• Imaging Science in Dentistry
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• v.30 no.4
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• pp.235-242
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• 2000

Purpose: To evaluate the effect of the systemic osteoporosis on radiographic density of alveolar bone and cortical thickness of mandible. Materials and Methods: The bone mineral density values of lumbar and femur were measured by dual-energy X-ray absorptiometry and T scores of lumbar, femur were obtained respectively. Radiographic densities of alveolar bones and panorama mandibular index (PMI, represents as cortical thickness) were analysed statistically according to age and T score variables. Results: The radiographic density of alveolar bone of maxillary molar showed significant difference by age and femur T group. That of mandibular molar showed significant difference between femur T group. Panorama mandibular index showed significant difference between age groups. Conclusion: The radiographic density of alvealar bones was more dependent on age and femur T than lumbar T. Cortical thickness of mandible was correlated with increasing age.

• Journal of Periodontal and Implant Science
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• v.24 no.2
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• pp.261-270
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• 1994

The purpose of this study was to evaluate relationship of probing attachment levels, radiographic measurements and surgical measurements according to gingival inflammatory condition. Patients with incipient to moderate periodontitis were selected. Upper and lower premolar and molar teeth excluding third molars were measured. At first visit, gingival index and bleeding on probing were taken, and subjects were grouped into 4 categories as follows : Experimental group I : gingival index 1 and no bleeding on probing. Experimental group II : gingival index 2 and no bleeding on probing absent. Experimental group III : gingival index 1 and bleeding on probing present. Experimental group IV : gingival index 2 and bleeding on probing present. Probing attachment levels were measured with manual probe on mesial and distal surfaces from cementoenamel junctions to terminal ends of probe. Radiographic measurements were made to assess bone loss by measuring the distance from cementoenamel junction to the alveolar crest. After thorough scating, a flap was raised exposing the alveolar bone and surgical measurements were made from cementoenamel junction to alveolar bone. The results were as follows: 1. Differences between probing attachment level and radiographic measurements showed $1.01{\pm}0.73mm$ for experimental group I, $0.98{\pm}0.48mm$ for experimental group II, $0.59{\pm}0.66mm$ for experimental group III, $0.98{\pm}0.38mm$ for experimental group IV and with no significant difference between groups. 2. Differences between probing attachment level and surgical measurements showed $1.36{\pm}0.80mm$ for experimental group I, $1.47{\pm}0.54mm$ for experimental group II, $1.06{\pm}0.39mm$ for experimental group III, $1.41{\pm}0.40mm$ for experimental group IV and with no significant difference between groups. 3. Differences between surgical and radiographic measurements showed $0.36{\pm}0.48mm$ for experimental group I, $0.51{\pm}0.54mm$ for experimental group II, $0.57{\pm}0.72mm$ for experimental group III, $0.41{\pm}0.49mm$ for experimental group IV and with significant difference between experimental group I and experimental group II, III, IV(P<0.05).

• Journal of Periodontal and Implant Science
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• v.33 no.3
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• pp.407-414
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• 2003

The aim of this study was to investigate the effect of third molar extraction on the periodontal status of the adjacent second molar. A total of 61 second molars in 31 adult periodontitis patients were examined. Among them, 27 second molars without adjacent third molars were included in the test group, and 34 second molars with third molar were included in the control group. Clinical parameters including plaque index, gingival index, and pocket depth and radiographic bone loss were measured around the second molar both in test and control group. The result showed that: (1) the mean plaque index and gingival index of control group were higher than these of the test group but the difference was not statistically significant, (2) the mean pocket depth of the control group was higher than the test group significantly at distal and buccal surface, (3) radiographic hone loss was greater in control group than test group significantly, (4) in Pearson correlation analysis between the age of extraction and radiographic bone loss in the test group, a positive relationship was shown(p<0.01). Within limitation of this study, it may be concluded that third molar extraction in periodontitis patients showed an improvement in periodontal status in contrast the patients group having third molar, therefore earlier a removal of third molar may minimize radiographic hone loss of the adjacent second molar.

• 대한족부족관절학회:학술대회논문집
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• 2008.11a
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• pp.24-25
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• 2008

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.46 no.3
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• pp.191-196
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• 2020

Objectives: Beyond the original application approved by the U.S. Food and Drug Administration, recombinant human bone morphogenetic protein-2 (rhBMP-2) is used for medication-related osteonecrosis of the jaw (MRONJ) treatment because of its bone remodeling enhancement properties. The purpose of the study was to investigate the bone formation effect of rhBMP-2/absorbable collagen sponge (ACS) in patients with MRONJ. Materials and Methods: In this retrospective cohort study, 26 female patients diagnosed with MRONJ and who underwent mandibular sequestrectomy at Ajou University Dental Hospital from 2010 to 2018 were included. The experimental group was composed of 18 patients who received rhBMP-2/ACS after sequestrectomy, while the control group was composed of 8 patients who did not receive rhBMP-2/ACS after sequestrectomy. A total dose of 0.5 mg of rhBMP-2 was used in the experimental group at a concentration of 0.5 mg/mL. Follow-up panoramic X-rays were taken immediately after the surgery and more than 6 months after the surgery. Using those X-rays, a radiographic index of bone defect area was calculated using the modified Ihan Hren method, which measures radiographic density of the normal bone and the defect site. Results: This study suggests that rhBMP-2 contributes to new bone formation. The mean radiographic index immediately after surgery and more than 6 months after the surgery for the experimental group was 68.4% and 79.8%, respectively. The mean radiographic index immediately after surgery and more than 6 months after the surgery for the control group was 73.4% and 76.7%, respectively (Wilcoxon signed rank test, P>0.05). The mean radiographic index increased 11.4% in the experimental group and 3.27% in the control group (Mann-Whitney U-test, P<0.05). Conclusion: Based on the results, use of rhBMP-2/ACS on bone defect sites after sequestrectomy could be a successful strategy for treatment of MRONJ patients.

• Journal of Periodontal and Implant Science
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• v.40 no.5
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• pp.249-253
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• 2010

Purpose: The purpose of this study was to evaluate the improvement of periodontal health of generalized aggressive periodontitis (GAgP) diagnosed patients treated with non-surgical periodontal therapy accompanying systemic antibiotics administration. Methods: Two patients with GAgP were chosen for this study. Clinical indices were taken and a radiographic examination was performed at the baseline of the study and they were treated by periodontal therapy accompanying systemic antibiotics administration. Post-surgical visits were scheduled at regular intervals to check clinical and radiographic changes. Results: Through non-surgical periodontal therapy accompanying systemic antibiotics administration, GAgP patients showed decreased probing pocket depth, sulcus bleeding index, and increased attachment level and clinical index when comparing the initial and six month follow up data. In the six month follow-up radiographic examination after non-surgical periodontal therapy, resolution of the bony defect was observed. Conclusions: Non-surgical therapy combined with systemic antibiotics administration in GAgP patients is suggested to be an effective approach to enhance the periodontal health.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.48 no.4
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• pp.219-224
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• 2022

Objectives: There have been few studies to date on the residual effect of bisphosphonate. This study investigated the radiographic changes of mandibular cortical thickness upon bisphosphonate drug holiday. Materials and Methods: This retrospective study includes 36 patients diagnosed with MRONJ (medication-related osteonecrosis of the jaw) at Ajou University Dental Hospital in 2010-2021. All patients stopped taking bisphosphonate under consultation with the prescribing physicians. Panoramic radiographs were taken at the start of discontinuation (T₀), 12 months after (T₁), and 18 months after (T₂) discontinuation of bisphosphonate, respectively. Mental index and panoramic mandibular index were calculated using Ledgerton's method. Paired t-tests were used to analyze differences over time. Results: The difference in indices (mental index and panoramic mandibular index) between T₀ and T₁ was not statistically significant (paired t-test, P>0.05). However, the difference in these indices between T₁ and T₂ was statistically significant (paired t-test, P<0.05). Conclusion: The cortical thickness of the mandible decreased in the late stage (after 18 months) as observed by panoramic radiograph.

• Journal of information and communication convergence engineering
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• v.6 no.4
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• pp.425-429
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• 2008

We investigated algorithm to detect and characterize interstitial lung abnormalities seen at chest radiographs. This method includes a process of 4 directional Laplaction-Gaussian filtering, and a process of linear opacity judgment. Two regions of interest (ROIs) were selected in each right lung of patients, and these ROIs were processed by our computer-analyzing system. For quantitative analysis of interstitial opacities, the radiographic index, which is the percentage of opacity areas in a ROI, was obtained and evaluated in the images. From or result, abnormal lungs were well differentiated from normal lungs. In our algorithm, the processing results were not only given as the numeric data named "radiographic index" but also confirmed with radiologists observation on CRT. The approach, by which the interstitial abnormalities themselves are extracted, is good enough because the results can be confirmed by the observations of radiologists. In conclusion, our system is useful for the detection and characterization of interstitial lung abnormalities.

• Journal of Periodontal and Implant Science
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• v.44 no.4
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• pp.194-200
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• 2014

Purpose: The purpose of this study was to assess and compare the clinical and radiographic outcomes of guided tissue regeneration therapy for human periodontal intrabony defects using two different collagen membranes: a porous nonchemical cross-linking collagen membrane (NC) and a bilayer collagen membrane (BC). Methods: Thirty subjects were randomly assigned and divided into the following 3 groups: a test group (NC+BM), in which a NC was used with xenograft bone mineral (BM), a positive control group (BC+BM), in which a BC was used with xenograft BM, and a negative control group (BM), in which only xenograft BM was used. The following clinical measurements were taken at baseline and 3 months after surgery: plaque index, gingival index, probing pocket depth, gingival recession, and clinical attachment level. Radiographic analysis was performed at baseline, 1 week and 3 months after surgery. Results: Membrane exposure was not observed in any cases. Significant probing depth reduction, attachment-level gain and bone fill were observed for both test and control groups compared to baseline at 3 months after surgery (P<0.05). However, there were no statistically significant differences in clinical improvement and radiographic bone fill between treatment protocols (P>0.05). Conclusions: Within the limitations of this study, the results suggest that both NC and BC were comparable in terms of clinical and radiographic outcomes for the treatment of periodontal intrabony defects in human subjects.

• Journal of Dental Rehabilitation and Applied Science
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• v.30 no.3
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• pp.223-230
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• 2014

Purpose: The purpose of this study was to evaluate the improvement and posttreatment stability of patients treated with extraction of lower incisors. Materials and Methods: The total of 20 patients with extracted lower incisors were analyzed by means of diagnostic models and panoramic x-rays at the time of initial, final and after 2 years of retention period of the treatment. Irregularity index, overjet, overbite, tooth size-arch length discrepancy (TSALD), intercanine width, intermolar width and American Board of Orthodontics cast/radiographic evaluation (ABO-CRE) were analyzed. Statistical analysis was performed using Wilcoxon signed-rank test. Results: After treatment, irregularity index showed significant decrease (P = 0.000). TSALD showed significant increase (P = 0.028). During retention period, irregularity index showed significant increase (P = 0.001). For ABO-CRE, total score showed significant decrease after treatment (P = 0.000) and showed average decreased which was not significant result (P = 0.053). Conclusion: Through evaluation of stability of extraction of lower incisors by means of diagnostic models and panoramic x-rays, it can be concluded that lower incisor extraction treatment had been stable for 2 years after treatment.