• 대한치과교정학회지
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• 제53권2호
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• pp.77-88
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• 2023

Objective: To develop a method for generating three-dimensional (3D) digital models of the periodontal ligament (PDL) using 3D cone-beam computed tomography (CBCT) reconstruction and to evaluate the accuracy and agreement of the 3D PDL models in the measurement of periodontal bone loss. Methods: CBCT data collected from four patients with skeletal Class III malocclusion prior to periodontal surgery were reconstructed at three voxel sizes (0.2 mm, 0.25 mm, and 0.3 mm), and 3D tooth and alveolar bone models were generated to obtain digital PDL models for the maxillary and mandibular anterior teeth. Linear measurements of the alveolar bone crest obtained during periodontal surgery were compared with the digital measurements for assessment of the accuracy of the digital models. The agreement and reliability of the digital PDL models were analyzed using intra- and interexaminer correlation coefficients and Bland-Altman plots. Results: Digital models of the maxillary and mandibular anterior teeth, PDL, and alveolar bone of the four patients were successfully established. Relative to the intraoperative measurements, linear measurements obtained from the 3D digital models were accurate, and there were no significant differences among different voxel sizes at different sites. High diagnostic coincidence rates were found for the maxillary anterior teeth. The digital models showed high intra- and interexaminer agreement. Conclusions: Digital PDL models generated by 3D CBCT reconstruction can provide accurate and useful information regarding the alveolar crest morphology and facilitate reproducible measurements. This could assist clinicians in the evaluation of periodontal prognosis and establishment of an appropriate orthodontic treatment plan.

• 대한치과의사협회지
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• 제17권2호통권117호
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• pp.129-135
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• 1979

This 27 year-old male patient had severe mandibular prognathism (right and left mesio-occlusion were 0.4㎝ and 1.2㎝ , respectively). He had good oral health relatively exception of missing teeth. We examined all of his oral and skeletal status with full mouth x-ray taking, study model, and cephalogram. His general condition was good but above examination indicated the surgical operation for the mandibular prognathism. His laboratory tests were within normal limits. We determined surgical operation which was done by extraoral approach bilaterally. Incisions were made bilaterally 1.5㎝ beneath the inferior border of the mandible in the selected area and then the inferior border of the ascending rami was exposed. Retracting the periosteum to the lingual and buccal a slight amount, the cut in the bone was performed by use of bone drill. Avoiding T.M.J. troubles, the proximal segmant was not fixed to anterior segment, being in overlapping state buccally, in order to expect a natural healing by the environmental muscles and ligaments. We had immobilization with intermaxillary fixation by using the multiple Stout's method. He was discharged 17 days after operation. His general condition and operation results were good and satisfactory.

• 치과방사선
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• 제22권2호
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• pp.259-269
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• 1992

The author has examined the abnormalities in panoramic radiographs of 668 edentulous patients. The distribution, type, incidence, and location of all abnormalities were analized, and the distances between alveolar crest and anatomical structures were measures. (Maxillary measurements were performed between alveolar crest and lower margin of the maxillary sinus and mandibular measurements between alveolar crest and upper edge of the mental foramen.) The obtained results were as follows: 1. Of the 668 panoramic radiographs examined, 103(15.4%) showed one or more abnormalities. 2. The incidence of abnormalities was decreased by years, which was 22.0% in 1970's and 16.8% in 1980's and 12.1 % in 1990's. 3. The distribution of abnormalities as follows; 43 (40.2%) superficial root fragments, 24(22.4%) impacted teeth, 9(8.4%) imbedded root fragments, 7 (6.5%) cysts, 7(6.5%) fractures, 5(4.7%) foreign bodies, 5(4.7%) abnormal radiolucencies, 4(3.7%) abnormal radiopacities, 2(1.9%) bony defects, 1(0.9%) tumor. 4. In the location of abnormalities, 42 cases (35.3%) were in the maxillary posterior region, 26 cases(21.8%) were in the maxillary anterior region, 20 cases(24.4%) were in the mandibular posterior region and 18 cases(15.1%) were in the mandibular anterior region. 5. In the distance between alveolar crest and maxillary sinus, 109 cases(9.7%) were below 0.5㎜, 757 cases(67.6%) were between 0.5㎜ and 10㎜, 254 cases(22.7%) were above 10㎜. In the distance between alveolar crest and mental foramen, 73 cases (8.8%) were below 0.5㎜, 501 cases (60.7%) were between 0.5㎜ and l0㎜ and 252 cases(30.5%) were above 100㎜.

• Journal of Periodontal and Implant Science
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• 제41권2호
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• pp.60-66
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• 2011

Purpose: The aim of this study is to evaluate the buccal and lingual bone thickness in the anterior teeth and the relationship between bone thickness and the tissue biotype. Methods: Three male and two female human cadaver heads (mean age, 55.4 years) were used in this study. First, the biotype of periodontium was evaluated and categorized into a thick or a thin group. Next, full thickness reflections of the mandible and the maxilla to expose the underlying bone for accurate measurements in the anterior regions were performed. After the removal of the half of the alveolar bone, the probe with a stopper was used to measure the thickness of bone plate at the alveolar crest (AC), 3 mm apical to the alveolar crest (AC-3), 6 mm apical to the alveolar crest (AC-6), and 9 mm apical to the alveolar crest (AC-9). The thickness of the buccal plates at the alveolar crest were $0.97{\pm}0.18\;mm$,$0.78{\pm}0.21\;mm$, and $0.95{\pm}0.35\;mm$ in the maxillary central incisors, lateral incisors, and canines, respectively. The thickness of the labial plates at the alveolar crest were $0.86{\pm}0.59\;mm$, $0.88{\pm}0.70\;mm$, and $1.17{\pm}0.70\;mm$ in the mandibular central incisors, lateral incisors and canines, respectively. Conclusions: The thickness of the labial plate in the maxillary anteriors is very thin that great caution is needed for placing an implant. The present study showed the bone thickness of maxillary and mandibular anteriors at different positions. Therefore, these data can be useful for the understanding of the bone thickness of the anteriors and a successful implant placement.

• 치과방사선
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• 제14권1호
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• pp.111-120
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• 1984

The author analyzed clinically and radiologically 319 radicular cysts which were proven histologically in Infirmary College of Dentistry Yonsei University and Seoul National University Hospital from 1965 to 1983, and which occurred in 167 males and 139 females between the ages of 6 and 70. This analysis was undertaken to discover the frequency and distribution of the radicular cysts with regard to the age and sex, the chief complaints of the patients, the regions, the radiographical appearances, the tooth changes, and the anatomical structures involved by the lesions. The obtained results were as follows: 1. The most frequently involved age group for the radicular cysts was the third decade of the patients, and the greatest number 69.9 per cent occurred between the ages of 11 and 40 years. The statistical analysis did not show any significant difference between male and female (P>0.05) 2. The frequently involved region for the radicular cysts was orderly the maxillary anterior region (44.9 per cent), the mandibular anterior region (15.9 per cent), the maxillary premolar region (14.8 per cent), and the mandibular premolar region (11.0 per cent). The maxillo-mandibular ratio of the radicular cysts was about 7:3. The statistical analysis did not show any significant difference between right and left sides (P>0.05). 3. The greatest number was 92.2 per cent, which were involved in apical portions of the radicular cysts, 88.7 per cent of the radicular cysts were found in the round shapes which were oval and elliptical, and 66.8 per cent of the radicular cysts were observed with the completely hyperostotic borders. 4. The radicular cysts caused the root resorption in 55.2 per cent and the migration of the involved tooth or teeth in 23.5 per cent respectively.

• 구강회복응용과학지
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• 제35권4호
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• pp.253-259
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• 2019

본 증례 보고는 하악 전치에 발생한 치은 퇴축을 laterally closed tunnel technique을 이용하여 처치하였다. 환자는 모두 과거 교정 치료 시 하악 전치의 경사도를 변화시켰으며 치주 적으로 얇은 생체형을 가지고 있었다. 터널링법으로 수여 부를 형성하고 구개 측에서 채득한 결합조직이식편을 터널내에 위치시킨 후 판막의 변연을 치근 중앙부를 향해 측방으로 이동시켜 봉합하여 이식편을 피개 하였다. 얇은 치주 생체형에도 불구하고 치근 피개를 성공적으로 얻을 수 있었으며 각화 치은의 획득과 주변 조직과의 색, 형태 조화로 심미성을 달성할 수 있었다.

• 치과방사선
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• 제20권1호
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• pp.19-27
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• 1990

The primary objective of this study was to analyze the hard and soft tissue profile and comparison of the both sexes in Korean adults using roentgenocephalometry. The subjects were 122 males and 116 females from 18 to 22 years of age selected on the basis of their excellent occlusion and harmonious profile. It was an investigation about the interrelationships in the angles which consisted of Frankfort horizontal plane (FH plane), Sella Nasion plane (SN plane), Nasal floor plane (NF plane) and Mandibular plane (Md plane) as reference planes, and of the axial inclinations of the upper anterior tooth to Nasal floor plane (NF Plane) and of the lower anterior tooth to Mandibular plane (Md Plane). Among the 14 categories estabilishied on the soft tissue land marks, the 6 categories were studied for the relationship to Frankfort horizontal plane (FH Plane), and the 8 categories were studied for the soft tissue contour. The results were as follows: 1. Among 8 measured angles in the hard tissue, the angle of FH-Md, NF-Md and SN-Md were greater in females than in males. 2. The axial inclinations of the anterior teeth to NF Plane and Md plane were slightly greater in males than In females. 3. Among 14 measured angles in the soft tissue, the angles of G-Sn-P and E-Pog-Sn were greater in males, and FH-G-Sn, GㆍSn-Sn. Pog and Pog-Sn-P were greater in females. 4. In males, the variability of measured values in both lips region were high.

• 대한치과보철학회지
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• 제52권4호
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• pp.359-365
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• 2014

치아가 얼마 남지 않은 부분 무치악 환자들에 있어 이중관(Double crown)을 이용한 치료의 성공적인 결과에 대해서 여러 문헌에서 보고 되고 있다. 이중관 가철성국소의치(Double crown removal partial denture)는 잔존치의 치주적인 상태가 좋지 않은 환자에게 치료의 대안이 될 수 있다. 이중관 가철성 국소의치는 특히 치주상태가 좋지 않고, 임플란트를 식립하기에는 의과적으로 문제가 있는 환자(Medically compromised patient)에게는 수술에 대한 부담 없이 치료할 수 있어 심리적이고 경제적인 이점이 존재한다. 본 증례에서는 상악은 다수의 치아가 잔존하여 고정성 보철물로 수복이 가능한 상태였고, 하악은 소수 잔존치만 남아있고 치주 상태가 매우 불량하여 잔존치를 이용한 클라스프 가철성 국소의치로는 수복하는 것이 거의 불가능하였다. 또한 환자는 1년 전에 하악 전치부 부위의 골수염으로 인한 수술병력으로 임플란트 식립이 어려운 상황이었다. 이러한 악조건에서 하악의 소수 잔존치를 이용한 이중관 의치는 2년이상의 기간동안 기능적, 심미적인 면에서 만족스러운 결과를 얻었기에 이를 보고하고자 한다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제32권5호
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• pp.459-466
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• 2010

Alveolar distraction osteogenesis (ADO) has been regarded as an acceptable treatment for the alveolar bone deficiency. For ADO at anterior maxillary area, the vector should be oriented to forward and down-ward direction to get an adequate occlusion with mandibular teeth and to increase bone length and width for implant placement. However, the conventional commercial distraction devices for ADO are designed to allow mainly downward movement of alveolar segment, even though a forward movement can be obtained a little by controlling of inclination of device. To make ADO with controllable bidirectional vector possible, we used customized devices using self-manufactured ABDUL (Alveolar Bone Distractor Using Lag screw principle) and commercial orthodontic palatal expansion device ($Hyrex^{(R)}$). In all cases (n = 4), ADO could be performed successfully and dental implants were able to placed with adequate occlusion. We report the procedures, advantages and disadvantages of these methods.

• Journal of Korean Dental Science
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• 제3권2호
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• pp.40-49
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• 2010

Dental clinicians often encounter cases wherein the patient's lost molar area was neglected and left untreated for an extended period of time, thereby causing the extrusion of opposite molars and occlusal disharmony as well as occlusion in the anterior teeth and consequently resulting in anterior displacement in the area. Clinicians normally carry out prosthetic treatment via occlusal plane lifting when such becomes absolutely necessary due to the lack of sufficient space needed for prosthetic therapy aimed at proper anterior and lateral induction. In this case report, we examined occlusal disharmony and VDO loss in a patient who had lost his molars and had not received prosthetic treatment for an extended period of time. We treated the maxillary area with dental implant prosthetics and Kennedy Class I RPD and the mandibular area with residual natural tooth-based implant placement and dental implant prosthetics. The patient reported treatment outcomes that were deemed satisfactory both functionally and aesthetically.