OBJECTIVE: The additional arch length required for leveling (AALL) the curve of Spee (COS) can be estimated by subtracting the two-dimensional (2D) arch circumference, which is the projection of the three-dimensional (3D) arch circumference onto the occlusal plane, from the 3D arch circumference, which represents the arch length after leveling the COS. The purpose of this study was to determine whether the cusp tips or proximal maximum convexities are more appropriate reference points for estimating the AALL. METHODS: Sixteen model setups of the mandibular arch with COS depths ranging from 0 mm to 4.7 mm were constructed using digital simulation. Arch circumferences in 2D and 3D were measured from the cusp tips and proximal maximum convexities and used to calculate the AALL. The values obtained using the two reference points were compared with the paired t-test. RESULTS: Although the 3D arch circumference should be constant regardless of the COS depth, it decreased by 3.8 mm in cusp tip measurements and by 0.4 mm in proximal maximum convexity measurements as the COS deepened to 4.7 mm. AALL values calculated using the cusp tips as reference points were significantly smaller than those calculated using the proximal maximum convexities (p = 0.002). CONCLUSIONS: The AALL is underestimated when the cusp tips are used as measurement reference points; the AALL can be measured more accurately using the proximal maximum convexities.
Dental Occlusion

OBJECTIVE: The purpose of this study was to evaluate the effects of three different surface conditioning methods on the shear bond strength (SBS) of metal brackets bonded directly to gold alloy with chemically cured resin. METHODS: Two hundred ten type III gold alloy specimens were randomly divided into six groups according to the combination of three different surface conditioning methods (aluminum oxide sandblasting only, application of a metal primer after aluminum oxide sandblasting, silica coating and silanation) and thermocycling (with thermocycling, without thermocycling). After performing surface conditioning of specimens in accordance with each experimental condition, metal brackets were bonded to all specimens using a chemically cured resin. The SBS was measured at the moment of bracket debonding, and the resin remnants on the specimen surface were evaluated using the adhesive remnant index. RESULTS: Application of metal primer after aluminum oxide sandblasting yielded a higher bond strength than that with aluminum oxide sandblasting alone (p < 0.001), and silica coating and silanation yielded a higher bond strength than that with metal primer after aluminum oxide sandblasting (p < 0.001). There was no significant change in SBS after thermocycling in all groups. CONCLUSIONS: With silica coating and silanation, clinically satisfactory bond strength can be attained when metal brackets are directly bonded to gold alloys using a chemically cured resin.
Adhesives ; Alloys* ; Aluminum Oxide ; Gold Alloys ; Silicon Dioxide*

OBJECTIVE: The purposes of this study were to determine the accuracy of crown and root length measurements of premolars using cone-beam computed tomography (CBCT) and to generate reference CBCT-based data on incisor, canine, and premolar lengths in patients with malocclusions. METHODS: Imaging was performed using a CBCT scanner with a 0.292-mm voxel size and 12-bit grayscale. The CBCT-based length measurements were compared with direct measurements of 94 subsequently extracted premolars without metal restorations using the paired t-test. Furthermore, the crown and root lengths of incisors, canines, and premolars in 62 Korean patients with malocclusions were measured using CBCT, and Pearson's correlation coefficients were calculated to examine the relationship between the crown and root length measurements of each tooth type. RESULTS: The differences between the CBCT-based and direct measurements of the extracted premolars were not significant, with 95% limits of agreement of -0.90 to 0.90 mm for crown length and -1.23 to 1.18 mm for root length. Weak positive correlations between the crown and root length measurements were observed for the mandibular canine and premolars. CONCLUSIONS: The CBCT-based measurements showed a wider range of limits of agreements for root length than for crown length. The CBCT-based data can be used as a reference for evaluating root length and resorption of teeth without metal restorations in patients with malocclusions.
Bicuspid* ; Cone-Beam Computed Tomography* ; Crowns* ; Humans ; Incisor* ; Malocclusion* ; Root Resorption ; Tooth

Blue toe syndrome is the most frequent manifestation of tissue ischemia caused by cholesterol embolization (CE), which can lead to amputation of affected lower extremities, if severe. However, any effective treatment is lacking. We experienced a case of spontaneously presenting blue toe syndrome and concomitant acute renal failure in a patient with multiple atherosclerotic risk factors. CE was confirmed by renal biopsy. Despite medical treatment including prostaglandin therapy and narcotics, the toe lesion progressed to gangrene with worsening ischemic pain. Therefore, we performed lumbar sympathectomy, which provided dramatic pain relief as well as an adequate blood flow to the ischemic lower extremities, resulting in healing of the gangrenous lesion and avoiding toe amputation. This is the first reported case of a patient with intractable ischemic toe syndrome caused by CE that was treated successfully by sympathectomy. Our observations suggest that sympathectomy may be beneficial in some patients with CE-associated blue toe syndrome.
Acute Kidney Injury* ; Amputation ; Biopsy ; Blue Toe Syndrome* ; Cholesterol* ; Embolism, Cholesterol ; Gangrene ; Humans ; Ischemia ; Lower Extremity ; Narcotics ; Risk Factors ; Sympathectomy* ; Toes

OBJECTIVE: The purpose of this study was to investigate the relationship between the enamel thickness of proximal surfaces and the morphologic features of mandibular incisors. METHODS: Mesiodistal/faciolingual (MD/FL) index, MD width, and height of contour width/cervical width ratio were measured in 40 incisors extracted from Koreans. For determining the height of contour width/cervical width ratio, the cervical width was measured as the distance between proximal cementoenamel junctions. Then, the labial surface was ground to the height of the contour level to measure enamel thickness. Pearson correlation analysis was used to investigate the correlation between enamel thickness and morphologic features. RESULTS: Enamel thickness was 0.75 +/- 0.07 mm per side, and MD width was 5.56 +/- 0.40 mm. Enamel thickness and MD width were significantly correlated. However, a significant relationship was not observed between enamel thickness and MD/FL index or the height of contour width/cervical width ratio. CONCLUSIONS: The results suggest that enamel thickness is affected only by MD width. Therefore, if the MD width is the same for mandibular incisors with a large MD/FL index or triangular shape and mandibular incisors with normal shape, then the limit of enamel reduction for reproximation will be the same.
Dental Enamel ; Incisor ; Tooth Cervix

Dexamethasone ; Durapatite ; Mandible ; Osteoblasts ; Osteogenesis ; Rabbits ; Silver Staining ; Transplants

Blood Platelets ; Centrifugation ; Intercellular Signaling Peptides and Proteins ; Mandible ; Osteoblasts ; Osteogenesis ; Platelet Count ; Platelet-Rich Plasma ; Transplants

Bone Marrow Cells ; Dexamethasone ; Mandible ; Osteoblasts ; Osteogenesis ; Platelet-Rich Plasma ; Rabbits ; Silver Nitrate

OBJECTIVE: To evaluate the possibility of cumulative blood lead and blood ZPP as surrogates of lead body burden and to investigate their association with renal function as an index of lead body burden. METHODS: The study subjects comprised 678 lead workers with past blood lead and blood ZPP data from their employment. Cumulative blood and ZPP were calculated by accumulating the every year mean value of both indices from the new employment since 1983. To assess the cumulative data of lead workers who started their lead work before 1983, the years before 1983 were simulated with the first available data from 1983. Study variables for lead body burden were tibia bone lead and DMSA chelatable lead, whereas those for current lead biomarkers were blood lead and blood ZPP. BUN and serum creatinine were selected as clinical renal biomarkers, while NAG (N-acetyl-D-glucosamine) and RBP (Retinol binding protein) were selected as early renal biomarkers. RESULTS: The association between cumulative blood lead and blood ZPP with tibia bone lead was statistically significant with determinant coefficients (r(2)) of 0.72 and 0.567, respectively, and their relationships were better explained by the curvilinear regression model. In multiple regression analysis of current lead biomarkers on the renal biomarkers after controlling for possible confounders (age, sex, job duration, smoking and drinking status), blood lead was associated only with log-transformed NAG, whereas blood ZPP was associated with 3 other renal biomarkers. On the other hand, in multiple regression analysis of biomarkers of lead body burden on renal biomarkers after controlling for possible confounders (age, sex, job duration, smoking and drinking status), cumulative blood ZPP and tibia bone lead were associated with all 4 renal function biomarkers, whereas cumulative blood lead and DMSA chelatable lead were associated with 3 renal biomarkers except BUN. CONCLUSION: Cumulative blood and ZPP were demonstrated to be good surrogates of lead burden. Furthermore, the cumulative blood ZPP was confirmed to have a better association than the cumulative blood lead.
Biological Markers* ; Body Burden* ; Creatinine ; Drinking ; Employment ; Hand ; Smoke ; Smoking ; Succimer ; Tibia

Peritonitis in continuous ambulatory peritoneal dialysis is a major cause of technical failure in peritoneal dialysis. The major pathogen is gram positive bacteria, and other main pathogens include gram negative bacteria, mixed infection and fungal infection actively involved in the order named. Coagulate-negative Staphylococcus, Streptococcus, Staphylococcus aureus and Enterococcus cause most of the gram positive bacterial infections, and cases with other pathogens are very rare. We hereby report a case of peritonitis by Listeria Monocytogenes that was not responsive to the usual antibiotics for CAPD-associated peritonitis. A 58-year-old male who has been treated with CAPD for 17 years visited our hospital for abdominal pain, fever and turbid peritoneal fluid. He was diagnosed as diabetes mellitus 20 years ago. White blood cell and neutrophil count increased at the initial peritoneal fluid analysis, so we diagnosed him as CAPD-associated peritonitis. Antibiotic therapy was initiated with intraperitoneal injections of cefazolin/tobramycin, which were soon changed to vancomycin/ceftazidime. However, vancomycin/ceftazidime regimen was also proven ineffective. On the sixth hospital day, L. Monocytogenes was cultured in the peritoneal fluid sampled on the first visiting day. So we accordingly changed the antibiotics for ampicillin/sulbactam, which led to clinical and laboratory improvement. In the cases of CAPD associated peritonitis in immunosuppressive patients such as the elderly, caused either by diabetes or by taking immunosuppressive agent, if they do not respond to the usual antibiotics, we should consider the possible infection by unusual pathogens. Gram positive rod in peritoneal fluid is a supporting evidence of peritonitis by L. monocytogenes.
Male ; Humans