Orthodontic mini-implants were recently developed and have been widely used in clinics. However, loosening of mini-implants, as well as infection and swelling of mucosal tissue at the placement site, are often observed during orthodontic treatment. Thus, clinical indices are greatly needed for the safe use of orthodontic mini-implants. This article presents information on mini-implants and offers suggestions on indications, placement technique, optimum design, and evaluation of the placement site for mini-implants. The author concludes that 1) mini-implants should be left in the placement site for 3 months before loading to allow for a healing period, which increases the success rate in adolescent patients, 2) placement torque should be considered when tightening mini-implants into bone, as excessively high or low torque results in low stability, 3) mini-implants with optimal screws should be placed in the correct position, and 4) a prepared site should be established in an area with a cortical bone thickness of greater than 1.0 mm, to improve the success rate. Finally, the vector of orthodontic forces in the arrangement with the center of resistance of the entire dental arch should be considered when developing treatment goals. (J Oral Sci 53, 407-412, 2011)
There are several degradation mechanisms of resin-composite restorations and possible deleterious effects created by leached components cannot be ignored. Additionally, the surface integrity influences the long-term clinical performance of resin-composite restorations and can be affected by several factors. Novel technologies have been proposed, but there is a lack of information considering the degradation resistance of such materials. The aim of this study was to investigate the degradation resistance of silorane (SIL), pure-ormocer (ORM) and dimethacrylate (ELS and GRD) resin-based dental composites. Water sorption and solubility tests were adapted from ISO4049, color change trough the CIELab parameters after 24h and 30d immersion in distilled water. Knoop hardness readings were performed at the aforementioned periods and the percentage of hardness decrease was considered. Results were analyzed with one-way ANOVA followed by Tukey’s test (P = 0.05). SIL and GRD produced lower water sorption than ORM and ELS. SIL presented the lowest solubility. All materials demonstrated acceptable results for color stability. SIL demonstrated the more stable surface, when considering surface hardness, in aqueous environment. It can be concluded that i) silorane and ormocer-based materials did not produced higher color stability than dimethacrylates in distilled aqueous media; and ii) silorane-based materials exhibited lower water solubility and lower hardness decreases after water immersion than dimethacrylate-based resin-composites, while the pure-ormocer-baed material not. (J Oral Sci 53, 413-419, 2011)
Candida species are a normal commensal of the oral cavity in healthy individuals, but can become an opportunistic pathogen when the oral ecosystem is unbalanced. Several virulence attributes have been identified in candidal infection, among which are the hydrolases, including the secreted aspartyl proteinases (Saps). This study evaluated and compared the in vitro level of Saps from Candida albicans in nonsmokers, smokers, and patients with leukoplakia and oral squamous cell carcinoma (OSCC). Candida cell count (CCC) at 48 h was also assessed. The Sap level was measured by spectrophotometry in 38 clinical isolates of C. albicans obtained from the oral cavity of the four different groups. Culturing was done in yeast carbon base-bovine serum albumin. Speciation of Candida was performed by using a Candida identification kit, and CCC was measured by hemocytometer. Sap levels and CCC were higher in individuals with leukoplakia and OSCC than in nonsmokers or smokers (P = 0.001); however, there was no significant difference in Sap levels or CCC between smokers and nonsmokers (P = 0.529). Further, an intragroup correlation between CCC and Sap level was also observed. The higher level of Saps from C. albicans in individuals with leukoplakia and OSCC suggests that this pathogen plays a role in disease development and could aid in identifying the pathogenic commensal. (J Oral Sci 53, 421-425, 2011)
Oral submucous fibrosis (OSMF) is a chronic, insidious and disabling condition affecting the oral cavity, being especially prevalent in India and South East Asia. However, considering its high prevalence and potential to undergo malignant transformation, OSMF has not been widely investigated with respect to levels of antioxidants, especially beta carotene. In the present study, an attempt was made to analyze serum levels of beta carotene in 45 patients with oral submucous fibrosis and 45 age- and sex-matched controls. The serum beta carotene level was estimated using the Bradley and Hornbeck method. The serum beta carotene level was significantly lower in the patients with oral submucous fibrosis than in the controls. When the values were compared between different disease stages, the maximum reduction of beta carotene was evident for Grade III OSMF, as compared with Grade I and II. From the present results, it is evident that beta carotene plays an important role in the pathogenesis of OSMF, and that its level decreases with disease progression. OSMF patients should be treated with a diet rich in beta carotene to reduce disease severity and progression towards malignancy. (J Oral Sci 53, 427-431, 2011)
The aim of this study was to determine the frequency of bifid mandibular condyle (BMC) using panoramic radiographs supported by different radiographic techniques. A retrospective study was carried out by evaluating panoramic radiographs of 18,798 patients referred to the Department of Dentomaxillofacial Radiology. T-tests were used to compare the frequency of BMC between left and right sides and between female and male patients. In this study, 98 patients (0.52%) were found to have BMC. Of these patients, 51 (52%) were females and 47 (48%) were males. Of the 98 patients, 71 (72.4%) had unilateral and 27 (27.6%) had bilateral BMC. A total of 125 BMCs were found in 98 patients. No statistically significant differences were found between the right and left BMCs or between female and male patients (P > 0.05). Because symptoms associated with BMC are either absent or minimal, it is usually discovered as an incidental finding during routine radiographic examination. Different appearances of BMC can be seen on panoramic radiographs. The exact orientation of the condyles can only be determined using 3D imaging techniques. BMC may be a more frequent condition in the Turkish population. (J Oral Sci 53, 433-437, 2011)
Panoramic radiography and cone-beam computed tomography (CT) were used to analyze asymptomatic radiopaque lesions in the jaw bones and determine the diagnostic relevance of the lesions based on their relationships to teeth and site of origin. One hundred radiopaque lesions detected between 1998 and 2002 were examined by both panoramic radiography and cone-beam CT. On the basis of panoramic radiographs, the region was classified as periapical, body, or edentulous, and the site was classified as molar or premolar. Follow-up data from medical records were available for only 36 of these cases. The study protocol for simultaneous use of cone-beam CT was approved by the ethics review board of our institution. A large majority of radiopaque lesions were observed in premolar and molar sites of the mandible; 60% of lesions were periapical, 24% were in the body, and 16% were in the edentulous region. An interesting type of radiopaque lesion, which we named a pearl shell structure (PSS), was observed on cone-beam CT in 34 of the 100 lesions. The PSS is a distinctive structure, and this finding on cone-beam CT likely represents the start of bone formation before bone sclerosis. (J Oral Sci 53, 439-444, 2011)
Individuals with periodontitis exhibit differential expression of mucin-glycoprotein-2 (MG2), a protein encoded by the MUC7 gene. It is well known that MG2 exerts bactericidal activity as well as exhibiting genetic polymorphism involving a variable number of tandem repeats (VNTR). In the present study, we assessed the distribution of allelic variants of the MUC7 gene in 22 individuals with aggressive periodonitis, 68 with chronic periodonitis, and 87 without periodonitis. Oral mucosal cells were collected, the DNA was extracted, and specific primers were used to amplify the region encoding the MUC7 tandem repeats (TRs). Polymerase chain reaction products were subjected to electrophoresis and analyzed on polyacrylamide gels stained with silver nitrate. Although the percentage distribution of homozygosity (6-6TR) and heterozygosity (5-6TR) showed variation among the groups, the observed differences were not statistically significant (P > 0.05; Fisher’s Exact Test). The present results indicate that the expression of different numbers of TRs in this salivary mucin in the oral environment does not interfere with the etiopathogenesis of aggressive or chronic periodontitis. (J Oral Sci 53, 445-449, 2011)
The oral route of human papillomavirus (HPV) transmission is not fully understood. It has been suggested that genital infection can act as a reservoir for oral HPV infection. We investigated the presence of oral HPV DNA and anti-HPV IgA in the buccal cavity of patients with a histopathologic diagnosis of cervical HPV infection. One hundred women underwent oral clinical examinations to detect HPV-DNA by polymerase chain reaction and salivary anti-HPV IgA by indirect immunofluorescence. Information on the personal habits of all the women was collected in personal interviews. Our results showed that 99% of the patients had no clinical manifestations of oral HPV. However, HPV DNA was detected in 81% of oral mucosa samples, and anti-HPV IgA was detected in the saliva of 44% of the patients. Consumption of alcoholic beverages was significantly associated with detection of oral HPV DNA and salivary anti-HPV IgA. Other behavioral risk factors associated with oral HPV and anti-HPV IgA are also discussed. In conclusion, patients with genital HPV infection are at risk for subclinical oral HPV infection. Thus, a molecular assay might be necessary to diagnose such infections. (J Oral Sci 53, 451-459, 2011)
Achieving successful anesthesia and pain control in a predictable, efficient manner is a challenge in the endodontic treatment of vital inflamed lower molars. The aim of this study was to evaluate the effect of oral ketamine on the dosage of local anesthetics required and postoperative pain management for irreversibly inflamed mandibular molars. In this randomized double-blind placebo-controlled clinical trial, 36 patients with irreversibly inflamed mandibular molars were randomly divided into two groups of 18. Ten mg of ketamine dissolved in 20 ml of fruit juice was administered orally to patients in the experimental group. The control group was given 20 ml of fruit juice alone as a placebo. After 30 min, inferior alveolar nerve block (IANB) anesthesia was induced using one cartridge of 2% lidocaine and 1:100000 epinephrine. Teeth were tested after 5 to 10 min using an electrical pulp tester. In patients showing a positive response, another IANB injection was applied, and the total number of anesthetic cartridges used was recorded. Postoperative pain was evaluated using a visual analogue scale (VAS). In addition, use of analgesic in the first 24 h after treatment was monitored using a questionnaire. Data were analyzed by t test using SPSS software. There were no significant differences in age or gender between the two groups. The number of anesthetic cartridges used in the ketamine group was significantly less than that in the control group (P = 0.003). Furthermore, postoperative pain in the ketamine group was significantly lower (P = 0.019). Also the number of analgesic tablets taken in the ketamine group was significantly lower (P = 0.011). It can be concluded that a low dose of ketamine might be beneficial for enhancing the effect of local anesthetics. (J Oral Sci 53, 461-465, 2011)
Recent evidence suggests that polymorphisms in Fcγ receptors are associated with different forms of periodontitis. However, the FcγR genotypes and their allele frequency differ among subjects from different ethnic backgrounds. The aim of the present study was to determine whether specific FcγRIIa, FcγRIIIa, and FcγRIIIb alleles and/or genotypes are associated with susceptibility to generalized aggressive periodontitits (GAgP) in a South Indian population. Buccal scrapings were obtained from 60 subjects with GAgP and 60 periodontally healthy individuals, and DNA was extracted from each of the samples. FcγRIIa and FcγRIIIa genotyping was performed by polymerase chain reaction (PCR) amplification of DNA with allele-specific primers followed by allele-specific restriction digestion of the products, whereas FcγRIIIb genotyping was done by allele-specific PCR. There was no significant difference in the distribution of the FcγRIIa H/R genotype between GAgP patients and healthy subjects, although significant over-representation of the R allele was noted in GAgP patients. With regard to FcγRIIIa F/V genetic polymorphism, the homozygous V/V genotype and V allele were significantly over-represented in the GAgP group, whereas the F/F genotype and F allele were over-represented in the controls. Furthermore, there was significant over-representation of the FcγRIIIb-NA2 allele and NA2/NA2 genotype in GAgP patients, and of the NA1/NA1 genotype and NA1 allele in the controls. These data suggest that the FcγRIIIa V/V genotype and/or V allele, as well as the FcγRIIIb NA2/NA2 and/or NA2 allele, along with the FcγRIIa- R allele, may be risk factors for GAgP in the population of South India. (J Oral Sci 53, 467-474, 2011)
To examine the pathogenesis of intravascular papillary endothelial hyperplasia (IPEH), a relatively uncommon benign, non-neoplastic vascular lesion, clinicopathological and immunohistochemical studies were performed. Paraffin-embedded tissue specimens of 78 vascular lesions were examined histologically, and 9 cases of IPEH were investigated immunohistochemically using antibodies against CD34, vimentin, factor VIII antigen, α-smooth muscle actin (α-SMA), podoplanin, CD105, and ki-67 antigen. A thrombus or ulcer was found near the sites of all IPEH specimens. Histologic examination revealed papillary proliferated endothelial cells located toward the lumen of enlarged blood vessels. Immunohistochemistry showed that CD34, α-SMA, and factor VIII antigen were positive in lining endothelial cells. Vimentin was positive in the mesenchymal components. Immunohistochemical staining for podoplanin and CD105 was partially positive. Labeling index was 4.7 to 9.2 in ki-67-positive cases. IPEH is believed to result from reactive proliferation of blood endothelial cells that is caused by an abnormal process of organization in thrombosed blood vessels. The pathogenesis of IPEH might be related to inflammation or mechanical stimulus such as irritation. (J Oral Sci 53, 475-480, 2011)
Conflicting data exist on the combined use of grafting materials and barrier membranes in comparison to guided tissue regeneration (GTR) with membrane alone. The aim of the present study was to compare the clinical outcomes of GTR with collagen membrane (CM) alone (control group) or CM combined with autogenous bone graft (test group 1) or autogenous bone mixed with bioactive glass (test group 2) in intrabony defects. A total of 32 intraosseous defects in 22 subjects were treated randomly. After 6 months, significant probing depth reduction, clinical attachment level gain (CAL) and defect resolution were observed in all groups with significantly greater improvements in the test groups. There was no significant difference between the two test groups in any parameter. Results of the present study suggest that autogenous bone can be mixed with bioactive glass if the amount of the harvested bone is not sufficient. (J Oral Sci 53, 481-488, 2011)
A sample of 308 extracted human permanent maxillary first molars from an Indonesian population was randomly selected. A rhomboid access cavity was made in all teeth in anticipation of identifying a second mesiobuccal canal (MB2). Ultrasonic tips were used to open the subpulpal groove to locate the second canal in the mesiobuccal root. Dentin was carefully removed from the trifurcation area at the expense of the mesial wall. If a second canal was located, a 0.8 C+ file was inserted into it until the file reached the apex. The prevalence of a second canal in the mesiobuccal root of the permanent maxillary first molar was 68.5% (95% CI: 63.1%-73.4%) in this population. Sections of the mesial root showed that the MB2 was a separate canal in 52.6% of the sample and a joined canal in 47.4%. The mean (SD) distance between MB1 and MB2 was 1.55 (0.66) mm. The data obtained from this study provide theoretical and experimental evidence to aid in the clinical management of the MB2 canal and may increase the success rate for root canal treatment of the maxillary first molar. (J Oral Sci 53, 489-494, 2011)
Twenty-three cases of accidental ingestion during dental procedures, which occurred at the Center for Dental Clinics of Hokkaido University Hospital between 2006 and 2010, were analyzed retrospectively. We examined not only the objects ingested, but also details of the circumstances (treated teeth, types of treatment, professional experience of the practitioners). Except for two cases (an unidentified endodontic file and the tip of an ultrasonic scaler, which were recovered by vacuuming), the other 21 accidentally ingested objects were all found in the digestive tract, and none in the respiratory tract, by radiographic examination of the chest and abdomen. The ingested objects were mostly metal restorations (inlays or onlays) or prostheses (crowns or cores). Ingestion occurred more frequently during treatment of lower molars, and when procedures were being conducted by practitioners with less than 5 years of experience. No adverse events related to ingestion were reported. The present study found no cases of aspiration or complications related to the ingested objects. However, considering the risk of life-threatening emergencies related to accidental aspiration and ingestion, dentists must take meticulous precautions and be ready to deal with this kind of emergency during dental procedures. (J Oral Sci 53, 495-500, 2011)
Since the introduction of cone-beam computed tomography (CBCT), several novel systems with different technical specifications and settings have become commercially available. Therefore, it is essential to evaluate CBCT systems for differences in the subjective quality of images obtained for various dental procedures. We evaluated the subjective image quality of cross-sectional scans obtained from various CBCT systems. Images of three cadaver mandibles were obtained from four different CBCT units: 1) Veraviewepocs 3D 40 × 40 mm field of view (FOV) (voxel size: 0.125 × 0.125 × 0.125 mm), 2) Iluma, low-resolution (voxel size: 0.3 × 0.3 × 0.3 mm), 3) Kodak, 50 × 3.7 cm FOV (voxel size: 0.076 × 0.076 × 0.076 mm), and 4) Vatech 12 × 8.5cm FOV (voxel size: 0.160 × 0.160 × 0.160 mm). We assessed subjective image quality and the visibility of 10 specific features, namely, caries, amalgam restoration, final implant drill, root canal filling, metal crown, mandibular canal, mental foramen, tooth (periodontal ligament space and lamina dura), trabecular pattern, and soft tissue. Images were viewed and scored by five calibrated observers, and image quality was ranked from best to worst. The Veraviewepocs 3D had the highest quality images for most of the assessed features, whereas the Iluma low-resolution scans were rated as the lowest quality images. (J Oral Sci 53, 501-508, 2011)
Periodontitis is a destructive disease that is likely the result of the activities of different microbial complexes, including anaerobic Gram-negative periodontopathic bacteria. Butyric acid (sodium butyrate; BA) is a major metabolic by-product of anaerobic Gram-negative periodontopathic bacteria present in subgingival plaque. This study was undertaken to examine the effect of BA on the expression of osteogenesis-related transcription factors and mineralized nodule formation in osteoblastic ROS17/2.8 cells. The cells were cultured with 0 (control), 10-5, 10-4, or 10-3 M BA for up to 7 days. The gene and protein expression levels of transcription factors such as Runx2, Osterix, Dlx5, Msx2, and AJ18, as well as extracellular matrix proteins such as bone sialoprotein (BSP) and osteocalcin, were examined using real-time PCR and Western blotting, respectively. Mineralized nodule formation was detected by alizarin red staining. The expression of Runx2, Osterix, Dlx5, and Msx2 decreased significantly in the presence of 10-3 M BA compared to the control, whereas AJ18 expression increased significantly. Mineralized nodule formation decreased markedly in the presence of 10-3 M BA. Alkaline phosphatase activity and the expression of bone sialoprotein and osteocalcin decreased significantly in the presence of 10-3 M BA compared to the control. These results suggest that 10-3 M BA suppresses osteoblastic differentiation and mineralized nodule formation in ROS17/2.8 cells. (J Oral Sci 53, 509-516, 2011)
Inadequate apical seal is the major cause of surgical endodontic failure. The root-end filling material used should prevent egress of potential contaminants into periapical tissue. The purpose of this study was to compare the sealing ability of four root-end filling materials: white mineral trioxide aggregate (MTA), gray MTA, white Portland cement (PC) and gray PC by dye leakage test. Ninety-six human single-rooted teeth were instrumented, and obturated with gutta-percha. After resecting the apex, an apical cavity was prepared. The teeth were randomly divided into four experimental groups (A: white MTA, B: gray MTA, C: white PC and D: gray PC; n = 20) and two control groups (positive and negative control groups; n = 8). Root-end cavities in the experimental groups were filled with the experimental materials. The teeth were exposed to Indian ink for 72 hours. The extent of dye penetration was measured with a stereomicroscope at 16× magnification. The negative controls showed no dye penetration and dye penetration was seen in the entire root-end cavity of positive controls. However, there was no statistically significant difference among the four experimental groups (P > 0.05). All retrograde filling materials tested in this study showed the same microleakage in vitro. Given the low cost and apparently similar sealing ability of PC, PC could be considered as a substitute for MTA as a root-end filling material. (J Oral Sci 53, 517-522, 2011)
Bilateral, asymmetric anomalies of the anterior bellies of digastric muscles were observed during dissection of the submental region. Specifically, four extra muscle bundles were found between the anterior bellies of the digastric muscle. Although anomalies of the anterior bellies of digastric muscles are often observed, this complicated pattern of digastric anomalies has not been previously reported. Our findings and previous observations illustrate the morphogenetic complexity of the anterior belly of the digastric muscle derived from the first pharyngeal arch, which gives rise to jaw musculature such as the mylohyoid muscle. (J Oral Sci 53, 523-527, 2011)
The aneurysmal bone cyst (ABC) rarely occurs in the jaws. It represents approximately 1.5% of all non-odontogenic and non-epithelial cysts of the jaws. The literature contains conflicting reports on the clinical and radiological features of ABC of the jaws. The radiographic appearance of ABC varies from a unicystic radiolucency or moth-eaten radiolucency to an extensive multilocular lesion. In this article, we describe the transition of an ABC in the maxillofacial region from a unilocular radiolucent lesion to a radiopaque lesion in a 40-year-old female over a 10-month period, which indicates diversity in the clinical and biologic behavior of ABCs. (J Oral Sci 53, 529-532, 2011)
A referred patient presented with a lesion of endodontic origin located at the apex of tooth #27. The tooth had been endodontically treated and re-treated. A periapical radiograph revealed a close relationship between the lesion and the maxillary sinus. A cone-beam computed tomography scan confirmed that the lesion had invaded the sinus cavity. The treatment plan consisted of periapical surgery using an endoscope as a magnification device. Due to a sinus membrane perforation, a new sinus membrane repair technique was performed. Twelve months after surgery, a cone-beam computed tomography scan revealed successful healing of the lesion. The continuous preservation of the sinus physiology was also observed. The use of an endoscope as a magnification device and a tailored technique for sinus membrane management allowed us to achieve a successful treatment outcome in the case of an endodontic lesion invading the maxillary sinus. (J Oral Sci 53, 533-538, 2011)
July 31, 2017 Due to the end of the Yahoo!JAPAN OpenID service, My J-STAGE will end the support of the following sign-in services with OpenID on August 26, 2017: -Sign-in with Yahoo!JAPAN ID -Sign-in with livedoor ID * After that, please sign-in with My J-STAGE ID.
July 03, 2017 There had been a service stop from Jul 2‚ 2017‚ 8:06 to Jul 2‚ 2017‚ 19:12(JST) (Jul 1‚ 2017‚ 23:06 to Jul 2‚ 2017‚ 10:12(UTC)) . The service has been back to normal.We apologize for any inconvenience this may cause you.
May 18, 2016 We have released “J-STAGE BETA site”.
May 01, 2015 Please note the "spoofing mail" that pretends to be J-STAGE.