• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.44 no.6
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• pp.251-258
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• 2018

Corticotomy was introduced as a surgical procedure to shorten orthodontic treatment time. Corticotomy removes the cortical bone that strongly resists orthodontic force in the jaw and keeps the marrow bone to maintain blood circulation and continuity of bone tissues to reduce risk of necrosis and facilitate tooth movement. In the 21st century, the concept of regional acceleratory phenomenon was introduced and the development of the skeletal anchorage system using screw and plate enabled application of orthopedic force beyond conventional orthodontic force, so corticotomy has been applied to more cases. Also, various modified methods of minimally invasive techniques have been introduced to reduce the patient's discomfort due to surgical intervention and complications after surgery. We will review the history of corticotomy, its mechanism of action, and various modified procedures and indications.

• Journal of Korean Dental Science
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• v.4 no.2
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• pp.39-45
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• 2011

Purpose: The goal of this research is to find the role of collagen membrane, which can reduce physical damage, as a scaffold for possible alternative to the corticotomy which causes Regional Acceleratory Phenomenon (RAP). Materials and Methods: The experiments were carried out on 12 New Zealand white rabbits, approximately 3.5 kg in bodyweight. We made an incision on the skin of the mandibular border and applied 37% phosphoric acid and collagen membrane to the mandibular bone surface of the first group (experimental group), and only phosphoric acid to the second group (control group). After 3 days, 1 week, and 2 weeks, 4 rabbits each were sacrificed and specimens were obtained. Each specimen was stained by H&E and Tartrate-resistant acid phosphatase (TRAP), and histological changes were observed by light microscope. Results: The demineralization of the experimental group was weak compared to the control group. It also showed a gradual increase of demineralization (after 3 days, 1 week, and 2 weeks) and the control group showed more extensive demineralization than the experimental group. Conclusion: This study demonstrates the amount of demineralization as a result of using phosphoric acid, and as time went by, demineralization increased. The absorbable collagen membrane was used as a scaffold to increase bone demineralization effect and prevent dispersion to adjacent tissues, but rather the amount of bone demineralization decreased. Therefore, the role of collagen membrane as a scaffold for RAP was weak.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.38 no.2
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• pp.96-100
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• 2012

Objectives: This study sought to evaluate trabecular changes in the mandible using fractal analysis and to explain the transient osteopenia related to rapid orthodontic tooth movement after orthognathic surgery. Materials and Methods: Panoramic radiographs were taken of 26 patients who underwent bilateral sagittal split ramus osteotomy. Radiographs taken before the surgery and 1 month after surgery were overlapped, and $40{\times}40$ pixel square regions of interest were selected near the mandibular canines and 1st molars. After the image processing procedure, the fractal dimension was calculated using the box-counting method. Results: Fractal dimension after orthognathic surgery decreased in a statistically significant manner (P<0.05). The change in fractal dimension on the canine side had greater statistical significance as compared to that seen on the 1st molar side. Conclusion: This study found that bone density decreases after orthognathic surgery due to transient osteopenia related to the regional acceleratory phenomenon. This result can provide a guide to evaluating orthodontic tooth movement after orthognathic surgery.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.41
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• pp.10.1-10.8
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• 2019

The "surgery-first" approach, defined as a team approach between surgeons and orthodontists for orthognathic surgery without preoperative orthodontic treatment, is aimed at dental decompensation. A brief historical background and indications for the surgery-first approach are reviewed. Considering the complicated mechanism of postoperative orthodontic treatment, the proper selection of patients is a vital component of successful surgery-first approach.

• The Journal of the Korean dental association
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• v.55 no.4
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• pp.296-302
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• 2017

The traditional orthognathic surgery treatment consists of three steps: preoperative orthodontic treatment, orthognathic surgery, and postoperative orthodontic treatment, and the average treatment period is usually two years. Also, patients with Class III malocclusion should spend more time getting their facial features worse during the decompensation process. However, most of the patients who want orthognathic surgery visit the chief complaints of appearance improvement, and resolve this address as soon as possible. The concept of $^{\circ}{\AE}$Surgery - First 'does not cause a facial imbalance caused by decompensation for the pre - operative correction period, and the patient can obtain an improved facial profile immediately after the operation. In addition, the correction period is shortened by Regional Acceleratory Phenomenon (RAP) after surgery. However, it is not applicable to all patients. Patients with severe crowding, severe curve of spee or reverse curve of spee, severe transverse discrepancy of the maxilla and mandibular arch, and severe incisal angles are less likely to apply the technique. Although it is not yet possible to apply this technique to all patients, it has many advantages over the conventional method. Especially, the patients' preference is increasing due to the rapid appearance improvement and the shortening of the total treatment period.