• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.4
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• pp.397-406
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• 2012

Loss of tooth results in remodeling and resorption of surrounding alveolar bone which causes atrophic edentulous ridge and gradually decreasing gingival attachment. As a result, edentulous patients face difficulty in using dentures due to pain, decrease of support, decline of masticatory efficiency of complete denture. To improve this, overdenture with implant in the mandible and attachment are considered as a treatment of choice as a favorable treatment. In this case, a patient with edentulous ridge for long period is rehabilitated by complete denture in maxilla and implant overdenture using Locator$^{(R)}$ attachment in mandible.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.46 no.3
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• pp.162-173
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• 2020

Dental implants are the first option for replacement of missing teeth. Failure usually involves additional cost and procedures. As a result, the physician should limit the risk factors associated with implant failures. Implant site is one of many factors that can influence the success or failure of dental implants. The association between early implant failure (EIF) and implant site has yet to be documented. This review aims to estimate the impact of insertion site on the percentage of EIFs. An electronic and manual search of studies that reported early failure of dental implants based on collection site. A total of 21 studies were included in the review and examined for the association between EIF and alveolar site. Subgroup analysis, including a comparison between implants inserted in four alveolar ridge regions of both jaws was performed. The early failure rate was higher for maxillary implants (3.14%) compared to mandibular implants (1.96%). Applying a random effect, risk ratio (RR), and confidence interval (CI) of 95% revealed higher failure in the maxilla compared to the mandible (RR 1.41; 95% CI [1.19, 1.67]; P<0.0001; I²=58%). The anterior maxilla is more critical for early implant loss than other alveolar bone sites. Implants in the anterior mandible exhibited the best success rate compared of the sites.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.3
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• pp.304-311
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• 2019

After the teeth were extracted, maxillary and mandibular alveolar ridges show the opposite resorption pattern and as a result, the mandibular arch is enlarged than maxillary arch relatively. In this situation, we should evaluate both alveolar ridge relationship and arrange the artificial teeth properly for stability of removable prosthesis. This case is a 77 years old male patient who wishes to make removable prosthesis and has atrophic alveolar ridge. By use of model scanner and CAD software, the angle between interalveolar crest line and occlusal plane was easily measured. Depending on the measurement, the artificial teeth are arranged in unilateral cross bite and after completion, patient was satisfied with the denture which showed proper stability, retention, support.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.5
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• pp.341-347
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• 2002

This study was designed to determine the location of the mandibular canal on lower molar areas. Thirty-three patients were examined with multi-planar reformatted CT scan($Dentascan^{(R)}$). Three kinds of measurements were performed. The first was the distances between the upper border of the mandibular canal and the root apices of the first and second molars, the second was the distance between the cortical plate of the mandible and mandibular canal, and the last was the location of the mandibular canal in the buccolingual plane. The obtained results are as follows 1. The distance between the root apices of lower molars and the superior border of mandibular canal was largest at the mesial root of the first molar, and shortest at the distal root of the second molar(p<0.05). 2. The longest distance between the outer surface of the buccal cortical plate of the mandible and mandibular canal was measured from the distal root of the second molar, and this distance decrease gradually mesially(p<0.05). 3. The distance between the mandibular base and inferior border of mandibular canal was longest at the distal root of the second molar, and shortest at the mesial root of the first molar(p<0.05). 4. The location of mandibular canal was lingually positioned in relation to the axis of teeth and alveolar ridge in molar areas.

• The Journal of Korean Academy of Prosthodontics
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• v.56 no.2
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• pp.120-125
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• 2018

Conventional denture impression techniques have limitations for edentulous patients with severe alveolar bone resorption and can cause problems from excessive border extension. Especially when a patient has movable tissue it is difficult to make accurate impression, thus might interrupt stable seating of complete denture. Fabrication of complete denture using closed mouth technique for edentulous patient with severe ridge resorption is thought to provide better stability and retention. In this case, an 86-year-old patient had both edentulous jaws with epulis fissuratum on maxillary anterior ridge and severe mandibular ridge resorption. Thus, tentative vertical dimension was determined by using Centric trayand individual tray attached with gothic arch tracer was fabricated. Complete denture was fabricated using closed mouth technique and the patient was satisfied with better stability and retention of the complete denture.

• The Journal of Korean Academy of Prosthodontics
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• v.52 no.4
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• pp.338-345
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• 2014

Fabrication of complete denture by Jiro Abe's method was introduced that enhance the retention and stability of denture by sealing around the denture border with mucous membrane to make negative pressure at the inner surface of denture base when swallowing or occlusion. In this case, taking impression and fabricating complete denture by the Jiro Abe's method for an edentulous patient with severe mandibular alveolar bone resorption allowed us to obtain clinically enhance stability of denture and improve satisfaction of patient.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.1
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• pp.107-118
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• 2007

Statement of problem: Implant-type distractor uses a removable distraction device that has an appearance similar to that of a dental implant and utilizes many of the same techniques for placement as are used for dental implants. Material and method: In this study, 48 implant type titanium distractors were inserted into the osteotomized alveolar bone of 12 beagle dogs. After a 7-day latency period, the alveolar bone was augmented by 5mm vertically at a rate of 1.0 mm/day. The dogs were sacrificed after 4weeks, 8weeks and 12 weeks for radiographic, histologic, and histomorphometric analysis. Result: Copper equivalent value showed significant difference between 4 weeks and the other weeks(8, 12 weeks)(p<0.05). But there was no significant difference between maxillary and mandibular groups. In the bone to metal contact analysis, there was a significant difference between 4 weeks and 12 weeks(p<0.05). On the contrary, there was no significant difference between maxilla and mandible. The bone area showed significantly higher values in 12 weeks compared to 4 weeks(p<0.05). Histologically mineralization began at the host bone margins. At 12 weeks, increasing accumulation of $Ca^{++}$ element was confirmed. Conclusion: From the results above, the new bone formation was increased according to consolidation period. Especially there was significant difference between 4 weeks and 12 weeks(p<0.05). Implant type distractors used in this study to augment vertical ridge defect may prove to be a clinically useful treatment option in selected cases.

• Imaging Science in Dentistry
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• v.39 no.1
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• pp.19-25
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• 2009

Purpose: To longitudinally observe the healing process of extracted socket and the alterations of the residual ridge in healthy adult dogs using cone beam CT (CBCT). Materials and Methods: The mandibular premolars of two beagle dogs were removed and the extraction sites were covered with the gingival tissue. CBCTs (3D X-ray CT scanner, Alphard vega, Asahi Co.) were taken at baseline and at 1 week interval for 12 weeks. Radiographic density of extracted wounds was measured on normalized images with a custom-made image analysis program. The amount of alveolar crestal resorption after the teeth extraction was measured with a reformatted three-dimensional image using CBCT. Bony healing pattern of extracted wound of each group was also longitudinally observed and analyzed. Results: Dimensional changes occurred during the first 6 weeks following the extraction of dogs' mandibular premolars. The reduction of the height of residual ridge was more pronounced at the buccal than at the lingual aspect of the extraction socket. Radiographic density of extracted wounds increased by week 4, but the change in density stabilized after week 6. New bone formation was observed at the floor and the peripheral side of extracted socket from week 1. The entrance of extracted socket was sealed by a hard-tissue bridge at week 5. Conclusion: The healing process of extracted wound involved a series of events including new bone formation and residual ridge resorption.

• The Journal of Korean Academy of Prosthodontics
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• v.58 no.2
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• pp.145-152
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• 2020

It is essential to record maxillomandibular relationship accurately for the harmony of esthetic and function in complete denture. Gothic arch tracing visually demonstrates the movement of the mandible, and is useful to establish accurate and reproducible centric relation. Proper retention and stability of complete denture in patients with severe alveolar bone resorption is difficult to attain. In such case, the closed mouth impression technique might be recommended. The denture border and impression are determined by patient's physiologic movement in the closed mouth impression technique. And, denture peripheral border is entirely closed with oral mucous membrane. This report presents satisfactory complete denture restoration using closed mouth impression technique and gothic arch tracing in patients with mandibular condyle fracture and severe absorption of mandibular alveolar ridge.

• The Journal of Korean Academy of Prosthodontics
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• v.28 no.1
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• pp.63-94
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• 1990

The purpose of this study was to analyze the displacement and the magnitude and the mode of distribution of the stresses in the lower overdenture, the mucous membrane, the abutment tooth and the mandibular supporting bone when various denture base materials, such as acrylic resin and 0.5mm metal base, and various denture base designs were subjected to different loading schemes. For this study, the two-dimensional finite element method was used. Mandibular arch models, with only canine remaining, were fabricated. In the first denture base design, a space, approximately 1mm thick, was prepared between the denture and the dome abutment. In the second denture base design, contact between the denture and the dome abutment was eliminated except the contact of the occlusal third of the abutment. In order to represent the same physiological condition as the fixed areas of the mandible under loading schemes, the eight nodes which lie at the mandibular angle region, the coronoid process and the mandibular condyle were assumed to be fixed. Each model was loaded with a magnitude of 10 kgs on the first molar region(P1) and 7 kgs on the central incisal region (P2) in a vertical direction. Then the force of 10 kgs was applied distributively from the first premolar to the second molar of each model in a vertical direction(P3). The results were as follows. : 1. When the testing vertical loads were given to the selected points of the overdenture, the overdenture showed the rotatory phenomenon, as well as sinking and the displacements of alveolar ridge, abutment and lower border of mandible under the metal base overdenture were less than those under the acrylic resin overdenture. 2. The maximum principal stresses(the maximum tensile stresses) being considered, high tensile stresses occured at the buccal shelf area, the posterior region of the ridge crest and the anterior border region of the mandibular ramus. 3. The minimum principal stresses(the maximum compressive stresses) being considered, high compressive stresses occured at the inferior and posterior border region of the mandible, the mandibular angle and the posterior border region of the mandibular ramus. 4. The vertical load on the central incisal region(P2) produced higher equivalent stress in the mandible than that on any other region(P1, P3) because of the long lever arm distance from the fixed points to the loading point. 5. Higher equivalent stresses were distributed throughout the metal base overdenture than the resin base overdenture under the same loading condition. 6. The case of occlusal third contact of the abutment to the denture produced higher equivalent stresses in the abutment, the mandibular area around the abutment and the overdenture than the case of a 1mm space between the denture and the abutment. 7. Without regard to overdenture base materials and designs, the amounts and distribution patterns of equivalent stresses under the same loading condition were similar in the mucous membrane.