Comparative Histomorphometric Analysis of Bone Regeneration According to Bone Graft Type.

PURPOSE: To use histomorphometric analysis to evaluate bone reconstruction in rabbit calvaria with autogenous bone, anorganic bovine bone, undecalcified human tooth bone (UdTB), and decalcified human tooth bone (dTB) grafts. MATERIALS AND METHODS: Extracted human teeth were crushed, and tooth bone with and without decalcification was prepared. Bony defects were made in 10 rabbit calvaria and allocated to one of the following four groups: group 1, in which UdTB was grafted; group 2, in which dTB was grafted; group 3, in which anorganic bovine bone was grafted; group 4, in which autogenous bone was grafted. The rabbits were sacrificed at 2 or 8 weeks postoperatively, and histomorphometric comparison was performed. RESULTS: Histologically, new bone formation was observed at the defect margin and around all graft materials. The dTB group revealed significantly greater new bone areas at 2 and 8 weeks compared to the UdTB group and the anorganic bovine bone group (P < .05). The dTB group revealed no significant difference in the new bone area at 2 weeks but revealed significantly less new bone area at 8 weeks compared to the autogenous bone group (P < .05). The dTB group also revealed significantly less graft material area compared to the anorganic bovine bone group at 8 weeks (P < .05). The autogenous bone group revealed significantly less graft material area and significantly greater bone marrow area compared to other groups at 8 weeks (P < .05). CONCLUSIONS: Grafting with dTB resulted in better bone regeneration than UdTB and anorganic bovine bone grafting at 8 weeks and addresses the potential disadvantages of autogenous bone grafting.

Accelerated national lot release on COVID-19 vaccines in Republic of Korea.

Independent quality testing of samples from vaccine lots is part of quality assurance, especially to ensure the consistency of production lot by lot. Effective national lot release system that ensures the quality of each lot of vaccine before it is on the market is important because vaccines are intended to healthy people. In order to respond more quickly to public health crises such as the COVID-19 pandemic, the MFDS implements accelerated national lot release for rapid vaccination in Republic of Korea. For the accelerated system, improvement has been made in terms of timing of application for lot release and required documents. In addition, the processing period has been shortened and sampling method and test items have been streamlined. A thorough preparation for accelerated lot release has been developed by establishing test methods for a new platform in advance. As a result, a total of 43.88 million doses have been released within eight days on average. The accelerated lot release system has contributed significantly to rapid COVID-19 vaccination in Korea.

Simplified Free Gingival Graft Around Implants Using Medical Grade Tissue Cyanoacrylate: A Case Series Report.

The free gingival graft (FGG) procedure using suturing techniques has been widely utilized to effectively increase the amount of attached keratinized gingiva. However, conventional suturing procedures are time-consuming and technique-sensitive. Simplified FGG procedure around teeth and dental implants using medical grade tissue adhesive (cyanoacrylate) is known to overcome drawbacks of traditional suture techniques. However, the clinical application of cyanoacrylate as a means of stabilizing the graft has not been a common practice. The aim of this report demonstrates simplified FGG procedures around dental implants using cyanoacrylate with follow-up results.

Comparative Histomorphometric Evaluation of Bone Regeneration with Different Preparations of Xenogeneic Tooth Block Bone.

PURPOSE: The aim of this animal study was to evaluate new bone formation in human dentin block grafted on rabbit calvaria according to a comparison of histologic analysis. MATERIALS AND METHODS: Human teeth were prepared according to four different types of dentin blocks: group 1, demineralized and microperforated dentin block; group 2, demineralized dentin block; group 3, undemineralized and microperforated dentin block; group 4, undemineralized dentin block. These four different dentin blocks were grafted on nine rabbit calvaria, and animals were sacrificed at 2, 4, and 8 weeks after the surgical procedure for histologic evaluation. RESULTS: In group 1, histologically, new bone formation was initiated at the interface between demineralized and microperforated dentin block and host bone and microholes at 2 weeks, and mature bone was observed at 8 weeks. In group 3, new bone formation was observed at 8 weeks in the undemineralized and microperforated dentin block bottom and microholes. The bone formation ratio of group 1 was significantly higher at 2, 4, and 8 weeks compared with groups 2, 3, and 4 (P < .05). The bone formation ratio in microholes at 2 and 8 weeks in group 1 was significantly greater than in group 3 (P < .05). CONCLUSION: New bone formation of the demineralized dentin block began more rapidly than the undemineralized dentin block, and perforated dentin block was more effective in bone formation than dentin block without microholes.

Bee venom attenuates Porphyromonas gingivalis and RANKL-induced bone resorption with osteoclastogenic differentiation.

Porphyromonas gingivalis (P. gingivalis) is one of the major periodontal pathogens leading to inflammation and alveolar bone resorption. Bone resorption is induced by osteoclasts, which are multinucleated giant cells. Osteoclastic bone resorption is mediated by enhanced receptor activator of nuclear factor-kappa B ligand (RANKL) signaling. Therefore, the down-regulation of RANKL downstream signals is regarded as an effective therapeutic target in the treatment of bone loss-associated disorders. The aim of this study was to evaluate whether purified bee venom (BV) could attenuate P. gingivalis-induced inflammatory periodontitis and RANKL-induced osteoclast differentiation. Inflammatory periodontitis induced by P. gingivalis increased alveolar bone resorption and increased expression of TNF-α and IL-1ß, while BV treatment resulted in decreased bone loss and pro-inflammatory cytokines. Similarly, RANKL-induced multinucleated osteoclast differentiation and osteoclast-specific gene expression, such as nuclear factor of activated T cells 1 (NFATc1), cathepsin K, tartrate-resistant acid phosphatase (TRAP), and integrin αvß3 were significantly suppressed by treatment with BV. We show that BV reduces P. gingivalis-induced inflammatory bone loss-related periodontitis in vivo and RANKL-induced osteoclast differentiation, activation, and function in vitro. These results suggest that BV exerts positive effects on inflammatory periodontitis associated osteoclastogenesis.

Distal appendicular skeletal involvement of diffuse large B-cell lymphoma on technetium-99m methylenediphosphonate bone scintigraphy and 18F-fluorodeoxyglucose positron emission tomography/computed tomography: a case report.

BACKGROUND: We report a case of a patient with appendicular bone involvement of diffuse large B-cell lymphoma visualized by whole-body technetium-99m methylenediphosphonate bone scintigraphy (bone scan) and 18F-fluorodeoxyglucose positron emission tomography/computed tomography. CASE PRESENTATION: A 73-year-old Asian man who had gingival swelling of the labial area of the left maxillary lateral incisor presented to our institution. Positron emission tomography/computed tomography demonstrated hypermetabolic lesions with maximum standardized uptake values of 12.15 in the left testis, 1.92 in the skin of the right chest, and 2.88 in the left ulna and third metatarsal bone. A bone scan showed multiple uptakes in the left ulna, hand, both tibiae, and the left foot. We diagnosed the tumor as diffuse large B-cell lymphoma by excision. Magnetic resonance imaging showed enhanced signaling of lesions with soft tissue edema in the olecranon of the left ulna, the third metacarpal bone of the left hand, and the third metatarsal bone of the left foot. Magnetic resonance imaging findings prompted a diagnosis of lymphoma. Eight cycles of chemotherapy plus external radiotherapy targeted to the involved bone sites were given for 5 months. Follow-up positron emission tomography/computed tomography and bone scanning revealed the disappearance of hypermetabolism and decreased uptake in lesions compared with the previous images. Laboratory data were also all within the normal limits after chemotherapy. CONCLUSIONS: This report highlights that appendicular bone involvement of diffuse large B-cell lymphoma can be detected on whole-body bone scans and by positron emission tomography/computed tomography.

A digital approach to fabricating an abutment replica to control cement volume in a cement-retained implant prosthesis.

If a cement-retained implant prosthesis is placed on an abutment, excess cement should be minimized or removed to prevent periimplant inflammation. Various methods for fabricating an abutment replica have been introduced to maintain tissue health and reduce clean-up time. The purpose of this article is to present an alternative technique for fabricating an abutment replica with computer-aided design/computer-aided manufacturing (CAD/CAM) technology.

Retrospective study of sintered porous-surfaced dental implants placed in the augmented sinus.

The purpose of this study was to analyze clinical and radiographic outcomes of sintered porous-surfaced dental implants placed in partially edentulous posterior maxillae. The study group consisted of 42 partially edentulous patients who received sinus augmentation using the lateral window technique or crestal approach at Catholic University Hospital of Daegu and one private clinic. The 42 patients received a total of 92 sintered porous-surfaced dental implants in the edentulous posterior maxillae. All implants were restored with fixed prostheses. Of the 92 implants, 17 implants were restored with individual (nonsplinted) crowns, while 75 implants were splinted to other implants. Panoramic views and periapical radiographs using the standardized long-cone paralleling technique were taken at the first visit, postoperatively, at the time of prosthesis seating, and at a follow-up visit. Survival rates of implants in relation to location, length, diameter, crown-to-implant (C/I) ratio, and type of prosthesis were investigated. Statistical data were analyzed using software with the chi-square test. Of the 92 implants, 8 (8.7%) were removed, and the cumulative survival rate was 91.3% after a maximum 9-year functional period (mean: 72.8 months; range: 11 to 107 months). There were no statistical differences in relation to the location of implants, C/I ratio, or type of prosthesis. However, there were statistical differences in relation to the length and diameter of implants. Average crestal bone loss was 0.68 mm at 1-year follow-up and 1.13 mm at final examination. All implants were inserted in the augmented maxillary sites. The cumulative survival rate of sintered porous-surfaced implants in posterior maxillae was 91.3%. Sintered porous-surfaced implants showed satisfactory results in the edentulous posterior maxillae.

Benefit of the replaceable bony window in lateral maxillary sinus augmentation: clinical and histologic study.

PURPOSE: This retrospective study demonstrates, by clinical and histologic evaluation, the benefit of the replaceable bony window as a homologous bony barrier in lateral sinus augmentation. MATERIALS AND METHODS: A total of 103 maxillary sinus augmentations were performed using a piezoelectric device and a Er,Cr:YSGG laser apparatus. The detached bony windows were repositioned over various bone grafts. Sixteen bone biopsy specimens were harvested at the time of uncovering or implant placement. RESULTS: Three sinuses developed postoperative infections (2.91%). After 6 to 8 months of healing, uncovering procedures were carried out. Radiographically, reconstruction of the lateral sinus wall was observed in all cone-beam computed tomogram. Clinically, complete bone healing between the replaceable bony window and the lateral sinus wall was observed in all cases, except for the 3 infected sinuses (100 sinuses, 97.09%). Histologically, favorable new bone formation was observed in all specimens without any fibrous connective tissue invagination. More mature bone was observed along the floor of the replaceable bony window than at the center of the graft site. CONCLUSION: This study demonstrates that the replaceable bony window acts as an osteoinductive homologous barrier membrane over various bone graft materials and accelerates new bone formation in lateral sinus augmentation.

Ligation of the left hepatic vein for dilated intrahepatic collaterals late after fontan operation.

A 17-year-old male presented with two episodes of syncope, cyanosis, and exercise intolerance 13 years after the Fontan operation. Echocardiography and magnetic resonance imaging showed dilated intrahepatic collaterals, which drained into the atrium through the left hepatic vein, and 24-hour Holter monitoring revealed sinus node dysfunction. We performed ligation of the left hepatic vein using intrahepatic collaterals as channels draining hepatic venous blood into the Fontan pathway, and implanted an epicardial dual chamber pacemaker. At one-year follow-up, the patient remained asymptomatic and his cardiac performance was much improved.

Flapless transcrestal sinus augmentation using hydrodynamic piezoelectric internal sinus elevation with autologous concentrated growth factors alone.

PURPOSE: The purpose of this retrospective study was to evaluate the success rate of implants and the amount of sinus augmentation using the flapless hydrodynamic piezoelectric internal sinus elevation (HPISE) technique with autologous concentrated growth factors (CGF) alone. MATERIALS AND METHODS: A total of 11 maxillary sinuses were augmented using the HPISE technique through the flapless transcrestal approach. Sixteen implants (average 11.38 mm in length and 4.83 mm in diameter), with 2 different surfaces, were placed simultaneously with CGF alone. Plain panoramic radiograms and cone-beam computed tomograms (CBCT) were taken in all patients to evaluate the sinus augmentation preoperatively and postoperatively. RESULTS: The sinus membranes were successfully elevated, averaging 13.95 ± 6.61 mm in immediate postoperative CBCT without any iatrogenic perforation. After an average 23.8 weeks, the average bone gain above the sinus floor was 8.23 ± 2.88 mm in the axial aspect of CBCT. No complications were recorded in any patients during the follow-up period. CONCLUSION: The flapless transcrestal approach to the sinus augmentation using the HPISE technique with autologous CGF alone could be an alternative to the lateral approach, even at severely resorbed edentulous posterior maxilla with insufficient bone height.

Comparative histomorphometric analysis of maxillary sinus augmentation with absorbable collagen membrane and osteoinductive replaceable bony window in rabbits.

PURPOSE: The aim of this animal study was to evaluate, through histomorphometric evaluation, bone regeneration in rabbit maxillary sinuses with absorbable collagen membranes and osteoinductive replaceable bony windows over bone grafts. MATERIALS AND METHODS: Bilateral sinus augmentation procedures were performed in 16 adult male rabbits. The rabbits were randomly assigned to 4 groups of 4 rabbits each. Rectangular replaceable bony windows were made with a piezoelectric thin saw insert. In control group, grafted ß-tricalcium phosphate (ß-TCP) was covered by absorbable collagen membranes. In experimental groups, ß-TCP was grafted and covered by replaceable bony windows. The rabbits were killed at 1, 2, 4, and 8 weeks postoperatively. The augmented sinuses were stained with hematoxylin-eosin and Masson trichrome stains and examined, under light microscopy, for newly formed bone and soft tissue changes in the maxillary sinuses. RESULTS: Histologically, significantly higher and faster new bone formation was observed in the augmented sinuses of the experimental groups, receiving homologous replaceable bony windows than in those of the control group receiving collagen membranes. CONCLUSION: This study demonstrates that, for augmentation, the use of the homologous replaceable bony window over bone graft material on the maxillary sinus accelerates bone regeneration.

Identification of KCNN2 as a susceptibility locus for coronary artery aneurysms in Kawasaki disease using genome-wide association analysis.

Kawasaki disease (KD) is often complicated by coronary artery lesions (CALs), including aneurysms. Because of the complications associated with KD, this disorder is the leading cause of acquired heart disease in children from developed countries. To identify genetic loci that confer a higher risk of developing CALs, we performed a case-control association study using previous genome-wide association study data for samples from KD cases only (n=186) by grouping KD patients without CALs (control: n=123) vs KD patients with extremely large aneurysms (diameter>5 mm) (case: n=17). Twelve loci with one or more sequence variants were found to be significantly associated with CALs (P<1 × 10(-5)). Of these, an SNP (rs17136627) in the potassium intermediate/small conductance calcium-activated channel, subfamily N, member 2 (KCNN2) at 5q22.3 was validated in 32 KD patients with large aneurysms (diameter>5 mm) and 191 KD patients without CALs (odds ratio (OR)=12.6, P(combined)=1.96 × 10(-8)). This result indicates that the KCNN2 gene can have an important role in the development of coronary artery aneurysms in KD.

Low pulmonary vascular compliance predisposes post-Fontan patients to protein-losing enteropathy.

BACKGROUND: Protein-losing enteropathy (PLE) is a life-threatening and poorly understood complication after the Fontan operation. We sought to determine the pre-operative risk factors for PLE which developed after the extracardiac conduit Fontan operation. METHODS: Two hundred thirty-five patients who underwent the extracardiac conduit Fontan operation as an initial Fontan type procedure (median age at operation: 3.5 years) were enrolled in this cross-sectional retrospective study. Pre-operative and peri-operative variables were surveyed through a review of medical records. RESULTS: Within the median follow-up duration of 5 years, 12 patients developed PLE (12/234, 5.1%) at a median interval of 2.2 years after the Fontan procedure, and 4 died of PLE at a median interval of 1.2 years (range 0.21-7.62) after diagnosis. Factors found to be related to the time to the development of PLE on univariate analysis were pulmonary vascular compliance (Cpv) (p=0.0019), central venous pressure at postoperative 12 hours (p=0.0026), days of ICU stay (P=0.0449), days of hospitalization (p=0.0135), and days of chest tube indwelling (p=0.0493). Multivariate analysis, however, showed that only Cpv (p=0.0367) remained significant. The range of Cpv was 8.8-26.1 mm(2)/m(2)/mmHg (median 17.9) in patients with PLE, and 6.6-122.3 mm(2)/m(2)/mmHg (median 26.8) in patients without PLE. CONCLUSIONS: Low pulmonary vascular compliance is associated with the development of PLE after the extracardiac conduit Fontan operation.

Outcomes of mechanical valves in the pulmonic position in patients with congenital heart disease over a 20-year period.

BACKGROUND: Homografts or bioprosthetic valves have been preferred in the pulmonic position in patients with congenital heart disease. However, unsatisfactory long-term results have aroused interest in the use of mechanical valves. In this study, we investigated the long-term outcomes of mechanical valves implanted in the pulmonic position. METHODS: The medical records of 37 patients (27 male, 73%) who underwent 38 mechanical pulmonary valve replacements between October 1988 and February 2011 were reviewed, retrospectively. The median age of patients was 13.5 years (range, 7 months to 23 years), and the median number of prior operations per patient was 2 (range, 0 to 5). Tetralogy of Fallot was the most common diagnosis (n=23). The median valve size was 23 mm (range, 17 to 27 mm), and the median follow-up duration after pulmonary valve replacement was 24.6 months (range, 1.3 months to 22.5 years). Events were defined as the following: valve failure, thrombosis, embolism, bleeding, reoperation, and death. RESULTS: There was no in-hospital mortality, but there were 2 late deaths (1 heart failure and 1 traffic accident at 10.8 months and 8.7 years postoperatively, respectively). Excluding the traffic accident death, survival rates were 97%, 97%, and 97%, at 1, 5, and 10 years, respectively. Freedom from thromboembolism or bleeding events was 92%, 92%, and 78.8%, at 1, 5 and 10 years, respectively. Two reoperations were performed at 6.8 and 10.2 years postoperatively. Freedom from reoperation was 100%, 100%, and 85.7%, at 1, 5, and 10 years, respectively. CONCLUSIONS: Durability of mechanical valve in pulmonic position was excellent. Thromboembolism or bleeding events due to anticoagulation therapy were rare. In growing patients who have undergone prior sternotomies requiring a pulmonary valve replacement, a mechanical valve could be an attractive option.

Bisphosphonates-related osteonecrosis of the jaw in Korea: a preliminary report.

OBJECTIVES: Bisphosphonates (BP) are widely used in medicine for inhibiting bone resorption; however bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a major side effect of BP. To date, there have been no specific reports on the incidence of BRONJ among Koreans. This study investigated the preliminary results from a nationwide survey of BRONJ in the Departments of Oral and Maxillofacial Surgery (OMFS) at individual training hospitals. MATERIALS AND METHODS: A total of 15 OMFS departments (10 from dental schools, 4 from medical schools, and 1 from a dental hospital) participated in a multi-centric survey. This study assessed every BRONJ case diagnosed between January 2010 and December 2010. The patient age and BP type were evaluated. RESULTS: A total of 254 BRONJ cases were collected. The majority of BRONJ cases were associated with oral BP therapy, while 21.8% of the cases were associated with intravenous administration. Alendronate was the drug most frequently related to BRONJ (59.2% of cases), followed by risedronate (14.3%) and zolendronate (17.0%). The average age of BRONJ patients was 70.0±10.1 years, with a range of 38-88 years of age. With the number of BP patients in Korea reported to be around 600,000 in 2008, the estimated incidence of BRONJ is at least 0.04% or 1 per 2,300 BP patients. CONCLUSION: The results suggest that the estimated incidence of BRONJ in Korea is higher than the incidence of other countries. Future prospective studies should be carried out to investigate the exact epidemiological characteristics of BRONJ in Korea.

Minimally invasive sinus augmentation using ultrasonic piezoelectric vibration and hydraulic pressure: a multicenter retrospective study.

PURPOSE: The purpose of this study was to evaluate the success rate of implants and vertical bone gain of edentulous posterior maxilla using ultrasonic piezoelectric vibration and hydraulic pressure, namely the hydrodynamic piezoelectric internal sinus elevation (HPISE) technique through a crestal approach. MATERIALS AND METHODS: A total of 250 maxillary sinuses were augmented using HPISE and 353 implants (averaging 11.8 mm in length and 4.5 mm in diameter), with 12 different systems, were placed simultaneously with or without additional bone grafting. Plain radiograms and cone beam computed tomograms were taken in all patients to evaluate sinus augmentation. RESULTS: Membrane perforation was recorded at 10 of the 353 implant sites. The perforation rate was 2.83%. The total success rate of implantation was 97.2% after an average of 69.3 weeks of loading. CONCLUSION: The crestally approached sinus augmentation using ultrasonic piezoelectric vibration and hydraulic pressure is an additional method of maxillary sinus augmentation.

The importance of neo-aortic root geometry in the arterial switch operation with the trap-door technique in the subsequent development of aortic valve regurgitation.

OBJECTIVE: Regarding neo-aortic valve regurgitation (neo-AR) after the arterial switch operation (ASO), the 'trap-door' technique was supposed to be a risk factor due to a distortion of the sinotubular junction (STJ) geometry. Here we report our results of the 'trap-door' technique with a special emphasis on root geometry including the ratio of STJ to annulus. METHODS: From August 1991 to March 2010, 240 patients with transposition of the great arteries underwent the ASO and who had at least 1 year of follow-up were included in this study. The medical records were retrospectively reviewed. RESULTS: The median age and body weight at the time of operation were 11 (0-1213) days and 3.4 (1.30-18.75) kg, respectively. The median follow-up duration was 79 months (range 12 months-19.5 years). At the latest echocardiographic follow-up, only six patients had neo-AR greater than Grade II (6 of 240, 2.5%). We found no relationship between neo-AR greater than Grade II and perioperative factors. The actual sizes of the neo-aortic annulus, mid-sinus and STJ were observed as having increased over time. However, most z-scores of STJ at the latest echocardiography varied between -2 and 2 and, more importantly, the ratio of STJ to neo-aortic annulus was 0.93 ± 0.20, which was near normal at the latest echocardiographic follow-up. CONCLUSIONS: Our results showed a very low incidence of significant neo-AR, which was relatively attributable to the preserved z-score of STJ and the normal range of STJ/annulus ratio. Therefore, we propose that it is important to maintain these factors adequately during the reconstruction of the neo-aortic root in the ASO.

Pulmonary hypertension due to obstructive sleep apnea in a child with Rubinstein-Taybi syndrome.

Rubinstein-Taybi syndrome (RTS) is characterized by peculiar facies, mental retardation, broad thumbs, and great toes. Approximately one-third of the affected individuals have a variety of congenital heart diseases. They can also have upper airway obstruction during sleep, due to hypotonia and the anatomy of the oropharynx and airway, which make these patients susceptible to obstructive sleep apnea (OSA). In our case, pulmonary hypertension was caused, successively, by congenital heart defects (a large patent ductus arteriosus and arch hypoplasia) and obstructive sleep apnea during early infancy. The congenital heart defects were surgically corrected, but persistent pulmonary hypertension was identified 2 months after the operation. This pulmonary hypertension was due to OSA, and it was relieved by nasal continuous positive airway pressure. This case is the first report of pulmonary hypertension from OSA in a young infant with RTS.