• Imaging Science in Dentistry
• /
• v.39 no.1
• /
• pp.7-11
• /
• 2009

Purpose: The purpose of this study was to assess the prevalence and radiographic characteristics of the nuchal ligament ossification on lateral cephalometric radiographs in Koreans. Subjects and Method: I review and interpreted the lateral cephalometric radiographs from 4,558 patients (1,857 males and 2,701 females, age range from 2 to 79 years) who visited the Kyungpook National University Dental Hospital from January 1, 2008 to February 3, 2009. I grouped the shapes of nuchal ligament ossification as round, rod-like, and segmented shape. And localized the ossification as the involvement of anterior cervical vertebral body. The data were analyzed by using chi-squared test with two-tailed and at a 5% significance level. Results: Among those who showed the nuchal ligament ossification, he mean age of the 143 males was 51.1 and that of the 97 females was 48.0 years. It as not observed completely below teens, and was observed 1% in twenties, 6.1% in thirties, 18.6% in forties, and 26.3% over fifties. It was significantly prevalent in older age group (P<0.01) and in males than females among the same age group (P<0.05). The shapes of nuchal ligament ossification were as follows in order of frequency: rod-like (49.2%), round (30.4%), and segmented (20.4%). The highest involvement of ossification as found at the level of C5 (67.9%), C4 (29.2%), C6 (22.9%), C3 (3.3%), C7 (2.9%), C2 (0.8%), and C1 (0.4%). Conclusion: The nuchal ligament ossifications on lateral cephalometric radiographs were showed as round, rod-like, or segmented shape. The nuchal ligament ossification is often observed after the age of 40 and is observed more frequently in males than females. The highest shape of nuchal ligament ossification was rod-like shape and the highest involvement of cervical spine was C5.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.33 no.6
• /
• pp.609-616
• /
• 2007

Purpose: The aim of the present study was to evaluate the effect of Bio-Oss on bone formation in terms of healing period and type of membrane so that determine the most suitable condition for implant fixation in grafted maxilla. Material & Method: Forty-five biopsy specimens from graft site were evaluated. Sinus lift was performed in the patients with reduced alveolar bone height(less than 5mm). The specimen was taken at the time of implant fixation, which was performed at least 5 months after the sinus lift procedure. All specimens were stained with H&E and Trichrome staining and evaluated histomorphometrically. Result: The results showed that Bio-Oss particle was in direct contact with newly formed bone in all cases. In the present study, the amount of newly formed bone and the residual bone substitute material were not statistically different according to various membrane and different healing period. There was no difference between the histological feature of the specimen of 5 and 31 months. No statistical significance was detected between male and female. Conclusion: The result implies that Bio-Oss does not seem to be resorbed over time regardless of the type of the membranes. The further investigation is needed to clarify this issue with the extended period of follow-up.

• Imaging Science in Dentistry
• /
• v.44 no.2
• /
• pp.121-128
• /
• 2014

Purpose: The present study was performed to compare the planning of implant placement based on panoramic radiography (PAN) and cone-beam computed tomography (CBCT) images, and to study the impact of the image dataset on the treatment planning. Materials and Methods: One hundred five partially edentulous patients (77 males, 28 females, mean age: 46 years, range: 26-67 years) seeking oral implant rehabilitation were referred for presurgical imaging. Imaging consisted of PAN and CBCT imaging. Four observers planned implant treatment based on the two-dimensional (2D) image data-sets and at least one month later on the three-dimensional (3D) image dataset. Apart from presurgical diagnostic and dimensional measurement tasks, the observers needed to indicate the surgical confidence levels and assess the image quality in relation to the presurgical needs. Results: All observers confirmed that both imaging modalities (PAN and CBCT) gave similar values when planning implant diameter. Also, the results showed no differences between both imaging modalities for the length of implants with an anterior location. However, significant differences were found in the length of implants with a posterior location. For implant dimensions, longer lengths of the implants were planned with PAN, as confirmed by two observers. CBCT provided images with improved scores for subjective image quality and surgical confidence levels. Conclusion: Within the limitations of this study, there was a trend toward PAN-based preoperative planning of implant placement leading towards the use of longer implants within the posterior jaw bone.

• Journal of Periodontal and Implant Science
• /
• v.24 no.3
• /
• pp.483-492
• /
• 1994

The purpose of this study was to assess the recolonization of the subgingival microflora following scaling and root planing on single and multiroot teeth with periodontal pockets which were above 5mm. 7 patients with deep pockets were selected for this study. They had not taken antibiotics for 6 months and no history of dental treatment for 6 months before the study. After initial clinical(plaque index, gingival index, probing pocket depth), microbiological and BANA test were determined, each subject received a single session of scaling and root planing, but they were not received oral hygiene instructions. Clinical indices, microbial parameters and BANA test were reassessed 1, 2, and 4 weeks after treatment. The results were as follows : 1. Plaue index, gingival index and pocket depth were not significantly when compared single root group with multiroot group, both groups were siginficantly reduced at 2weeks in plaque index and 2, 4 weeks in gingival index(P<0.05), probing pocket depth was siginificantly changed at 2, 4weeks in multiroot teeth group and 4 weeks in single root teeth group(P<0.05). 2. Percentage of cocci was significantly increased at 4weeks in single root teeth group(P<0.05), motile rod was significantly changed at 4weeks in both group(P<0.05), spirochetes and nonmotile rods were not significantly changed. 3. BANA test was significantly reduced at 1 and 2 weeks (P<0.05) in single root teeth group, multiroot teeth group was not significantly all weeks. This results were suggested that clinical and microbiological effect following scaling and root planing on periodontal disease.

• The Journal of Korean Academy of Prosthodontics
• /
• v.52 no.3
• /
• pp.252-257
• /
• 2014

It is important to produce a provisional restoration reflecting the patient's jaw relation, occlusal plane, lip support, shape of teeth, and occlusion type for fully edentulous patients before making a definite prosthesis. The patient introduced in this study showed bad prognosis of remained tooth after severe periodontal diseases. Therefore, remaining teeth were extracted and replaced with dental implants. Provisional restorations were fabricated and the the patient's vertical and horizontal jaw relationship, occlusal plane, amount of overjet and overbite, size of teeth, and length of anterior tooth were recorded. Provisional restorations were scanned and CAD/CAM techniques were used to fabricate a monolithic zirconia bridge, which contour is identical with the provisional restorations. The patient was satisfied with the treatment results on functional, esthetic aspects and the prosthesis retained stable during the four-month clinical observation period.

• Journal of Periodontal and Implant Science
• /
• v.40 no.6
• /
• pp.283-288
• /
• 2010

Purpose: The aim of this case report is to present a case of incomplete bone formation after sinus augmentation. Methods: A patient having alveolar bone resorption of the maxillary posterior edentulous region and advanced pneumatization of the maxillary sinus was treated with sinus elevation using deproteinized bovine bone in the Department of Periodontology, Kyung Hee University School of Dentistry and re-evaluated with computed tomography (CT) follow-up. Results: Even though there were no significant findings or abnormal radiolucency on the panoramic radiograph, incomplete bone formation in the central portion of the augmented sinus was found fortuitously in the CT scan. The CT scan revealed peri-implant radiolucency in the apical portion of the implant placed in the augmented maxillary sinus. Nevertheless, the dental implants placed in the grafted sinus still functioned well at over 15 months follow-up. Conclusions: The result of this case suggests that patients who received maxillary sinus augmentation may experience incomplete bone formation. It is possible that 1) osteoconductive graft material with poor osteogenic potential, 2) overpacking of graft material that restricts the blood supply, and 3) bone microbial contamination may cause the appearance of incomplete bone formation after sinus augmentation. Further studies are needed to elucidate the mechanism of this unexpected result and care must be taken to prevent it.

• The Journal of Korean Academy of Prosthodontics
• /
• v.51 no.3
• /
• pp.221-225
• /
• 2013

Proper management of provisional prosthesis is key to success in prosthodontics. Provisional restoration on maxillary anterior missing area frequently come across a incident of falling off especially in patients with long span pontics and oval arch shape. This is because maxillary anterior teeth are more exposed to horizontal force than the posterior teeth and additional anterior cantilever effect will negatively affect to the retention of provisional prosthesis. Beside that maxillary anterior provisional prosthesis should provide proper incisal guidance during the mandibular functional movements. However occlusal contacts on the prosthesis in maximum intercuspal position are located on opposite side of fulcrum line of prosthesis which will cause removing force against the provisional prosthesis. This case report present that provisional implant prevent pre-described harmful effect on maxillary anterior fixed provisional prosthesis and provide comfort and satisfactory result during post-extraction healing period.

• Journal of Periodontal and Implant Science
• /
• v.46 no.5
• /
• pp.329-336
• /
• 2016

Purpose: The aim of this study was to clinically assess the impact of a prefabricated implant-retained stent clipped over healing abutments on the preservation of keratinized mucosa around implants after implant surgery, and to compare it with horizontal external mattress sutures. Methods: A total of 50 patients were enrolled in this study. In the test group, a prefabricated implant-retained stent was clipped on the healing abutment after implant surgery to replace the keratinized tissue bucco-apically. In the control group, horizontal external mattress sutures were applied instead of using a stent. After the surgical procedure, the width of the buccal keratinized mucosa was measured at the mesial, middle, and distal aspects of the healing abutment. The change in the width of the buccal keratinized mucosa was assessed at 1 and 3 months. Results: Healing was uneventful in both groups. The difference of width between baseline and 1 month was $-0.26{\pm}0.85mm$ in the test group, without any statistical significance (P=0.137). Meanwhile, the corresponding difference in the control group was $-0.74{\pm}0.73mm$ and it showed statistical significance (P<0.001). The difference of width between baseline and 3 months was $-0.57{\pm}0.97mm$ in the test group and $-0.86{\pm}0.71mm$ in the control group. These reductions were statistically significant (P<0.05); however, there was no difference between the 2 groups. Conclusions: Using a prefabricated implant-retained stent was shown to be effective in the preservation of the keratinized mucosa around implants and it was simple and straightforward in comparison to the horizontal external mattress suture technique.

• The Journal of Korean Academy of Prosthodontics
• /
• v.56 no.2
• /
• pp.166-172
• /
• 2018

In case of the treatment of maxillary anterior teeth, it should be taken into account the proper morphology, arrangement and color satisfying patient's esthetic demands. For this purpose, facial composition, dentofacial composition, dental composition and dentogingival composition should be considered making diagnosis and treatment plan in an esthetic point of view. In adjustable temporary crown state, careful evaluation and correction of the esthetic and functional aspect were performed, and the definite restoration was reproduced using double scan.

• Korean Journal of Cleft Lip And Palate
• /
• v.8 no.1
• /
• pp.11-22
• /
• 2005

There ate anteroposterior$\cdot$vertical maxillary underdevelopment, transverse maxillary deficiency and wide cleft alveolus$\cdot$oroanual fistula among cleft lip ant palate related maxillary deformities. For treatment of these deformities, ones have used conventional treatment methods, there were often unsatisfactory results to patients and operators both. Since llizarov introduced effective technique of bone lengthening and augmentation for a variety of limb defotmities, application of distraction osteogenesis on maxillofacial area has been used to solve those disadvantages of conventional methods. Authors introduced following three cases about use of distraction osteogenesis. The first case is the application of RED(rigid external distraction) II system for the treatment of the anteroposterior$\cdot$vertical maxillary hypoplasia after several times of surgery and end of development in bilateral cleft lip and palate patient. The second case is the application of the USPD(unilateral segmental palatal distraction) for the resolution of the unilateral posterior crossbite and transverse dental arch asymmetry after alveolorraphy in growing unilateral cleft lip and palate patient. The third case is the application of transport distraction osteogenesis far closure of the wide clef alveolus and oroantral fistula in growing bilateral cleft lip and palate patient. There were satisfactory results in these cases. Particularly, in comparison with the decreases of relapse rates, the reduction of the hospitalization time and post-operative discomfort owing to minimal surgical intervention.