• The Journal of Korean Academy of Prosthodontics
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• v.8 no.1
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• pp.37-41
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• 1968

The purpose of this paper is to evaluate the number of occlusal contacts in centric occlusion. The 50 strictly selected subjects, who have good natural dentition and occlusion, were impressioned with Alginate Impression material, and dental stone models were madel. After transfering the models from mouth to Hanau Articulator Model H2 by means of SM type Face-Bow, condylar guidances were registered, red articulating papers($13{\mu}$ in thickness) were inserted between upper and lower posterior teeth, and the red marked points and lines were counted as occlusal contact points. 1. The number of occlusal contact points in centric occlusion were 1st Molars 2nd Molars, 2nd Premolars and 1st Premolars in order. 2. The number of occlusal contact points of right side showed comparatively much more than those of left side. 3. The number of occlusal contact points of upper in Premolar area were much more than those of lower, and in Molar area were the reverse. 4. The total number of occlusal contact points in centric occlusion were approximately 105 points.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.23 no.5
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• pp.471-477
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• 2001

Failure to use effective methods of reduction, fixation, and immobilization may lead to nonunion with osteomyelitis, owing to the compound nature of most fractures of the mandible. Nonunion results in fibrous pseudoarthrosis at the fracture site with instability that, once formed, does not improve spontaneously. Once the nonunion with osteomyelitis secondary to fractures has become established, intermaxillary fixation and drainage of infected tissue should be instituted as early as possible, because the fixation & drainage enhances the patient comfort and hinders ingress of microorganisms & debris by movement of bone fragments. The authors treated three cases of nonunion with osteomyelitis by intermaxillary fixation, incision & persistent drainage on the previous fistula site and endodontic drainage of infected teeth in the fracture site of mandible. The localization & sequestration of the infected bone around the fracture was better performed persistently by natural homeostatic mechanism in $8{\sim}10$ weeks and the bony union was then attained without bone grafting.

• Korean Journal of Ichthyology
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• v.21 no.4
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• pp.307-310
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• 2009

A specimen (862.3 mm standard length) of Pisodonophis cancrivorus (Richardson, 1848), family Ophichthidae, was first collected from the coast of Uljin-gun in Gyeongsangbuk-do, Korea in September 2008. This species is characterized by the following: fleshy protrusions of upper jaw in the front and rear of the posterior nostril, 3~5 irregular rows of granular teeth in bands on maxilla, mandible and vomer, and origin of dorsal fin above the middle of the pectoral fin. Based on the fleshy protrusions found on its upper jaw, a new Korean name "dol-gi-ba-da-baem" has been proposed for this species.

• Journal of Periodontal and Implant Science
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• v.39 no.3
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• pp.375-381
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• 2009

Purpose: Root resection can be a valuable procedure when the tooth in question has a high strategic value. The prognosis of root resection has been well documented in previous studies, but the results focused on the palatal root resection have not been discussed in depth. I represent here the short term effectiveness of palatal root resection of maxillary first molars. Methods: Palatal root resection was performed on maxillary first molars of three patients. All the palatal roots were floating state on the radiographic finding and showed full probing depth and purulent exudation at initial examination. Reduction of palatal cusp and occlusal table was performed concomitantly. Endodontic therapy was completed after root resection. Results: Compromised maxillary first molars were treated successfully by palatal root resection in 3 cases. The mobility of resected tooth was decreased a little bit. The probing pocket depth of remaining buccal roots was not increased compared to initial depth. All the patients satisfied with comfort and cost effective results and the fact they could save their natural teeth. Conclusions: Within the above results, palatal root resection is an effective procedure treating compromised maxillary first molar showing advanced palatal bone loss to root apex with or without pulp involvement when proper case selection is performed.

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.3
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• pp.366-374
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• 2000

FRC/ceromer system provides the clinician with a durable, flexible, and esthetic alternative to conventional porcelain fused to metal crowns. FRC is the matrix which is silica-coated and embedded in a resin matrix. The ceromer material which is a second generation indirect composite resin contains silanized, microhybrid inorganic fillers embedded in a light-curing organic matrix. FRC/ceromer restoration has a several advantages: better shock absorption, less wear of occluding teeth, translucency, color stability, bonding ability to dental hard tissues, and resiliency. It has versatility of use including inlay, onlay, single crown, and esthetic veneers. With adhesive technique, it can be used for single tooth replacement in forms of inlay adhesion bridge. In single tooth missing case, conventional PFM bridge has been used for esthetic restoration. However, this restoration has several disadvantages such as high cost, potential framework distortion during fabrication, and difficulty in repairing fractures. Inlay adhesion bridge with FRC/ceromer would be a good alternative treatment plan. This article describes a cases restored with Targis/Vectris inlay adhesion bridge. Tooth preparation guide, fabrication procedure, and cementation procedure of this system will be dealt. The strength/weakness of this restoration will be mentioned, also. If it has been used appropriately in carefully selected case, it can satisfy not only dentist's demand of sparing dental hard tissue but also patient's desire of seeking a esthetic restorations with a natural appearance.

• The Journal of the Korean dental association
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• v.51 no.5
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• pp.250-254
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• 2013

Modern theories and concepts of occlusion for implants and natural teeth have originated in complete denture construction. Bilateral balanced occlusion as the occlusal scheme of choice has a long history in complete denture construction. The reason that occlusion has always been a consideration in the provision of removable prosthetics is because the adoption of good occlusal practice has a significant and immediate impact on the overall success of the treatment, as it affects denture stability. However, clinicians must remember that there are multiple ways, both successful and unsuccessful, to complete the restoration of a patient's occlusion. The goal is to meet the physiologic, functional, and esthetic needs of the individual patient while applying knowledge, accurate diagnosis, experience, clinical judgement, and attention to detail. This paper describes the features of an ideal occlusion in removable prosthodontics, why these features make it ideal for denture stability, and some technique for achieving these aims.

• Journal of Oral Medicine and Pain
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• v.14 no.1
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• pp.43-55
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• 1989

The need of age estimation for identification was increased by complexity of society, and the tooth was used widely for age estimation because of less individual deviation than the other organ. The age estimation using the tooth had several methods. Recently, the one using the racemization of aminoacid in the tooth was admitted more accurate than the other methods, especially in old age. But, this study was not tried in our country, and I would report the result of experiment about age estimation using racemization of dentine. I selected 40-Whole dentine sample from extracted teeth, those were reserved in natural dried condition for 2 weeks~ 1year and calculated the estimation of age from the ratio of D-aminoacid and L-aminoacid (D/L ratio) using gaschromatography and the results were below. 1. The aminoacids showed apparent K/L ratio in dentine were aspartic acid, serine. 2. The aspartic acid showed the highest racemic rate and its rate was 0.0012$\pm$0.0003/yr. 3. The relation between the actual age and K/L ratio was very positive correlation(r+0.954) in the estimation of age using aspartic acid. 4. The deviation between the estimated age using D/L ratio of aspartic acid and actual age was $\pm$3.32.

• The Journal of Korean Academy of Prosthodontics
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• v.31 no.1
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• pp.151-162
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• 1993

The author installed $3.75mm\times10mm$ $Br{\aa}nrmark$ osseointegrated implants and $3.5mm\times8mm$ I.T.I. hollow screw implants(Benefit) as a free standing abutment to replace lower left and right molars of 44-year-old female patient. Form the foregoing procedure, the author obtained the following results. 1. Free-standing $Br{\aa}nrmark$ and I.T.I. Hollow screw implants(Benefit) could be used to replace molars effectively without reduction of adjacent natural teeth, 2. Rotation of occlusal gold screw of $Br{\aa}nrmark$ implants was observed under occlusal force. 3. Adjustment of height of I.T.I. abutments was necessary in the mandibular second molar because of the limited occlusal clearance. 4. Form the oral examination, patient comments, panoramic and periapical radiographs, there were no pain, gingival imflammation and mobility, but slight reduction of alveolar bone level was shown around both implant systems. 5. Patient comments were comfortable on both systems. but the patient complained about economic problem of $Br{\aa}nrmark$ system and long treatment treatment time of both systems.

• Journal of KSNVE
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• v.5 no.4
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• pp.565-575
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• 1995

Gearboxes are often used in the petrochemical and electrical power plants to transmit mechanical power between two branches of a machinery train rotating at different speeds. When the gearboxes are connected with rotors supported by journal bearings, bearing loads vary in magnitude and direction with rotor speed and torque transmitted by the gearboxes. In this study, dynamic characteristics of the system which consists of gearboxes and a rotor supported by journal bearings are investigated analytically and experimentally by employing the polynomial transfer matrix method and modal analysis under different speeds and torque levels. Journal bearing loads due to the transmitted torque are claculated analytically and the stiffness and damping coefficient of the journal bearings are obtained using finite element method. Comparison of the analytical and experimental results shows that the cross coupled stiffness coefficients increase with increasing rotor speed, while the cross coupled damping coefficients decrease. This generates the oil whirl instability in the journal bearings. As the transmitted torque level goes up, the stiffness coefficients of the journal bearing and the first horizontal natural frequency increase. High levels of the transmitted torque produce high bearing stiffness since the contact loads of the mating gear teeth increase. The logarithmic decrement, which is a stability indicator, is shown to decrease with increasing speed and decreasing torque. Thus, at the low torque level, the system become unstable even at the low shaft speed.

• Journal of Korean society of Dental Hygiene
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• v.6 no.1
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• pp.13-23
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• 2006

A number of studies are beginning to show that oral disorders can have a significant impact on the functional, social and psychological well-being of adult. The aim of this study was to measure, the Oral Health Impact Profile(OHIP), which has recently been tested in studies of oral health of adult aged 55 years and older. The sample consisted of 380 adults The measure proved to be reliable and valid, while data collected using this measure indicated that oral conditions have negative impact on the daily, this impact was particularly marked among both edentulous and dentulous individuals who did not make regular visits for dental care. The relationship between the OHIP 7 demention compared with the group based on their dental state and age group was statistically Signification(pE0.01) people with denture were more likly to report having many problems in all seven dimention corvered by OHIP scale than those with natural teeth only These results indicated that the OHIP has a negative impact on the daily lives of a substantial proportions of older people. This impact was particularly noticeable among the edentulous and denture wearers.