No abstract available.
Humans

No abstract available.

This is to report a case of immediate reconstruction after hemimandibulectomy by using of bicorticocancellous block bone harvested from the iliac crest in the case of an ameloblastomaon the mandible. Because the lesion involved condylar area, it was reconstructed with titanium artificial condyle attached to A/O metal plate. Three weeks after the operation, infection developed with suppuration and was well treated with adequate antibiotic therapy and drainage. The patient has been followed up over a four-year period and taken an orthopantomogram every three or six month for the examination of mandibular movement, the potentiality of recurrence and the remodeling of the grafted bone. At present, the patient is satisfied with her appearence and has a normal occlusion with proper masticatory function, and there is no sign of recurrence.
Ameloblastoma* ; Drainage ; Humans ; Mandible ; Mandibular Osteotomy ; Recurrence ; Suppuration ; Titanium ; Transplants*

The objective of this study was to find out whether the unilateral distraction of mandible has an influence on temporomandibular joint and if it does, how significant the influence is. Four beagle dogs were used in this study. Each dog had two implants placed into the left mandible. The mandible was distracted for 14days with an distraction device as an amount of 0.75mm, twice per day after osteotomy between two implants. Each animals were sacrificed at the second, fourth, sixth and eighth week after the total distraction amount of 10.5mm were gotten. Upon embedding and staining, the specimens were evaluated with a light microscope. The results were as follows. 1. For the second week group, the articular cartilage and osteoid seam of temporal bone and condyle were relatively well maintained. There were not any significant differences between distraction side and non distraction side. 2. For the fourth week group, the periosteal reaction was activated and the articular cartilage and osteoid seam of temporal bone and condyle were severely thickened-especially at posterior portion of distraction side. This findings revealed that the unilateral distraction forces has more influence on distraction side than on non distraction side, and on posterior portion than on anterior portion. 3. For the sixth and eighth week group, the thickness of meniscus in distraction side gradually recovered to the initial level. The thickened articular cartilage and osteoid seam of temporal bone and condyle were decreased in distraction side and showed relatively stable in non distraction side. From this results, we suggest that several considerations are required such as using an occlusal splint, maintaining the stability of bone distraction device and evaluating bone distraction rate to minimize the damages of temporomandibular joint tissues in early stage of distraction side.
Animals ; Cartilage, Articular ; Dogs ; Mandible* ; Occlusal Splints ; Osteotomy ; Temporal Bone ; Temporomandibular Joint*

In this study, the rate of bone formation and the pattern of bone to implant contact surface around HA coated implant and pure Ti implant inserted into the irradiated tibia of rabbit were compared. Sixteen mongrel mature male rabbits were used as experimental animal. Each rabbit received 15 Gy of irradiation. Four weeks after irradiation, two holes were prepared on the tibia of each rabbit for placement of HA coated type and pure Ti type implants. Prior to implant placement, one group received steroid irrigation and the control group was similarly irrigated with normal saline. This was immediately followed by placement of the two different types of implants. Postoperatively, tetracycline was injected intramuscularly for 3 days. For fluorescent labelling, 3 days of intramuscular alizarine red injection was given. 2 weeks before sacrifice, followed by intramuscular calcein green on the last 3 days before specimen collection. Each rabbit was sacrificed on the second, fourth, sixth and eighth week after the implantation. The specimens were observed by the light microscope and the fluorescent microscope. The results were as follows; 1. All implants inserted into the irradiated tibia of rabbit were free from clinical mobility and no signs of bony resorption were noted around the site of implant placement. 2. Under the light microscope, new bone formation proceeded faster around implants that received steroid irrigation compared to the control group irrigated with saline. Bone to implant contact surface was greater in the steroid irrigated group than the saline irrigated group. Therefore, better initial stabilization was observed in the group pretreated with steroid irrigation. 3. Under the light microscope. HA coated implants showed broader bone to implant contact surface than pure Ti implants, and HA coated implants had better bone healing pattern than pure Ti implants. 4. In the steroid pretreated group, acceleration of bone formation was demonstrated by fluorescent microscopy around the 2, 4 weeks group and the 6 weeks HA coated implant group. The difference in the rate of bone formation proved to be statistically significant (P<0.05). Faster bone formation was noted in the saline irrigated group in the 6 weeks pure Ti implants and 8 weeks group. The difference was not statistically significant(P<0.05). 5. For the rabbits that were sacrificed on the second and fourth week after the implant placements, the rates of bone formation around HA coated implants proceeded faster than those around pure Ti implants under the fluorescent microscopy. For the rabbits that were sacrificed on the sixth week after the implant placements, the rates of bone formation around pure Ti implants proceeded faster than those around HA coated implants under the fluorescent microscopy. But this result did not show statistical significance (P<0.05) For the rabbits that were sacrificed on the eighth week after the implant placements, the rates of bone formation around HA coated implants proceeded faster than those around pure Ti implants under the fluorescent microscopy. This result was statistically significant (P<0.05).
Acceleration ; Animals ; Humans ; Male ; Microscopy ; Osteogenesis* ; Rabbits ; Specimen Handling ; Tetracycline ; Tibia*

The condyle head of mandible was usually influenced by the stressful forces generated from a voluntary movement of bone fragment after the sagittal ramus osteotomy which would be mainly performed for the mandibular deformity patient. In this study we measured the stress values exerted on condyle and evaluated which area of condyle had a more stress concentration while condyle head moved in X, Y and Z axis by using a 3 dimensional finite element model. The result were as follows: 1. On bodily movement, the value of maximum force was 40.98Kg/cm2 at the (-X) direction and the stress area was the center of superiposterior nonaticular area of the condyle. 2. On ratational movement, the value of maximum force was 173.1Kg/cm2 at the (+Y) direction and the stress area was the anterior area of condyle neck. 3. From the general point of view there were more stress on rotational movement than on bodily movement. 4. The stress concentration area was the condyle head on bodily movement and the condyle neck on ratational movement. 5. From the result of this study. We found out that this results were a correspondence with clinical predictions in which a condyle head got the most stress concentration only when a condyle head in the posterior rotational position during orthognathic surgery. 6. The results of this study show that we should consider not to place the condyle head in the posterior position and posterior rotational position during orthognathic surgery.
Axis, Cervical Vertebra ; Congenital Abnormalities ; Head ; Humans ; Mandible ; Mandibular Condyle* ; Neck ; Orthognathic Surgery ; Osteotomy

The techniques of the dental treatment are well known to common people, but the dental implant as one of the treatment options to rehabilitate patient's mouth is little known to them. Taking these situation into consideration, we, writers made actual analyses of statistics by putting into the form of diagrams based on questionnaires. Three hundreds of common people over 20 years old were picked up and we used convenience sampling method which is one of nonprobability sampling methods Statistics are about these questions. 1. How much common people know about dental implant as a treatment option. 2. How much common people know about the detailed portions of the dental implant for rehabilitaton. 3. How common people got to know the dental implant. We present actual answers of the common people.
Dental Implants* ; Humans ; Mouth ; Surveys and Questionnaires* ; Young Adult

Distraction osteogenesis is a biologic process in which new bone is formed between bone fragments being separated by a tractional force. This technique has the advantage of initiating new bone growth without bone transplantation and promoting the growth of soft tissue. Mandibular distraction osteogenesis has shown to be effective to treat congenital or acquired mandibular hypoplasias. On the basis of positive results with implant-supported prostheses, the use of implants in the distracted site can significantly help stabilize the prosthesis. We obtained good result in the patient with mandibular deficiency due to trauma, who have been reconstructed with distraction osteogenesis and implant. We report our experiences with literature view.
Bone Development ; Bone Transplantation ; Humans ; Osteogenesis, Distraction* ; Prostheses and Implants* ; Traction

The purpose of this study was to evaluate and compare the influence of Steroid topical irrigation and implant surface on bone healing in the irradiated rabbit tibia. Implant to bone contact surface ratio and the pattern of bone healing around hydroxyapatite(HA) coated implant and pure titanium (Ti) implant which were inserted into the irradiated rabbit tibia were compared. 16 Korean house mature male rabbits were used as experimental animal. Each rabbit received 15 Gy of irradiation. 4 weeks after the irradiation, two holes were prepared in the irradiated tibia of each rabbits, where two surface type of implants were inserted :1) HA coated type and 2) pure Ti type. Right before placing implants, one group of rabbit received steroid irrigation and the other group did saline. After the irrigation, two implants of HA coated type and pure Ti type were inserted into the tibia of each rabbits. Each rabbit were sacrificed at 2nd, 4th, and 8th week after the implantation and the specimens were observed by the light microscope. The pattern of bone healing and histomorphometric analysis of the implant-bone interface were done. The results were as follows. 1. All implants inserted into the irradiated tibia of rabbit did not show any sign of clinical mobility and the bone around implants inserted into the irradiated tibia of rabbit did not show any resorption. 2. The bone to implant contact surface ratio around HA coated implants that received steroid irrigation got more bone to implant contact surface ratio than that of the saline irrigation. This result showed statistically significant(p<0.05). There was no statistically significant difference in 8th week group. 3. Though there was no statistically significant difference HA coated implants had more bone to implant contact surface ratio than pure Ti implant in 2nd and 4th groups, and there was no difference in 8th week group. 4. All implants inserted into the irradiated tibia of rabbit had exhibited successful osseointegraion.
Animals ; Durapatite ; Humans ; Male ; Rabbits ; Tibia* ; Titanium

There are three designs of thread form in screw type implants: V-thread, Reverse buttress thread and Square thread. The purpose of this study was to find out how thread form designs have an influence on the equivalent stress, equivalent strain, maximum shear stress and maximum shear strain and which design of thread form generates more maximum equivalent stress and strain. 3-D finite element analysis was used to evaluate the stress and strain patterns of three tread types. The results of this study were as follow. 1. Under the 200N of axial load, the value of maximum equivalent stress is smallest in square thread and there is no significant difference between that of V thread and reverse buttress thread. 2. Under the 200N of axial load, the value of maximum equivalent strain is largest in V thread and smallest in square thread. 3. Under the 200N of axial load, the value of maximum shear stress is smallest in square thread and there is no significant difference between that of V thread and reverse buttress thread. 4. Under the 200N of axial load, the value of maximum equivalent strain is largest in V thread and there is no significant difference between that of square thread and reverse buttress thread. 5. Above results show that the square thread has special advantages in stress and strain compared with other thread types, especially in shear stess which is most determinant to implant-bone interface. Considering the superior biomechanical properties of square form implant, we presume that square form implant has better clinical results than the other types of implants in the same clinical conditions.
Finite Element Analysis*