American Journal of Orthodontics and Dentofacial Orthopedics
Efficacy of intraarch mechanics using differential moments for achieving anchorage control in extraction cases☆,☆☆,★,★★
Section snippets
MATERIALS AND METHODS
The study design was a prospective longitudinal investigation with one observation subsequent to the initial observation. No plan for unbiased allocation by randomization was followed because patients were selected on the basis of anchorage needs, and there was no comparison group selected.
The sample consisted of 24 subjects (14 females, 10 males) from the orthodontic department, University of Illinois at Chicago. Ages ranged between 12 years, 5 months, to 43 years, 10 months, with a mean
RESULTS
On average, canine retraction time was 7.1 months with a range of 3 to 12 months. In three patients, complete retraction of the canines was not performed because treatment needs at that time necessitated that the posterior teeth be allowed to move mesially to complete the space closure. The data for the latter three cases were included in the study, because it was decided the findings would not be influenced.
The means and standard deviations for the cephalometric variables are listed in Table I
DISCUSSION
The current study primarily evaluated anchorage control of the molars in the anteroposterior dimension. The horizontal, vertical, and angular positions of the incisors and molars were measured both before treatment and after canine retraction to determine whether the auxiliary arch wire produced side effects (particularly molar extrusion, incisor intrusion, and incisor proclination) that could be unfavorable in some cases. No statistically significant differences were found in the vertical and
CONCLUSIONS
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Maxillary canines can be retracted into extraction sites with minimal (clinically insignificant) horizontal anchorage loss of the molars by controlling forces and moments.
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These results suggest that cervical headgear, Nance holding arches, and other adjunctive appliances are not necessary for horizontal molar anchorage control in the maxillary arch.
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When using these mechanics, marked mesiopalatal molar and distopalatal canine rotation occurred, which indicated the need for counteractive forces
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Cited by (42)
Comparison of direct and indirect skeletal anchorage systems combined with 2 canine retraction techniques
2016, American Journal of Orthodontics and Dentofacial OrthopedicsEfficacy of the Nance appliance as an anchorage-reinforcement method
2015, American Journal of Orthodontics and Dentofacial OrthopedicsCitation Excerpt :Furthermore, the patients in the study of Shpack et al required extraction of the first premolars; consequently, the mechanics used may have been designed to reduce the AL. This may support the findings of earlier studies, which suggested that orthodontic mechanics during treatment may play a more decisive role than cortical bone in controlling anchorage.47-49 The percentages of AL and DTM to the total space closure in this study were significantly different between the 2 groups at 10 and 15 weeks.
Efficacy of second molar to achieve anchorage control in maximum anchorage cases
2010, Medical Journal Armed Forces IndiaCitation Excerpt :The U6 ANG movement was statistically significant for both the groups and the difference was also statistically significant meaning that though the molar experienced angular movement or tipping it was better controlled in Group II. This finding is contrary to Lisa et al [6] who have reported insignificant U6 ANG movement after canine retraction. Mean U1 ANG movement is −18.9063° in Group I and −12.9643° in Group II.
Analysis of temporary skeletal anchorage devices used for en-masse retraction: A preliminary study
2009, American Journal of Orthodontics and Dentofacial OrthopedicsCorrelation between miniscrew stability and bone mineral density in orthodontic patients
2009, American Journal of Orthodontics and Dentofacial OrthopedicsChanges over time in canine retraction: An implant study
2009, American Journal of Orthodontics and Dentofacial OrthopedicsCitation Excerpt :Iwasaki et al36 recently demonstrated this relationship clinically. Differences between controlled and uncontrolled tipping are clinically relevant because rates of tooth movement can be slowed or increased, relatively, by moving teeth in different ways (ie, uncontrolled tipping, controlled tipping, and translation).28,29 Importantly, post-hoc tests showed that our study had insufficient power to rule out a difference between jaws in the amounts of canine cusp retraction.
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This article is based on research by Dr. Rajcich submitted as partial fulfillment of the requirements for the Degree of Master of Science in Oral Sciences in the Graduate College of the University of Illinois at Chicago, 1996.
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aProfessor.
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Reprint requests to: Dr. Cyril Sadowsky, University of Illinois at Chicago, 801 S. Paulina, Chicago, IL 60612.
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