• Maxillofacial Plastic and Reconstructive Surgery
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• v.19 no.4
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• pp.351-361
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• 1997

This study was performed to evaluate the change of the soft tissue facial profile after mandibular set back surgery during time intervals. For this study, 33 patient, 8 males and 25 females, were selected and their lateral cephalograms were taken and analyzed periodically. Hard and soft tissue changes during postoperative time intervals, correlation between surgical skeletal changes and postoperative soft tissue changes, and prediction for long-term soft tissue changes were established through varying statistical methods. The results were as follow : 1. There were meaningful changes of anteroposterior skeletal position at 6 months and 2 years after mandibular set back by mandibular ramus osteotomy. Two years postoperatively, there was 30%, 32%, 29% relapse on B point, pogonion, menton each. 2. Two years after the mandibular ramus osteotomy, the relative changes of the soft tissue to their osseous counterparts showed 76% on the lower lip and 91% on the pogonion. 3. The movements of the mandibular landmarks in correlation to anteroposterior position of the lower lip and soft tissue of the chin showed to be effective on a long-term basis. 4. Using surgical changes of pogonion, prediction of changes in soft and hard tissue pogonion was useful and the coefficient of determination was 0.46 each and their reliability decreased 2 years postoperatively. 5. The upper lip position after the mandibular set back surgery was somewhat anterior 2 years postoperatively, but that has no statistical meanings.

• The korean journal of orthodontics
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• v.50 no.4
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• pp.258-267
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• 2020

Objective: This study aimed to analyze the correlation of horizontal and sagittal planes used in two-dimensional diagnosis with lip canting by using three-dimensional (3D) analysis. Methods: Fifty-two patients (25 men, 27 women; average age: 24 years) undergoing treatment for dentofacial deformity were enrolled. Computed tomography images were acquired, and digital imaging and communication in medicine files were reconstructed into a 3D virtual model wherein horizontal and sagittal craniofacial planes were measured. Subsequently, the correlations of lip canting with these horizontal and sagittal planes were investigated. Results: The mandibular symmetry plane, the occlusal plane, Camper's plane, the mandibular plane, Broadbent's plane, and the nasal axis plane were correlated with the amount of lip canting (Pearson's correlation coefficients: 0.761, 0.648, 0.556, 0.526, 0.438, and 0.406, respectively). Planes associated with the lower part of the face showed the strongest correlations; the strength of the correlations decreased in the midfacial and cranial regions. None of the planes showed statistically significant differences between patients with clinical lip canting (> 3°) and those without prominent lip canting. Conclusions: The findings of this study suggest that lip canting is strongly correlated with the mandibular symmetry plane, which includes menton deviation. This finding may have clinical implications with regard to the treatment of patients requiring correction of lip canting. Further studies are necessary for evaluating changes in lip canting after orthognathic surgery.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.6
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• pp.506-513
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• 2006

The purpose of this study was to examine the familial tendency of the patients with mandibular prognathism in three generations and to define the relationship between the familial tendency and the skeletal class III morphology. The probands of this study were 103 orthognathic surgery patients with skeletal Class III malocclusions who had undergone (48 men, 55 women) mandibular set-back surgery. A questionnaire was given to patients who sought surgical treatment for excessive mandibular length, and all answers were confirmed in interviews. Lateral cephalograms were analyzed in cranial base parameters, mandibular positional parameters and mandibular skeletal parameters. In the examined families, 58.3% had at least one member other than the proband who had mandibular prognathism. The affected ratio of total relatives was 4.5%, and the value was higher in first-degree (13.4%) than second-degree (5.9%) and third-degree relatives (1.7%). The affected ratio was 51.9% in the offsprings who had at least one affected father or mother. The comparison of the groups according to the familial tendency showed no significant craniofacial skeletal measurments. In conclusion, skeletal class III malocclusion showed high familial tendency, suggesting a significant genetic influence in the etiology. However, the patient's familial tendency did not show the special craniofacial patterns compare to the subjects without familial tendency.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.3
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• pp.197-201
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• 2010

Introduction: In a surgery of the oral cavity, nasotracheal intubation is often carried out to secure the surgical field. By passing a tracheal tube through the nasal cavity to the pharynx, the nasotracheal intubation can lead to complications that do not occur with oral intubation, such as nasal bleeding and submucosal aberration etc. The purpose of this study is to examine the method of CT evaluation and pretreatment for a safe nasotracheal intubation. Materials and Methods: Among 30 patients who orthognathic surgery was performed at Chung-Ang University Hospital during the period August 2009 to October 2009, 30 patients were included. The 30 patients were divided into two groups; 15 patients intubated with CT evaluation with pretreatment, and the other 15 patients intubated with no pretreatment. We evaluated nasal bleeding of the two groups during nasotracheal intubation. Results: CT evaluation with pretreatment group had a significantly lower incidence of nasal bleeding than the group with no pretreatment. Conclusion: CT evaluation with pretreatment helps to minimize nasal bleeding during nasotracheal intubation.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.41
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• pp.12.1-12.5
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• 2019

Background: Le Fort I osteotomy is one of the surgical procedures now routinely and safely performed. It is possible to move the maxilla in three dimensions, but it is necessary to separate the bones around the maxillary sinus. Therefore, with surgery, maxillary sinus mucosal thickening occurs. By knowing the changes in the sinus mucosa after surgery and the factors affecting it, it is possible to better predict the outcomes of surgery and contribute to safer surgery. In this study, thickening of maxillary sinus mucosa before and after surgery in Le Fort I osteotomy was evaluated using multidetector-row computed tomography (MDCT) images, and the changes in mucosal thickening and the related factors were examined. Methods: Using MDCT images, the maxillary sinus mucosa of 125 patients who had undergone Le Fort I osteotomy was retrospectively evaluated before surgery, 1 month after surgery, and 1 year after surgery. On the MDCT images, the maxillary sinus was judged as mucosal thickening and classified into three grades according to the proportion occupying the maxillary sinus. In the evaluation of factors related to mucosal thickening, the following eight factors were examined: sex, age, diagnosis, operating time, amount of postoperative bleeding, with/without bone graft, with/without multisegmental osteotomy, and with/without macrolide therapy after surgery. Results: The mean age at the time of surgery was 25.6 ± 8 years. Of all 125 patients, 66 had bilateral thickening, 19 had unilateral thickening, and 40 had no thickening. Factors that were significantly related to mucosal thickening were the operative time for the maxilla, bone grafts, and macrolide therapy after surgery. Conclusions: Operative time for the maxilla, bone grafts, and macrolide therapy after surgery were found to be related to mucosal thickening. In addition, MDCT scanning 1 month after surgery was considered to be appropriate for evaluation of maxillary sinus mucosal thickening.

• The korean journal of orthodontics
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• v.25 no.1 s.48
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• pp.101-110
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• 1995

The purpose of this study was to observe the tissue response to the orthodontic force applied immediately after buccal horizontal subapical osteotomy of maxilla. Five mongrel cats weighing about 2.5 Kg were used for this experiment. The left upper canine and premolar of each cat served as a experimental side and the right ones as a control side. On the experimental side, a 100gm orthodontic force was applied between the upper canine and premolar immediately after the osteotomy. On the control side, the same orthodontic force was applied without the osteotomy. After 7days, the experimental animals were sacrificed. The results were as follows: 1. In the pressure zones of the experimental group, significant increase of osteoclasts and direct resolution along the alveolar bone surface was observed as compared with those of the control group. 2. In the pressure 2ones of the experimental group, a less extensive hyalinized zone was observed than those of the control group. 3. In the pressure zones of both group, no root resorption was found. 4. Tn the tension zones of the experimental group, new bone deposition increased along the alveolar bone surface as compared with those of the control group. In conclusion, the results suggest the possibility that early orthodontic treatment after orthognathic surgery may have some benefits if the stability of the repositioned segment at surgery is secured.

• The korean journal of orthodontics
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• v.29 no.3 s.74
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• pp.285-301
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• 1999

There is a need for more accurate prediction in surgical orthodontic treatment. Video imaging is an important technology in planning orthognathic surgery and educating patients about the esthetic results after treatment. Preoperative and postoperative lateral cephalogram of 30 patients who had one piece Le Fort I osteotomy advancement and mandibular set back by bilateral intraoral vertical ramal osteotomy with or without genioplasty were used in this study. The computer generated soft tissue line drawing prediction were compared with the actual postoperative cephalograms .The results are as follows. 1. 14 variables showed Statistically significant differences from 24 variables between computer predicted profile and post operative profile 2. Most of the differences were found in the maxilla-related soft tissue landmarks. 3. The predicted results were more accurate in the groups who had small amount of mandibular set back. 4. The predicted results were more accurate in the groups who had no genioplasty. Most of these differences were within 2mm ranges. Therefore profile change prediction by video imaging could be considered clinically acceptable.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.3
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• pp.355-364
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• 2008

Skeletal anterior open bite is a difficult problem to correct in orthodontic treatment. To treat adult patients who have skeletal anterior open bite, we considered two methods. Combination treatment of orthodontics & surgery and camouflage orthodontic treatment. In adults, treatment of severe skeletal anterior open bite consists mainly of surgically repositioning the maxilla or the mandible. However, camouflage therapy is often the treatment of choice for skeletal open bite patients who have mild to moderate skeletal discrepancies when growth modification is no longer possible. But excellent results generally require careful coordination of the orthodontic and surgical phases of treatment. This is a case report of a skeletal anterior open bite patients who were treated with orthodontic treatment and orthognathic surgery. First case was diagnosed as skeletal class I malocclusion & bimaxillary protrusion with anterior open bite, and finally treatment ended for removal of open bite with orthodontic procedure and bimaxillary anterior segmental osteotomy surgery. Second case was diagnosed as skeletal class II malocclusion with open bite & mandibular retrusion, and was treated with only camouflage orthodontics because she feared to have a surgery. In a regular follow up visit after debonding we proposed to the patient advanced genioplasty, and in her agreement her facial esthetics was improved through the 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.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.5
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• pp.537-542
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• 2008

BSSRO is most frequently operated among orthognathic surgery techniques for repairment of maxillofacial deformities. In case of patients with maxillofacial asymmetry accompanying mandibular protrusion who are operated by BSSRO, this study considers the recovering time for masticatory force of each tooth and Masseteric EMG and the adequate time enabling normal occlusion. The patients who are operated with BSSRO under general anesthesia in Dankook Dental Hospital, Department of OMS are selected for this study. The control group is devided into 2. 26 patients with facial asymmetry accompanying mandibular protrusion are selected for group 1 and their maximum voluntary bite force and masseteric EMG are measured. Group 2 is formed by volunteers with healthy dentition who are measured maximum bite force and masseteric EMG on both sides of the mouth. At the week of 3rd, 5th, 7th, 9th and 11th, Mann-Whitney U test is carried on for statistical analysis and the result is as follows. 1. Patients with mandibular protrusion showed apparently low maximum bite force and masseteric EMG than patients with normal occlusion. 2. In comparison with control group 1, Occlusal force is regained in incisors and canines at the 9th week and in premolars and molars, 11th week and masseteric EMG is regained at 11th week. 3. Comparing to normal occlusal patients, no recovery could be found in experimental group in every parts of the mouth.