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Aims:. To investigate the rates of space closure achieved by elastomeric chain and nickel titanium coil springs with the evaluation of the effects of using different bracket types on the rate of space closure during its retraction along different sizes of orthodontic arch wires using typodont simulation system (Ormco). Materials and Methods: The standardization criteria were all typodont teeth situated in well aligned position, covered and immobilized by the acrylic bite except canine, elastic chain and nickeltitanium closed coil spring exerting 180 gm of force on canine measured carefully by tension gauge. The available space was 13.5mm (the rate of space closure). Results: The present study showed that when using elastic chain as a method of canine retraction gave rise to a a significant decrease in the rate of space closure as compared with nickeltitanium closed coil spring also sliding the canine using ceramic brackets gave rise significant reduction in the rate of space closure than when using stainless steel brackets. Another finding of the present study showed that sliding the canine on large rectangular arch wire (0.019x0.025 inch) gave rise to a significant reduction in the rate of space closure when compared with 0.018 inch and 0.018x0.022 inch arch wires were used. Conclusions: It was concluded that the canine retraction with 0.018 inch wire on Roth stainless steel bracket by closed coil spring gave rise a large amount of space closure rate. While the opposite is true for canine retraction with 0.019x0.025 inch wire on standard ceramic bracket by elastic chain retraction method.

The purposes of this study are to determine the faciolingual inclinations of tooth crowns in Class I normal occlusion of Iraqi adolescent in Mosul City, investigate the possible significant differences between genders, and determine the correlation of the faciolingual inclination of teeth crown with each others.The sample of this study consisted from 35 Iraqi adolescents (19 males and 16 females) aged 12-16 years selected according to certain criteria from Mosul City. Stone casts were taken for each subject, the faciolingual inclinations were made on the dental models of the subjects by using torque angle gauge.The data were analyzed with the Statistical Package for Social Sciences program and it was found that each tooth distally to the central incisor had more lingual inclination than did its neighbor. The females had more labial inclination of upper lateral incisor and more lingual inclination of the lower canine, premolars and first molar as compared with the males. Most intraarch teeth torque correlation were positive and decreased with remoteness while most interarch teeth correlation showed weak negative correlation.

Background: Since the introduction of modern orthodontics, several indices have been proposed to help prediction normal maxillary arch width that would relieve crowding, maintain occlusion stability and reduces future relapse. Among these indices Pont had proposed an index in 1909 to estimate maxillary arch width depending upon the sum of maxillary incisors mesiodistal dimensions. Aims: The present study tried to investigate the reliability of Pont's index in estimating dental arch width. Materials and Methods: The sample consisted of 22 boys and 22 girls aged 14-16 years. Measurements of all study models were done using a sliding caliper. The arch width was measured in first premolar region between distal pits, and in first permanent molar region between central fossae. Results: Statistical analysis, using correlation coefficient; revealed a poor correlations existed between Pont's estimation for the arch width and the actual arch width measured from the casts for both sexes. The arch widths were generally underestimated for all test groups. Conclusion: It was concluded that Pont's index is not a precise method for prediction of maxillary dental arch width.

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OBJECTIVES: The objective of this study is to determine whether submucosal local injection of i-PRF may affect orthodontic relapse by increasing bone density, which further leads to reducing orthodontic relapse. MATERIALS AND METHODS: Forty-five adult male albino rabbits were randomly divided into three groups: group I (control) with 15 rabbits injected with 200 μl of phosphate-buffered saline (PBS), group II with 15 rabbits injected with 200 μl of i-PRF, and group III of 15 rabbits inject with 400 μl of i-PRF. The lower incisors of rabbits moved distally by a modified orthodontic appliance for 2 weeks; then, the appliance was maintained in position to retain the gaining space for 2 weeks. During the retention period, each group was injected with the specific drug every 7 days. After the retention period, teeth were allowed to relapse by removal of the orthodontic appliance. The results were evaluated by measuring the amount of orthodontic relapse and bone density. The statistical analysis performed by ANOVA and Duncan ( P < 0.05 was considered significant). RESULTS: I-PRF groups showed a significant reduction in the amount of relapse at 10, 13, 17, and 20 days compared to the control group, indicated by the highest percentage of relapse for the control group at the end of the study (20 days); it was (90.4%) in compared to lowest percentage of relapse for i-PRF groups—they were 61.2% and 59.9%, respectively. CONCLUSION: Results indicated that i-PRF has the potential to enhance the stability of teeth after orthodontic tooth movement and could have the ability to reduce relapse, probably by increasing the alveolar bone density.

Aims:To investigate whether extraction status and gender had any significant influence on the maxillary arch dimensions. Materials and Methods: A sample of 40 orthodontic patients (20 extraction and 20 non extraction) were included in this study. Males and females were evenly represented in both groups. All patients were treated with fixed edgewise appliances. Dental casts were taken before and after final orthodontic treatment, fifteen maxillary arch parameters were evaluated at pre-and posttreatment stage and included; dental arch width at the canine, 1 st premolar, 2 nd premolar, 1 st molar (at mesiobuccal and distobuccal cusp tips), arch depth at canine and 1 st molar, arch lengths (incisal canine length, canine molar length and incisal molar length), and arch perimeter. A paired sample t-test was used to evaluate the treatment changes in the extraction and non extraction groups and also to compare between males and females before treatment and after treatment. Results: Generally, in both genders, most pretreatment arch dimensions were not significantly different between extraction and non extraction groups, while after treatment the extraction treatment resulted in the reduction in the arch perimeters, arch depth, and arch length. Where as the non extraction group showed a significant increase in most maxillary arch dimensions. In addition both the extraction and non extraction treatment did not cause narrowing of the dental arch at the canine region. The direction of post treatment changes were similar in male and female subjects. However, the magnitude of the post treatment changes in some parameters differed significantly between females and males particularly in the non extraction group. Conclusions: the extraction and non extraction groups showed similar trend in some maxillary dimensions and different in other dimensions, thus it was concluded that the kind of treatment may affect the maxillary arch dimensions. In addition the non extraction group had a larger number of significant gender differences between females and males than the extraction group.

Aims: This paper aims to estimate and compare the pharynx and soft palatal dimensions of Iraqi adolescent and adults with class I normal occlusion at Mosul City and to identify any gender dimorphism within each group. Materials and Methods: Lateral cephalometric radiographs of 160 normal Iraqis what were separated into two groups (80 adolescents and 80 adults). Each group was additionallydivided into two subgroups according to gender (40 of each gender). Twelve linear measurements were made in all subjects; gender dimorphism and comparison between two age groups were analysed by students t test.Results:No gender differences in all variables except in retropalatal airway space (U-MPW) in the adolescents group. While, in the adults the only significant gender differences were found in the thickness of posterior nasopharyngeal wall (ad1-Ba)and in the vertical airway space (Pm-Eb).The adults had significantly larger values for superior nasopharyngeal(pm-ad2) and inferior nasopharyngeal depth (pm-ad1) than adolescents .While ,adolescents had larger value for superior nasopharyngeal thickness (ad2-s) and posterior nasopharyngeal thickness(ad1-Ba) than adults in both genders .The adult male had a higher value for (Pm-Eb) than adolescent male .While ,adolescent female had a higher value for soft palate thickness (SPT) than adult female. Conclusions: Data derived from this study should be a useful reference for assessment of sleep apnea and other conditions in the Iraqi population.Developmental changes were found in all nasopharyngeal parameters except the Pm-ba(sagittal depth of the bony nasopharynx).