The "sagittal first" approach to Class II correction in orthodontic treatment involves correcting the antero-posterior (AP) relationship of the maxillary and mandibular dentition prior to the leveling and aligning phase of orthodontic treatment. The Carriere Motion Appliance (CMA) was made to provide sagittal correction prior to orthodontic treatment with minimal secondary tooth movements that are typically seen with Class II correction. The aim in this study is to explore the efficacy and efficiency of Class II molar correction in adolescent patients using the sagittal first approach with either a sectional, in-office fabricated appliance or the CMA, by measuring total treatment duration (in months) as well as comparing dental and skeletal measurements taken from lateral cephalometric radiographs obtained prior to Class II correction (T0) and immediately after removal of the appliance (T1). The investigators will also be comparing secondary molar and canine rotational movements after Class II correction by comparing digital dental casts obtained at T0 and T1.
The investigators will be recruiting 12 to 17-year 11-month old patients with a Class II molar relationship,who are presenting for comprehensive orthodontic treatment at the Postgraduate orthodontic clinic at University at Buffalo School of Dental Medicine. Recruited subjects will be randomized into one of 2 groups. Both groups will be receiving a method of Class II correction using the Sagittal First approach, which means the Class II molar relationship will be corrected prior to the leveling and aligning phase of orthodontic treatment. Subjects will be treated using either the Carriere Motion Appliance (CMA), or a sectional appliance fabricated with materials that are commonly found in orthodontic practice. Both appliances will be used according to the CMA guidelines. After Class II correction and removal of appliance, and prior to the next stage of treatment, an additional digital scan of the mouth and a lateral cephalometric radiograph will be taken. Dental and skeletal measurements from initial cephalometric radiographs and models will be subtracted from the corresponding measurements taken on radiographs and models obtained after Class II correction, and comparisons will be made between the two treatment treatment groups. Efficiency will be determined by number of months until Class II molar and canine correction was obtained, and efficacy will be determined by the skeletal and dental measurements obtained.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
SINGLE
Enrollment
4
A 0.022 Slot MBT™ second molar mini tube that has been modified to have a 2 mm length will be placed on the maxillary first molar and a 0.018 slot MBT™ maxillary canine bracket will be placed on the maxillary canine, with a 0.016x0.022 stainless-steel wire spanning from the maxillary first molar to the maxillary canine. A bayonet bend will be placed mesial to the molar tube. A curve will be bent into the wire, so that the wire is able to passively rest on the buccal surface of the maxillary canine. A stainless-steel closed coil will span the molar to canine and lay flush to the mesial portion of the molar tube and the distal portion of the canine bracket. The wire will be cinched mesial to the maxillary canine tie-wing and also 2-3 mm distal to the maxillary first molar to ensure that the molar can rotate during treatment, if needed. A stainless-steel tie will be used to secure the wire into the canine bracket. AP correction will be completed following CMA protocol
A bar spanning from the maxillary first molar to canine with a ball and socket joint at the molar and a canine pad at the canine. A slight bend is present between the molar and canine bracket. The ball and socket is designed to allow the molar to rotate to -15 degrees along it's longitudinal axis. The appliance claims that it allows for Class II correction with minimal secondary tooth movements when used with mandibular anchorage.
University at Buffalo School of Dental Medicine
Buffalo, New York, United States
Total Treatment Time
Months
Time frame: From date of Class II correction appliance delivery to date of removal of Class II correction appliance after Class I molar and canine relationship has been established (approximately 120-180 days).
Skeletal Changes
Degrees, Millimeters
Time frame: From date of Class II correction appliance delivery to date of removal of Class II correction appliance after Class I molar and canine relationship has been established (approximately 120-180 days).
Dental Changes
Degrees, Millimeters
Time frame: From date of Class II correction appliance delivery to date of removal of Class II correction appliance after Class I molar and canine relationship has been established (approximately 120-180 days).
Maxillary Canine and Maxillary First Molar Rotation
Degrees
Time frame: From date of Class II correction appliance delivery to date of removal of Class II correction appliance after Class I molar and canine relationship has been established (approximately 120-180 days).
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