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Aims: This report describes a case of eleven years old female with impacted maxillary central incisors and presence of two supernumerary teeth .The surgical exposure and orthodontic traction of bilaterally impacted central incisors after removal of impacted supernumerary teeth is presented in this report. Materials and Methods: Clinical, radiographic follow-up and treatment was conducted at the department of orthodontic and maxillofacial surgery in the college of dentistry ,mosul university .The surgical removal of supernumerary teeth done then surgical exposure and orthodontic traction done. Results: The impacted maxillary central incisors were successfully positioned and presented an acceptable gingival contour after treatment. Conclusion: Maxillary permanent central incisors were successfully positioned in the maxillary arch by surgical exposure and orthodontic traction, which showed good stability.

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Aims:To study the effect of artificial saliva and time interval on the amount of force values of nitinol and superelastic NiTi wires. Materials and Methods: Two types of orthodontic wires chosen for the study nitinol and superelastic NiTi wires of a guage of 0.016 inch in diameter (Dentaurum, Germany). Specimens of the wires were divided in to two groups ;the control group(dry condition) contained the wires as -received condition and experimental groups for the study of the force value of wires which subjected to artificial saliva for three time incubation periods (3 days, 7 days, 28 days) . At end of each incubation periods ,the wire specimens were tested for the effect of artificial saliva on force values of the wire. The measurement of force values of arch wires done with a universal tensile testing machine ,the force values of specimens were evaluated with the help of three point bending test. The results were subjected to the descriptive statistics and to the ANOVA and Duncan's Multiple Range Analysis Tests to detect the amount of changes among these groups . Result: The findings of the present study showed that the control group of nitinol wires had the highest rate of force value with significant difference (P≤ 0.05) with experimental groups, while the experimental group after 28 days gave rise to the lowest one with significant difference (P≤ 0.05) from other groups. For the superelastic nickel titanium the result showed that the control group had the highest rate of force value while the experimental group after 28 days gave rise to the lowest one with significant difference (P≤ 0.05) from control and non significant difference (P> 0.05) with the experimental groups after 3 days and 7 days. Conclusion: The nitinol wires showed a continuous change in force values with increase time in artificial saliva, so this required reactivating or changing the wire at a certain interval of use. While force values of the superelastic nickel titanium wires decreased after 3 days interval and remained constant after that .

Aims:To evaluate the force values of different types of arch wires. Materials and Methods: Five types of arch wires used. The sample consisted of 150 wires specimens divided into three deflections (1 mm, 2mm and 3 mm). A universal tensile testing machine with the use of special designed fixture was used to perform Three Point Bending Test and the force value related to gram (gm) was measured during loading (activation) of the wire to 1 mm, 2 mm or 3 mm deflections. Results: The results of this investigation showed a significant difference (P≤ 0.05) in force values among all arch wires. Conclusions: The conclusions of this study showed that the solid stainless steel wires provided a heavy force, while the multistranded gave rise to the lowest force value.