3.The change of head posture after orthognathic surgery in mandibular prognathism.
Jung Hyun PARK ; Ji Ho YOO ; Choung Kook YI
Journal of the Korean Association of Oral and Maxillofacial Surgeons 1993;19(4):429-444
No abstract available.
Head*
;
Orthognathic Surgery*
;
Posture*
;
Prognathism*
4.Diagnosis and treatment of facial asymmetry.
Choong Kook YI ; Hyun Ho CHANG ; Hee Kyung KIM
Journal of the Korean Association of Oral and Maxillofacial Surgeons 1991;17(3):1-10
No abstract available.
Diagnosis*
;
Facial Asymmetry*
5.Diagnosis and treatment of facial asymmetry.
Choong Kook YI ; Hyun Ho CHANG ; Hee Kyung KIM
Journal of the Korean Association of Oral and Maxillofacial Surgeons 1991;17(3):1-10
No abstract available.
Diagnosis*
;
Facial Asymmetry*
6.EXPERIMENTAL STUDY ON RELAPSE AFTER RAMAL LENGTHENING IN DIFFERENT SURGICAL METHODS-RADIOGRAPHIC EVALUATION.
Choong Kook YI ; Hyun Ho CHANG ; Jung Hyun PARK
Journal of the Korean Association of Oral and Maxillofacial Surgeons 2000;26(6):636-643
Facial asymmetry is the most frequent disease in craniofacial deformities. And the primary causing area of that is mostly placing in mandible. That is to say, it is known that primarily, mandible grows excessively or deficiently, and other facial region involving maxilla undergoes compensatory growth secondarily, so asymmetric face develops. In facial asymmetry, the surgical correction of undergrowth is more difficult than that of overgrowth and the reason of it is the postoperative relapse caused by stress of surrounding soft tissues. It means the stress of surrounding soft tissues occurring after bone lengthening and reducing above stress is the same meaning with reducing postoperative relapse. Among various areas, mandibular ramus is the most difficult area to lengthen vertically and maintain its length. The reason of it is considered by many authors as the stress of surrounding pterygomasseteric sling which is enveloping lower border of mandible and interrupting elongation of ramal height. So we applied two different surgical procedures in which pterygomasseteric slings have different stress respectively to monkeys which have similar masticatory function and anatomy to human being and compared relapse by radiographic film and observed periodically the histochemical change of masseteric muscle fiber. So we could see the following results. The relapse was less in EVRO group in which we separated pterygomasseric sling in inferior border and didn't approximate muscle sling after vertical lengthening to minimize the stress of soft tissues than IVRO group in which we elongated ramal height preserving pterygomassetric sling. Of course, we could see a problem in EVRO group such as bone resorption in inferior border caused by uncovering the periosteum of inferior border. But we expect that such problem will be solved by developing periosteum substitutes for covering the exposed bone and minimizing the surgical trauma. In histochemical study of masseteric muscle fiber, the fiber constituents of EVRO group in which we minimized soft tissue stress was changed immediately after operation and maintained it for 1 year, whereas that of IVRO group in which we preserved soft tissue stress was changed in more portion after operation and recovered it by 1 year . By the histochemical results, we can see that the recovery of fiber constituents reflect the recovery of muscle stress and it is closely related with relapse phenomenon.
Bone Lengthening
;
Bone Resorption
;
Congenital Abnormalities
;
Facial Asymmetry
;
Haplorhini
;
Humans
;
Mandible
;
Maxilla
;
Periosteum
;
Recurrence*
;
X-Ray Film
7.A Study On The Change Of Airway Space And Cranial, Cervical Angulation After Mandibular Setback Operation.
Hyun Ho CHANG ; Jae Seung KIM ; Choong Kook YI
Journal of the Korean Association of Oral and Maxillofacial Surgeons 2000;26(2):115-131
In the study of craniofacial deformity, it is very important that identifying the factor which can affect the morphology and which is closely related to the morphology, because it can not only improve the comprehension of growth and developmental process but also be applied in growth prediction and treatment modality. Several investigators have already mentioned the characterstics of head posture and airway space in relations to morphologic difference. But it is very meaningful work in clarifying the correlation between morphology, head posture and airway space that observing the change of head posture after morplologic change caused by operation and the change of airway space after same procedure. To investigate above correlation, I selected normal group which is consisted of 43 adults and mandibular prognathism group which is consisted of 47 adults who had been operated by sagittal split ramus osteotomy and were followed up more than 1 year. With their lateral skull radiograghs, reference lines which can evaluate each measuring points and areas without effect of postural change were first determined. And using above reference lines, change of airway space, positional change of tongue and hyoid, change of cranial and cervical angulations were measured. The results obtained from the study were as follows 1. In the change of head posture, the position of tongue and hyoid neighboring to pharynx is more closely related to the reference line of cervical column than to reference line of cranium. 2. After mandibular setback operation, the airway dimension was decreased to 81.6% of preoperative state at 1 month postoperatively and was slightly increased to 89.7% at 1 year postoperatively. 3. Posterior movement of tongue plays important role in decrease of airway dimension and inferior movement of hyoid was closely correlated with posterior movement of tongue. 4. Postoperative anterior movement of mandible, namely, morphologic relapse had correlation with relapse phenomenon of airway dimension. 5. Craniocervical angulation increased postoperatively. Especially in the postoperative early state, there was increased foreward inclination of cervical angulation rather than increase of cranial angulation. But at postoperative 1 year it was observed that cervical inclination was returned to preoperative state and cranial angulation was increased gradually. 6. Increase rate of airway dimension was correlated with the increase of cranial angulation from postoperative 1 month to 1 year. In conclusion, relapse tendency of airway dimension following increase of cranial angulation was found after mandibular setback operation and it is considered that increase of cranial angulation is one of compensatory mechanism in airway maintenance.
Adult
;
Comprehension
;
Congenital Abnormalities
;
Growth and Development
;
Head
;
Humans
;
Mandible
;
Osteotomy, Sagittal Split Ramus
;
Pharynx
;
Posture
;
Prognathism
;
Recurrence
;
Research Personnel
;
Skull
;
Tongue
8.Energy Spectrum of KRISS 60Co Irradiation System.
Chul Young YI ; KooK Jin CHUN ; Suck Ho HAH ; Hyun Moon KIM
Korean Journal of Medical Physics 2008;19(2):139-141
The photon energy spectrum of KRISS 60Co irradiation system (AECL Eldorado 8) was calculated by means of the Monte Carlo method. The collimators were modeled realistically, and the material and dimensions of the 60Co sealed source were extracted from the source certificate given by the manufacturer. It was confirmed that the photon energy spectrum of KRISS 60Co irradiation system was in similar shape with those of NRC and BIPM.
Monte Carlo Method
9.The Outcome of Laparoscopic Common Bile Duct Exploration (LCBDE) for the Choledocholithiasis that ERCP Failed to Remove.
Hyun Sub LEE ; Seog Ki MIN ; Sun Young YI ; Hyeon Kook LEE
Journal of the Korean Surgical Society 2008;75(3):191-194
PURPOSE: With the advent of endoscopic technology, ERCP (endoscopic retrograde cholangiopancreatography)/ES (endoscopic sphincterotomy) has become the main treatment for CBD stones. However, when ERCP fails to remove CBD stones, it remains unclear whether laparoscopic treatment is an alternative or not. The aim of this study was to investigate the outcome of LCBDE for the management of difficult choledocholithiasis. METHODS: This study was a retrospective analysis of 68 LCBDE cases that were performed at the Ewha Womans University School of Medicine, Mokdong Hospital from January, 2000 to March, 2006. Group A was defined that primary LCBDE was performed without ERCP/ES. Group B was defined that secondary LCBDE was performed after ERCP/ES had failed. The operative outcomes and postoperative complications were compared between the two groups. RESULTS: Primary LCBDE was performed for 33 patients (Group A) and secondary LCBDE after failure of ERCP/ES was performed for 35 patients (Group B). No significant differences in gender, mean age and associated diseases were noted between the two groups. The stone clearance rate was 100% for both groups. There were no significant differences between the two groups for the mean operative time (201.5 min for Group A vs 188.7 min for Group B: P=0.415), the open conversion rate (9.1% vs 0%, respectively: P=0.068), the complication rate (12.1% vs 8.6%, respectively: P=0.630) and the duration of the hospital stay (14.3 days vs 11.9 days, respectively: P=0.169). The recurrence rate along with a mean follow-up of 24 months showed no significant difference between the two groups (12.1% vs 2.9%, respectively). CONCLUSION: When ERCP is impossible or stone retrieval is incomplete, LCBDE is an alternative treatment for difficult CBD stones.
Cholangiopancreatography, Endoscopic Retrograde
;
Choledocholithiasis
;
Common Bile Duct
;
Female
;
Follow-Up Studies
;
Humans
;
Length of Stay
;
Operative Time
;
Postoperative Complications
;
Recurrence
;
Retrospective Studies
10.Maxillary growth following cultured epidermal tissue graft and the administration of TGF-beta3 on surgically created palatal defects in rat.
Jung Hyun PARK ; Byung Ho CHOI ; Jung Wan KANG ; Jong In YOOK ; Jin KIM ; Choong Kook YI
Journal of the Korean Association of Oral and Maxillofacial Surgeons 2000;26(6):565-580
This study was designed to evaluate the influence of cultured epidermal tissue graft and the administration of transforming growth factor(TGF)-beta3 on maxillary growth in surgically created palatal defects. A total of 155 rats were divided into 2 groups according to surgical timing : postnatal 2 weeks(n=95), 4 weeks(n=40) and control(unoperated) group(n=20). The postnatal 2-week surgical group was subdivided into 3 groups according to repair methods: conventional surgery(Von Langenbeck technique)group(n=23); cultured tissue graft group(n=25); and full thickness skin graft group(n=25). Additionally, recombinant human TGF-beta3 was administered(30ng or 150ng) on collagen matrix in surgically created palatal defects during surgery(9 conventional surgeries, 9 cultured tissue grafts) in 2-week-old rats. The results showed that all types of surgical treatment decreased maxillary growth compared with the control(unoperated) group(p<0.0001). On the other hand, the tissue graft group, whether cultured tissue or grafted skin, contributed to increased maxillary growth(p<0.0001).And exogenous TGF-beta3 might play a role in connective tissue proliferation and new bone generation during wound healing on palatal defects. Our results suggest that grafting cultured epidermis with collagen matrix decreases the scar tension on maxillary growth more than conventional palatal surgery does. Therefore, exogenous TGF-beta3 may contribute to accelerate wound healing on palatal defects.
Animals
;
Cicatrix
;
Cleft Palate
;
Collagen
;
Connective Tissue
;
Epidermis
;
Hand
;
Humans
;
Rats*
;
Skin
;
Transforming Growth Factor beta3*
;
Transplants*
;
Wound Healing