The Use of Corticotomy for Upper Incisors Retraction

Evaluation of Treatment Outcomes of Corticotomy-accelerated Upper Incisors' Retraction: A Randomized Controlled Trial

We aim to assess the treatment outcomes following upper incisors retraction accelerated by corticotomy procedure. So, we intend to randomize orthodontic patients with class II division I malocclusion into two groups: experimental group and control group. Both groups will start orthodontic treatment. Once a 0.019*0.025-inch stainless steel wire is fully engaged to the brackets, 1st premolars will be extracted. Canines will be retracted in the conventional manner. Then, the actual evaluation period starts when the upper incisors are retracted using two different methods.

In the last three decades, the number of adult patients seeking short orthodontic treatment time has apparently increased as the conventional orthodontic treatment usually lasts for 20-24 months. Furthermore, orthodontic treatment is often associated with root resorption, bone degradation and caries development. Patients nowadays desire to end the orthodontic treatment as soon as possible due to phsycosocial reasons and to get the goals of the treatment without affecting their social life . So many tooth movement accelerating methods have been proposed. However, the surgical approached are considered the most effective and promising methods in accelerating tooth movement. The current research aims to evaluate the efficacy of the a new proposed surgical method compared to the conventional method in upper incisors' retraction.

Corticotomy-assisted retraction will be performed in order to help in accelerating upper incisors' retraction

Using a tunneling technique, the researcher will perform the intervention in the alveolar bone surrounding the upper incisors before retraction.

The distance that the incisors moved during retraction divided by the time required to retract the four upper incisors to their ideal positions.

This will be measured at the completion of the retraction procedure, and is expected to take 2 months in the experimental group and four months in the control group.

The time required from the beginning of incisors' retraction till the the completion of this procedure.

This will be measured at the completion of the retraction procedure, and is expected to be within 2 months in the accelerated group and 4 months in the control group.

the angle between the long axis of the upper incisor and a reference plane drawn on a later cephalometric radiograph teken at two assessment times.

A radiograph will be taken at T1: one day before upper incisors' retraction and T2: one day after the completion of upper incisors' retraction. Completion of upper incisors' retraction is expected to be within 2 months in the accelerated group and 4 mo

the amount of anchorage loss (in mm), which is the distance from a perpendicular line to the midpalatal suture and extends between central fossa of both upper first molars to the third palatal rugae . These measurements are made on plaster study models.

This will be measured one day following the completion of retraction of the upper four incisors using plaster study models and is expected to be within 2 months in the accelerated group and 4 months in the control group

This variable is related to the amount of incisor root resorption after treatment in both groups. This is measured on a panoramic image. The amount of root resorption = the length of an incisor after retraction subtracted from the length of an incisor before retraction. Two radiogrpahs are needed.

An panoramic image will be taken at T1: one day before the commencement of incisor retraction and T2: one day following the completion of retraction and is expected to be within 2 months in the accelerated group and 4 months in the control group

Inclusion Criteria: Adult patients 15 to 27 years , with permanent dentition , without hypodontia . Overjet less than 10 mm Normal or increased growth pattern (Diagnosed by Y-axis angle) Mild to moderate crowding (Less than 3 mm) After canines retraction , at least 3 mm space should be available distal the lateral incisors Midline deviation shouldn't be more than 3 mm Exclusion Criteria: Medically contraindicated patients to oral surgery . Existence of general health issue that affect orthodontic teeth movement Previous orthodontic treatment Mixed dentition Hypodontia (Except third molars) Bad oral hygiene

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