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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.

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.

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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