Development of New Orthognathic Model Surgery Technique Based on the Reference Points onto the Teeth and the Use of Occlusal Index

Heterotopic Gastrointestinal Cyst of the Tongue: Case Report

The Efficacy of Postoperative Prophylactic Antibiotics in Orthognathic Surgery: A Prospective Study in Le Fort I Osteotomy and Bilateral Intraoral Vertical Ramus Osteotomy

PURPOSE: This study examined the efficacy of the postoperative prophylactic antibiotics used in orthognathic surgery. The prevalence of surgical site infections (SSIs) was determined according to the use of postoperative prophylactic antibiotics. PATIENTS AND METHODS: Fifty-six patients were divided into 2 groups. Each patient intravenously received 1.0 g of a third-generation cephalosporin (Cefpiramide) 30 minutes before surgery. Among them, 28 patients in the control group received 1.0 g Cefpiramide twice daily until the third day after surgery. The postoperative wounds were examined regularly for the presence of infectious signs. RESULTS: There was no significant difference in the incidence of postoperative wound infections between patients who had received postoperative prophylactic antibiotic administration and those who had not (p = 0.639). CONCLUSION: Prolonged prophylactic antibiotic use after orthognathic surgery may not be necessary, provided that there are no other significant factors for wound infections.

Image fusion accuracy for the integration of digital dental model and 3D CT images by the point-based surface best fit algorithm

PURPOSE: The goal of this study was to develop a technique for creating a computerized composite maxillofacial-dental model, based on point-based surface best fit algorithm and to test its accuracy. The computerized composite maxillofacial-dental model was made by the three dimensional combination of a 3-dimensional (3D) computed tomography (CT) bone model with digital dental model. MATERIALS AND METHODS: This integration procedure mainly consists of following steps : 1) a reconstruction of a virtual skull and digital dental model from CT and laser scanned dental model ; 2) an incorporation of dental model into virtual maxillofacial-dental model by point-based surface best fit algorithm; 3) an assessment of the accuracy of incorporation. To test this system, CTs and dental models from 3 volunteers with cranio-maxillofacial deformities were obtained. And the registration accuracy was determined by the root mean squared distance between the corresponding reference points in a set of 2 images. RESULTS AND CONCLUSIONS: Fusion error for the maxillofacial 3D CT model with the digital dental model ranged between 0.1 and 0.3 mm with mean of 0.2 mm. The range of errors were similar to those reported elsewhere with the fiducial markers. So this study confirmed the feasibility and accuracy of combining digital dental model and 3D CT maxillofacial model. And this technique seemed to be easier for us that its clinical applicability can good in the field of digital cranio-maxillofacial surgery.

The Efficacy of Prophylactic Antibiotics for Mandibular Third Molar Extraction

This study analyzed the incidence of wound infection after the operation of mandibular third molar extraction in relation with antibiotic prophylaxis with the object of young and healthy patients. The study object was 1,177 mandibular third molars of 850 men of 20 to 25 years old without any specific systemic disease. Three methods of preventive antibiotic medication were selected according to the preventive antibiotic medication previously reported; three experimental groups were selected based on them, and the antibiotic used was amoxicillin((R)Kymoxin, Yuhanyanghaeng, Seoul). The group 1 includes the patients that took the antibiotic orally before the operation(one hour earlier, 500mg) and for three days after the operation(250mg per time, three times/day), the group 2 is the ones that took the same antibiotic orally only once about one hour before the operation(500mg), and the group 3 did not take any antibiotics before and after the operation. And to compare the difficulties and the degrees of extraction during operations which can be possibly related to the wound infection after the operations, the mandibular third molars' impacted depths and extraction methods were investigated as well. To check if the wound was infected, observations with an internal of one week were performed twice after the operation, and the meaningfulness of the infection incidence was verified through Chi-square test using SPSS program(SPSS Inc., IL, USA). There was no statistically significant difference between the antibiotic medication methods and the wound infection incidence after the operation among the experimental groups. As examining the relations between the mandibular third molar operation methods and the wound infection incidence after the operation, there existed a statistically meaningful difference in the infection incidence according to the operation methods(p=0.020). And there was no statistically significant difference in the wound infection incidence according to the impacted depth of the mandibular third molar. Therefore, it is thought that there exists little necessity of prophylatic antibiotics medication when extracting the mandibular third molar of young and healthy men without any systemic disease in general; however, in case when it is expected that the possibility of infection will be high or the wound on the tissue will be severe, it is sure that the prophylactic antibiotics medication will be necessary.

Langerhans Cell Histiocytosis in the Juvenile Mandible

Accuracy of digital model surgery for orthognathic surgery: a preclinical evaluation

The relationship between the symptoms of the patients and post-surgical application of antibiotics in orthognathic surgery

The effectiveness of post operative administration of antibiotics in orthognathic surgery: infection frequency based on post-surgical application of antibiotics

Reconstruction of alveolar clefts with iliac cancellous particulate or block bone grafts: a comparative study

OBJECTIVE: The objective of this study was to determine which forms of iliac cancellous bone grafts better restore alveolar clefts. STUDY DESIGN: Forty consecutive patients who required a unilateral alveolar cleft graft were studied. Group I(20 patients) had reconstruction with iliac cancellous particulate bone grafts and group II(20 patients) had reconstruction with iliac cancellous block bone grafts. The two groups were evaluated radiographically and clinically. RESULTS: The group with the block bone grafts showed less postoperative problems and better incorporation of the bone graft than the group with the particulate grafts. CONCLUSION: Surgical reconstruction of alveolar process defects in patients with alveolar cleft using iliac cancellous block bone is a more reliable method than particulate bone grafts both for closing the oronasal fistula and for building interalveolar septal height.

Effect of Platelet-Rich Plasma on Bone Formation In Distracted Area of Canine Mandible

Distraction osteogenesis refers to the biological process responsible for new bone formation between bone segments by gradual distraction after osteotomy. For the past several years, various inconveniences including a protracted consolidation period that requires patients to wear a distractor frame longer, as well as higher medical costs, have not been remedied by improvements in osteotomy, distraction rate and monitoring system. Furthermore, side effects such as pin tract infections and soft tissue swelling may arise due to the long treatment period. These drawbacks form the rationale of this study which purports to seek a method by which the consolidation period can be reduced. This paper examines how platelet-rich plasma (PRP), known to facilitate osteogenesis, influences bone formation when applied in distracted area. Ten mongrel dogs, which were made to wear external distractor frames after osteotomy in both sides of the mandible, were used as subjects. After a 7day period of latency, distraction was carried out at a rate of 1mm/day for 14 consecutive days. After the onset of distraction, 2ml of PRP and a mixture of calcium gluconate and thrombine were injected into the center of the distracted callus on the left side of the mandible. The left was injected with PRP while the right side was set as the control site without PRP treatment. Execution at the onset of distraction and in 2 weeks, 4 weeks and 8 weeks after the consolidation period, clinical and radiographic tests, bone mineral density examination, histological examination and histomorphometric analysis were conducted to compare both sides. The results are summarized as follows: 1. Based on the clinical examination at two weeks, more remarkable cortical bone formation was found on the buccal and lingual side of the distracted area in the PRP treatment site than in the control site. No visual difference was found between the PRP treatment site and the control site at four and eight weeks. 2. Based on the radiological examination, a distinct increase in the radiopaque appearance of the PRP treatment site was revealed at two weeks, but this increase appeared to slow down at four and eight weeks. 3. Examination of bone mineral density revealed a significant difference at two weeks with the PRP treatment site yielding density two times higher than the control site. This difference lessened after four weeks, and disappeared at eight weeks. 4. The histomorphometric examination revealed that about 20% more bony trabeculae area (20% higher) was formed in the PRP treatment site than in the control site. In conclusion, it can be said that PRPs effect on stimulating bone formation in the PRP treatment site manifest as early as two weeks. Trabeculae formation likewise increased throughout the whole period. If this result can be applied to humans, the consolidation period can be reduced by injecting PRP into the distracted area.

THE HISTORY AND PRESENT SITUATION OF MONGOLIAN ORAL & MAXILLOFACIAL SURGERY

Mongolia is a huge, landlocked, middle-Asian country bordering Russia in the north, and China in the south. Mongolia was under socialism from 1921 to 1990, and its political system has started moving toward capitalistic democratism in 1990. The history of the Mongolian Oral & Maxillofacial Surgery can be divided into four periods; the incipient period(1956~1971), the period of early development(1971~1981), the period of active development(1981~1991), and the period of reformation(1991~). Mongolian Oral & Maxillofacial Surgery had been developed by the cooperation of Soviet Union and Eastern European countries before the 1990s, but the role of Korea, Japan, and western countries has been increasing from the 1990s. In Mongolia Oral & Maxillofacial Surgery is well recognized to the people and is considered as one of the specialized medical field. There are specialized departments of Oral & Maxillofacial Surgery in State Central Hospital, Child & Maternal Research and Clinical Center, and Oncology Center in Ulaanbaatar. Now, the basic knowledge and surgical technique of the Mongolian Oral & Maxillofacial Surgeons are satisfactory. But because of the difficult social and economic situation, there is a shortage of surgical instruments and materials, and acquirement of new knowledge is not easy. In 1998 the Mongolian Association of Oral & Maxillofacial Surgeons was established and its members want to have international relationship to keep up with the new medical information. Mongolia and Korea have ethnic, linguistic and cultural similarity, so the interchange and cooperation between Mongolian and Korean Oral & Maxillofacial Surgeons are recommended to make a beautiful one-world.

Maxillary growth following cultured epidermal tissue graft and the administration of TGF-beta3 on surgically created palatal defects in rat

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.

EXPERIMENTAL STUDY ON RELAPSE AFTER RAMAL LENGTHENING IN DIFFERENT SURGICAL METHODS-RADIOGRAPHIC EVALUATION

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.

A Study On The Change Of Airway Space And Cranial, Cervical Angulation After Mandibular Setback Operation

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.

A Study on the Relation between Delaire's Ideal Occlusal Plane and Masticatory Muscle Activity in Korean Normal Angle Class I Occlusion Individuals

According to the functional matrix theory, Delaire proposes that individual occlusal plane was determined by variable effects of teeth, maxilla, mandible, cranium, cranial base and soft tissue matrix including the orofacial musculature. and that there is the ideal occlusal plane determined by the most proper spatial position of maxilla and mandible, functionally and esthetically. This study was designed to find out the relation between Delaire's ideal occlusal plane and muscle activity of masticatory muscles in individuals who have normal maxillo-mandibular relationships. Lateral cephalometric radiographs were taken and his/her individual occlusal plane and ideal occlusal plane were analyzed with Delaire's architectural and structural craniofacial analytic method. For evaluation of muscle activities of masticatory muscles, electromyography of anterior temporal muscle, superficial masseter muscle, and anterior belly of digastric muscle was recorded in fifty Korean normal Angle class I occlusion individuals. According to the average value of ideal occlusal plane, fifty normal Angle class I occlusion individuals were classified into three groups: Ideal occlusal plane group(I group), hyperrotation group(I+ group) and hyporotation group(I-group). The result of this study was as follows: 1. The results of Delaire's architectural and structural craniofacial analysis of lateral cephalography of the fifty Korean normal Angle class I occlusion individuals are that twelve persons(24%) have consistent or parallel with ideal occlusal plane and the average of angular difference was 1.22 degrees +/-3.69 degrees. 2. There is no significant difference in muscle activities of masticatory muscles during resting(p0.05) 4. Although there is no significant differences of masticatory muscle activities among the three groups, the fact that increasing tendency of masseter muscle activity of ideal occlusal plane group(I+) than those of any other groups(I+ and I-) during bilateral clenching was noted. There is only the implication that occlusal plane makes some effects on masticatory muscle activities, espacially that of masseter muscle during bilateral clenching. In conclusion, the hypothesis that occlusal plane is one of the factors which affect the muscle activities of masticatory muscles and that anyone whose occlusal plane consistent with Delaire's ideal occlusal plane has an extraordinary functional advantage in masticatory muscle function cannot be proven with electromyography methods.

A classification and prototyping of skeletal class iii on etio-pathogenic basis

Regional thickness of parietal bone in korean adults

Mandibular anatomy related to sagittal split ramus osteotomy in Koreans

Sagittal split ramus osteotomy (SSRO) is one of the surgical techniques used to correct mandibular deformities. In order to prevent many surgical anatomical problems, we observed the anatomical structures related to SSRO. In dry mandibles of Koreans, lingular tips were located somewhat posteriorly and superiorly on the mandibular ramus. On the coronal sections of mandible, the mean cortical width of facial cortex was increased toward the ramus region while the lingual cortex was thinnest in the ramus region. On the same sections, all the fusion points of the buccal and lingual cortical plate were located above the mandibular lingula and beneath the mandibular notch. So, performing the SSRO on Koreans, medial horizontal osteotomy should be done through the superior aspect of the mandibular lingula. The cut line is extended 5-8 mm posterior to the mandibular lingula to preserve sufficient cortical width to strengthen the involved osseous segments and reduce possible surgical complications.

Autologous blood transfusion in oral and maxllofacial surgery

No abstract available.