Randomized clinical trial comparing control of maxillary anchorage with 2 retraction techniques
| Autor: | Robert L. Boyd, Sheldon Baumrind, Xiaoyun Zhang, Hee Soo Oh, Tianmin Xu, Edward L. Korn |
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| Rok vydání: | 2008 |
| Předmět: |
Male
Cuspid Adolescent Tooth Movement Techniques Cephalometry Dentistry Orthodontics Pilot Projects Malocclusion Angle Class I Malocclusion Angle Class II law.invention Canine retraction Sex Factors stomatognathic system Randomized controlled trial law Statistical significance Maxillary first molar Maxilla Orthodontic Anchorage Procedures Medicine Extraoral Traction Appliances Humans Orthodontic Appliance Design Displacement (orthopedic surgery) In patient Child business.industry Lateral cephalograms Puberty Age Factors medicine.disease Molar Incisor Treatment Outcome Orthodontic Space Closure Feasibility Studies Female Malocclusion business Follow-Up Studies |
| Zdroj: | American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics. 138(5) |
| ISSN: | 1097-6752 |
| Popis: | The objective of this pilot randomized clinical trial was to investigate the relative effectiveness of anchorage conservation of en-masse and 2-step retraction techniques during maximum anchorage treatment in patients with Angle Class I and Class II malocclusions.Sixty-four growing subjects (25 boys, 39 girls; 10.2-15.9 years old) who required maximum anchorage were randomized to 2 treatment techniques: en-masse retraction (n = 32) and 2-step retraction (n = 32); the groups were stratified by sex and starting age. Each patient was treated by a full-time clinic instructor experienced in the use of both retraction techniques at the orthodontic clinic of Peking University School of Stomatology in China. All patients used headgear, and most had transpalatal appliances. Lateral cephalograms taken before treatment and at the end of treatment were used to evaluate treatment-associated changes. Differences in maxillary molar mesial displacement and maxillary incisor retraction were measured with the before and after treatment tracings superimposed on the anatomic best fit of the palatal structures. Differences in mesial displacement of the maxillary first molar were compared between the 2 treatment techniques, between sexes, and between different starting-age groups.Average mesial displacement of the maxillary first molar was slightly less in the en-masse group than in the 2-step group (mean, -0.36 mm; 95% CI, -1.42 to 0.71 mm). The average mesial displacement of the maxillary first molar for both treatment groups pooled (n = 63, because 1 patient was lost to follow-up) was 4.3 ± 2.1 mm (mean ± standard deviation). Boys had significantly more mesial displacement than girls (mean difference, 1.3 mm; P0.03). Younger adolescents had significantly more mesial displacement than older adolescents (mean difference, 1.3 mm; P0.02).Average mesial displacement of the maxillary first molar with 2-step retraction was slightly greater than that for en-masse retraction, but the difference did not reach statistical significance. This finding appears to contradict the belief of many clinicians that 2-step canine retraction is more effective than en-masse retraction in preventing clinically meaningful anchorage loss. |
| Databáze: | OpenAIRE |
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