• Korean Journal of Cleft Lip And Palate
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• v.6 no.1
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• pp.43-51
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• 2003

Patients with unilateral cleft lip and palate (UCLP) usually present unilateral cross bite due to collapse of the maxillary minor segment. Unequal expansion of the palate is needed to resolve this problem in UCLP patient. Unilateral segmental palatal distraction (USPD) after Le Fort I osteotomy and the oblique placed orthodontic expansion screw (Hyrax) can be used to correct the unilateral cross bite. 1his case report describes the effects of USPD of the collapsed maxillary minor segment on patient with unilateral cleft lip and palate.

• Journal of Korean Dental Science
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• v.16 no.1
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• pp.87-98
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• 2023

This report presents a case of successful treatment of skeletal Class III malocclusion with transverse discrepancy in adult by surgery-first approach. Traditionally dental decompensation is necessary prior to surgery in 2-jaw surgery to correct transverse and rotational discrepancy. However, the hyrax-type palatal expansion appliance was used to improve maxillary expansion accuracy and postoperative stability in this surgery-first approach (segmental Le Fort I osteotomy and mandibular setback surgery). It was established to be an effective means of precisely predicting postoperative occlusion and achieving stable retention after surgery of skeletal Class III malocclusion with maxillary transverse discrepancy.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.5
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• pp.413-419
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• 2011

Purpose: Reposition of the maxilla is a common technique for correction of midfacial deformities. To achieve the goal of the surgery, the maxilla should be repositioned based on the precisely planned position during surgery. The internal reference points (IRPs) and the external reference points (ERPs) are usually used to determine vertical dimension of maxilla, which is an important factor for confirming maxillary position. However, the IRPs are known to be inaccurate in determining the vertical dimension. In this study, we investigated the correlation of positional change of the modified IRPs with repositioned maxilla. Methods: The study group consisted of 26 patients with dentofacial deformities. For the simulation of the surgery, patient maxillary CT data and 3-D virtual surgery programs (V-$Works^{(R)}$ and V-$Surgery^{(R)}$) were used. IRPs of this study were set on both the lateral wall of piriform aperture, inferior margin of both infraorbital foramen, and the labial surfaces of the canine and first molar. The distance from the point on lateral wall of the piriform aperture to the point on the buccal surface of the canine was defined as IRP-C, and the distance from the point on the inferior margin of the infraorbital foramen to the point on the buccal surface of the $1^{st}$ molar was defined as IRP-M. After the virtual simulation of Le Fort I osteotomy, the changes in IRP-C and IRP-M were compared with the maxillary movement. All measures were analyzed statistically. Results: With respect to vertical movements, the IRP-C (approximately 98%) and the IRP-M (approximately 96%) represented the movement of the canine and the $1^{st}$ molar. Regarding rotating movement, the IRPs changed according to the movement of the canine and the $1^{st}$ molar. In particular, the IRP-C was changed in accordance with the canine. Conclusion: IRPs could be good indicators for predicting vertical movements of the maxilla during surgery.

• The korean journal of orthodontics
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• v.35 no.3 s.110
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• pp.238-249
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• 2005

The contemporary two-jaw surgical approach usually involves a Le Fort osteotomy of the maxilla and a ramal osteotomy of the mandible with 3-dimensional repositioning of the jaws as well as the occlusal planes. After making the surgical treatment plan. the surgical movements are duplicated in the model surgery. During this procedure, reference poings and lines are drawn on the base of the models over the dental arch and sawcuts are mads according to these marked osteotomy lines. This technique, however, has been found to be inexact. especially when the laws are moved in several dimensions simultaneously. To overcome this. different methods have been developed for an accurate repositioning of the jaws as planned. A new appliance. Surgical Jaw Relater, has been devised by th8 author for the simple 3-dimensional relocation of the upper and lower models, resulting in the easy construction of the splints such as centric relation splint, intermediate and final splint. This article describes an introduction and a clinical application of this appliance. Through the application of this system to the orthognathic cases including two-law surgery. it is proved that the row device is very clinically useful.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.41
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• pp.35.1-35.7
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• 2019

Background: The purpose of this study was to measure the time of the conventional surgical planning (CSP) and virtual surgical planning (VSP) in orthognathic surgery and to compare them in terms of cost. Material and method: This is a retrospective study of the patients who underwent orthognathic surgery at the Pusan National University Dental Hospital from December 2017 to August 2018. All the patients were analyzed through both CSP and VSP, and all the surgical stents were fabricated through manual and three-dimensional (3D) printing. The predictor variables were the planning method (CSP vs. VSP) and the surgery type (group I: Le Fort I osteotomy + bilateral sagittal split osteotomy [LFI+BSSO] or group II: only bilateral sagittal split osteotomy [BSSO]), and the outcomes were the time and cost. The results were analyzed using the paired t test. Results: Thirty patients (12 females, 18 males) met the inclusion criteria, and 17 patients were excluded from the study due to missing or incomplete data. There were 20 group I patients (LFI+BSSO regardless of genioplasty) and 10 group II patients (BSSO regardless of genioplasty). The average time of CSP for group I was 385 ± 7.8 min, and that for group II was 195 ± 8.33 min. The time reduction rate of VSP compared with CSP was 62.8% in group I and 41.5% in group II. On the other hand, there was no statistically significant cost reduction. Conclusions: The time investment in VSP in this study was significantly smaller than that in CSP, and the difference was greater in group I than in group II.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.4
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• pp.407-413
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• 2000

To evaluate the stability after orthognathic surgery in cleft lip and palate patients using rigid fixation, 20 patients underwent primary repair in childhood and later developed a jaw deformity and malocclusion that required orthognathic surgery were reviewed. Two groups, one of 10 patients performed Le Fort I osteotomy with sagittal split ramus osteotomy and one of 10 patients with sagittal split ramus osteotomy of the mandible, were evaluated. Each group had unilateral cleft only and all alveolar cleft sites had been grafted with autogeneous bone before the orthognathic surgery. The amount of surgical movement and relapse were compared in both horizontal and vertical dimensions. Two-jaw surgery group was more stable than mandibular surgery only group in mandibular position (p< 0.05). Statistically significant relapse was observed in mandibular skeletal point in mandibular surgery group (p<0.05). There was no statistically significant relapse in the skeletal point of two-jaw surgery group. However, the correlation between the horizontal surgical movement and relapse was detected (r = 0.88). This correlation indicates the need of overcorrection. The presence of scar tissues and relatively deficient maxillary bone could be attributed to this close relation between the surgical change and relapse.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.11 no.2
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• pp.19-27
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• 1989

Hemifacial microsomia is characterized underdevelopment of the TMJ, mandibular ramus, and associated muscles of mastication. The Maxilla and malar bones on the affected side frequently are underdeveloped. The contiguous parotid gland may be hypoplastic. Preauricular sinus tracts and tags may exist, along with underdevelopment of the associated external ear, and affected facial nerve and muscles of facial expression may also show dysfunction. Children exhibiting the more classic signs will be identified at birth. Little is known about the etiology of hemifacial microsomia. We have corrected surgically a 22-year-old woman with hemifacial microsomia. We have performed leveling Le Fort I osteotomy with iliac bone graft on the maxilla, reverse-L osteotomy and iliac bone graft on the right mandibular ramus, vertical ramus osteotomy on the left side, onlay bone graft on the right mandibular body, and augmentation genioplasty. The postoperative course was uneventful and restoration of facial asymmetry was achieved.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.40
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• pp.36.1-36.5
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• 2018

Background: Botulinum toxin-A (BTX-A) injection into muscle reduces muscular power and may prevent post-operative complication after orthognathic surgery. The purpose of this study was (1) to evaluate BTX-A injection into the masseter muscle on the prevention of plate fracture and (2) to compare post-operative relapse between the BTX-A injection group and the no injection group. Methods: Sixteen patients were included in this study. Eight patients received BTX-A injection bilaterally, and eight patients served as control. All patients received bilateral sagittal split ramus osteotomy for the mandibular setback and additional surgery, such as LeFort I osteotomy or genioplasty. Post-operative plate fracture was recorded. SNB angle, mandibular plane angle, and gonial angle were used for post-operative relapse. Results: Total number of fractured plates in patients was 2 out of 16 plates in the BTX-A injection group and that was 8 out of 16 plates in the no treatment group (P = 0.031). However, there were no significant differences in post-operative changes in SNB angle, mandibular plane angle, and gonial angle between groups (P > 0.05). Conclusions: BTX-A injection into the masseter muscle could reduce the incidence of plate fracture.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.16 no.3
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• pp.247-258
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• 1994

We got this conclusion from an investigation about complications from 144 cases of 130 patients who were to be searched their personal records, admission chart, clinical laboratory sheet, anesthetic record, consult sheet and radiographic opinion. They had orthognathic surgery for maxillofacial deformity treatment at the department of oral and maxillofacial surgery in dental school of Kyung Hee university for 4 years and 10 months, from March 1989 to December 1993. 1. In the intraoperative phase, by the frequency of complication, blood vessel injury was found the most-22%, and then soft tissue injury, unfavorable osteotomy split, and there were some cases of tooth injury and inappropriate osteotomy. In the mandibular segmental osteotomy, blood vessel injury was found the most frequently-20 cases (27%), soft tissue injury, unfavorable osteotomy split were the second frequent cases, and then unfavorable fragment position was found. In the extraoral vertical ramus osteotomy and Le Fort I osteotomy also, blood vessel injury and nerve injury were found the most. 2. In the postoperative hospitalization phase, by the frequency of complication, hematoma (23%) was happened the most, except for that, lkie the complication that can be happened by adverse reaction of medicine or long hospital life. In the case of SSRO, there were 21 cases (20%) of hematoma, and this wal the most frequently case. In the case of EVRO, hematoma wasn't happened that much-2 case (4%). 3. In the follow up phase, relaps, numbness and TMJ dysfunction were happened. In mandibular surgery, the forward relapse percentage of point B, was 27% when used wire fixation on SSRO, was 15% by miniplate fixation on SSRO and was 7% on EVRO. In the case of SSRO, numbness was kind of high, comparing to ordinary surgery-12 cases(16 There were many difficulties in analyzing this data accurately, Although orthognathic surgery is done many times, only available date is from the "success" stories and data is not consistently recorded for the cases with complications. In this manner, much essential informantion is lost and overlooked. When data is charted including those cases that are seemingly insignificalt, we can have a much clearer understanding and more accurate guide on treatment protocols.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.5
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• pp.447-453
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• 2010

The hemifacial microsomia is characterized by variable underdevelopment of the craniofacial skeleton, external ear, and facial soft tissues. So, patients with hemifacial microsomia have an occlusal plane canting and malocclusion with facial asymmetry. Distraction osteogenesis (DO) with an intraoral or extraoral device is a technique using tension to generate new bone with gradual bone movement and remodeling. DO has especially been used to correct craniofacial deformities such as a hemifacial microsomia, facial asymmetry, and mandible defect that could not adequately be treated by conventional reconstruction with osteotomies. It has a significant advantage to lengthen soft and hard tissue of underdeveloped site without bone graft and a few complication such as nerve injury or muscle contracture. A 13-years old girl visited our clinic for the chief complaint of facial asymmetry. She had a left hypoplastic maxilla and mandible, occlusal plane canting and malocclusion. We diagnosed hemifacial microsomia and lanned DO to lengthen the affected side. Le Fort I osteotomy, left mandibular ramus and symphysis osteotomy were performed. The internal distraction devices fixed with screw on maxillary and mandibular ramus osteotomy sites. External devices were adapted to lower jaw for DO on symphysis osteotomy site and to upper jaw for rapid maxillary expansion (RME). At 7days after surgery, distraction was started at the rate of 1mm per day for 13days, and after 4months consolidation periods, distraction devices were removed. Simultaneous multiple maxillo-mandibular distraction osteogenesis with RME resulted in a satisfactory success in correcting facial asymmetry as well as occlusal plane canting for our hemifacial microsomia.