• The Journal of Korean Academy of Prosthodontics
• /
• v.51 no.2
• /
• pp.107-112
• /
• 2013

Complications increases when crown height space is excessive and one should be careful of choosing type of fixed prosthesis in case crown height space is over 12 mm. In this condition, tooth seems to be longer, therefore, it is needed to use gingival shade in aesthetically important area for fixed prosthesis. In this case, fixed prosthesis which has inappropriate maintenance and hygiene could hold food, plaque, calculus, thus increase incidence of inflammation and infection. Moreover, it could lead to chronic inflammation and infection and in that case surgical improvement could be necessary. In present case report, gingival inflammation and swelling developed around prosthesis after having made it considering articulation and aesthetic view in patient who had excessive crown height space. Finding out that design of prosthesis is a factor to make it hard to maintain oral hygiene, a temporary prosthesis which has enough interproximal space and proper emergence profile was fabricated. After two months of observation, significant abnormal symptoms are not found and oral reconstruction is performed using fixed prosthesis with zircornia infrastructure and porcelain build-up based on convenient self hygiene design. Through serial treatment, inappropriate soft tissue response is not observed and satisfactory result in functional aspect comes out.

• The Journal of Korean Academy of Prosthodontics
• /
• v.46 no.6
• /
• pp.561-568
• /
• 2008

STATEMENT OF PROBLEM: Currently, many implant systems are developed and divided into two types according to their joint connection: external or internal connection. Regardless of the connection type, screw loosening is the biggest problem in implant-supported restoration. PURPOSE: The purpose of this study is to assess the difference in stability of abutment screws between the external and internal hexagonal connection types under cyclic loading. MATERIAL AND METHODS: Each of the 15 samples of external implants and internal abutments were tightened to 30 N/cm with a digital torque gauge, and cemented with a hemispherical metal cap. Each unit was then mounted in a $30^{\circ}$ inclined jig. Then each group was divided into 2 sub-groups based on different periods of cyclic loading with the loading machine (30 N/ cm - 300 N/cm,14 Hz: first group $1{\times}10^6$, $5{\times}10^6$ cyclic loading; second group $3{\times}10^6$, $3{\times}10^6$ for a total cyclic loading of $6{\times}10^6$) The removal torque value of the screw before and after cyclic loading was checked. SPSS statistical software for Windows was used for statistical analysis. Group means were calculated and compared by ANOVA, independent t-test, and paired t-test with ${\alpha}$=0.05. RESULTS: In the external hexagonal connection, the difference between the removal torque value of the abutment screw before loading, the value after $1{\tims}10^6$ cyclic loading, and the value after $1{\times}10^6$, and additional $5{\times}10^6$ cyclic loading was not significant. The difference between the removal torque value after $3{\times}10^6$ cyclic loading and after $3{\times}10^6$, and additional $3{\times}10^6$ cyclic loading was not significant. In the internal hexagonal connection, the difference between the removal torque value before loading and the value after $1{\times}10^6$ cyclic loading was not significant, but the value after $1{\times}10^6$, and additional $5{\times}10^6$ cyclic loading was reduced and the difference was significant (P < .05). In addition, in the internal hexagonal connection, the difference between the removal torque value after $3{\times}10^6$ cyclic loading and the value after $3{\times}10^6$, and additional $3{\times}10^6$ cyclic loading was not significant. CONCLUSION: The external hexagonal connection was more stable than the internal hexagonal connection after $1{\times}10^6$, and additional $5{\times}10^6$ cyclic loading (t = 10.834, P < .001). There was no significant difference between the two systems after $3{\times}10^6$, and additional $3{\times}10^6$ cycles.

• Journal of Korean Dental Science
• /
• v.16 no.2
• /
• pp.128-148
• /
• 2023

Dementia is an umbrella term that describes the loss of thinking, memory, attention, logical reasoning, and other mental abilities to the extent that it interferes with the activities of daily living. More than 50 million individuals worldwide live with dementia, which is expected to increase to 131 million by 2050. Recent research has shown that poor oral health increases the risk of dementia, while oral health declines with cognitive decline. In this narrative review, the literature was based on the "hypothesis" that dementia and oral health have a close relationship, and appropriate oral health and occlusal rehabilitation treatment can improve the quality of life of patients with dementia and prevent progression. We conducted a literature search in PubMed and Google Scholar databases, using the search terms "dementia," "major neurocognitive disorder," "dentition," "occlusion," "tooth loss," "dental prosthesis," "dental implant," and "occlusal rehabilitation" in the title field over the past 30 years. A total of 131 studies that scientifically addressed dementia, oral health, and/or oral rehabilitation were included. In a meta-analysis, the random effect model demonstrated significant tooth loss increasing the dementia risk 3.64-fold (pooled odds ratio=3.64, 95% confidence interval [2.50~5.32], P-value=0.0348). Tooth loss can be an important indicator of cognitive function decline. As the number of missing teeth increases, the risk of dementia increases. Loss of teeth can lead to a decrease in the ascending information to the brain and reduced masticatory ability, cerebral blood flow, and psychological atrophy. Oral microbiome dysbiosis and migration of key bacterial species to the brain can also cause dementia. Additionally, inflammation in the oral cavity affects the inflammatory response of the brain and the complete body. Conversely, proper oral hygiene management, the placement of dental implants or prostheses to replace lost teeth, and the restoration of masticatory function can inhibit symptom progression in patients with dementia. Therefore, improving oral health can prevent dementia progression and improve the quality of life of patients.

• The Journal of Korean Academy of Prosthodontics
• /
• v.55 no.2
• /
• pp.156-163
• /
• 2017

People with class I intellectual disability need lifelong assistance and protection from their surroundings due to impaired adaptive functioning. They have poor oral health and show higher prevalence of dental caries, periapical inflammation and tooth loss that require proper prosthetic restoration. Because removable prostheses for intellectually disabled patients often lack stability, retention, and maintenance, fixed prostheses are essential and the only available option is dental implants. In this case, a 45 year-old male patient with class I intellectual disability had poor oral hygiene with most of his teeth missing and visited the clinic to recover his masticatory function. Due to such systemic conditions, the definitive restoration of choice was the implant-supported fixed dental prosthesis made of biocompatible and highly strong monolithic zirconia. In consequence of the treatment process, the patient was able to improve his oral environment aesthetically and functionally.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.20 no.2
• /
• pp.121-134
• /
• 2004

This article describes a clinical protocol for the conventional rehabilitation of patient diagnosed with partial anodontia. A combined dental therapy approach was used and included endodontic therapy and root capping on the maxillary central incisors, fabrication of a maxillary overdenture, and fabrication of mandibular konus overdenture supported by 3 konus abutments. Within this protocol, tooth-supported overdenture prostheses are used for 2 purposes: first, to obtain the most rigid retention and function at an established maxillary-mandibular relationship; and second, to continuously maintain function and esthetic appearance applying immediate dentures after teeth extraction. The idea behind this protocol and its associated clinical procedures is presented along with a discussion compared with implant therapy. In the case introduced, and after 7 years of observation, the therapy can be seen as a success. We increased the occlusal vertical height in this case, but it would be more appropriate to see this as recovering the occlusal vertical height that was lost. The process of increasing the occlusal vertical height, that is restoration of the face, modification of the extrinsic occlusion of the incisors, and retraction of the mandible is very difficult and important. Ultimately, class III malocclusion is fixed, adequate occlusal vertical height is gained, and the retracted posterior anodontial portion is restored by prosthodontic dentures based on the rigid support theory. The result of the therapy done on the later-achieved malocclusion with partial anodontia on the posterior portion must consider the following in order to maintain the safety of the esthetics of the tooth and face for a period of time: 1) occlusal restoration with an ideal occlusal vertical height, 2) allowance of the final occlusion induced by the functional relationship of the upper and lower jaw, 3)final occlusion functionally induced by the lip competence limit.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.36 no.4
• /
• pp.272-281
• /
• 2020

Agenesis of permanent tooth in adolescent patients can be treated either by orthodontic treatment for space closure or by maintaining the space until implant restoration can be carried out in adult. However, gradual atrophy of alveolar bone width makes it difficult to restore the prosthesis in the future or may cause unaesthetic results. Therefore, maintaining of not only the missing space but also the alveolar bone width should be considered. This case is a treatment whereby a temporary replacement of missing 2 mandibular incisors in adolescent patient was carried out using 2 temporary anchorage devices (TADs). Two TADs were placed horizontally 2 - 3 mm below the top of alveolar ridge, and fixed with artificial teeth by stainless steel wires extended. During the 2 year follow-up, neither gingival inflammation nor loss of the TADs have occurred. In the radiographic evaluation, the growth of the adjacent alveolar bone was not inhibited, and the width of the alveolar bone was maintained.

• The Journal of Korean Academy of Prosthodontics
• /
• v.61 no.4
• /
• pp.308-315
• /
• 2023

In the case of a patients who have lost the centric stop and have a staggered occlusion of the residual teeth, various movements occur when the denture is loaded. Implant placement is necessary to reinforce the retention, support, and stabilization elements to reduce denture movement. However, in this case, considering the patient's age, aversion to surgery, and bone loss, implants were not placed and restoration was performed with a removable partial denture. In this case, it is important to set the correct mandibular position for restoration because the patient has a habit of chewing with the remaining teeth. In this case, a stable mandibular position was established using a gothic arch tracing, and good results were obtained by restoring with partial dentures, so this is reported.

• Journal of Periodontal and Implant Science
• /
• v.38 no.4
• /
• pp.729-736
• /
• 2008

Purpose: Anterior ridge defect after tooth extraction results in unfavorable appearance. Ridge augmentation procedures should be preceded by careful surgical-prosthetic treatment planning, and various techniques can be used in anterior ridge augmentation. Materials and Methods: Three patients showed deformed ridges after tooth extraction. Three different techniques ; onlay-interpositional connective tissue graft; bovine hydroxyapatite graft with free connective tissue graft; bovine hydroxyapatite graft with resorbable collagen membrane following free connective tissue graft; were used for anterior ridge augmentation. Result: Soft tissue graft can be used in small amount of ridge defect, hard tissue graft combined with soft tissue graft can be used in large amount of ridge defect. After ridge augmentation, about three months of healing period, augmented tissue was stabilized. The final restoration was initiated after this healing period, and the tissue form was maintained stable. Conclusion: Careful diagnosis and surgical-prosthetic treatment planning with joint consultation prior to surgery should be performed in order to attain an optimal esthetic results.

• Archives of Reconstructive Microsurgery
• /
• v.2 no.1
• /
• pp.13-19
• /
• 1993

Although the etiology of $Kienb\"{o}ck's$ disease is clearly related to avascular changes in the lunate, but the actual cause leading to this vascular impairment has remained elusive. Therefore, a great many different surgical procedures have been proposed for the correction of the multiple factors leading to lunate collapse or for the treatment of the lunatomalacia. The treatment modalities includes lunate excision, intercarpal arthrodesis, lunate implant resection arthroplasty, joint levelling operation(e.g ulnar lengthening & radial shortening), pronater quadratus pedicle graft and vascular loop graft. In the period from Jan. 1981 to Dec. 1992, we performed operative treatment in 19 cases of $Kienb\"{o}ck's$ disease. Among them, 6 cases were treated with vascular loop graft. We analysed all patients who were treated with vascular loop graft after followed up of 4 year 6 months, on an average(range from 1 year to 8 year 10 months). The results analysed are as follows, 1. All cases were stage III according to Lichtman's classification. 2. Ulnar variance was -1.5(range$-2{\sim}0$), on an average. 3. The average age of patients were 37.7years old(range 31-41). 4. Postoperatively, there were considerable restoration of range of motion and complete relief of pain in all cases, but continued decrease of grip power in one case. 5. Decreased sclerosis, loss of fragmentation and new bone formation were appeared in the last follow up film, in all cases. The vascular loop graft considered as a useful method for the treatment of the $Kienb\"{o}ck's$ disease.

• Journal of Periodontal and Implant Science
• /
• v.34 no.1
• /
• pp.19-28
• /
• 2004

Tooth is the most important element in esthetic consideration on facial area. Tooth alignment which is in harmony with gingiva, lips, and face is also key element. The purpose of this study was to give a clinical discipline for restoration of gingival contour, which contains a ratio of maxillary 6 anterior teeth, research for gingival contour etc., in case of rehabilitation of maxillary anterior teeth. 300 Dankook university dental school students ,who is their twenties and free from periodontitis, participate in this study. The result was from each 70 males and females who had normal occlusion and tooth alignment. Length, width and length/width ratio of maxillary 6 anterior teeth were 0.74-0.81 in male, 0.81-0.84 in female. There was significant difference between male and female. The most deepest position of gingiva in maxillary central incisor and canine was located in distal part of teeth and maxillary lateral incisor was middle portion. In maxillary central incisors, gingival line of the most deepest point appeared significant difference between male and female (p<0.01) whereas there was no difference in lateral incisors and canines. Distance between interdental papilla apex and the most deepest portion appeared significant difference between male and female. Distance of the deepest position of gingiva is statistically significant except maxillary central incisors and lateral incisors. Standard deviation and mean of the width of labio-lingual were measured in cervical area and there was a significant difference both male and female.(p<0.01) From this result, we could get the mean of maxillary anterior gingival line and these results have great value in clinical guidance in studying maxillary anterior teeth.