• Journal of the korean academy of Pediatric Dentistry
• /
• v.36 no.4
• /
• pp.591-596
• /
• 2009

In the case of the impacted teeth, the clinician has to consider development of tooth, site of impaction, eruption path, and cooperation of patient. Treatment options for the management of impacted teeth are separated into four categories: observation, intervention, orthodontic or surgical relocation and extraction. Autotransplantation may be defined as the transplantation of embedded, impacted or erupted teeth, from one site to another in the same individual into extraction site or surgically prepared sockets. Autotransplantation ensures preservation of natural tooth, induction of alveolar bone growth and root development, offers one of the fastest and most economically feasible means in the replacement of young patients' missing teeth. This case presents a malpositioned impacted mandibular premolar of an 11-year-old girl. It was thought that orthodontic traction was difficult because of its unfavorable impacted position. Therefore the tooth was treated by autotransplantation, we can observe good healing pattern during 12 months.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.40 no.3
• /
• pp.209-215
• /
• 2013

Cleft lip and palate, the most common craniofacial anomalies, are severe congenital defects that have an incidence of 0.28 to 3.74 per 1000 live births. Although there has been great improvement in the field of cleft surgery, surgical approach cannot be the single solution to resolve the various problems encountered in patients with cleft lip and palate. The concept of presurgical infant orthopedics (PSIO) for gradual closure of the cleft gap and simplified surgical performance was first introduced by McNeil in 1950. Recently, there are many attempts not only to approximate the alveolar segments but also to reshape the nasal cartilage. Three infants with unilateral cleft lip and palate were referred from the department of Plastic Surgery for presurgical nasoalveolar molding (PNAM). Maxillary appliances using resin with orthodontic wire were fabricated. Then these appliance was applied until patients underwent lip surgery. In all cases, the patients could wear the appliance all day since they were able to eat even with the appliance on, This resulted in significant improvements in the nasal symmetry were found. Our appliance, namely K-NAM, extends the wearing time within the limited period and as a result it is expected to maximize the treatment effects. Used properly, this appliance would play a major role in enhancing nasal symmetry with satisfactory results.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.25 no.4
• /
• pp.391-401
• /
• 2009

The successful outcome of dental implants is mainly the result of intial implant stability following placement. The aim of this study was to investigate the effect of a self-tapping blades and implant design on initial stability of two tapered implant systems in poor bone quality. The two different implant systems included one with self-tapping blades and one without self-tapping blades. D4 bone model using Solid Rigid Polyurethane Form was used to simulate poor bone densities. The insertion torque during implant placement was recorded. Resonance frequency Analysis (RFA), measured as the implant stability quotient (ISQ), was assessed immediately after insertion. Finally, the implant-bone specimen was transferred to an Universal Testing Machine to measure the axial pull-out force. Insertion torque values and maximum pull-out torque value of the non self-tapping implants were significantly higher than those in the self-tapping group (P = 0.008). No statistically differences were noted between the two implant designs in RFA. Within the each implant system, no correlation among insertion torque, maximum pull-out torque and RFA value could be determined. Higher insertion torque of the non-self-tapping implants appeared to confirm higher clinical initial stability. In conclusion, implants without self-tapping blades have higher initial stability than implants with self-tapping blades in poor bone quality.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.25 no.4
• /
• pp.437-444
• /
• 2009

The purpose of this study was to evaluate the physical properties of different automixing resin cements and the shear bond strength on dentin. For this study, two self-adhesive automixing resin cement(Rely-X Unicem(3M ESPE, St. Paul, USA), Embrace resin cement(Pulpdent, Oakland, USA)) and one chemical polymerizing resin cement(Resiment Ready-Mix(J.L.Blosser Inc., Liberty Missouri, USA)) were used. To evaluate the physical properties, compressive strength, diametral tensile strength and flexural strength were measured. The specimens were fabricated using Teflon mould according to manufacturers' instructions and stored for 24 hours in an atmosphere of 100% humidity. To evaluate the shear bond strength on dentin, each cements were adhered to buccal dentinal surface of extracted human lower molars in 2mm diameter. Physical properties and shear bond strengths were measured using universal testing machine(Z010, Zwick GmbH, Ulm, Germany) at a crosshead speed of 0.5mm/min. The physical properties and shear bond strength of different automixing resin cements were statistically analyzed and compared between groups using One-way ANOVA test and Schffe post-hoc test at the 95% level of confidence. The result shows that chemical polymerizing automixing resin cement represents the relatively higher physical properties and shear bond strength than self-adhesive automixing resin cements.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.26 no.4
• /
• pp.373-388
• /
• 2010

Fracture causes serious problems in many instance of prosthetic failures. But it is hard to find the definite causes when fractures occur. Fractography encompasses the examination of fracture surfaces that contain features resulting from the interaction of the advancing crack with the microstructure of the material and the stress fields. All fractured specimens(implant retaining screw) retrieved from Gangneung-Wonju national university dental hospital for 3 years(from 2007 to 2009). After pretreatment of samples, the scanning electon microscope were used for surface examination and fracture analysis. In case of most of the fractured specimens, fracture took place by fatigue fracture and fractured surface represents fatigue striation. Fatigue striation indicate the progression of the crack front under cyclic loading, are characteristic of stage 2 crack growth. The site of crack initiation and stage 1 crack growth were not easily identified in any of the failure, presumably because of the complex microstructural features of the polycrystalline sample. In case of fractured by overload, dimpled or cleavage surface were observed. Using the interpretation of characteristic markings(ratchet mark, fatigue striation, dimple, cleavage et al) in fracture surfaces, failure events containing the crack origin, crack propagation, material deficiency could be understand. Using the interpretation of characteristic markings in fracture surfaces, cause and mechanism of fractures could be analyzed.

• Journal of Oral Medicine and Pain
• /
• v.38 no.2
• /
• pp.215-219
• /
• 2013

The descending control system is composed of a group of structures in the midbrain, medulla oblongata and pons that form a network of descending inhibitory projections. In the clinical setting, it has been shown that the application of a electrical counterirritant to these structures and diminishes the pain in patients. Thus, depression and anxiety have been shown to predict the development of chronic neuropathic pain state. These factors could influence pain might also involve descending controls. Interestingly, reduced descending controls are seen in patients with irritable bowel syndrome and theses patients had greater anxiety, depression compared to controls. And, the influence of anxiety on the chronicity of pain and on the descending control pathways should be tested in animal models, using modern techniques. Given this Knowledge, it is no wonder that pain is a highly personal experience that is susceptible to a variety of biologic, pharmacologic, and environmental influences.

• Journal of Periodontal and Implant Science
• /
• v.36 no.3
• /
• pp.591-600
• /
• 2006

Purpose: This study assessed the impact of self-reported periodontal health on the oral health-related quality of life among elderly Koreans. Methods: Four hundred twenty one elderly Koreans in Seoul and suburban areas were selected with a cluster (institution) sampling method, and were requested to take oral examinations and finish questionnaires on the Oral Health Impact Profile-14(OHIP-14). and self-reported periodontal health status, such as periodontal symptoms, self-rated periodontal health and periodontal treatment need. As the dependent variable, OHIP-14 showed a positive skewed distribution (skewness: 1.17), we transformed to square-root form to apply parametric analyses. Bivariate analysis by t-test and ANOVA, and multivariate analysis with the two-level regression model accounting clusters were implemented. Results: Mean age of the subjects was 74.6 years and 66.5% were women. Fourteen items of OHIP-14 were summarized to one factor explaining 78.6% of total variance and produced the Chronbach alpha coefficient of 0.92. Results from the multivariate model, adjusting for age, sex, type of institutions, ability to pay, and number of teeth present, showed significantly lower OHIP-14 with reporting less than 3 periodontal symptoms (p(O.OOO1), rating their own periodontal health as above average level (p=O.0144), and thinking they don't need any periodontal treatments in the near future (p=O.0148), than their counterparts. The intraclass-corrrelation estimated by the final model was 0.028. Conclusion: This study demonstrates a significant association between self-reported periodontal health status and the oral health-related quality of life.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.26 no.4
• /
• pp.616-622
• /
• 1999

The primary objective of pulp treatment is to maintain the integrity and health of the oral tissues. The most important and difficult aspect of pulp therapy is determining the health of the pulp, or its stage of inflammation, so that a decision can be made regarding the best form of treatment. Immature permanent teeth are good candidates for many pulp healing procedures, due to their rich blood supply, which is believed to enhance the pulp's ability to react successfully to various insults. Healing was considered to have taken place when the tooth fulfilled the following criteria: 1. Abscence of clinical symtoms 2. Radiographic evidence of dentin bridge formation 3. No intrapulpal or periapical pathosis was evident radiographically 4. Continued root development and closure of the apex in immature teeth 5. Normal dentin apposition in mature teeth 6. Positive response to electrical pulp test This presents a report of cases in which immature permanent teeth, pulp-exposed by caries or trauma, was treated successfully by partial pulpotomy.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.37 no.3
• /
• pp.368-373
• /
• 2010

The incisors function as instruments for biting and cutting food during mastication. They also support the lips and face and maintain vertical dimension. In addition, they contribute to overall normal arch appearance. They play important role during the articulation of speech and assist in guiding jaw closure. Extraction and space maintenance are the most common treatment for a tooth with poor prognosis. However, in the mixed dentition, extraction of the upper permanent incisors results in many complications, such as resorption of alveolar bone, poor esthetics, pronunciation, and mastication. Considering these various roles of incisors in oral cavity, approach for traumatized incisors, even the ones with poor prognosis, should be considered first prior to simple extraction. The dentist must take into account the age of the patient, growth potential, occlusion, oral hygiene status, economic status and motivation towards dental health in addition to patient compliance. In this case, although the prognosis was predicted to be unfavorable due to short root and mobility, we could save the central incisor using conservative treatment, reposition by orthodontic appliance instead of extraction.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.28 no.1
• /
• pp.37-46
• /
• 2012

The ultimate goal of periodontal therapy is the regeneration of supporting tissues. It is recommended to avoid probing until 6~9 months following the regenerative therapy because the probing may jeopardize the newly formed tissues. We can measure tooth mobility objectively using Periotest. The purpose of this study is to investigate whether Periotest can be used to evaluate the treatment results alternatively, and whether there are the correlations between the changes of Periotest value (PTV) and other clinical parameters. Regenerative treatments have been performed on 29 teeth of twenty five patients, at Department of Periodontology, Pusan National University Hospital. We measured the tooth mobility by Periotest and other parameters at the baseline, 6 and 12 months after regenerative treatment. Compared to the baseline, there were the statistically significant improvements in all the parameters at 6 months and 12 months. There were statistically significant correlations among the probing depth, attachment level, gingival recession and PTV at baseline, 6 months, and 12 months. Also there was the correlation between changes in PTV and in the attachment level at each time of observation period. We may conclude that regenerative therapy would improve the clinical parameters and periodontal status and PTV would be an alternative index to evaluate the healing process after regenerative surgery.