• Journal of Dental Rehabilitation and Applied Science
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• v.22 no.1
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• pp.37-53
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• 2006

Purpose: The purpose of this study was to investigate the influences of the jaw dimension on the bone stress. Materials and Methods: Root analogue implant of Frialit-2 Synchro model in the jaw bone of various thickness from 8mm to 13mm were modelled axisymmetrically for a series of finite element analyses. As load conditions, non-axisymmetric lateral load of 20N and an oblique load of 50N, as well as an axisymmetric vertical load of 50N were taken into consideration. Results: The cervical area of implant under the axisymmetric load and the base cortical bone under the non axisymmetric load condition were the areas of main concern where the higher level of stress were likely to be obtained. Conclusion: The results indicated that at the two concerned areas drastically different stress distribution could take place as a function of the load conditions. Under the vertical load, the lower level of stress was observed for the narrow jaw bone at the cervical cortical bone whereas stress at the base cortical bone remained virtually unchanged. Under the non axisymmetric load condition, however, the stress at the base cortical bone increased very rapidly as the jaw bone width increased without inducing any significant change in the stress level at the cervical area.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.6
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• pp.477-482
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• 2011

Introduction: Bone regeneration of cystic defects of the jaws after a cyst treatment requires lengthy healing periods. Generally, the bony changes are observed periodically through a visual radiographic reading as well as by the clinical opinion and radiographic images (panorama, periapical view), but it is difficult to compare the objective bony changes using only the radiographic density. In addition, it is difficult to observe minute bony changes through a visual radiographic reading, which can lead to a subjective judgment. This study exmined the bone density after the enucleation of a jaw cyst by fractal analysis. Materials and Methods: Eighteen patients with a cystic lesion on the jaw were assessed. Panoramic radiographs were taken preoperatively, immediately postoperatively, and 1, 3, 6 and 12 months after cyst enucleation. The images were analyzed by fractal analysis. Results: The mean fractal dimensions increased immediately after surgery and 3, 6 and 12 months postoperatively. The postoperative 6 and 12 months fractal dimension was similar to the controls. Conclusion: Fractal analysis was used to overcome the limit of a subjective reading during an assessment of bone regeneration after cyst enucleation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.5
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• pp.494-498
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• 2007

Purpose: This study was done to know the usefulness of fractal analysis when evaluating the radiologic changes after decompression on jaw bone cystic lesions using fractal analysis. Materials and methods: 30cases of cystic lesions were followed up after decompression. Panoramic image was used to observe radiologic changes around the cystic lesion. The part of the panoramic image which showed radiologic change was defined as region of interest(ROI); The fractal dimension of the ROI was calculated using box-counting method. Results: Using sign-rank test, there was a statistically significant difference in fractal dimensions after decompression therapy(P<0.0001). The fractal dimensions statistically increased after decompression(the median of D:0.12). Conclusions: The ROI after decompression showed higher fractal dimensions which offer the objective proof of the bone healing around cystic lesions after decompression treatment.

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.6
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• pp.814-820
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• 2000

Statement of Problem. Commonly used classification systems do not inform for dentists the dimension of the available bone at a potential implant site although regarding a variety of morphologic and pathophysiologic aspects using schematic graphs. However, for the implantologist the availability of bone substance is most important independent whether it concerns the jaw basis or the alveolus. Purpose of Study. The present article refers to a new evaluation form, to analyze the available bone with regard to optional immediate loading site by site. According to a new systematic implant planning concept will be presented in two case reports. Results. The feasibility of the classification for planning and documentation of immediately loaded implants is presented in two case reports. Conclusion. The factor of bone support for immediate functional stability is important in dental implantology. The new systematic implant planning helps to systematically estimate the dimension (ASCIi classification) of the alveolus site by site to evaluate the possibility of immediate loading. The Gottingen classification thus aids to determine the degree of stability that can be expected for the planned solution.

• Imaging Science in Dentistry
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• v.51 no.3
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• pp.323-328
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• 2021

Tooth extraction after head and neck radiotherapy exposes patients to an increased risk for osteoradionecrosis of the jaw. This study reports the results of a radiographic analysis of bone neoformation after tooth extraction in a case series of patients who underwent radiation therapy. No patients developed osteoradionecrosis within a follow-up of 1 year. Complete mucosal repair was observed 30 days after surgery, while no sign of bone formation was observed 2 months after the dental extractions. Pixel intensity and fractal dimension image analyses only showed significant bone formation 12 months after the tooth extractions. These surgical procedures must follow a strict protocol that includes antibiotic prophylaxis and therapy and complete wound closure, since bone formation at the alveolar socket occurs at a slower pace in patients who have undergone head and neck radiotherapy.

• The korean journal of orthodontics
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• v.30 no.6 s.83
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• pp.699-712
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• 2000

Reduced nasal breathing can influence the growth at)d development of facial structures. It nay have many causes, and enlarged adenoid is the most frequent one. To investigate the effects of adenoids to jaw growth, we must first understand the normal growth of adenoids and jaws, and the relationship between size of adenoids and the values lot the jaw variables. The purpose of this study is to present a more objective standard of nasopharyngeal size and jaw dimension at each bone age, by using Cervical Vertebrae Maturation Index(CYMI) of Hassel, from normal occlusion children aged 6 to 17. The results of this study suggests as follows : 1. At same bone age, female's chronologic age was about 2 year older than male. 2. There was a growth peak of nasopharyngeal(NP) height and depth between CVMI 1 to 2 in male, hut in female NP height and depth gradually increase through CVMI 1 to 6. 3. Relative airway of nasopharynx increases the most between CVMI 1 to 2 period in both gender 4. Among adenoid measurements, Ad2-related variables and upper pharynx, and among dentofacial measurements inter canine width in both arch, maxillary intermolar width and palatal depth had high correlation coefficient with adenoid percentage.

• Imaging Science in Dentistry
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• v.48 no.3
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• pp.153-160
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• 2018

Purpose: This study aimed to assess the reliability of ultrasonography (US) in comparison with cone-beam computed tomography (CBCT) as a tool for monitoring the healing of jaw lesions. Materials and Methods: Twenty-one radiolucent lesions in jaws referred to the Oral Surgery Department at our institution were selected for this study. All lesions underwent CBCT and US examinations. The anteroposterior, superoinferior, and mesiodistal dimensions of the lesions were measured on CBCT and US images before surgery and at 6 months after surgery. The dimensions were compared between the US and CBCT images. Blood-flow velocity around the lesions was measured by color Doppler before surgery and at 1 week and 6 months after surgery to assess the capability of US to show changes in blood-flow velocity around the lesion. Results: Before surgery, there were no significant differences between US and CBCT in the mesiodistal and anteroposterior dimensions, although a significant difference was found in the superoinferior dimension (P<.05). However, at 6 months after surgery, significant differences were found between US and CBCT in all dimensions, and it is likely that the US measurements more accurately reflected the extent of healing. The average blood-flow velocity increased at 1 week after surgery (5.84 cm/s) compared with the velocity before surgery (4 cm/s) (P<.05). Then, at 6 months after surgery, the blood-flow velocity significantly decreased (3.53 cm/s) compared to the velocity measured at 1 week after surgery (P<.05). Conclusion: US with color Doppler was confirmed to be a more efficient tool than CBCT for monitoring bone healing.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.2
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• pp.243-249
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• 2006

Statement of problem: It is important to have a correct presurgical treatment plan before any implant surgery. It must contain substantial information about the patient concerned. However, the standard classification only notifies the dentist about various structural, pathological and physiological dimensions Due to diverse structure of the jaw bone, current standard classification does not tell spatial dimensions of the available bone for implant insertion sites. Purpose of study: The purpose of this study is to report the establishment of the systematic implant treatment plan and its clinical treatment using $Implan^(R)$ program which is based on ASCIi-classification that is available for future diagnosis and scale of treatment and for systematic implant insertion. Results: By assisting the systemic measurement of the available alveolus dimension during implant surgery, it was easy to set initial implant treatment plan. Conclusion: Using $Implan^(R)$ program which is based on ASCIi-classification system that allows the establishment of systemic implant treatment plan and successful clinical performance, it was possible to establish the founding or initial implant treatment plan , the acquisition of information, and the systematization of documentation.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.3
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• pp.233-240
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• 2007

Osteochondroma is a common benign tumor of the axial skeleton, especially the distal metaphysis of the femur and proximal metaphysis of the tibia. However, it occurred rarely on the facial skeleton. The coronoid and condylar processes have been considered to be the most common sites of occurrence for osteochondroma of the facial skeleton. The first treatment of osteochondroma is condylectomy, whereas extirpation was done by excision with condyle salvage. Condylectomy presents decrease of vertical dimension, jaw deviation, malocclusion. So, reconstruction is need. Methods of reconstruction are as follows: no reconstruction, condyloplasty, discectomy, costochondral graft, discplication or coronoidectomy, eminoplasty, alloplastic spacer placement, Le Fort I level maxillary osteotomy, extraoral and intraoral vertical ramus osteotomy. This is a case report of a 28-year old woman who had facial asymmetry, malocclusion and temporomandibular joint pain. We obtained moderate functional and cosmetic results with surgical removal of the osteochondroma by condylectomy and concomitant reconstruction of condyle by vertical ramus osteotomy with sliding technique.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.4
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• pp.382-394
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• 2022

The treatment of patients with severe periodontitis should be proceeded step-bystep through an accurate diagnosis of each patients' individual tooth and with a strategic treatment plan. Implant-supported fixed prosthetic restoration has the advantage of high patient satisfaction and stable vertical dimension compared to the removable partial denture. However, multiple teeth defect areas lacking hard tissue may be disadvantageous in aesthetic failure and longer treatment time. In addition, it takes a certain period of time to manufacture and install a conventional fixed prosthesis, and during this process, the provisional prosthesis must satisfy the mechanical, biological, and aesthetic requirements of teeth. The purpose of this article is to describe the fabrication of implant-supported fixed prosthesis through a step-by-step approach in a partially edentulous patient.