• The Journal of the Korean dental association
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• v.50 no.6
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• pp.312-321
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• 2012

Permanent canine are very important teeth in point of function as well as esthetic. Therefore impaction of canines is a frequently encountered clinical problems. The incidence of impaction ranges between 1-3%. The cause of canine impaction can be result of ectopic position of tooth germ, defect of dental follicle, early loss or delayed exfoliation primary canine, space problem, supernumarary teeth, cyst, odontoma, Impaction frequently involves further complication such as root resorption of adjacent teeth, cyst formation and migration of the neighboring teeth. Various treatment modalities include extraction of primary canine, surgical opening and orthodontic traction, autotransplantation, surgical extraction of impacted canine.

• The Journal of the Korean dental association
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• v.52 no.5
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• pp.281-290
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• 2014

Tooth eruption disturbance is seen commonly in mixed dentition or early permanent dentition. During this period of time, children experience the growth and development of craniofacial skeleton and dentition, so the impaction and eruption disturbance of permanent teeth make many problems in oral and maxillofacial areas. Eruption guidance of impacted tooth is not simple because many factors related to impaction are considered. Several factors such as etiology, tooth development stage, location of impacted teeth or eruption pathway, patient cooperation, etc. need to be taken into consideration in deciding the management of the impacted tooth. In the present study, it was assessed the etiology and impaction status of impacted tooth through various cases, and try to explain the treatment method to guide eruption by surgical exposure.

• The Journal of the Korean dental association
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• v.52 no.8
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• pp.491-505
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• 2014

Food impaction between the implant prostheses and adjacent teeth is the most frequently observed problem. It may be caused by the migration of the adjacent teeth. This symptom may be observed at the mesial aspect of implant prostheses especially, and related with the multiple contributing factors including teeth vitality and antagonist. Idal proximal contact with optimal strength and shape should be made for preventing the food impaction. Shape of customized abutment and prosthesis should have optimal emergence profile. Long duration from the extraction to the delivery of implant prostheses, the adjacent teeth and antagonist teeth may have possibility of occlusal interferences. Remained teeth mobility can induce the food impaction regardless of interproximal contact strength. Occlusal adjustment to remove occlusal interferences can be a method for enhancing the stability of interproximal contact.

• The korean journal of orthodontics
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• v.28 no.4 s.69
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• pp.669-679
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• 1998

During diagnostic process of the orthodontic patients, it is not unusual to find canine impaction. Generally, the chief complaint of the patients is crowding or antetior crossbite which is not related with canine impaction, but sometimes they complainted delayed eruption of the canine or deviation of the adjacent teeth caused by canine impaction. Orthodondists have to make the proper treatment plan according to final treatment goals. On the following cases, two patients were diagnosed as a malocclusion with canine impaction, and were treated by different accesses, one by extraction, and the other by non-extraction each.

• The korean journal of orthodontics
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• v.23 no.4 s.43
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• pp.493-501
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• 1993

It is the aim of this study to determine the impacts of radicular development of lower third molars on its eruption/impaction and to grope the prediction for eruption and/or impaction in advance. Three hundred and thirty cases of orthopantomogram were employed and classified as mesial root-dominant group, distal root-dominant group and Identical group according to the radicular development of lower third molars. This presentation has carried out the incipient mesial inclination, radicular development, impaction/eruption rate and changes of mesial inclination of the very teeth. Consequently the following summary and conclusions were drawn; Radicular development dominated mesial root than the distal and dominant mesial root invited higher potentialities for normal eruption. The mesial or honzontal impactions were detected on the distal root-dominant group. This analysis has been suggested the potential eruption/impaction of lower third molars were dependent upon the radicular development and the incipient mesial inclination.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11b
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• pp.430-437
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• 2000

Fertilizer impaction mechanism was simulated using a commercial program RecurDyn$^{(R)}$ a dynamic program that could handle contact problems. Even if there had been numerous papers on modeling of fertilizer applicator, the performance predictions were not satisfactory due to simplification in modeling. The most significant simplification was assumption of fertilizer particles as a solid particle. The assumption would eliminate rotation of fertilizer particles during the impaction mechanism. However, impaction of rotating body would be different from that of a solid particle. This paper introduced how the impaction was modeled using RecurDyn$^{(R)}$. In order to simulate, restitution coefficient and contact time was measured. A stiffness coefficient and a damping coefficient of a fertilizer was theoretically estimated using the measured data. Validity of the simulation result was not proved yet, but judged to be promising.ged to be promising.ing.

• The korean journal of orthodontics
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• v.23 no.2 s.41
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• pp.165-177
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• 1993

Upper canine is important because it protects and maintains the stability of the dental arch and also, joins the anterior with the posterior teeth. The incidence of impaction of upper canine is the second most frequent next to the third molar because it takes a long period of time to develop, and has a complicated path of eruption, and erupts lately. After the age of 10, clinical and radioglaphic examination can be used in revealing the possibility of impaction and efforts should be put to reduce the side effects. To prevent impaction, selective extraction of primary canine at the age of 8 to 9 could be considered and prolonged retention of primary canine in oral cavity should be avoided at this time. Once the impaction is iden, the first stage of the treatment is to lcocalize the lesion by radiographic examination and According to the severity, orthodontic traction or autotransplantation should be considered and comprehensive diagnosis and treatment plan of malocclusion should be established. Generally, labial impaction is due to arch length discrepancy and palatal impaction is due to malposition or morphologic pathosis of lateral incisors rather than arch length discrepancy. In surgical procedure, peridontal problems should be considered and the minimum amount of bone and soft tissue should be reduced and direct bonding method of many attachment methods should be recommended. Especially in traction of labially impacted canine, it should be guided to erupt through the keratinized zone and proper forced magnitude should be applied. The importance of periodontal condition should always be in mind following the patient education to mintain the good oral hygiene at each stage of treatment. Properly managed impacted canine can provide function and esthetic by proper diagnosis and treatment if extraction of canine is not indicated.

• Journal of ILASS-Korea
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• v.1 no.2
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• pp.24-32
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• 1996

Most of the research of small engines to date focused on developing spark ignition engines occupied much parts. Recently the number of a small direct injection diesel engine applied in small cars has been increased and considered as a next generation power source for passenger cars because of its high efficiency. Therefore the combustion chamber becomes smaller and the fuel injection pressure goes higher, which makes fuel sprays impinged easily on the combustion chamber walls. When strong swirls are not induced, the fuel may not mix with air because of fuel deposition on the wall. As a positive way, the combustion chamber systems which is using spray wall impaction has been introduced and assessed by an experimental or a simulate manner. In these systems the raised lands are positioned in tile chamber for spray impaction in order to break up the fuel drops into much smaller and direct them into desirable direction. This study addresses to the effects of rho position and size of the raised land or glow plug to help the chamber design using spray wall impaction. The characteristics of the spray impinged on various lands are investigated and compared with each other. Then the chamber shapes are discussed with the characteristics and their proper position and size is proposed in any chamber volume.

• The korean journal of orthodontics
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• v.22 no.1
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• pp.159-168
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• 1992

To predict eruptive path of maxillary canine, 13 male and 11 female malocclusions were longitudinally studied for 4 years. And to study frequency and distribution of impaction of maxillary canine, 1500 malocclusions were studied. The path, velocity and duration of maxillary canine eruption were determined by periodic angular and linear measurement using periodic orthopantomograms and cephalograms. The following results were obtained. 1. Maxillary canine was erupted with $14.5^{\circ}$ distal tipping from initial stage $98.1^{\circ}$ to final stage $83.6^{\circ}$ of axial inclination on orthopantomogram. 2. Eruptive velocity of maxillary canine was fastest on stage 4, and mean eruptive velocity was 10.5mm per year on stage 4. 3. Eruption of maxillary canine was completed 12 year 5 months in male and 11 years 8 months in female. 4. To predict the duration for eruption completion by position of maxillary canine on cephalogram, regression equation was obtained. 5. Frequency of impaction of maxillary canine was 1.47% in malocclusion and more frequent in male. Distribution of buccal and palatal, right and left impaction was no different, but unilateral impaction was more frequent.

• Journal of the korean veterinary medical association
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• v.27 no.3
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• pp.166-168
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• 1991

Clinical symptom, diagnosis and operative surgery was discussed on a case of cecal impaction due to eation too many bones or foreign materials due to a depraved appetite in a Chindo-mongrel dog. The diagnosis and successful correction of such an impaction