000			03744nam a22002897i 4500
999			_c13002 _d13002
008			120329s2019 ua a f bm 000 0 eng d
041	0		_aeng _bara
082	0	4	_a617.643 _bA.A.F _222
100	1		_aAl Mohammad, Ahmed Fareed, _eauthor.
245	1	0	_aEvaluation of external root resorption during maxillary and mandibular canine retraction at 2, 4, 6 and 8 weeks reactivation intervals using power chain in 1st premolars extraction cases _ba Randomized Controlled Trial / _cBy Ahmad Fareed Al Mohammad (BDS (2012), Damascus University, Department of Orthodontics, Faculty of Oral and Dental Medicine, Future University in Egypt)
246	3	5	_aتقييم الامتصاص الخارجى للجذر أثناء ارجاع الناب العلوي والسفلي خلال اعادة تفعيل قوة المطاط السلسلس كل 2،4، 6 و8 أسابيع في حالات قلع الضواحك الاولى: دراسة عشوائية مراقبة
264			_c2019
300			_a67 pages, 2 pages : _billustrations (some color) ; _c30 cm
336			_atext _btxt _2rdacontent
337			_aunmediated _bn _2rdamedia
338			_avolume _bnc _2rdacarrier
500			_aSupervisors : Dr. Nagwa Helmy Al-Mangoury (Professor of Orthodontic, Faculty of Oral and Dental Medicine,Future University in Egypt), Dr. Hend Salah El Sayed (Associate Professor of Orthodontics and Pediatric Dentistry, National Research Centre, Egypt)
502			_aThesis (M. Sc.)-Future university in Egypt, faculty of oral and dental medicine, Department Orthodontics, 2019.
504			_aIncludes bibliographical reference
520	3		_aIntroduction: root resorption is an iatrogenic undesirable consequence of the orthodontic treatment. The purpose of this study is to evaluate the external root resorption during maxillary and mandibular canine retraction at 2, 4, 6 and 8 weeks reactivation intervals using power chains. Methods: The sample consisted of 30 patients (114 quadrants) with bimaxillary protrusion or severe crowding requiring first premolar extraction. The sample was divided into four groups. Group I activation every 2weeks, group II activation every 4 weeks, group III activation every 6 weeks and group IV activation every 8 weeks. Canine retraction was initiated by extending the power chain from the power arm to the mini implant in each quadrant with 150 g of force applied. CBCT was taken for each patient before canine retraction (T0) and after 6 months (T1).The amount of root resorption assessed by direct vertical measurements of the canine length at T0 and T1. Results: Group I showed the greatest amount of root shortening (1.26 mm) while Group IV showed the least amount of root shortening (0.57 mm). Group III and IV showed (1.08 mm) and (0.72 mm) of root shortening respectively. There was a significant difference in the means of root resorption between the four groups [P˂0.001]. Conclusion: Different periods of power chains reactivation during canine retraction produce varying amounts of root resorption. According to the results of this study: 1. Root resorption progressively increased with the increase of the reactivation frequency. 2. The maximum root resorption occurring at the 2 weeks reactivation interval was within the range reported in previous literature. 3. The more frequent activations of canine retraction will result in an increased amount of the inflammatory phase of orthodontic tooth movement without an appropriate healing stage which increases the root resorption process.
546			_aText in English, Abstract Arabic and English
650		0	_aOrthodontics
650		0	_aMaxilla _xsurgery
650		0	_aoral surgery.
650		0	_aTeeth _xDiseases.
942			_cTHESIS