• Title/Summary/Keyword: Bicuspid

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FINITE ELEMENT ANALYSIS OF STRESSES AND DEFLECTIONS INDUCED BY FIXED PARTIAL DENTURE USING ENDOSTEAL IMPLANT (골내 임프란트를 이용한 고정성 국소의치 하에서 변위 및 응력에 관한 유한요소법적 분석)

  • Choi, Su-Ho;Chung, Chae-Heon
    • The Journal of Korean Academy of Prosthodontics
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    • v.29 no.1
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    • pp.233-248
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    • 1991
  • The purpose of this study was to qunatatively analyze the stress patterns induced in the abutment, superstructure, supporting bone and to determine the deflection of abutment and superstructure by appling occlusal force to natural teeth supported fixed prostheses and implant-supported fixed prostheses. The analysis has been conducted by using the two dimensional finite element method. The implant and natural tooth-supported bridge has a first molar pontic supported by mandibular second bicuspid and implant posterior retainer, which were rigidly(Model A) or flexible(Model B). The natural teeth-supported bridge has a first molar pontic supported by mandibular second bicuspid and second molar, which were rigidly splinted together(Model C). 63.5kg(Load P1) of localized load on central fossa of first molar pontic and 24kg(Load P2) of distributed load on each occlusal surface were applied respectively. 1. The coronal portion of premolar pontic and posterior abutment in fixed partial denture deflected inferiorly in order of Model B, Model C and Model A under Load P1 and Load P2. 2. Mesial displacement of the coronal portion of premolar showed in Model A, Model B and Model C under Load P1, but mesial displacement of that in Model B and distal displacement of that in Model A and Model C showed under Load P2. 3. Mesial displacement of the coronal portion of the pontic and distal displacement of the coronal portion of posterior abutment showed in Model A, Model B and Model C under Load P1 and Load P2. Displacement in the case of Model B was greater than that of Model A and Model C. 4. In the case Model A under Load P1 and Load P2, high stress apically was concentrated in the mesiocervical portion of the posterior abutment than in the disto-cervical portion of the premolar. 5. In the case of Model B under Load P1 and Load P2 high stress was concentrated in the case of the premolar than in that of posterior abutment and high stress especially was concentrated in the connected portion of pontic and posterior abutment. 6. In the case of Model C under Load P1 and Load P2, high stress was concentrated in the distal area of the cornal portion of premolar and the mesial area of the coronal portion of posterior abutment, and stress pattern was anteroposterially symmetric around the pontic. 7. Load P1 and Load P2 compared, stress magnitude was different but stress pattern was similar in Model A, Model B and Model C. 8. Under Load P1 and P2, stress magnitude in the mesial distal portion and the portion of root apex of the posterior abutment was in order of Model B, Model A and Model C.

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A MORPHOLOGIC CHARACTERISTICS STUDY OF CROWN OF LINGUAL SURFACE WITH NORMAL OCCLUSION IN KOREAN ADULTS (한국인 성인 정상교합자 치관의 설측면 특징에 관한 연구)

  • Yu, Hyung-Seog;Park, Young-Chel
    • The korean journal of orthodontics
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    • v.22 no.3 s.38
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    • pp.675-690
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    • 1992
  • The purpose of this study was to obtain the lingual morphology (size, angulation, contour, eminence) of adults with normal occlusion in order to provide the basic data for lingual bracket and lingual arch form in Korean. The subjects (Male: 50, Female: 50) were selected who have normal occlusion and dental casts were prepared. Tooth size, angulation, arch width, horizontal contour, lingual eminence were measured for all 28 teeth both upper and lower arch. The results were as follows: 1. Measuring items of all individual teeth for adults with normal occlusion were obtained. 2. In comparison tests, there was a statistically difference between intermolar widths $(\underline{6}\;to\;\underline{6})$ before occlusal reduction and intermolar width $(\underline{6}\;to\;\underline{6},\underline{7}\;to\;\underline{7})$ after occlusal reduction only all the other measuring items showed no statistically differences. 3. There was small variation in horizontal contour of lingual surface on lower incisors and upper and lower bicuspids. The other teeth showed somewhat greater variations. 4. There was offset between canine and bicuspid in upper arch while there was no prominent offset in lower arch.

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A RADIOGRAPHIC STUDY ON EXPERIMENTAL BONY LESIONS (실험적 골조직 병소부에 관한 방사선학적 연구)

  • Lee Eun Kee;Kim Jae Duk
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.17 no.1
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    • pp.233-248
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    • 1987
  • The author studied the effect of periapical bone loss on radiographic interpretation by using a dry adult human mandible. Artificial bony lesions were created at the apices of two mandibular second molars and four mandibular bicuspids. The jaw was stabilized and various artificial lesions were radiographed under ideal circumstances. Radiographic pictures were recorded and compared with the size of the actual lesions. The obtained results were as follows: 1. The size of actual lesions were always larger than their radiographic pictures. 2. The size of actual lesion had a greater discrepancy in the molar area where the cortical plates were havier, but the lesions in the bicuspid areas were only slightely larger than their radiographic pictures, and in these areas the cortical plates were quite thin. 3 Periapical lesions located in cancellous bone did not appear on a radiograph, regardless of the size of the created lesion, but when the junctional bone was involved or the cortical plate was perforated, the definite bone destructive change was observed on the roentenogram. 4. Removal of the entire buccal or lingual plate did not affect the trabecular pattern of bone on the roentgenogram. 5. When the cancellous bone and junctional bone were removed simultaneously, altered trabecular patterns were observed on the roentgenogram.

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OLIGODONTIA Report of case. (선천성(先天性) 치아(齒牙) 결손증(缺損症) 1례(一例) 증례보고(症例報告))

  • Lee, Jong-Gap;Choi, Sun-Ok;Son, Heung-Kyu;Hur, Man-Uk
    • Journal of the korean academy of Pediatric Dentistry
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    • v.7 no.1
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    • pp.41-45
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    • 1980
  • The term "Oligodontia" or "Hypodontia" have been used to describe variable degrees of reduction in number of teeth. Oligodontia may occur alone or as a result of some syndrome. Although the teeth are derived in part from ectoderm, the current opinion of reason of oligodontia should be reserved for those disorders in which there is abnormal development of one or more ectodermal tissues. 7 year 5 months old female was refered to the department of pedodontics, college of dentistry Yonsei university for evaluation and replacement of absent teeth. She had no special inf.ectious disease in her childhood, and her parents were healthy. She had no special syndrome of ectodermal disorders except the saddle nose, yellow and fine hair, and notched upper anterior central incisor. Panex radiogram was showing 6 anterior primary teeth, 2 permanent first molars and 2 unerupted first bicuspid in mandible. Another permanent teeth were absent. and normal number of primary and permanent teeth in maxilla. Lateral cephalogram showed no special abnormality in growth pattern. We had evaluated lower anterior decayed teeth with jacket resin and chrome steel crown and removable partial denture at missing area. We had got good results for rehabilitation of function and aesthetic.

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A STUDY ON ELECTRON-MICROSCOPIC FINDINGS AFTER ACID ETCHING ON ENAMEL AND DENTIN (법랑질(琺瑯質)과 상아질(象牙質)의 산처리후(酸處理後)의 전자현미경(電子顯微鏡) 소견(所見)에 관(關)한 연구(硏究))

  • Kim, Yung-Hai
    • Restorative Dentistry and Endodontics
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    • v.9 no.1
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    • pp.115-119
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    • 1983
  • The purpose of this study was to compare the solubility of enamel and dentin to an etchant after fluoride application. Specimens were collected from extracted anterior and bicuspid and each tooth was cut into several pieces. These specimen were allocated in 7 group; 1%, 2%, 3% NaF, 1%, 8%, 20% $SnF_2$, and control group. Five specimens in each group was exposed to pre-determined fluoride solution for 3 minutes, and washed with running water. These specimens were etched by Hipol (commercial label) etchant for 30 seconds. Following are the findings obtained through S.E.M. 1. All specimens with acid etching revealed preferential removal of prism periphery leaving prism core. 2. Specimens treated with 1%, 2% NaF solution showed that the shape of prism tip was thin and sharp like a needle. The case of 3% NaF showed rather round shape at prism end. 3.1% of $SnF_2$ case showed similar findings with the control group but 8% and 20% $SnF_2$ case revealed needle shape at the prism and was less clear than NaF case. Preferential removal of prism periphery was partialy observed and un decalcified area is fused to prism forming reidge. 4. Dentine treated by fluoride compound in low concentration showed the orifice of dentinal tubule was clearly enlarged whereas in high concentration the orifice was not widened.

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Application of Homograft in the Surgical Correction of Complex Congenital Cardiac Malformations (선천성 복잡 심기형 환자의 외과적 교정술시 동종이식편의 적용에 관한 연구)

  • 지현근
    • Journal of Chest Surgery
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    • v.28 no.11
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    • pp.1038-1044
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    • 1995
  • We have been used cryopreserved homograft valves for right ventricular outflow tract[RVOT reconstruction since November 1993. The homograft valves were harvested from the hearts of brain dead patients or hearts of transplant recipients. There were 12 male and 10 female patients. Their ages ranged from 5 months to 13 years[mean age,39.2 $\pm$ 37.4 months and the weight ranged from 5 to 48kg [mean weight, 13.7$\pm$ 9. l kg . The diagnoses included pulmonary atresia with ventricular septal defect [n=14 , tetralogy of Fallot[n=4 , truncus arteriosus[n=3 , and double outlet right ventricle with pulmonic stenosis[n=l .Monocuspid homograft patches were used for RVOT widening or REV[reparation l`etage ventriculaire operations in 4 patients. We also used homograft as valved conduits for RVOT reconstruction in 17 patients and left ventricular outflow tract reconstruction in anatomically corrected transposition in 1 patient. Among them size-reducing technique [converting a tricuspid valved conduit into a bicuspid valved conduit were applied to six patients for the correction of size mismatching. The mean follow-up period was 10.6 $\pm$ 5.4 months. There was one operative death[4.5% due to bleeding and one reoperation for removal of vegetation on the homograft leaflet. Postoperative echocardiography documented no significant homograft insufficiency and RVOT obstructions.In short-term, the homograft valves provide excellent hemodynamic characteristics, even though further studies are necessary to evaluate the long-term results.

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Surgical Treatment of Coarctation of Aorta Less Than 2 Years Old (2세 이하의 대동맥교약증)

  • 홍은표
    • Journal of Chest Surgery
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    • v.26 no.8
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    • pp.604-608
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    • 1993
  • Coarctation of aorta is rather common congenital cardiovascular disease in the western contries, but it is known to be less than 2 % in Korea. From June 1986 to December 1992, seven patients of surgically treated coarctation of aorta who were less than 2 years old, were experienced at Department of Thoracic and Cardiovascular Surgery, Yeungnam University Hospital. The patients included six male and one female, with ages in the range of one month and 24 months. Four patients were preductal type and three juxtaductal. Associated cardiac anomalies were present in all patients and they were PDA[6 cases], ASD[3], VSD[2], bicuspid aortic valve[2], aortic stenosis[1], mitral regurgitation[1], and tricuspid regurgitation[1]. The operative procedures were four end to end anastomosis and three subclavian flap aortoplasty. Mean aortic cross clamping times were 37.3 minutes in patients with end to end anastomosis and 30.3 minutes in patients with subclavian flap aortoplasty. There were two operative deaths in patients who were treated with subclavian flap aortoplasty and pulmonary artery banding. One patient who had been treated with subclavian flap aortoplasty was complicated with postoperative mild paraplegia in lower limb. Pulmonary artery banding has been disappointing in our patients, and the data was suggestive that earlier total repair of complicated coarctation might improve survival.

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Distalization of the lower first molar using Jones Jig (Jones Jig를 이용한 하악 제 1 대구치 원심이동의 치험례)

  • Lee, Sang-Min;Kim, Jong-Bum;Hahn, Se-Hyun
    • Journal of the korean academy of Pediatric Dentistry
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    • v.24 no.3
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    • pp.543-548
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    • 1997
  • The first permanent molar takes important place in the occlusion. Malposition of the lower first molar is frequently due to mesial migration, which is occurred by early exfoliation of the second deciduous molar or proximal caries of deciduous teeth. Above things happen without any consideration of space maintainer, prompt measures for space regaining have to be started. Especially in the case with early loss of the second deciduous molar, it has been said that there is no suitable appliance for maintaining the space before the eruption of the permanent first molar. In distalizing the upper first molar, headgears have been routinely used, which its result was definitely depended on cooperation of the patients. Nowadays, appliances such as pendulum appliances, K-loop, magnets, which can be used without cooperation of the patients, are introduced. Jones Jig, one of the molar distalizing appliances, was used on the patients who visited department of pediatric dentistry in Seoul National University Dental Hospital complaining of no eruption space for the lower second bicuspid. Either removable splint or lingal arch was used as the anchorage. Jones Jig was favorably used in the lower molar, where vestibule is shallow, and this is a case report on the satisfactory result thereof.

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First Record of Cosmocephalus obvelatus (Acuariidae) in Common Gulls (Larus canus) from Gangneung, Korea

  • Kim, Se-Min;Park, Bae-Keun;Jung, Bae Dong;Kim, Hyeon-Cheol
    • Parasites, Hosts and Diseases
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    • v.53 no.1
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    • pp.101-104
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    • 2015
  • A nematode species belonging to the genus Cosmocephalus was collected from the stomach of 2 common gulls, Larus canus. The common gulls were found dead on the seaside of Gangneung City, the Republic of Korea. The worms were identified and classified by light (LM) and scanning electron microscopy (SEM) on the basis of important taxonomic characters. The nematodes were characterized by a body length 9.1-9.3 mm (males) and 15.5-15.9 mm (females) and cordons recurrent in anterior direction and anastomosing laterally at about the level of anterior quarter of the buccal cavity. The salient bicuspid deirids were located on the posterior to the cordons. Lateral alae were well-developed, extending from the level just posterior of deirids to the level about middle of the body. LM and SEM observations identified the worms as C. obvelatus. This is the first reported case of C. obvelatus infection in common gulls in Korea.

Double-Outlet of Left Ventricle in Corrected Transposition of Great Arteries -One case report- (좌심실 이중유출로를 동반한 교정형 대혈관전위증 -1예보고-)

  • 권중혁
    • Journal of Chest Surgery
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    • v.12 no.2
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    • pp.119-126
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    • 1979
  • This is one case report of the extremely rare congenital cardiac malformation, Double-outlet of left ventricle in corrected transposition of great arteries. 11-year-old boy complained acrocyanosis and exertional dyspnea, the parents noticed cyanosis since birth. Physical examination revealed acrocyanosis, clubbed fingers and toes, G-III pansystolic murmur on 2nd and 3rd ICS, LSB. Right heart catheterization revealed significant $O_2$ jump in ventricular level. Right and left ventriculography showed the both catheters arriving in the same ventricle i.e. anterior chamber, morphological left ventricle was in right and anterior position, simultaneous visualization of aorta and pulmonary artery and aorta locating anterior and right side of pulmonary artery. Echo cardiogram surely disclosed interventricular septum. Conclusively it was clarified that the patient has Double-outlet of left ventricle and corrected transposition of great arteries [S.L.D.]. Operation was performed to correct the anomalies under extracorporeal circulation with intermittent moderate hypothermia. Right-sided ventriculotomy disclosed the following findings. 1. Right-sided ventricle was morphological left ventricle. 2. Left-sided ventricle was morphological right ventricle. 3. Right side atrioventricular valve was bicuspid. 4. Left side atrioventricular valve was tricuspid. 5. Aortic valve was superior, anterior and right side of pulmonary valve. 6. Subpulmonary membranous stenosis. 7. Non-committed ventricular septal defect. We made a tunnel between VSD and aorta with Teflon patch so that arterial blood comes through VSD and the tunnel into aorta. After correction the patient needed assisted circulation for 135 min. to have adequate blood pressure. Postoperatively by any means, adequate blood pressure could not be maintained and expired in the evening of operation day.

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