• 대한치과보철학회지
• /
• 제14권1호
• /
• pp.41-46
• /
• 1976

The purpose of the current study was to investigate histologic changes in the alveolar bone of the lower molar region subsequent to the loss of their opposite molars, and to characterize chemical alterations by utilization of histochemical procedures. Twenty five rats(Sprague Dawley), approximately 150-200gm body weight, were used in this experiment. In the treated animals, upper molars were removed. The animals were decapitated by groups at the following intervals after teeth removals: 10th, 20th, 50th, 70th and 100th day. The normal, untreated rats were used as controls. The molar region of lower jaw, including the intact alvelar bone and teeth was dissected and specimens were decalcified in 3% formic acid. After the tissues were fully decalcified, the specimens were embedded in celloidin and sectioned in mesiodistal plane. These sections were stained in the following staining methods. Mallory azan stain and hematoxylin-eosin stain were utilized for structural evaluation. Polysaccharides were demonstrated by means of the PAS reaction. Acidmucopolysaccharides were studied by means of the colloidal iron stain. Alloxan-Schiff reaction was used for protein. The results were as follows: 1) In the control animals, bone resorption was noted in the distal alveolar bone proper and bone apposition was shown in the mesial alveolar bone proper. But in the treated animals, bone apposition was observed on the mesial and distal walls of the alveolus and osteoclastic activity was not noted in any walls. 2) Bone apposition was most prominent from the 10th to 20th day after treatment. 3) Appositional growth of cementum along the surface of root was prominent from the 50th to 70th day after treatment. 4) In the area where osteoblastic activity was apparent, osteoblasts were stained strongly in the PAS and alloxan-Schiff reaction. A plastic resorption line showed strong alloxan-Schiff reaction. 5) In the colloidal iron stain, the alveolar wall adjacent to the cementum apposition area was stained more strongly than the other areas.

• 대한치과보철학회지
• /
• 제31권4호
• /
• pp.533-541
• /
• 1993

This study was designed to help to be given esthetics in construction of denture and prosthodontic rehabilitation of anterior tooth region. The author took the facial straight photograph of 100 old aged people(male 50, female 50) above 55 years of age, who have natural teeth in anterior tooth region, in a resting and a smiling position. And the author measured and analyzed the lip shape, the relation between the lip and the teeth and the change of lip length and height when they were smiling. The results of this study were as follows : 1. In the shape of the upper lip, when the upper lip curved downward, it was 53%, straight was 28% and curved upward was 9%. 2. In the relation between the upper lip and the teeth, average smile was 53% , high smile was 26% and low smile was 21%. 3. In the parallel relation between the lower lip and maxillary anterior incisal curvature, the group of straight was 54%, the group of parallel was 40% and the group of reverse was 6%. 4. In the relationship between maxillary anterior incisor and lower lip, the group of not-touching was 92%, the group of touching was 5% and the group of the maxillary anterior incisor were slightly covered by the lower lip was 3%. 5. In the teeth displayed in a smile, displayed to second premolar was 50%, displayed to first molar was 34%, displayed to first premolar was 12%, and displayed to canine and second molar were 2%. 6. At smiling, the width of the mouth was 0.94 times of the interpupillary distance and 0.45 times of the full face width. 7. At smiling, the length of the upper lip was 0.73 times and lower lip was 0.98 times of the length in a resting postion and the width of the mouth corner was 1.19 times of the resting position.

• 대한치과교정학회지
• /
• 제50권2호
• /
• pp.108-119
• /
• 2020

Objective: The primary objective of this study was to quantitatively analyze the bone parameters (thickness and density) at four different interdental areas from the distal region of the canine to the mesial region of the second molar in the maxilla and the mandible. The secondary aim was to compare and contrast the bone parameters at these specific locations in terms of sex, growth status, and facial type. Methods: This retrospective cone-beam computed tomography (CBCT) study reviewed 290 CBCT images of patients seeking orthodontic treatment. Cortical bone thickness in millimeters (mm) and density in pixel intensity value were measured for the regions (1) between the canine and first premolar, (2) between the first and second premolars, (3) between the second premolar and first molar, and (4) between the first and second molars. At each location, the bone thickness and density were measured at distances of 2, 6, and 10 mm from the alveolar crest. Results: The sex comparison (male vs. female) in cortical bone thickness showed no significant difference (p > 0.001). The bone density in growing subjects was significantly (p < 0.001) lower than that in non-growing subjects for most locations. There was no significant difference (p > 0.001) in bone parameters in relation to facial pattern in the maxilla and mandible for most sites. Conclusions: There was no significant sex-related difference in cortical bone thickness. The buccal cortical bone density was higher in females than in males. Bone parameters were similar for subjects with hyperdivergent, hypodivergent, and normodivergent facial patterns.

• 구강회복응용과학지
• /
• 제23권4호
• /
• pp.313-326
• /
• 2007

With rising prevalency of mouth breathing children caused by developing civilization and increasing pollution, there are many maxillary transverse discrepancy patients with undergrowth of maxilla. For improving this, maxillary mid-palatal suture splitting was often performed. The purpose of this study was to analyse the stress distribution on the craniofacial suture and cranium after rapid maxillary expansion by finite element model. The boy(13Y6M) was chosen for taking computed-tomography for finite element model. Three-dimensional model of maxilla, first premolar, first molar, buccal and lingual part of rapid maxillary expansion were constructed. 1. The alveolar bone adjacent to the first molar and the first premolar that was affected directly by rapid maxillary expansion was displaced laterally approximately 4.04mm at maximum. The force decreased toward anterior region and frontal alveolar bone displaced laterally about 3.18mm. 2. A forward maximum displacement was exhibited at zygomatic process middle region. 3. At maximum, maxillary median part experienced 0.973mm downward repositioning and 0.65mm upward repositioning at lateral alveolar bone. 4. Von mises stress was observed the largest stress distribution around teeth and zygomatic buttress. 5. The largest tensile force was observed around alveolar bone of teeth, while compression force was observed at zygomatic buttress.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제49권6호
• /
• pp.347-353
• /
• 2023

This case report presents inferior alveolar nerve (IAN) repositioning as a viable approach for implant placement in the mandibular molar region, where challenges of severe alveolar bone width and height deficiencies can exist. Two patients requiring implant placement in the right mandibular molar region underwent nerve transposition and lateralization. In both cases, inadequate alveolar bone height above the IAN precluded the use of short implants. The first patient exhibited an overall low alveolar ridge from the anterior to posterior regions, with a complex relationship with adjacent implant bone level and the mental nerve, complicating vertical augmentation. In the second case, although vertical bone resorption was not severe, the high positioning of the IAN within the alveolar bone due to orthognathic surgery raised concerns regarding adequate height of the implant prosthesis. Therefore, instead of onlay bone grafting, nerve transposition and lateralization were employed for implant placement. In both cases, the follow-up results demonstrated successful osseointegration of all implants and complete recovery of postoperative numbness in the lower lip and mentum area. IAN repositioning is a valuable surgical technique that allows implant placement in severely compromised posterior mandibular regions, promoting patient comfort and successful implant placement without permanent IAN damage.

• 대한치과보철학회지
• /
• 제26권1호
• /
• pp.153-169
• /
• 1988

There is a little scientific documentation reporting the stress, distribution to the edentulous mandible by different concepts of occlusal scheme. So, this study was to investigate the hypothesis that the magnitude and distribution of the occlusal stresses, transmitted through a mandibular complete denture base to the edentulous mandible, would be influenced by the lingualized occlusion. This investigation was performed to analyze the stresses induced in a three-dimensional photoelastic edentulous mandible, when a load is applied to the denture arranged into lingualized occlusion in centric relation, lateral and protrusive functional position. The mounted denture on a Dentatus Type ARO articulator was loaded in a pure vertical direction with 15kgs on the center of articulator in each case and the stresses were frozen into epoxy edentulous model at $127^{\circ}C$ in the stress freezing furnace. The stress-frozen epoxy models were sliced with diamond disc saw into 4mm thick. The slices were examined with a circular polariscope. The results were as follows: 1. In centric relation, the stresses were low at anteriors, and gradually increase to the premolar, molar area and highest at the first molar and gradually decrease from the second molar and lowest at the retromolar pad region. The lingual side showed higher stresses than labiobuccal side. 2. In lateral functional position, the working side showed higher stresses than the balancing side. In working side, the lingual side showed higher stresses than the buccal side and in balancing side, the buccal side showed higher stresses than the lingual side. 3. In protrusive position, stress distribution was symmetrical on the posteriors and the stresses were concentrated at the labial side of the anteriors.

• 한국의학물리학회지:의학물리
• /
• 제12권1호
• /
• pp.31-39
• /
• 2001

핵자기공명분광학(NMR Spectroscopy)을 이용해서 우리는 생물체의 조직안에 있는 각종 대사물질들을 측정할 수 있게 되었으며, 이것은 또 지금까지 알려진 여러 방법 중에서 생물체내의 신진대사 물질이나 생화학적인 변화를 비침습적(noninvasive)으로 알아낼 수 있는 유일한 방법에 속한다. 양성자 핵자기공명분광학은 최근들어 사람이나 흑은 동물뇌의 생화학적인 특성을 연구하는데 많이 사용되어오고 있다. 핵자기공명영상은 주로 물분자에 있는 양성자의 밀도와 그들의 이완현상(relaxation phenomena)을 측정하여 영상화하지만 핵자기공명분광학은 생체조직내의 신진대사에 관한 생화학적인 정보를 제공한다. 많은 경우에 있어서 핵자기공명분광학은 CT나 MRI 영상에서는 발견할 수 없는 정보를 제공함으로써 특정질병의 진단에 사용될 수 있으며, 따라서 환자들의 질병상태를 효과적으로 진단하는데 쓰여질 수 있다. 따라서 본 연구에서는 사람의 뇌에서 수소 핵자기공명분광학을 이용하여 대사물질들의 농도를 정량화하는 방법을 시도하였다. 이를 위해 펀텀을 이용하여 대사물질들 각각의 스팩트럼을 구했고, 성인 남녀 16명을 대상으로 insula gray matter 부위의 대사물질들의 농도를 측정하였다. 그리고 이 값들은 다른 연구자들에 의해 밝혀진 값들과 매우 근사한 값을 제공하였다.

• 치과방사선
• /
• 제17권1호
• /
• pp.163-171
• /
• 1987

The author has clinically and radiologically investigated 57 cases of odontogenic keratocyst in 47 patients consisted of 26 males and 21 females aged from.2 to 63 years, who were pathologically diagnosed as odontogenic keratocyst at infirmaries of dental colleges, Yonsei University and Seoul national university during 1965-1986. The results were as follows: 1. The peak incidence of the disease was on their teenagers (29.8%). The ratio of Male/Female was 1.23:1 and incidence rate of males showed higher than their counterpart. 2. The most frequent complaints were swelling in (65.9%) followed by pus discharge, unknown mass, pain, residual root. 3. The most common site was mandibular third molar and mandibular ramus region (15.8%) followed by mandibular body and ramus, mandibular third molar, mandibular anterior teeth. Incidence of this disease in mandible was higher than in maxilla. 4. The lesions not associated with adjacent teeth were (14.0%) and in the lesions associated with adjacent teeth (35.1%) showed root resorption, (50.9%) were without root resorption, (35.1%) showed tooth migration and (50.9%) were without tooth migration. 5. The border types of the lesions were scalloped type in (52.6%), smooth type in (47.4%) and morphological type were unilocular in (50.9%), multilocular in (49.1%). 6. The radiologic cyst type of the lesions were follicular type (42.1%) followed by primordial, unclassified odontogenic, residual, lateral periodontal, median mandibular, globulomaxillary type.

• Archives of Pharmacal Research
• /
• 제27권12호
• /
• pp.1275-1283
• /
• 2004

Fate of the nascent thyrolglobulin (Tg) molecule is characterized by multimerization. To establish the formation of Tg multimers, the partially unfolded/reduced Tg or deoxycholate-treated/ reduced Tg was subjected to protein disulfide isomerase (PDI)-mediated multimerization. Oxidized glutathione/PDI-mediated formation of multimeric Tg forms, requiring at least an equivalent molar ratio of PDI/Tg monomer, decreased with increasing concentration of reduced glutathione (GSH), suggesting the oxidizing role of PDI. Additional support was obtained when PDI alone, at a PDI/Tg molar ratio of 0.3, expressed a rapid multimerization. Independently, the exposure of partially unfolded Tg to GSH resulted in Tg multimerization, enhanced by PDI, according to thiol-disulfide exchange. Though to a lower extent, a similar result was observed with the dimerization of deoxycholate-pretreated Tg monomer. Consequently, it is implied that intermolecular disulfide linkage may be facilitated at a limited region of unfolded Tg. In an attempt to examine the multimerization site, the cysteine residue-rich fragments of the Tg were subjected to GSH-induced multimerization; a 50 kDa fragment, containing three vicinal dithiols, was multimerized, while an N-terminal domain was not. Present results suggest that the oxidase as well as isomerase function of PDI may be involved in the multimerization of partially unfolded Tg or deoxycholate-treated Tg.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제32권4호
• /
• pp.374-379
• /
• 2006

Central granular cell odontogenic tumor(CGCOT) is a very rare lesion that consists of densely packed granular cells with numerous scattered strands of odontogenic epithelium interspersed throughout the tissue. CGCOT was initially reported in 1962 by Cough et al as central granular cell ameloblastic fibroma. But, recently, this term is inappropriate because of histologic and chronologic differences. CGCOT is usually present as painless swellings. Radiographs show a well-demarcated radiolucent or mixed radiopaque-radiolucent lesion. The average age on presentation of CGCOT is 47.3 and women are 75% more likely to develop this lesion than men. The tumor only occur in tooth bearing areas of the jaw with 88% of cases occurring in the mandible and 12% involving the maxilla, usually in an equal distribution between the caninepremolar-molar areas. This tumor is benign, and care is effected by localized surgical excision. We report an additional case of CGCOT that occurred in the Rt. Maxillar premolar/molar region of a 32-year old man with literature review.