontic problems. This study was a cross-sectional and descriptive one done on 30 girls and 30 boys with normal occlusion. The mean age were 12 years, 4 months and 13 years, 4 months respectively by gender. The samples were selected randomly from 1940 guidance schools children of 4 different areas of Mashhad. These children and their parents were born there. Medical and dental histories, study casts and lateral cephalograms in natural head position were taken. Cephalograms were traced; SPSS software and Dahlberg formula were used, student T-test was done and results were extracted. The results of this investigation showed that in Mashhad children axial inclination of the lower anterior teeth is more prominent and the lower one-third of their facial height is more than northern European Caucasians. These variables are more in boys than in girls [P<0.05]. Regarding to the findings of this investigation which showed differences in dentofacial characteristics of Mashhad children in comparison northern European Caucasians, attention should be paid in diagnosis and treatment planning

[Evaluation of load-deflection rate of stainless-steel orthodontic wires available in Iran's commercial market]

Different behavior of stainless-steel wires manufactured by different companies is observed in clinical situations. The purpose of this study was to compare the load-deflection rate of a specific size of stainless-steel wire from different companies which are available in Iran,s commercial market. This comparison allows classification of these wires and also the wire with best characteristics will be clarified. This experimental study was carried on cross-sectional base. Round 0.016 inch stainless-steel wires from 9 different companies were used in this investigation. 14 wires from each company were chosen on random base. 14 Wires from each company were divided in two groups of 7, group A and B with 3 and 1.5mm deflection respectively. The tests were done using Zwick testing machine model Z250. Loading and Unloading forces of wires in predetermined distances were measured. The total of 126 tests were measured. Upon these measurements, the load-deflection curve was drown. Using SPSS software the one-way analysis of variance [ANOVA] was done and each wire from a company was compared to other companies using Tukey analysis. The load deflection curves obtained were similar to typical curve of stainless-steel wires. The one-way analysis of variance [ANOVA] showed that there was no significant difference between the wires belonged to group A in three different deflection, i.e. 2.5, 2, and 1.5mm at a level of 5%, but he difference between the wires belonged to group B in 1.5 mm deflection was significant [P<0.001]. In this study it was found out that among the 9 different wires, tested, the RMO wites produced the minimum force levels and Dentaurum wires produced the maximum force levels in both groups. This means that RMO wires had better tissue compatibility. Moreover, it was found out that even the wires made by the same factory did not have a similar behavior. Among the tested wires, the Ortho technology wires had minimum and the GAC ones had maximum similarity to each other

[Dentofacial characteristics of boys with Down syndrome living in the city of Mashhad]

The aim of this study was to determine the dentofacial characteristics of adolescents with Down syndrome and compare the results with the same characteristics in children with normal occlusion in Mashhad to be used in diagnosis and treatment planning of the above-mentioned patients. This study was cross-sectional, descriptive and was done on 29 boys mean age 11.9 years with Down syndrome selected randomly from Mashhad special schools for disabled children under a research project. Close examination of mouth was done, anthropometric measurements carried out, required records including photographs, study casts, OPG and lateral cephalograms in NHP were taken and evaluated. Statistical analyses using SPSS software and student t-test were done and compared to the data extracted on a study on 30 boys mean age 13.4 years with normal occlusion. It was found that in patients with Down syndrome palate was deeper, carries, missing teeth, spacing was more frequent, cephalic index and Bolton index was higher and frenum was longer and deeper than children with normal occlusion and the differences were statistically significant. Moreover it was found that in these patients, cross-bite, open-bite and class III malocclusion are more prevalent. With regarding to the findings of this investigation it can be concluded that there are significant differences between dentofacial characteristics of patients with Down syndrome comparing to the children with normal occlusion which need more attention when diagnosing and treatment planning of the above-mentioned patients

Prevalence of TMJ disorders among students and its relation to malocclusion

The main object of this study was to find out the correlation between types of malocclusion and temporomandibular joint [TMJ] disorders among students. This study was descriptive and cross-sectional In which 425 persons were examined. From this number, 308 persons were male, and 117 were female. All samples were students of Mashhad University of Medical and Dental Sciences. The range in age was 19 to 32 years with a mean of 26.1 years. Samples were selected randomly. SPSS soft ware was used and statistic evaluation was done. The correlation between malocclusion and TMJ discomfort at a level of ?=0.05 was not significant. The highest level of correlation existed between TMDs and Cl II malocclusion. The rate of TMJ discomfort in various types of malocclusion was respectively as follow: Cl II>CI I>CI III. The correlation between TMJ discomfort and head, neck and back pain was meaningful [P=0.0298]. The rate of women with TMJ discomfort to men was 1.6: 1. Most patients with TMJ discomfort complained of joint noises and a small number of them remarked symptoms such as pain, jaw opening limitation, and other symptoms of the disorder. Joint noises were mainly in the form of clicking. TMJ discomfort accompanied by gastric disorder [generally speaking] was meaningful [P=0.0214]. From this study it was concluded that there was no significant correlation between malocclusion and TMJ discomfort at a level of alpha=0.05 among students. The highest level of correlation, which still was not statistically significant, existed between TMDs and Cl II malocclusion. The correlation between TMJ discomfort and head, neck and back pain was significant. It is suggested that specific studies be done to clear out the exact relation between gastric disorder and TMJ discomfort

Prevalence of TMJ disorders among students and its relation to malocclusion

The main object of this study was to find out the correlation between types of malocclusion and temporomandibular joint [TMJ] disorders among students. This study was descriptive and cross-sectional. In this study 425 persons were examined. From this number, 308 persons were male, and 117 were female. All samples were students of Mashhad University of Medical and Dental Sciences. The range in age was 19 to 32 years with a mean of 26.1 years. Samples were selected randomly. The correlation between malocclusion and TMJ discomfort at a level of alpha=0.05 was not significant. The highest level of correlation existed between TMDs and Cl II malocclusion. The rate of TMJ discomfort in various types of malocclusion was respectively as follow: Cl II>Cl I>Cl III. The correlation between TMJ discomfort and head, neck and back pain was meaningful [P=0.0298]. The rate of women with TMJ discomfort to men was 1.6: 1. Most patients with TMJ discomfort complained of joint noises and a small number of them remarked symptoms such as pain, jaw opening limitation, and other symptoms of the disorder. Joint noises were mainly in the form of clicking. TMJ discomfort accompanied by gastric disorder [generally speaking] was meaningful [P=0.0214]. From this study it was concluded that there was no significant correlation between malocclusion and TMJ discomfort at a level of alpha=0.05 among students. The highest level of correlation, which still was not statistically significant, existed between TMDs and Cl.II malocclusion. The correlation between TMJ discomfort and head, neck and back pain was significant. It is suggested that specific studies be done to clear out the exact relation between gastric disorder and TMJ discomfort

Cephalometric criteria of patients with Down's syndrome

To determine the Cephalometric criteria of preadolescent boys with Down's syndrome and compare the results with Cephalometric criteria of preadolescent children with normal occlusion in Mashhad to be used in diagnosis and treatment planning of the above-mentioned patients. The investigation was done on 30 with Down's syndrome with the mean age 11.9 years selected randomly [one boy omitted because of inadequate documents]. Medical and dental histories, study casts, lateral Cephalograms in NHP and photographs were prepared. Cephalograms were traced, statistical analyses were done and after comparing the data Cephalometric criteria of children with normal occlusion, results were extracted. The results of this investigation showed that in boys with Down's syndrome the cranial-base length is shorter, basal angle is flatter, height and length of the middle-third of the face as well as the size of the mandible are significantly smaller than of children with normal occlusion. With regard to the findings of this investigation it was found that there are significant differences between Cephalometric criteria of preadolescent boys with Down's syndrome compared to the children with normal occlusion and attention should be paid to these difference when diagnosing and treatment planning of the above-mentioned patients

Comparative assessment of accuracy of contemporary cephalometric analyses in diagnosis of antero-posterior jaw relationship

Natural head position [NHP] provides the key for meaningful cephalometric analyses because an extracranial reference line is used instead of intracranial reference lines, known to be subject to considerable biological variation in their inclination. In many instances lateral cephalograms are taken or have been taken with conventional technique. The aim of this study was to compare the accuracy of some conventional analyses in diagnosis of antero-posterior jaw relationship. This study was based on tracing of 60 lateral cephalograms that were taken with NHP technique. In the sample, there were 22 boys and 38 girls aged between 10 to 13 years old. Twenty of the x-ray films were normal occlusion. Others were class II and III, 20 of each. All cephalograms were taken in the Department of Radiology of Mashhad University Dental School. At first lateral cephalograms were analyzed with NHP method as gold standard and according to the results, patients were classified by angle classification coincided with skeletal categories. Then lateral cephalograms were analyzed with Downs, "Wits", Sassouni and Steiner methods. Finally, by using SPSS software, the validity criteria including sensitivity, specificity, positive predictive value, negative predictive value as well as their accuracy were compared to each other. This study showed that Downs and "Wits" analyses were the most accurate methods in diagnosis of class I cases. Furthermore, the sensitivity of downs analyses for class I patients was the highest. But the most accurate analyses in diagnosis of class II jaw relationship were downs and Steiner methods and for class III jaw relationship was downs analyses. If analyses for evaluation of sagittal relationships of the patients are needed, downs analyses is suggested because this method had the most correlation with NHP analyses

[Cephalometric template for children aged 11-13 with normal occlusion in Mashhad]

Introduction: the aim of this study, which has been done for the first time in Mashhad, was to prepare lateral cephalometric templates for boys and girls with normal occlusion in Mashhad and use of them for diagnosing and treatment planning of malocclusions in orthodontic patients

Materials and Methods: in this study 29 girls and 25 boys, aged 11 to 13, were chosen from schools of Mashhad. After preparing files and taking impressions, their lateral cephalograms were taken in NHP and the template preparation process with a new technique was carried out and the templates were extracted

Results: 4 templates were extracted: 2 for girls aged 11 and 12, and 2 for boys aged 12 and 13

Conclusion: using template is a very fast and reliable way for diagnosing and treatment planning in orthodontics. The templates of this study can be used for patients of the above-mentioned age group

[Preparation of lateral and frontal cephalometric templates for men with normal occlusion]

Introduction: using template is a very fast and reliable way for diagnosing and treatment planning in orthodontics. The aim of this study, which was done for the first time in Iran, was to prepare lateral and frontal cephalometric templates for men with normal occlusion to be used for diagnosis and treatment planning of patients who need orthodontic and ortho-surgical services

Materials and Methods: 31 male students of Islamic Azad University with normal occlusion, aged 19 to 25 with the mean age of 21.3 years, were selected. After preparing files and taking impressions, lateral and frontal cephalograms were taken in NHP and cephalometric analyses were done. Data were analyzed using SOSS software [Student t-test]

Results: 2 templates were extracted, one lateral and one frontal or posterio-frontal

Conclusion: using template is a very fast and reliable way for diagnosis and treatment planning in orthodontics. The templates of this study, which are available and will be submitted on request, can be used for patients of the above-mentioned age group