• Imaging Science in Dentistry
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• v.52 no.4
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• pp.365-373
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• 2022

Purpose: This study investigated whether the relationship between the maxillary sinus and the root of the maxillary premolar is correlated with the root position and whether there is a difference in the long axis angle of premolars and the buccal bone thickness according to the sinus-root relationship and root position. Materials and Methods: Cone-beam computed tomographic images of 587 maxillary first premolars and 580 second premolars from 303 patients were retrospectively reviewed. The maxillary sinus floor-root relationship was classified into 4 types, and the root position in the alveolar bone was evaluated as buccal, middle, or palatal. The long axis angle of the maxillary premolars in the alveolar bone and the buccal bone thickness were measured. The correlation between these parameters was analyzed. Results: The maxillary sinus floor-root relationship showed a statistically significant correlation with the root position in the alveolar bone. Most maxillary first premolars were buccally located, and more than half of the second premolars had their roots in the middle. The long axis angle of the premolars was significantly larger in buccal-positioned teeth than in middle-positioned teeth, and the buccal bone was thinner. Conclusion: When the root of the maxillary premolar was separated from the sinus floor, the premolar was often located on the buccal side. Most of the maxillary first premolars had a thinner buccal bone and larger inclination than the second premolars. It is recommended to evaluate the root position, sagittal angle and buccal bone thickness using CBCT for implant treatment planning.

• The Journal of Korean Academy of Prosthodontics
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• v.62 no.1
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• pp.28-37
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• 2024

Severe cases of mandibular prognathism can be treated with orthodontic therapy or surgical correction, but there are situations where only prosthetic improvement is possible. An understanding of class III patients is needed, including a vertical chewing pattern and the absence of anterior guidance. Additionally, it is relatively easy to increase occlusal vertical dimension to correct the anterior crossbite, but this approach can sometimes lead to unfavorable results, necessitating careful diagnosis and treatment planning. In this case report, oral rehabilitation was conducted in a patient with mandibular prognathism and asymmetry, utilizing implants and fixed dental prosthesis. Through a step-by-step treatment approach, the existing occlusal vertical dimension was maintained, and the final fixed dental prosthesis restoration was completed. Accordingly, it shows functional and aesthetically appropriate results, and reports on the patient's diagnosis and treatment process.

• Archives of Plastic Surgery
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• v.50 no.6
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• pp.593-600
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• 2023

Background Soft tissue reconstruction around the knee area is still an open question, particularly in persistent infections and multiple reoperations scenario. Flap coverage should guarantee jointmobility and protection, even when foreign materials are implanted. The chimeric harvesting of the musculocutaneous gastrocnemius flap, based on the sural artery perforators, can extend its applicability in soft tissue reconstruction of the upper leg, overcoming the drawbacks of the alternative pedicled flaps. Methods A multicenter retrospective study was conducted enrolling patients who underwent to a pedicled, chimeric gastrocnemius musculocutaneous-medial sural artery perforator (GM-MSAP) or lateral sural artery perforator (GM-LSAP) flap for knee coverage in total knee arthroplasty (TKA) recurrent infections and oncological or traumatic defects of the upper leg from 2018 to 2021. Outcomes evaluated were the successful soft tissue reconstruction and flap complications. Surgical timing, reconstruction planning, technique, and rehabilitation protocols were discussed. Results Twenty-one patients were included in the study. Nineteen GM-MSAPs and 2 GM-LSAPs were performed (soft tissue reconstruction in infected TKA [12], in infected hardware [4], and in oncological patients [5]). Donor site was closed primarily in 9 cases, whereas a skin graft was required in 12. Flap wound dehiscence (1), distal flap necrosis (1), distal necrosis of the skin paddle (1), and donor site infection (1) were the encountered complications. Flap reraise associated to implant exchange or extensive debridement was successful without requiring any further flap surgery. Conclusion The propeller-perforator GM-MSAP offers qualitative defect coverage and easiness of multiple flap reraise due to skin availability and its laxity.

• The Journal of Korean Society for Radiation Therapy
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• v.31 no.1
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• pp.25-32
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• 2019

Purpose: The size, shape, and volume of prosthetic appliance depend on the metal artifacts resulting from dental implant during head and neck treatment with radiation. This reduced the accuracy of contouring targets and surrounding normal tissues in radiation treatment plan. Therefore, the purpose of this study is to obtain the images of metal representing the size of tooth through MVCT, SMART-MAR CT and KVCT, evaluate the volumes, apply them into the proton therapy plan, and analyze the difference of dose distribution. Materials and Methods : Metal A ($0.5{\times}0.5{\times}0.5cm$), Metal B ($1{\times}1{\times}1cm$), and Metal C ($1{\times}2{\times}1cm$) similar in size to inlay, crown, and bridge taking the treatments used at the dentist's into account were made with Cerrobend ($9.64g/cm^3$). Metal was placed into the In House Head & Neck Phantom and by using CT Simulator (Discovery CT 590RT, GE, USA) the images of KVCT and SMART-MAR were obtained with slice thickness 1.25 mm. The images of MVCT were obtained in the same way with $RADIXACT^{(R)}$ Series (Accuracy $Precision^{(R)}$, USA). The images of metal obtained through MVCT, SMART-MAR CT, and KVCT were compared in both size of axis X, Y, and Z and volume based on the Autocontour Thresholds Raw Values from the computerized treatment planning equipment Pinnacle (Ver 9.10, Philips, Palo Alto, USA). The proton treatment plan (Ray station 5.1, RaySearch, USA) was set by fusing the contour of metal B ($1{\times}1{\times}1cm$) obtained from the above experiment by each CT into KVCT in order to compare the difference of dose distribution. Result: Referencing the actual sizes, it was appeared: Metal A (MVCT: 1.0 times, SMART-MAR CT: 1.84 times, and KVCT: 1.92 times), Metal B (MVCT: 1.02 times, SMART-MAR CT: 1.47 times, and KVCT: 1.82 times), and Metal C (MVCT: 1.0 times, SMART-MAR CT: 1.46 times, and KVCT: 1.66 times). MVCT was measured most similarly to the actual metal volume. As a result of measurement by applying the volume of metal B into proton treatment plan, the dose of $D_{99%}$ volume was measured as: MVCT: 3094 CcGE, SMART-MAR CT: 2902 CcGE, and KVCT: 2880 CcGE, against the reference 3082 CcGE Conclusion: Overall volume and axes X and Z were most identical to the actual sizes in MVCT and axis Y, which is in the superior-Inferior direction, was regular in length without differences in CT. The best dose distribution was shown in MVCT having similar size, shape, and volume of metal when treating head and neck protons. Thus it is thought that it would be very useful if the contour of prosthetic appliance using MVCT is applied into KVCT for proton treatment plan.

• Journal of Dental Rehabilitation and Applied Science
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• v.26 no.3
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• pp.221-239
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• 2010

Bone loss may occur depending on the loading conditions. careful treatment planning and prosthetic procedures are very important factors for the proper distribution of stress. Evaluate the stress distributions according to numbers and location of implants in three-unit fixed partial dentures. A mandible missing the right second premolar, first molar and second molar was modeled. Using the CT data. we modeled a mandible with a width of 15mm, a height of 20mm and a length of 30mm, 2mm-thickness cortical bone covering cancellous bone mallow. An internal type implant and A solid type abutment was used. A model with 3 implants placed in a straight line, offset 1.5 mm buccally, offset 1.5 mm lingually and another model with 3 implants offset in the opposite way were prepared. And models with 2 implants were both end support models, a mesial cantilever model and a distal cantilever model. Three types of loading was applied; a case where 155 N was applied solely on the second premolar, a case where 206 N was applied solely on the second molar and a case where 155 N was applied on the first premolar and 206 N was applied on the first and second molar. For all the cases, inclined loads of 30 degrees were applied on the buccal cusps and vertical loads were applied on the central fossas of the teeth. Finite element analysis was carried out for each case to find out the stress distribution on bones and implants. This study has shown that prostheses with more implants caused lower stress on bones and implants, no matter what kind of load was applied. Furthermore, it was found out that inclined loads applied on implants had worse effects than vertical loads. Therefore, it is believed that these results should be considered when placing implants in the future.

• Journal of Periodontal and Implant Science
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• v.44 no.4
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• pp.158-168
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• 2014

Purpose: The present study was conducted to evaluate the impact of scaling and root planing (SRP) on the C-reactive protein (CRP) levels of gingival crevicular fluid (GCF) and serum in chronic periodontitis patients with type 2 diabetes mellitus (T2DM-CP) or without type 2 diabetes mellitus (NDM-CP). Methods: Forty-eight human participants were divided into two groups: an experimental (T2DM-CP) group (group I, n=24) comprising chronic periodontitis patients with random blood sugar ${\geq}200mg/dL$ and type 2 diabetes mellitus, and control (NDM-CP) group (group II, n=24) of those with chronic periodontitis and random blood sugar <200 without T2DM for the study. All subjects underwent nonsurgical periodontal therapy (NSPT) including complete SRP and subgingival debridement. Periodontal health parameters, plaque index (PI), gingival index (GI), probing pocket depth (PPD), clinical attachment level (CAL), GCF volume (GCF vol), GCF-CRP, random blood glucose (RBS), glycated hemoglobin, and systemic inflammatory markers, serum CRP, total leukocyte count (TLC), neutrophil count (Neutr) and lymphocyte count (Lymph), were evaluated at baseline, 1 month, and 3 months after SRP. Results: NSPT resulted in statistically significant improvement in periodontal health parameters (PI, GI, PPD, CAL, GCF vol), CRP levels in serum as well as GCF of both groups I and II. The mean improvement in periodontal health parameters (PI, GI, PPD, CAL, GCF vol), CRP levels in serum and GCF was greater in group I than group II after NSPT. There was nonsignificant increase in GCF-CRP, TLC, Lymph, and RBS, and a significant increase in Neutr and Serum CRP in group II at 1 month. The Serum CRP level of 20 out of 24 group II patients had also increased at 1 month. Conclusions: The CRP levels in both GCF and serum were higher in T2DM-CP patients than in NDM-CP patients. Although there was a significant improvement in both the groups, greater improvement was observed in both GCF and serum samples of T2DM-CP patients.

• Journal of Periodontal and Implant Science
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• v.34 no.2
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• pp.281-292
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• 2004

Periodontal defects of the furcation are characterized by several inherent anatomic factors that can make successful periodontal therapy difficult and results unpredictable. The severity and rate of occurrence of periodontal disease are directly related to the location of the furcation relative to the cementa-enamel junction and anatomical form of the root by limiting the accessibility and effectiveness of the periodontal instrumentation. This study investigated the reliability and accuracy of panoramic radiograph diagnoses of the periodontal state of mandibular molars, particularly regarding the diagnosis of furcation area periodontal defects, treatment planning, and prognosis prediction. This study examined a total of 110 teeth belonging to 33 subjects (19 male, 14 female) presenting with incipient to moderate periodontitis 4-7mmpocket depth. The alveolar bone level, length and width of the root trunk, and root separation angle were measured using the panoramic radiograph and compared to the results taken directly by retracting a full-thickness flap. The results of the study are as follows: 1. Data regarding the alveolar bone level of the mandibular first molar showed that the directly taken surgical measurements resulted in $5.1{\pm}0.9mm$ that was slightly deeper than the corresponding panoramic measurement resulted in $4.8{\pm}0.8mm$, but these differences were statistically insignificant (p>0.05). 2. The data of the directly taken surgical measurement of the mandibular second molar $(5.1{\pm}1.1mm)$ was slightly deeper than the corresponding panoramic measurement $(4.7{\pm}1.2mm)$, but these differences were statistically insignificant (p>0.05). 3. The measured values of the length and width of the mandibular first molar root trunks were determined to be $4.1{\pm}0.6mm$ and $7.3{\pm}0.9mm$, respectively, while the values of the mandibular second molar root trunks were determined to be $4.6{\pm}1.3mm$ and $7.6{\pm}0.9mm$ respectively. The differences between these values were found to be statistically significant (p<0.01). 4. The measured values of the root separation angle showed that the mandibular first molars averaged $34.5{\pm}4.4^{\circ}$, while the mandibular second molars averaged $23.0{\pm}10.0^{\circ}$. The differences between these values were found to be statistically significant (p<0.01).

• Journal of Periodontal and Implant Science
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• v.24 no.3
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• pp.633-648
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• 1994

Synthetic bone graft materials have been used for the regeneration of periodontal tissue lost due to periodontal disease, but the limitations of these materials had prompted the use of composite grafts. Among those, a composite graft of calcium carbonate(CC) and calcium sulfate(CS) is one of those materials that has not been studied extensively. CC, which is extracted from a natural coral, is known to possess osteoconductive property. SC can play an adjunctive role in the regeneration of bone tissue, and has shown good resorbability and biocompatibility. This study was conducted in order to investigate the effects of CC and CS composite graft to the regeneration of bone in the intrabony defects of dogs. 3-wall intrabony defects ub size of $4mm{\times}4mm{\times}4mm$ were created in the alveolar bone in the premolar areas. Then those defects that were treated with root planning only were designated as control, while the experimental group 1 and 2 each received the CC and CS composite grafts in the ratio of 8 : 2 and 5 : 5 the animals were sacrificed after 8weeks and the specimens were histologically analyzed. The results were as follows ; 1. No inflammation or foreign body reaction were observed in all subjects. CS has not been seen due to complete resorption, and resorption pattern of CC was observed. 2. Significant differences(p<0.05) in new cementum formation were observed between control($1.42{\pm}0.64mm$) and experimental groups(group 1 ; $2.53{\pm}0.94mm$, group 2 ; $2.23{\pm}0.96mm$) but the difference between the two experimental groups was not significant. 3. Significant differences(p<0.01) in new bone formation were observed between control($0.59{\pm}0.55mm$) and experimental groups(group 1 ; $2.27{\pm}0.61mm$, group 2 ; $2.05{\pm}0.56mm$) but the difference between the two experimental groups was not significant. 4. The extent of apical epithelial migration has shown no significant difference between control($1.18{\pm}1.24mm$) and experimental groups(group 1 ; $0.51{\pm}0.54mm$, group 2 ; $0.73{\pm}0.70mm$). 5. The extent of bone formation was generally limited to the extent of cementum formation for all groups, and significant correlation was found in the amount of bone formation and cementum formation in experimental group 1.(Co.=0.86, p<0.01) These results suggest that the composite graft of CC and CS is biocomplatible and effective in the new bone and new cementum formations. In the case of 3-wall intrabony defects of dogs, the composite ratio of 8 : 2 and 5 : 5 had shown no significant differences in the healing.

• Journal of Periodontal and Implant Science
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• v.36 no.3
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• pp.653-659
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• 2006

Oral malodor may cause a significant social or psychological handicap to those suffering from it. Oral malodor has been correlated with the concentration of volatile sulfur compounds (VSC) produced in the oral cavity. Specific bacteria identified in the production of VSC have been reported and many of these bacteria are commonly suspected periodontal pathogens. The aim of this study was to estimate the change of the VSC concentration after periodontal treatment, Twenty subjects with probing depth $(PD)\;{\geq}5mm$ (experimental group) and 20 subjects with PD<5mm (control group) participated. VSC concentration measurement was made with gas chromatography. VSC concentration was measured at pre-treatment, 2 weeks after scaling and 1 month after periodontal treatment(root planning and flap operation). Maximum probing depth and bleeding on probing(BOP) were also examed at pretreatment and 1 month after periodontal treatment, The conclusions were as follow: 1. In the experimental group VSC concentration and CH3SH/H2S ratio were higher than control group. (p<0.05) 2. Both VSC concentration and CH3SH/H2S ratio showed decrease after periodontal treatment, But only CH3SH/H2S ratio after 1 month periodontal treatment was statistically significantly different from pre-treatment. (p<0.05) 3. CH3SH/H2S ratio tended to be on increase according to maximum probing depth and bleeding on probing. Periodontal disease could be a factor that caused oral malodor and oral malodor could be decreased after periodontal treatment.

• Journal of Periodontal and Implant Science
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• v.27 no.1
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• pp.217-234
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• 1997

The purpose of present study is to compare the effect of treatment using $Guidor^{(R)}$ as a barrier membrane in conjunction with platelet-derived growth factor and insulin like growth factors on experimental dehiscence defects. Following the resection of premolar crowns, roots were submerged. After 12 weeks of healing period, experimental dehiscence defects of 4mm in height and 4mm in width were surgically created on the mid-facial aspect of the lower premolar roots in each of 4 adult dogs. After root planning and demineralization of the root surface with citric acid, the control groups received 4% methylcellulose gel only, the test group I received 4% methylcellulose gel and were covered by $Guidor^{(R)}$ and the test group II were treated with PDGF and IGF and 4% methylcellulose gel with $Guidor^{(R)}$ coverage. Histological and histomorphometric analysis following 8 weeks of healing revealed the following results. 1. The new bone formation showed no statistically significant difference in all groups with $0.59{\pm}0.82mm$($14.03{\pm}19.60%$) for control, $0.70{\pm}0.39mm$($16.30{\pm}9.01%$) for group I, $0.87{\pm}0.76mm$($18.74{\pm}16.03%$) for group II. 2. The new cementum formation showed no statistically significant difference in all groups with $0.54{\pm}0.48mm$($l6.38{\pm}14.57%$) for control, $0.95{\pm}0.38mm$($23.43{\pm}9.30%$) for group I, $1.01{\pm}0.75mm$($22.10{\pm}16.ll%$) for gorup II. 3. The root resorption showed statistically significant differences betweenthe control group and all test groups(p<0.05) with $2.11{\pm}0.53mm$($52.93{\pm}12.32%$) for control, $0.63{\pm}0.27mm$($15.32{\pm}7.05%$) for group I, $0.89{\pm}0.33mm$ ($19.26{\pm}7.11%$) for group II. On the bases of these results, there were no statistically difference between treatment using resorbable membrane and resorbable membrane in conjunction with PDGF and IGF in the dehiscence defects, where it was difficult to maintain space. The use of membrane seemed to be more effective in the inhibition of root resorption.