• The korean journal of orthodontics
• /
• v.27 no.3 s.62
• /
• pp.421-430
• /
• 1997

Alveolar bone grows with development of tooth germs and roots; bone deposition occurs with tooth eruption. Bone components undergoes processes of resorption and deposition, and when the balance between them is disrupted, decrease in alveolar bone height or excessive bone deposition result. It has been hon that repositioning of teeth through orthodontic treatment can cause alveolar bone resorption which result in decreased alveolar bone height, and there have been many studies to evaluate such effects. X-ray films that could be replicated and standardized were chosen in clinical studies, and among them, bitewing films were used for objective evaluation of changes in alveolar bone level. Twenty subjects, 10 to 13-year- old (average 12.2) children with Cl I molar key, healthy oral condition, no congenital missing, no periodontal disease, and pre-and post-orthodontic bitewing films, were randomly selected for comparison of alveolar bone heights. Amounts of tooth and changes in alveolar bone heights were analyzed. The following results were obtained: 1. Amount of tooth movement in canine, premolar, and molar regions, changes in tooth axis, and changes in alveolar bone heights were measured, and the mean and median values were obtained. 2. When pre-and post-orthodontic alveolar bone levels were compared, larger changes were noticed in maxilla than mandible. 3. When mesio-distally compared, larger changes were observed in the distal sides of 3D3 and 4M3, mesial sides of 4M3 and 4D3, distal sides of 4D3 and 5M3, mesial sides of 5M3 and 5D3, md distal sides of 5D3 and 6M3. 4. When the amounts of tooth movements(TX, TY)and changes in tooth axis(A) were compared,34TX, 34TY, 34A of both sides in maxilla were greater, iud changes in alveolar bone level were greater than any other region.

• Journal of dental hygiene science
• /
• v.18 no.2
• /
• pp.130-135
• /
• 2018

The aim of this study was to investigate the role of osteal macrophages (osteomac) and osteocytes in bone remodeling using a mathematical model. We constructed the bone system with pre-osteoblasts, osteoclasts, osteocytes, and osteomac. Each link of the parameters and ordinary differential equations followed the Graham's model in 2013 except for the parameters of osteomac signaling and osteocytes signaling to link preosteoblasts and osteoblasts. We simulated the changes in each cell and bone volume according to the changes in the parameters of osteomac signaling and osteocytes signaling. The results showed bone volume was unstable and decreased gradually when the effectiveness of osteocytes and osteomac dropped below a certain level. When the parameters of osteomac signaling and osteocytes signaling to link preosteoblasts and osteoblasts had a value less than 1, bone volume increased with the increase in the parameter of osteomac signaling to link preosteoblasts and osteoblasts. Moreover, although the parameter of osteocytes signaling to link preosteoblasts and osteoblasts, increased in case of a small parameter of osteomac signaling, bone volulme decreased. If the parameters of osteomac signaling to link preosteoblasts and osteoblasts were over a certain level, bone volume was positively maintained, despite the parameter of osteocyte signaling to link preosteoblasts and osteoblasts. We suggested the osteomac may affect bone remodeling and may play an important role in bone cell network.

• The korean journal of orthodontics
• /
• v.40 no.4
• /
• pp.239-249
• /
• 2010

Objective: The aim of this study was to identify the expression of nitric oxide synthases (NOS) in the mandibular condyle during mandible advancement by functional appliance and to correlate it with the histologic changes and bone remodeling. Methods: Twenty-four female, 35-day-old Sprague-Dawley rats were randomly divided into 3 experimental groups. In all experimental groups, the mandibles of the rats were kept in a continuous forward position with a fixed bite jumping appliance. The rats were sacrificed on the 3rd, 14th, and 30th days of experiment. More than 2 rats in each group were used for staining. Results: There were no remarkable histologic changes and NOS expression differences in the control group. The most prominent histologic changes occurred in the 14th day experimental group. NOS decreased in the 30th day experimental group. There was increased expression of $NOS_2$ and $NOS_3$ in all experimental groups, comparative to the control group. In all the experimental groups and control group, the expression of $NOS_2$ was greater than that of $NOS_3$. Conclusions: It is postulated that $NOS_2$ and $NOS_3$ in the mandibular condyle might play an important role in bone remodelling of the mandibular condyle.

• The korean journal of orthodontics
• /
• v.32 no.6 s.95
• /
• pp.455-466
• /
• 2002

The objective of this study was to evaluate the changes that occurred over time in the distracted periodontal ligament space following the rapid retraction of a tooth by periodontal distraction after bone undermining surgery had been conducted in the dogs. The upper second premolars were extracted on the left and right side in 4 male beagle dogs. Immediately after extraction, the interseptal bone distal to the upper first premolar was thinned and undermined by grooving to decrease the bone resistance. Activating an individualized distraction appliance at the rate of 0.225mm twice a day, the upper first premolar was retracted rapidly toward the extraction socket. Periodontal distractions were performed for 5, 10, and 20 days, and 20-day-distraction cases were followed by maintenance periods of 0, 14, 28, and 56 days. After 20 days of rapid retraction, the average distal movement of the upper first premolar was 5.02mm, and the average mesial movement of the upper third premolars serving as an anchorage unit was 0.18 mm. On histological examination, the regeneration of bone occurred in a highly organized pattern. Distracted periodontal ligament space was filled with newly formed bone oriented in the direction of the distraction, and this was followed by extensive bone remodeling. This result was similar to those observed in other bones after distraction osteogenesis. In the periodontal ligament, the relationship between collagen fibers and cementum began to be restored 2 weeks after the distraction was completed, and showed almost normal features 8weeks after the completion of the periodontal distraction. However, on the alveolar side, the new bone formation was still in process and collagen fiber bundles and Sharpey's fibers were not present 8 weeks after the completion of the periodontal distraction. Reactions in the periodontal ligament of the anchorage tooth represented bone resorption on the compressed side and new bone deposition on the tension side as occurred in conventional orthodontic tooth movement. In conclusion, the results of this study showed that periodontal structures on the distracted side of the periodontal ligament were regenerated well histologically following rapid tooth movement.

• The korean journal of orthodontics
• /
• v.37 no.1 s.120
• /
• pp.73-84
• /
• 2007

The maxillary protraction headgear has been widely used in the treatment of skeletal Class III children with maxillary deficiency. A variety of treatment objectives which allow dentoalveolar movements may be established, but when only maxillary protraction without dentoalveolar movement is needed, one of the limitations in maxillary protraction with conventional tooth-borne anchorage is the loss of dental anchorage. This is because a bone remodeling occurs not only at circummaxillary sutures but also within the periodontal tissues. During protraction treatment in the mixed dentition phase, in older children or for the patient with multiple congenitally missing teeth, it is not uncommon to observe undesirable mesial movement of maxillary teeth. Such a side effect can be eliminated or minimized using absolute anchorage such as skeletal anchorage. The purpose of this case report is to introduce a new technique of the maxillary protraction headgear treatment using surgical miniplates.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.13 no.1
• /
• pp.110-116
• /
• 1991

Fracture site osteomyelitis begins rarely with an acute event but rather has a subacute onset. It develops almost exclusively in the mandibular region. The treatment principles of mandibular fracture site osteomyelitis are complete removal of inflammatory tissue and drainage, rigid fixation with or without autogenous bone bone graft and specific antibiotic therapy. But hyperbaric oxygen used as a modality in the treatment of intractable osteomyelitis. In this paper, we reported that the three patients who have osteomyelitis accompying secondary in fection after mandibular fracture.

• The Korean Journal of Malacology
• /
• v.27 no.3
• /
• pp.159-165
• /
• 2011

The anatomy and ultrastructure of the digestive diverticulum of Saxidomus purpuratus were described using light and electron microscopy. The digestive diverticulum of dark green color was situated on the gonad and connected to stomach by a primary duct. Digestive diverticulum is composed of numerous digestive tubules. The epithelial layer of digestive tubule, which is simple, is composed of basophilic cells and digestive cells. Basophilic cells are columnar in shape, and the electron density is higher than that of the digestive cell. The cytoplasm has a well-developed endoplasmic reticulum, tubular mitochondria, Golgi complex and membrane-bounded granules of high electron density. Digestive cells are columnar in shape, with development of microvilli on the free surface. Pinocytic vasicles, lysosomes and numerous mitochondria were observed in the apical cytoplasm of digestive cells. The results of this study suggest that basophilic cells and digestive cells in the digestive tubule are specialized in the extracellular and intracellular digestions, respectively.

• The korean journal of orthodontics
• /
• v.35 no.4 s.111
• /
• pp.275-285
• /
• 2005

Ipriflavone (isoprofoxyisoflavone), a synthetic derivative from soy isoflavone diazein, has been shown to inhibit bone resorption and perhaps stimulate bone formation This study was performed to examine the effects of ipriflavone on the proliferation and bone remodeling in rat calvarial cells in vitro The rat calvarial cells were isolated from fetus aged 20 to 21 days and cultured In BGJb media The graded concentration of ipriflavone $(10^{-9}\;10^{-5}M)$ was administered into cultured cells. When the cell proliferation was estimated through the measurement of MTT assay, there was no increase in cellular proliferation of the rat calvarial cell at any ipriflavone concentration. The cellular activity was evaluated through the formation of mineralized nodules stained by alizarin red. The formation of mineralized nodules significantly increased at concentrations of $10^{-8}M,\;10^{-7}M\;and\;10^{-6}M$ ipriflavone. Reverse transcription-polymerase chain reaction analyses (RT-PCR) were done at 7 and 14 days after culture to detect the expression of Bone Sialoprotein (BSP), Type I Collagen (COL I) and Osteocalcin(OCN) As a result, the expressions of BSP and COL I increased on the 7th day of culture and the expression of OCN increased on the 14th day of culture. These results indicate that ipriflavone facilitates the bone remodeling process bvy promoting rat calvarial cell differentiation aid stimulating mineralization through increased expression of extracellular matrix genes. such as BSP. COL I and OCN.

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

• Journal of Periodontal and Implant Science
• /
• v.33 no.1
• /
• pp.79-89
• /
• 2003

치주질환은 세균감염에 의해 치조골이 파괴되는 염증성질환으로서 치아상실의 주된 원인이다. Treponema denticola는 성인성 치주염의 병소에서 자주 발견되는 세균으로서 부착능 및 단백분해효소생성능과 같은 독성 인자가 밝혀져 치주조직 파괴에 있어서 중요성이 강조되어 왔다. 골개조는 조골세포의 골형성및 파골세포에 의한 골흡수의 균형에 의하여 유지되며 치주염시 야기되는 치조골파괴는 조골세포 및 파골세포 기능의 불균형에 의하여 야기되는 것으로 설명되고 있다. 골세포에 대한 영향으로서 T. denticola는 파골세포의 형성을 촉진시키는 것으로 보고되었으나 조골세포에 대한 영향은 아직 밝혀져 있지 않다. 따라서 본 연구에서는 T. denticola가 골형성에 미치는 영향을 알아보고자 마우스의 두개골세포로부터 조골세포를 분리한 후 T. denticola분쇄액으로 처리하여 본 세균이 조골세포의 alkaline phosphatase(ALPase) 활성, 석회화결절 형성 및 Prostaglandin $E_2\;(PGE_2)$ 생성에 미치는 영향을 평가하였다. ALPase활성은 p-nitrophenylphosphate분해능, 석회화결절형성은 Von Kossa 염색법, 그리고 PGE2의 농도는 효소면역측정법으로 측정하였다. T. denticola분쇄액 (2.5 ug/ml)은 마우스 두개골세포의 ALPase활성을 억제하였으며 석회화결절의 형성을 감소시켰다. 또한 동일한 농도의 균분쇄액은 마우스 두개골세포의 $PGE_2$ 생산을 증가시켰다. 균분쇄액과 prostaglandin의 합성억제제인 indomethacin으로 세포를 동시에 처리한 경우 T .denticola분쇄액에 의한 $PGE_2$의 생산은 감소되었으나, ALPase의 활성억제에는 변화가 없었다. 균분쇄액을 열처리하여 마우스 두개골세포에 처리하였을 때에도 ALPase의 활성이 억제되는 것에는 변함이 없었다. 이러한 결과는 T. denticola의 구성성분 중 열에 안정한 물질이 prostaglandin과 무관한 경로를 통해 조골세포의 분화를 억제함을 시사하며 이와 같은 T. denticola에 의한 골형성억제가 치주염시 야기되는 치조골 파괴에 관여할 수 있을 것으로 생각된다.