• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.1
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• pp.36-42
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• 2011

Introduction: The current study examined the morphological characteristics of maxillary sinus septum by computed tomography (CT). Materials and Methods: Two hundred and four patients (408 maxillary sinuses) who visited dental clinic were evaluated. CT were examined. The height of the septum measured from the sinus floor to the apex of the septum more than 3 mm was defined as "sinus septum". Results: The prevalence of sinus septa was 21.3% (87/408), and 31.4% (64/204) of patients had more than 1 sinus septum. Females showed higher and thinner sinus septa than males. The anatomic location of the septa were distributed in the 2nd molar region (43.7%), 1st molar region (31.0%), 2nd premolar region (21.8%) and 1st premolar region (3.5%). In 57 patients with chronic disease, there was no significant difference between sinus disease and the presence of sinus septa. The loss of remaining teeth and teeth adjacent to the sinus septum area was not related to the presence of sinus septa. Older subjects showed a reduced height and length of the septum, and a thicker septum. Conclusion: These results show that the maxillary sinus septum undergoes atrophy with age.

• Journal of the korean academy of Pediatric Dentistry
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• v.11 no.1
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• pp.1-6
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• 1984

The author studied the prevalence of proximal dental caries of deciduous molar by observing intraoral radiographies of 478 children aging from 2 to 5 who visited the Dep. of Pedodontics, Seoul National University Hospital. The following results were obtained; 1. The prevalence of proximal caries of deciduous molar did not show significant difference between male and female, right and left side. 2. Mandibular deciduous molar had higher prevalence than maxillary deciduous molar. 3. The prevalence was increased with age. 4. The prevalence was highest in the distal surface of lower 1st deciduous molar and lowest in the distal surface of upper 2nd deciduous molar.

• The korean journal of orthodontics
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• v.19 no.2
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• pp.57-73
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• 1989

The purpose of this study was to investigate the tissue response of the rat molar periodontium incident to intermittent orthodontic force. The author intended to observe the healing process of injured periodontium and the response of injured tissue to the resumed force. Oxytetracyclin 50mg/Kg was given to each rat intraperitonially. 5 days later, maxillary 1st molars were moved mesially from the incisors with closed coil spring of 100gram. 7 days later, the appliances were removed and 20mg/Kg of calcein were given intraperitonially to each rat. At the same time, maxillary left 1st molars of 15 rats were moved by the same method, but force was lowered to 20 gram. After 1 day, maxillary left 1st molars of another 15 rats were moved by the same method and 50mg/Kg of oxytetracycline was given intraperitonially. After 4 days, another 15 rats were treated as above. After 7 days, another 15 rats were treated as above. 1,4,7,10 and 14 days after change of force, 3 rats were sacrificed in each group respectively. 2 rats were decalcified, embedded in paraffin, and stained with hematoxylin-eosin stain and with Masson's trichrome stain. Another rat was embedded in polyester resin and undecalcified specimen were made. Microradiograms were taken with the undecalcified sections. Observations were made with light and fluorescence microscope. Following conclusions were made. 1. Connective tissue cells and vessels were infiltrated into the hyalinized tissue from the bony cleft and along the border of the hyalinized tissue with bone and root surface. At the same time, elimination of hyalinized tissue, bone and root resorption occurred. 2. Bone and root were resorbed directly and indirectly. 3. Hyalinized tissue was removed within 5 days after force removal. 4. Hyalinized zone was less extensive and easily removed as the rest period prolonged. 5. Hyalinized tissue developed more rapidly and extensively and lasted over 10 days as the force resumed on the already formed hyalinized tissue.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.27 no.2
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• pp.135-144
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• 1997

The primary intra-osseous carcinoma (PIOC) is a very rare lesion. PIOC is an odontogenic carcinoma defined as a squamous cell carcinoma arisinig within a jaw having no initial connection with the oral mucosa, and presumably developing from residues of the odontogenic epithelium. The authors diagnosed a 51-year-old female as primary intra-osseous carcinoma after undergoing clinical, radiological and histological examinations. The characteristics were as followed : 1. The patient complained of gingival bleeding on the premolar area in the left maxilla 2. The conventional radiograms showed a relatively well-defined unilocular radiolucent lesion from the mesial aspect of the upper left canine to the mesial aspect of the upper left 1st molar. The 2nd premolar was separated from the 1st molar and the floor of the maxillary sinus was elevated by the lesion. There was a external root resorption of the upper left canine, the 1st premolar, and the 2nd premolar. 3. On the computed tomograms, the osteolytic bony lesion expanded the cortical plate of the left maxilla and displaced the margin of the left maxillary sinus upwards. But the bony lesion was separated from the maxillary sinus by a bony septum. 4. Bone scintigram with /sup 99m/Tc demonstrated the increased uptake in the left maxilla. Sonograms in the neck area and chest P-A radiogram didn't show any abnormalities. 5. Histologically, the tumor islands infiltrating into the surrounding bone increased in alveolar pattern, composed of the malignant cells, and there was a necrosis in the center of the tumor islands.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.4
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• pp.485-489
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• 2008

Basal cell nevus syndrome is a hereditary disease of an autosomal dominant trait with variable conditions such as basal cell carcinomas of the skin, deformity of rib, fusion of vertebrae, mental retardation, hypertelorism, and multiple odontogenic keratocysts. A 32 years old man with pus discharge from fistula on the vestibule of left upper 1st molar visited to Chosun University Dental Hospital. Radiographic evaluation revealed multiple maxillary and mandibular cysts that had multilocular radiolucency on left mandibular body area, thining of inferior border of left border of ramus and well defined unilocular radiolucency above right upper 1st and 2nd molar and from left upper 1st premolar to 2nd molar. In chest PA view, he had a forked rib in the left 4th rib and in skull PA view the calcification of falx cerebri was observed. There was not any skin lesion. After the preliminary evaluation, the patient was diagnosed with basal cell nevus syndrome and he underwent marsupialization for decreasing the size of cystic lesion and came to hospital for dressing 3days a week. As time goes by, the size of lesion decreased. So, one and half year after marsupialization, he underwent cyst enucleation and iliac bone graft for the mandibular lesion and buccal fat pad grafts for the maxillary lesions. After the surgery, the patient experienced normal healing without any complications and he is on long-term follow-up.

• Journal of Oral Medicine and Pain
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• v.8 no.1
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• pp.121-126
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• 1983

This study is conducted with a view to make correct sexual differentiation by the utilization of discriminant functions. For that purpose were randomly sampled out 148 young adults testes, comprising 67 males and 81 females, ranging from 15 through 18 years fo age. Based on the values made available from the measurement of 6 items corresponding to the maxillary cast models, a statistical analysis was made to abstract feasible discriminant functions. The results findings are as follows: 1. The mean value by sex indicates, in all items, higher one in male group than in female group. 2. Through the measurement were defined as singnificant items in sexual differentiation the bucco-lingual dimensions of canine, 1st-molar, 2nd molar, and 1st bimolat width. 3. Derived from the value from measurement items were discriminant functions with the intention of applying them to sexual differentiation, as follows: 1) Y=-25.4112+0.7513BL3+0.3298BL4-0.2854BL5+0.7350BL6-0.3482BL7+0.2893AW (as tested by Method I) 2)Y=-25.0628+0.7737BL3+0.7468BL6-0.3885BL5+0.2951AW(as tested by Method II) BL3 : Bucco-lingual dimension of upper canine BL4 : Bucco-lingual dimension of upper first prmolar BL5 : Bucco-lingual dimension of upper second premolar BL5 : Bucco-lingual dimension of upper first molar BL6 : Bucco-lingual dimension of upper second molar AW : Upper first bimolar width 4. Sexual defferentiation in terms of descriminant functions represented a probility of 74.6%.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.21 no.2
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• pp.297-306
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• 1991

The purpose of this study is to improve the availabilities of radiographic technics as diagnostic methods to evaluate maxillary sinus in dental clinic. For the morphologic study of maxillary sinus, 20 dry maxillas were used and intraoral standard views, orthopantomograms, and skull P-A views were taken. For measuring the vertical image magnification rates, 5 sites in maxillary molar regions of 5 dry mandibles were selected radndomly and 25 wires of the determined sizes for selected portions were attached to the sites, after then, intraoral radiograms with bisecting technic and orthopantomograms were taken. The acquired results were as follows: 1. The anterior extension of the maxillary sinus on orthopantomogram was the distal side of the canine in 45.45% of subjects, the mesial side of the canine in 27.27%, the lateral incisor in 9.09%, the mesial side of the 1st premolar in 9.09%, and the mesial side of the 2nd pre-molar in 9.09%. 2. The positional relationship between the floor of maxillary sinus and the apex of alveolar socket revealed superimposed type in 58.3% of subjects, approached type in 33.3%, and separated type in 8.4%. 3. The morphology of inferior border of maxillary sinus was simple V or U shape in edentulous stage and V or wide U shape in alveolar socket stage. 4. The vertical image length on intraoral film taken by bisecting technic was magnified by 27.23% on the average and the length on orthopantomogram by 12.35%. 5. The inferior borders of maxillary sinus coinciding with each of the areas bearing the anterior and the posterior teeth on skull P-A view were determined.

• Journal of Periodontal and Implant Science
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• v.40 no.2
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• pp.56-60
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• 2010

Purpose: The sinus lift procedure requires detailed knowledge of maxillary sinus anatomy and the possible anatomical variations. This study evaluated the location and prevalence of maxillary sinus septa using computed tomography (CT). Methods: This study was based on the analysis of CT images for posterior maxilla which were obtained from patients who visited Chonbuk National University Dental Hospital during the period of June 2007 to December 2008. With the exclusion of cases presenting any pathological changes, 236 maxillary sinuses in 204 patients were retrospectively analyzed. The average age of the patients was 50.9. The cases were divided into two groups, an atrophy/edentulous segment and a non-atrophy/dentate segment, and maxillary sinus septa of less than 2.5 mm were not taken in-to consideration. The location of septa was also divided for analysis into 3 regions: the anterior (1st and 2nd premolar), middle (1st and 2nd molar) and posterior (behind 2ndmolar) regions. Results: In 54 (20.9%) of the 204 patients there were pathologic findings, and those patients were excluded from the analysis. Sinus septa were present in 58 (24.6%) of the 236 maxillary sinuses and in 55 (27%) of the 204 total patients. In the atrophy/ edentulous ridge group (148 maxillary sinuses), 41 cases (27.7%) were found, and 17 cases (19.3%) were found in the non-atrophy/ dentulous ridge group (88 maxillary sinuses). In terms of location, septa were found in 18 cases (27.3%) in the anterior, in 33 cases (50%) in the middle and in 15 cases (22.7%) in the posterior regions. Conclusions: In the posterior maxilla, regardless of type of ridge (atrophy/edentulous or non-atrophy/dentate), the anatomical variation of sinus septa is diverse in its prevalence and location. Thus, accurate information on the maxillary sinus of thepatient is essential and should be clearly understood by the surgeon to prevent possible complications during sinus lifting.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.5
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• pp.413-419
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• 2011

Purpose: Reposition of the maxilla is a common technique for correction of midfacial deformities. To achieve the goal of the surgery, the maxilla should be repositioned based on the precisely planned position during surgery. The internal reference points (IRPs) and the external reference points (ERPs) are usually used to determine vertical dimension of maxilla, which is an important factor for confirming maxillary position. However, the IRPs are known to be inaccurate in determining the vertical dimension. In this study, we investigated the correlation of positional change of the modified IRPs with repositioned maxilla. Methods: The study group consisted of 26 patients with dentofacial deformities. For the simulation of the surgery, patient maxillary CT data and 3-D virtual surgery programs (V-$Works^{(R)}$ and V-$Surgery^{(R)}$) were used. IRPs of this study were set on both the lateral wall of piriform aperture, inferior margin of both infraorbital foramen, and the labial surfaces of the canine and first molar. The distance from the point on lateral wall of the piriform aperture to the point on the buccal surface of the canine was defined as IRP-C, and the distance from the point on the inferior margin of the infraorbital foramen to the point on the buccal surface of the $1^{st}$ molar was defined as IRP-M. After the virtual simulation of Le Fort I osteotomy, the changes in IRP-C and IRP-M were compared with the maxillary movement. All measures were analyzed statistically. Results: With respect to vertical movements, the IRP-C (approximately 98%) and the IRP-M (approximately 96%) represented the movement of the canine and the $1^{st}$ molar. Regarding rotating movement, the IRPs changed according to the movement of the canine and the $1^{st}$ molar. In particular, the IRP-C was changed in accordance with the canine. Conclusion: IRPs could be good indicators for predicting vertical movements of the maxilla during surgery.

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.2
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• pp.203-211
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• 2008

Minimizing damage to anatomical structure is a prerequisite for skeletal anchorage system to install a miniscrew. This research has focused on evaluating the stability and safety of installation in the maxillary molar buccal area, in which most miniscrews are installed clinically and initial fixation is weak. CT (computerized tomography)images were taken for surveying the possibility of damaging to adjucent teeth in accordance with installation angle. If we install a mini-screw($1.2{\times}6.0mm$) in the maxillary molar buccal area, it would be located generally in the 5~8mm upper of CEJ and 3~5mm inner of the cortical bone surface. We has measured the space between roots And comparison has been made for gender and the space between roots in accordance with the 3 different angles of installation(30 degree, 40 degree, 60 degree) in 3 categories. Category 1 : between 1st molar and 2nd molar Category 2 : between 1st molar and 2nd premolar Category 3 : between 1st premolar and 2nd premolar The result are as follow; 1. The space for category 1 was significantly small. 2. For the installation angle, it was safer to install with steeper angle in category 1 and category 2, but not in category 3. According to these results, the installation a miniscrew in category 2, 3 is safer than in category 1. And it is safer to install with steeper angle in category 1 and category 2.