• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.25 no.4
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• pp.356-360
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• 1999

PURPOSE : This is to review the complicated jaw fractures that had been referred for revision of the unsatisfactory results, and to provide proper managements for the easily complicated jaw fractures. MATERIALS & METHODS : Twenty-nine patients who had been revised due to malunion or complicated fractures of facial bones for last 3 years were reviewed. The main problems required for revision, type of fractures complicated, the primary managements to be reclaimed, the specialties to be involved, the management to be reclaimed, time elapsed to seek reoperation, type of revision surgeries, residual complication were analysed with medical records, radiographs and final examinations. RESULTS: The major complaints were malocclusion(79.3%), facial disfigurement(41.3%), TMJ problems (13.7%), neurologic problems(10.3%), non-union(10.3%), and infection(6.8%). Unsatisfactory results were occurred most frequently after improper management of the multiple fractures of the mandible (62.2%), combined fractures of maxilla and mandible (20.6%), fracture of zygomatico-maxillary complex and midpalate (17.2%). The complications to be corrected were widened or collapsed dental arches (79.3%), improperly reduced condyles (41.3%), painful TMJ (34.4%), limited jaw excursion (31.0%), over-reduction of zygoma (13.7%), and nonunion with infection(13.7%). and dysesthesia (10.3%). The primary managements were nendereet by plastic surgeons in 82.7%(24/29) and by oral surgeons in 7.6%(2/29). Main causes of malunion are inadequate ORIF in 76%, unawareness & delay in 17%, and delayed due to systemic cares in 17%. 76% of 29 patients had been in state of intermaxillary fixation for over 4 weeks. Revision were done by means of "refracture and ORIF"in 48.2%(14/29), orthognathic osteotomies with bone grafts in 55.1%(16/29), and camouflage countering & alloplastic implantations in 37.9%(11/29), TMJ surgeries in 17.2%, micro-neurosurgeries in 11.6%. Residual complications were limited mouth opening in 24.1% (7/29), paresthesia in 13.7%, resorption of reduced condyle in 10.3%. CONCLUSIONS : Failure of initial treatment of jaw fractures is due to improper diagnosis and inadequate treatment with lack of sufficient knowledge of stomatognathic system. It is crucial to judge jaw fracture and patients accurately, moreover, the best way of treatments has to be selected. Consideration of these factors in treatment could minimize the complication of jaw fractures.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.25 no.4
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• pp.337-349
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• 1999

The extracellular matrix(ECM) is a complex network of different combination of collagens, glycosaminoglycans, laminin, fibronectin, and many other glycoproteins including proteolytic enzymes. The composition and organization of the ECM contributes to the uniques physical or biomechanical properties of a tissue. Fibronectins(FN) are dimeric glycoproteins located on cell surfaces, in the matrix of connective tissue, and in blood. Fibronectins mediate cell attachment to collagen substratum and have been implicated in a variety of important biological processes, including embryogenesis and cell differentiation. The purpose of this study was to determine the effects of surgical induction of anterior disk displacement(ADD) on distribution of fibronectin in the rabbit temporomandibular joint(TMJ) tissues included the articular cartilage, disc, retrodiscal tissue, articular eminence using an immunohistochemical technique. The left TMJ was exposed surgically, and all discal attachments were severed except for the posterior attachment. The disk was then repositioned anteriorly and sutured to the zygomatic arch. The right TMJ served as a shamoperated control. Normal joints were used as a nonoperated control. Fourty-five rabbits were used for experiments in total. For fibronectin immunohistochemical study, eighteen rabbits (one normal group and 5 experimental groups, each group consists of 3 rabbits) were used. The experimental rabbits were sacrified after operation period of 2, 3, 4, 6 and 8 weeks on fibronectin. The obtained results were as follows ; 1. Fibronectin immunoreaction on all TMJ tissues(mandibular condyle, articular disc, retrodiscal tissue, articular eminence) in the normal rabbit was observed. Especially the reverse cell layer and proliferation zone of articular cartilage of condyle show strong positive reaction. 2. Depletion of fibronectin in the all TMJ tissues except hypertrophic zone of articular cartilage occurred at 2 weeks following induction of ADD. 3. The restoration of immunoreaction at 4 weeks was observed and a progressive increasing reaction at 6 weeks, 8 weeks also was found. Our study generally showed degenerative changes in TMJ tissues after ADD although TMJ tissues adapted or degenerated to abnormal loads and stress distribution according to the remodeling capacity of TMJ tissues.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.2
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• pp.116-129
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• 2005

Distraction osteogenesis is a new bone formation technique. There is a advantage of the environmental adaptation when distraction force is applied to the gap between osteotomy lines. But it has a disadvantage of long-term wearing of the appliance and long consolidation period. Therefore we make an effort to reduce it and repair normal function. Extracellular matrix proteins have a function to control the cellular growth, migration, shape and metabolism. In these, hyaluronic acid is a member of polysaccharide glycosaminoglycans (GAGs) and has a important function as bone formation and osteoinduction property. Purpose : In this experimental study in rabbit mandibular distraction osteogenesis, we investigated the bone enhancing property of hyaluronic acid and the expression of extracellular proteins such as osteocalcin and osteonectin. Materials and Methods : The experimental study was carried out on 24 Korean male white rabbits (both mandibular body, n=48). Distraction group was divided to distraction experimental (A, n=16) and distraction control (B, n=16) by the application of hyaluronic acid (Hyruan, LGCI, Seoul, Korea). Normal control group (C, n=16) was only osteotomized. After 5 days latency, distraction devices were activated at a rate of 1.4 mm per day (0.7 mm every 12hours) for 3.5 days. Animals were sacrificed at postoperative 3, 7, 14, and 28 days. H&E stain and immunohistochemical stain was done on decalcified section. Additionally RT-PCR analysis was done for the identification of the expression of osteocalcin and osteonectin. Results : The bone formation in distraction experimental group was much more than that in distraction and normal control group at postoperative 28 days. In immunohistochemical stain, osteocalcin was enhanced at only postoperative 14 days, but osteonectin was not different at each post-operation days. In RT-PCR analysis, osteocalcin was not different at each post-operation days, but osteonectin was strongly expressed in distraction experimental group at postoperative 7 days. The expression of osteocalcin and osteonectin was elevated during the healing period. Conclusion : We found the good bone formation ability of hyaluronic acid in distraction osteogenesis through the immunohistochemistry and RTPCR analysis to osteocalcin and osteonectin, known as a bone formation marker. The application of hyaluronic acid in distraction osteogenesis is a method to reduce the consolidation period.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.1
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• pp.34-42
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• 2004

The appropriate care to the dental emergency patients is much important in the aspect of community dental service. To attain such a purpose, the sacred duty of the training of oral and maxillofacial surgeons is required. So, a retrospective study on the characteristics of dental injuries and diseases in emergency care unit will be very meaningful. This study was carried by reviewing the charts and radiographic films of 3,394 patients, treated for dental emergency at Wonju Christian Hospital, Republic of Korea, from January 1, 1993 to December 31, 2002. All patients were classified to 6 groups including trauma, toothache, infection, hemorrhage, TMJ disorder and the others. The clinical characteristics of diseases and treatment modalities according to each group were analyzed. The trauma (73.9%) was the most frequent cause in dental emergency patients, and acute toothache, odontogenic infection, oral hemorrhage, and TMJ disorder were next in order. Gender prediction was male (68%), there were many patients on May and December in the monthly frequency, and the most frequent age group was from 0 to 9 years. In the trauma group, male (68.6%) was predominant, and soft tissue injuries and primary closures were the most frequent type of injury and treatment. In jaw fractures, traffic accidents were the most cause and the weakest site was mandibular symphysis area, and mandibular angle, condyle, and body area were next in order. In the acute toothache group, the cause was dental pulpitis mostly and treatment for that was drug administration mainly. Buccal space abscess in infection group had the largest incidence (24.5%), and common treatments were incision and drainage and medications. In the hemorrhage group, a major cause was postoperative bleeding (60.3%) and hemostasis was obtained by pressure dressing, curettage and suture. For the TMJ disorder group, the peak incidence (63.8%) was shown in the post-traumatic myofascial pain dysfunction syndrome and its primary care was medication such as analgesics and sedatives. In the other group, the various specific symptoms were complained due to acute sialadenitis, trigeminal neuralgia, acute stomatitis, chemical burn, terminal stage neuritis of head and neck cancer, and foreign body aspiration. In conclusion, for the rapid and proper care of the emergency dental diseases, well-trained education should be presented to the intern and resident course of oral and maxillofacial surgery. And it is demanded that oral and maxillofacial surgeons must be prepared in knowledge and skill for such emergency care.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.1
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• pp.1-16
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• 2004

The use of artificial nerve conduit containing viable Schwann cells is one of the most promising strategies to repair the peripheral nerve injury. To fabricate an effective nerve conduit whose microstructure and internal environment are more favorable in the nerve regeneration than existing ones, a new three-dimensional Schwann cell culture technique using $Matrigel^{(R)}$. and dorsal root ganglion (DRG) was developed. Nerve conduit of three-dimensionally arranged Schwann cells was fabricated using direct seeding of freshly harvested DRG into a $Matrigel^{(R)}$ filled silicone tube (I.D. 1.98 mm, 14 mm length) and in vitro rafting culture for 2 weeks. The nerve regeneration efficacy of three-dimensionally cultured Schwann cell conduit (3D conduit group, n=6) was assessed using SD rat sciatic nerve defect of 10 mm, and compared with that of silicone conduit filled with $Matrigel^{(R)}$ and Schwann cells prepared from the conventional plain culture method (2D conduit group, n=6). After 12 weeks, sciatic function was evaluated with sciatic function index (SFI) and gait analysis, and histomorphology of nerve conduit and the innervated tissues of sciatic nerve were examined using image analyzer and electromicroscopic methods. The SFI and ankle stance angle (ASA) in the functional evaluation were $-60.1{\pm}13.9$, $37.9^{\circ}{\pm}5.4^{\circ}$ in 3D conduit group (n=5) and $-87.0{\pm}12.9$, $32.2^{\circ}{\pm}4.8^{\circ}$ in 2D conduit group (n=4), respectively. And the myelinated axon was $44.91%{\pm}0.13%$ in 3D conduit group and $13.05%{\pm}1.95%$ in 2D conduit group to the sham group. In the TEM study, 3D conduit group showed more abundant myelinated nerve fibers with well organized and thickened extracellular collagen than 2D conduit group, and gastrocnemius muscle and biceps femoris tendon in 3D conduit group were less atrophied and showed decreased fibrosis with less fatty infiltration than 2D conduit group. In conclusion, new three-dimensional Schwann cell culture technique was established, and nerve conduit fabricated using this technique showed much improved nerve regeneration capacity than the silicone tube filled with $Matrigel^{(R)}$ and Schwann cells prepared from the conventional plain culture method.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.1
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• pp.43-48
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• 2004

Purpose: Among the various surgical methods used for the effective treatment of cystic lesion in the jaws historically, decompression procedure has some of superior prognosis compare to direct enucleation. In order to propose the efficacy of decompression we performed this retrospective study to compare decompression procedure with one-stage enucleation in clinical results and prognosis. Patients and Methods: We reviewed 175 patients who had been histopathologically diagnosed cystic lesions from 1996 to 2000 in our department. Patients who had been received decompression alone or secondary enucleation after decompression were 31 cases, and enucleation alone were 144 cases. The age and sex of the patients, the area, size, and histological type of the lesions, and detailed operation and complications including recurrence were investigated. The minimal follow-up period was 2 years. Results: In 31cases of decompression, male patients were 22cases(71%) similar to male predilection(62.3%) in total 175 cases. Cystic lesions were developed evenly in all age groups totally. Decompression was mainly performed in teenagers but enucleation was used in elder decades. In decompression cases the lesions were located in mandibular posterior, maxillary posterior, mandibular anterior, and maxillary anterior in order, which had some differences in total and enucleation cases. In enucleation cases, less than 3cm in size was 77.1% but larger than 3cm was 93.5% in decompression cases. Histopathologically, dentigerous cysts(54.8%), unicystic ameloblastomas(16.1%), and odontogenic keratocysts(12.9%) were seen in decompression cases and no recurrence or metaplasia and infection was observed. On the other hand, permanent tooth loss, numbness, recurrence, and so on were accompanied after enucleation. Conclusion: Although decompression procedure has disadvantages such as many of visiting times and slow recovery of the surgical defect, decompression is the best choice of treatment for large cystic lesions of the jaws, because it prevents functional and cosmetic defect, allows bone regeneration, and makes easy secondary enucleation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.2
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• pp.170-177
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• 2005

The pleomorphic adenoma is well recognized as the most common salivary neoplasm. We examined 49 patients who had received surgical excision of the pleomorphic adenoma from 1989 to 1998 with over 5 years follow-up period. We retrospectively evaluated the patients' age, sex, chief complaints, surgical methods, and recurrence or complication rates after analysis of one's clinical and surgical records. The results are as follows : 1. There were 15 cases in parotid gland, 23 cases in palate, 8 cases in submandibular gland, and 3 cases in cheek. The ratio of male to female was 1 : 1.13. The mean age was 44. The tumor of submandibular gland occurred in more younger age than that of other salivary gland. 2. In 15 patients of parotid pleomorphic adenoma, there was 1 case(6.7%, 1/15) of recurrence. That was transformed into the malignant pleomorphic adenoma after 4 years of first surgery. We performed superficial parotidectomy of 9 cases(56.2%, 9/16), total parotidectomy of 6 cases(37.5%, 6/16), and radical parotidectomy of 1 case(6.3%, 1/16). 3. We used the rotational Sternocleidomastoid muscular flap to cover the exposed facial nerve in 12 cases(75%) after parotidectomy(7 cases of superficial parotidectomy and 5 cases of total parotidectomy). We could see 3 cases(18.7%) of facial nerve palsy and 1 case(6.3%) of Frey's syndrome after parotidectomy. We examined Frey's syndrome in only 1 case which was not used SCM muscular flap after parotidectomy. 4. In 23 patients of palatal pleomorphic adenoma, there were 2 cases(8.7%) of recurrence. In recurrence cases, We performed re-excision after 4 and 5 years of first surgery, respectively. We preserved partial thin overlying palatal mucosa during tumor excision in 5 cases(20%), which were proved as benign mixed tumor in preoperative biopsy. That mucosa-preserved cases had thick palatal mucosa, did not show mucosa ulceration and revealed well encapsulated lesions in preoperative CT. 5. In palatal tumors, we could see the 13 cases(52%) of bony invasion in preoperative CT views and the 4 cases(16%) of oro-nasal fistula after tumor excision. In two cases of recurrence, one(20%, 1/5) was in palatal mucosa-preserved group and the other(5.5%, 1/18) was in palatal mucosa-excised group. 6. We excised tumors with submandibular glands in the all cases of submandibular pleomorphic adenoma. There was no specific complication or recurrence in these cases. 7. After excision of the cheek pleomorphic adenomas, we could not see any complication or recurrence.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.5
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• pp.380-385
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• 2010

Introduction: The iliac crest has been the accepted place to obtain bone for reconstruction in oral and maxillofacial surgery. The iliac crest has many advantages because of its accessibility, large amount of cancellous bone, relative ease of bone harvest, possibility of two team approach and ability to close the wound primarily. This study evaluated retrospectively the morbidity of bone harvesting from the anterior iliac crest to provide a logical guide for recognizing the complications and morbidities of an iliac crest bone graft. Materials and Methods: Fifty healthy patients (mean age of 35.5 years; range 7 to 59) underwent iliac crest bone harvesting for a maxillofacial reconstruction from January 2007 to September 2009 at the Department of Oral and Maxillofacial Surgery in Kyungpook National University Hospital. Age, sex, size and kind of grafted bone, duration of pain on donor site, duration of gait disturbance, sensory deficit, scar, contour defect were measured in each patients by retrospective research. Results: The mean duration of pain is 6.7 days, and mean duration of gait disturbance is 7.2 days. Most patients were free from gait disturbances and pain within 2 weeks and there was no correlation between the size of the harvesting block bone and the duration of gait disturbance or pain. However, this study showed that the duration of pain is associated with gait disturbance. In addition, most patients had no complaints regarding their surgical scar and contour defect, and only one patient had permanent impairment of the sensory function. Moreover, an iliac bone graft did not extend the length of hospitalization. Conclusion: This study suggests that split thickness bone harvesting from the inner table of the anterior iliac crest is a well accepted procedure with relatively low morbidity.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.6
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• pp.460-465
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• 2010

Introduction: A cleft palate is a common birth defect in humans with an incidence of 1/500 to 1/1,000 births. It appears to be caused by multiple genetic and environmental factors during palatogenesis. Many molecules are involved in palate formation but the biological mechanisms underlying the normal palate formation and cleft palate are unclear. Accumulating evidence suggests that transforming growth factor $\beta$/bone morphogenetic proteins (TGF-$\beta$/BMP) family members mediate the epithelial-mesenchymal interactions during palate formation. However, their roles in palatal morphogenesis are not completely understood. Materials and Methods: To understand the roles of TGF-$\beta$/BMP signaling in vivo during palatogenesis, mice with a palatal mesenchyme- specific deletion of Smad4, a key intracellular mediator of TGF-$\beta$/BMP signaling, were generated and analyzed using the Osr2Ires-Cre mice. Results: The mutant mice were alive at the time of birth with open eyelids and complete cleft palate but died within 24 hours after birth. In skeletal preparation, the horizontal processes of the palatine bones in mutants were not formed and resulted in a complete cleft palate. At E13.5, the palatal shelves of the mutants were growing as normally as those of theirwild type littermates. However, the palatal shelves of the mutants were not elevated at E14.5 in contrast to the elevated palatal shelves of the wild type mice. At E15.5, the palatal shelves of the mutants were elevated over the tongue but did not come in contact with each other, resulting in a cleft palate. Conclusion: These results suggest that mesenchymal Smad4 mediated signaling is essential for the growth of palatal processes and suggests that TGF-$\beta$/BMP family members are essential regulators during palate development.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.2
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• pp.108-118
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• 2010

Introduction: Maxillary posterior region, compared to the mandible or maxillary anterior region, has a thin cortical bone layer and is largely composed of cancellous bone, and therefore, it is often difficult to achieve primary stability. In such cases, sinus elevation with bone graft is necessary. Materials and Methods: In this research, 121 patients who had implant placement after bone graft were subjected to a follow-up study of 5 years from the moment of the initial surgery. The total survival rate, 5-year cumulative survival rate and the influence of the following factors on implant survival were evaluated; the condition of the patient (sex, age, general body condition), the site of implant placement, diameter and length of the implant, sinus elevation technique, closure method for osseous window, type of prosthesis and opposing teeth. Results: 1. The 5-year cumulative survival rate of total implants was 90.5%, there was no significant difference between sex, age, the site of implant placement, diameter and length of the implant, sinus elevation technique, and the type of opposing teeth. 2. Patients with diabetes mellitus < osteoporosis and smooth-surfaced machined group < hydroxyapatite (HA)-treated group and homogenous demineralized freeze dried allogenic bone (DFDB) bone graft only group had significantly lower survival rate. 3. With less than 4 mm of residual alveolar ridge height, lateral approach without closing the osseous window resulted in a significantly lower survival rate. 4. Restoration of a single implant showed a significantly lower survival rate, compared to cases where the superstructure was joined with several implants in the area. Conclusion: Patients with diabetes or osteoporosis need longer period of time for osseointegration compared to the normal, and the dentists must be prudent when choosing a surface treatment type and the bone graft material. Also, as the vertical dimension of the residual alveolar ridge can influence the result, staged implant placement should be considered when it seems difficult for the implant to gain primary stability from the residual bone with less than 4 mm of vertical dimension. It is recommended to obdurate the bone window and that the superstructure be connected with several impants in the peripheral area.