This study will compare the techniques of piezocision and alveolar corticotomies in accelerating orthodontic retraction movement of canines. In a second phase, this clinical trial will evaluate the effectiveness of micro-osteoperforations in accelerating the retraction of maxillary incisors.
The first phase will consist of a split-mouth study in patients who require the extraction of the first premolars to correct malocclusion. The canine will be retracted using corticotomy and piezocision surgical techniques, as well as without any intervention, being this the control side. In addition, it will be evaluated the inflammatory biomarkers present in the gingival crevicular sulcus during the dental movement, as well as data related to pain and discomfort. The second phase will evaluate the effects of micro-osteoperforations in the retraction of maxillary incisors. The following parameters will be evaluated in the upper arch: anteroposterior incisors and first molars displacement, space closure, inclination and length of central incisors.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
DOUBLE
Enrollment
45
The first maxillary premolars will be extracted with orthodontic purpose. After 3 months of extraction, the orthodontic alignment and dental leveling will be obtained and a 0.016x0.022 stainless steel wire will be placed, as well as orthodontic mini-implants (Morelli®, Sorocaba, SP, Brazil). The retraction of the canines will begin using closed nickel-titanium spring (120g). The piezocision surgery will be performed only in one side of the mouth. Three vertical piezo-incisions will be performed near the edentulous region and mesially to the canine root, in the vestibular alveolar cortical bone with the Ultrasonic instrument (BS1 insert Piezotome ™, Satelec Group Acteon Merignac, France) in depth of 3 mm. The intraoral digital scans will be performed with 7 and 14 days after the start of retraction, and then 14 in 14 days to a maximum period of 6 months. The patients will be advised to take analgesics (paracetamol or dipyrone) only if necessary.
The first maxillary premolars will be extracted with orthodontic purpose. After 3 months of extraction, the orthodontic alignment and dental leveling will be obtained and a 0.016x0.022 stainless steel wire will be placed, as well as orthodontic mini-implants (Morelli, Sorocaba, SP, Brazil).The retraction of the canines will begin using closed nickel-titanium spring (120g).The corticotomy surgery will be performed at the day of begining of canine retraction only in one side of the mouth.A mucoperiosteal flap will be raised from the extraction region to the mesial of the canine.Perforations will be performed using a number 2 spherical drill bit in low speed handpiece under irrigation, only in the cortical none depth.The intraoral digital scans will be performed with 7 and 14 days after the start of retraction, and then 14 in 14 days to a maximum period of 6 months.The patients will be advised to take analgesics (paracetamol or dipyrone) only if necessary.
Pontifícia Universidade Católica de Minas Gerais
Belo Horizonte, Minas Gerais, Brazil
Orthodontic Canine Retraction Rate
The main objective is to evaluate and compare the canine retraction velocity in the different groups. Digital intra-oral scans will be performed (3Shape A / S®, Kopenhagen, Denmark) as registration method, every 14 days, up to 6 months.
Time frame: Up to 6 months
Anteroposterior displacement of the upper incisors
The anteroposterior displacement of the upper incisors was assessed on superimposed digital models through the distance of points on the incisal edge and palatal cervical margin of these teeth to a coronal reference plan created on the initial CBCT scan.
Time frame: Up to 4 months
Space closure
The space closure was assessed by the distance between the most menial point of the medial surface of the canine to the most distal point of the distal surface of the lateral incisor.
Time frame: Up to 4 months
Duration of the effect of the surgical procedures
The retraction of the canine will be accompanied by up to 6 months after surgery to verify the duration of its effect, if it occurs.
Time frame: Up to 6 months
Evaluation of biomarkers
To evaluate the expression of the inflammatory biomarkers present in the gingival crevicular sulcus of the canines to be retracted. At T0, immediately before retraction, and 15 in 15 days.
Time frame: Up to 6 months
Patient Pain and discomfort
VAS questionnaire will be used after the surgical procedures, as well after TADs placement, separator placement and premolar extraction. Always 7 days after each procedure.
Time frame: Up to 6 months
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The first maxillary premolars will be extracted with orthodontic purpose. Fixed orthodontic appliance will be bonded (0.022x0.025 slot with MBT prescription in incisors and Standart in the other teeth) with a power arm welded in the bracks upper canines brackets. After 3 months of extraction, the alignment and dental leveling will be obtained and a 0.016x0.022 stainless steel wire will be placed, as well as orthodontic mini-implants (Morelli®, Sorocaba, SP, Brazil) between the roots of the second premolars and molars. At that time an intra-oral digital scan will be performed. The retraction of the canines will begin using closed nickel-titanium spring (120g of force) from the power arm to the mini-implant. No surgery will be done at this side. The intraoral digital scans will be performed with 7 and 14 days after the start of retraction, and then 14 in 14 days to a maximum period of 6 months.
All micro-osteoperforations will be performed only once time in the experimental group on the same day of the installation of the upper incisors' retraction mechanics. Perforations will be performed with an individualized surgical guide and a 1.6 mm diameter stainless steel surgical drill perpendicular to the alveolar bone, 3 mm deep on the buccal surface, and 5 mm, on the palate. The depth of the perforations will be controlled and standardized by a cursor developed and patented by the research group. Two micro-osteoperforations will be aligned vertically distally from each upper incisor. Due to the proximity of the roots in the cervical third, only the most apical perforation will be performed between the two central incisors. The first perforation will be performed 6 mm away from the gingival margin, and the second, 5 mm from the first, in the vertical direction.
First molars anchorage loss
The first molars anchorage loss was assessed on superimposed digital models through the distance of a point on the mesiobuccal cuspid to a coronal reference plan created on the initial CBCT scan.
Time frame: Up to 4 months
Changes of the inclination of the central incisors
The initial and final CBCT were superimposed by the "voxel-based method" in the Dolphin Imaging software (Chatsworth, CA, USA), using the cranial base as reference. The inclination of the central incisors was then assessed by means of the angle formed by the long axis of each central incisor in the initial and final CBCT.
Time frame: Up to 4 months
Changes of the length of the central incisors
The initial and final length of the central incisors were measured by creating a 2D line, passing through the lowest point of the incisal edge and the highest point of the root apex. To perform these measurements, a sagittal cut was used in which the longest length of these teeth was seen.
Time frame: Up to 4 months