• 대한소아치과학회지
• /
• 제35권1호
• /
• pp.92-101
• /
• 2008

본 연구는 전남 해안지역에 거주하는 유치열기 아동의 치아 우식 발생 양상과 빈도 및 유구치 교합관계를 조사하였다. 이를 위해 전라남도 해안지역에 소재하는 유치원 및 어린이집의 만 3-5세 순수 유치열기 아동 2272명을 대상으로 각 치아 및 치면별 우식 발생 양상과 교합 관계를 조사한 결과 다음과 같은 결론을 얻었다. 1. 유치우식경험자율(dmf rate)은 3세에서 66.8%, 4세에서 77.7%였으며 5세에서 83.5%로 나타났으며 남녀간에 유의한 차이가 없었다(p>0.05). 2. 우식경험유치지수(dmft index)는 3세에서 3.62개, 4세에서 4.73개이었으며, 5세에서 5.96개로 나타났으며 남녀간에 유의한 차이가 없었다(p>0.05). 3. 우식의 발생 빈도가 가장 높은 유치는 하악 제2유구치로 3세 39.48%, 4세 49.73%, 5세 63.85%로 나타났다. 4. 전체 연령을 대상으로 보았을 때 우식 경험률은 하악 제2유구치 52.34%, 하악 제1유구치 45.61%, 상악 제2유구치 38.81%, 상악 유중절치 38.36%, 상악 제1유구치 30.04%순으로 높은 빈도를 보여주고 있다. 5. 유구치 교합관계에 있어 좌우 양측이 Class 1 pattern인 경우가 53.26%를 차지하였으며, Class 2 pattern인 경우가 1.41%, Class 3 pattern인 경우 30.02%로 나타났으며 우측이 Class 2 pattern이고 좌측이 Class 3 pattern은 없었다.

• 대한치과교정학회지
• /
• 제46권4호
• /
• pp.199-211
• /
• 2016

Objective: Given the considerable disagreement between the Peer Assessment Rating (PAR) index and the American Board of Orthodontics Cast-Radiograph Evaluation, we aimed to develop a novel assessment system-the Improvement and Completion of Outcome (ICO) index-to evaluate the outcome of orthodontic treatment. Methods: Sixteen criteria from 4 major categories were established to represent the pretreatment malocclusion status, as well as the degree of improvement and level of completion of outcome during/after treatment: dental relationship (arch length discrepancy, irregularity, U1-SN, and IMPA); anteroposterior relationship (overjet, right and left molar position, ANB); vertical relationship (anterior overbite, anterior open-bite, lateral open-bite, SN-MP); and transverse relationship (dental midline discrepancy, chin point deviation, posterior cross-bite, occlusal plane cant). The score for each criterion was defined from 0 or -1 (worst) to 5 (ideal value or normal occlusion) in gradations of 1. The sum of the scores in each category indicates the area and extent of the problems. Improvement and completion percentages were estimated based on the pre- and post-treatment total scores and the maximum total score. If the completion percentage exceeded 80%, treatment outcome was considered successful. Results: Two cases, Class I malocclusion and skeletal Class III malocclusion, are presented to represent the assessment procedure using the ICO index. The difference in the level of improvement and completion of treatment outcome can be clearly explained by using 2 percentage values. Conclusions: Thus, the ICO index enables the evaluation of the quality of orthodontic treatment objectively and consecutively throughout the entire treatment process.

• 대한치과보철학회지
• /
• 제42권2호
• /
• pp.154-166
• /
• 2004

Statement of problem: In distal extension removable partial denture, the preservation of health of abutment teeth are very important, but they are always subjected to unfavorable stress. Purpose: The purpose of this study was performed to investigate the effects of abutment splinting and design of direct retainer on the stress distribution of abutments in unilateral distal extension removable partial dentures. Material and method: Abutments were splinted by different method. In group 1, autment teeth were not splinted, in group 2, canine and 1st premolar were splinted, and in group 3, canine, 1st and 2nd premolars were all splinted. Three different types of direct retainer such as Akers clasp, RPI clasp, and wrought wire clasp were designed. Strain was measured with Switch & Balance Unit(SB-10, Measurement Group Instruments Division, Raleigh USA) and Strain Indicator(P-3500, Measurement Group Instruments Division, Raleigh, USA) 15kg of vertical and oblique loads was applied at central fossa of missing 2nd molar area. Results : The strain on lingual side of 2nd premolar was the greatest, and abutment splinting induced decrease of strain on buccolingual side of 2nd premolar. The strain of loaded area was decreased by abutment splinting and there was no statistical difference of strain between Group2 and Group 3, and strain on 2nd premolar in wrought wire clasp was the least. Conclusion: Within the limitations of this study, splinting of two distal abutment teeth is enough for stress distribution widely, and wrought wire clasp was more benefitable than others.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제16권3호
• /
• pp.477-497
• /
• 1994

The purpose of this study was to investigate the effect of timing of implant insertion on osseointegration after tooth extraction. Fifteen mongrel dogs, weighing 15kg or more, were used. The lower right 1st, 2nd, 3rd, 4th premolars and 1st molar were extracted under general anesthesia. Implants were inserted at 2, 4, and 8 weeks after extraction of the teeth, being designated as 2-, 4-, and 8-week groups, respectively. Results obtained were as follows. 1. Macroscopically there was neither an infection at the implant site nor an exposure of the implant. 2. Histologically the surrounding bone of the implant was less mature in the 2-week group than in the 4- and 8-week groups. 3. The implant-bone contact ranged from 75 to 82%, with no significant differences among the groups. No increase in the implant-bone contact was found with increasing healing periods from 4 to 12 weeks after implant insertions. 4. The average depth (0.64mm) of the fibrous connective tissue ingrowth in the 2-week group was slightly deeper than those in the 4- (0.51mm) and 8-week (0.53mm) groups at 12 weeks after implant insertion. 5. the implant-bone interfacial bond strengths were 73.05 kgf in the 2-week group, 69.71 kgf in the 4-week group and 73.76 kgf in the 8-week group. No significant difference was noted in pullout force among the groups. The degree of confidence of interfacial bone strength was highest in the 8-week group, followed by the 4- and 2-week groups. These results indicate that at least 4 weeks of healing period will be required before implant is to be inserted following tooth extraction.

• 대한화학회지
• /
• 제40권1호
• /
• pp.87-95
• /
• 1996

이성분계 rendom copolyeseters인 Poly(butylene succinate-co-butylene terephthalate)(PBS/PBT)를 합성하고 $^1H$ NMR spectroecopy를 이용하여 전 조성범위에 걸쳐 sepuence distribution을 조사하였다. PBS/PBT 공중합물의 융점(Tm)은 공중합물내 dimethyl terephthalate(DMT)의 함량이 증가함에 따라 점차적으로 감소하는 현상을 나타냈고 ST3(DMT 65.8mol%)에서 최저융점(eutetic point) 거동을 보였다. 이러한 공중합물의 융점거동은 공중합물의 몰분율(Xa)보다는 triad fraction으로 계산된 sequence propagation probability(P)에 더욱 의존하는 경향을 보였다. 또한 succinate unit(또는 terephthalate unit)의 함량이 많은 공중합물들은 terephthalate unit(또는 succinate unit)를 완전히 배제시키면서 단지 PBS(또는PBT)만의 결정을 형성하였다.

• 대한치과보철학회지
• /
• 제36권2호
• /
• pp.293-301
• /
• 1998

The purpose of this study was to investigate the effects of load on root that was applied to edentulous area in three simulated situation, in each case the guiding planes of abutment were right vertical, 95 degrees, or 100 degrees to residual ridge. The 2-dimensional finite element method was used and the finite element model was prepared as fellows. Right mandibular 1st and 2nd molar was lost and the 2nd premolar with distal rest was used as primary abutment which had three different degrees of guiding plane. Then 150N of compressive force was applied to central fossae of the 1st and 2nd molars and von Mises stress and displacement was measured. The results were as follows; 1. Irrespective of slopes of guiding planes, the stress was concentrated on mesial side of root apex and distal side of coronal portion of root, in particular on junction with distal alveolar bone. As slopes of guiding planes were increased. stress on root and compact bone surrounding abutment was increased but no considerable effect was seen on compact bone of residual ridge. 2. Distal side of coronal portion of root limited by periodontal ligament was displaced distally and mesial side of apical portion was mesially. With slope of guiding plane increasing, the pattern of displacement was similar with one another but the quantity was increased. 3. Both abutment & alveolar bone were displaced downward and root of abutment, especially distal side of coronal portion, was displaced severely. As the guiding plane was tiffed more mesially over $90^{\circ}$, the degree of displacement was also increased.

• 치과방사선
• /
• 제24권1호
• /
• pp.129-135
• /
• 1994

This study was performed to evaluate the accuracy of orthopantomogram by measuring the actual and radiographic tooth length and by analyzing the vertical magnification rate. For this study, total 90 teeth of the maxilla and mandible teeth and a dry skull were used. This experiment was attached with metal balls of 1±0.02㎜ at the root and the crown cusp tips of central, 2nd premolar, 1st molar of the maxilla and mandible and the teeth were embedded in dry skull, and then orthopantomogram was taken. The obtained results were as follows: 1. The average of tooth length in orthopantomogram was longer than that of actual tooth length. 2. The average of vertical magnification rate in the orthopantomogram to actual tooth length was 17-26%. 3. Vertical magnification rate of the maxilla teeth was 18-26% and that of mandibular teeth was 17-23%, and the magnification of maxillary teeth was larger than that of mandible teeth(P<0.0l). 4. Vertical magnification rate of posterior area was 22-26% and that of anterior area was 17-18%, and the magnification of anterior area was less than that of posterior area(P<0.01).

• Journal of Periodontal and Implant Science
• /
• 제27권1호
• /
• pp.111-116
• /
• 1997

The oral cavity is easily accessible for direct exposure of a malignant disease. 1 percent of the oral malignant tumors are of metastatic origin and approximately 10 percent to 25 percent of the 1 percent fraction originate from the lungs. A case of metastatic lung carcinoma to the gingiva in a 88-year-old male is reported. He complained of pain and swelling between right maxillary 1st premolar and 2nd molar. Although surgical excision of the lesion has been done, the gingival lesion developed as a quickly growing mass and recurred 2 weeks after surgical excision. The gingival mass was histopathologically diagnosed as an undifferentiated carcinoma. Epithelial layer was continuous without ulceration and it seems that the cancer cells are originated from primary tumor. Infiltrated cancer cells were pleomorphic and dyskeratotic. The cells had 2 or more nuclei, not showing squamous or glandular differentiation. Immunohistochemical study revealed the cells originated from the epithelial cells. The prognosis is poor, because prognosis depends on surgical elimination of the primary tumor.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제37권6호
• /
• pp.530-534
• /
• 2011

This paper reports two cases of schwannomas arising from the oral cavity. One is an intraoral ancient schwannoma located at the left cheek, which evolved over a period of 13 years. The tumor was a well-demarcated buccal mass, which was located in the left lower first premolar area, with an obliterated the buccal vestibule, leaving the overlying mucosa intact. The second case was a central intraosseous schwannoma located from the left lower 1st molar periapical area to the left 3rd molar periapical area. Pathologically, the first mass was composed of the spindle shaped tumor cells with wavy nuclei beneath the fibroconnective tissue of the gingiva but second case mass was not. Occasional nuclear pleomorphism was observed but mitosis or necrosis was absent. There were Antoni A and B areas along with strong, diffuse staining with the S-100 protein. Ancient schwannomas were diagnosed. Schwannoma is a slow-growing benign tumor, and an ancient schwannoma that shows cellular atypism is a variant of a schwannoma caused by purely degenerative changes. To date, only limited cases of ancient schwannomas in the oral cavity have been reported.

• 한국식품영양과학회지
• /
• 제40권10호
• /
• pp.1430-1437
• /
• 2011

본 연구에서는 카놀라유(canola oil)를 이용하여 코코아버터 유사 재구성지질 합성의 최적조건을 연구하였다. 반응기질로는 카놀라유와 palmitic ethyl ester와 stearic ethyl ester를 이용하였으며, 효소는 Lipozyme TLIM을 사용하여 반응기질의 몰비율과 반응효소의 양, 반응시간을 독립변수로 하고, D-optimal 계획에 의한 반응표면분석에 따라 합성을 실시하였다. 반응을 통해 acyl-migration은 최소로 일어나며, POS 및 SOS, POP의 함량은 최대로 합성되는 조건을 최적화 조건으로 결정하였다. D-optimal 계획에 의한 반응표면분석을 실행한 결과, sn-2 위치 지방산 조성의 변화를 일으키는 acyl-migration($Y_1$)은 최소로 일어나고 POS($Y_2$)와 SOS($Y_3$), POP($Y_4$)는 최대로 일어나는 조건은 기질의 몰비율은 canola oil : palmitic ethyl ester : stearic ethyl ester=1:3:9이며, 반응효소의 양은 6%이고, 반응시간은 40 min이었다. 이와 같은 반응조건으로 합성된 재구성지질의 acylmigration(% of palmitic acid+stearic acid, $Y_1$)은 10.43%, POS($Y_2$)의 함량은 25.31%, SOS($Y_3$)는 19.79%, 그리고 POP($Y_4$)는 11.22%로 측정되었다.