• Journal of the Korean Society of Radiology
• /
• v.15 no.4
• /
• pp.491-498
• /
• 2021

In this study, the effective dose was measured using the PCXMC v2.0 program by examining the conditions used to set the diagnostic reference level for intraoral imaging recommended by the government, and the effect of the Al additive filter was confirmed. In oral imaging, the largest effective dose was calculated from the oral mucosa among 11 organs. The effect of the Al additive filter showed an excellent radiation reduction effect at 2mm rather than 1mm. In the case of children aged 5 years, the overall effective dose was calculated to be high in all 11 organs because they are more sensitive to radiation than adults. And as a result of evaluating the image quality according to the use of an additional filter during intraoral imaging, there was no significant difference in SNR and CNR changes compared to before the additional filter was used. Based on this study, it is thought that additional filter settings can be recommended for intraoral imaging.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.38
• /
• pp.50.1-50.6
• /
• 2016

Background: The aim of this study was to evaluate the clinical outcomes of implants that were placed within the maxillary sinus that has a perforated sinus membrane by the lateral window approach. Methods: We examined the medical records of the patients who had implants placed within the maxillary sinus that has a perforated sinus membrane by the lateral approach at the Department of Oral and Maxillofacial Surgery of Chonnam National University Dental Hospital from January 2009 to December 2015. There were 41 patients (male:female = 28:13). The mean age of patients was $57.2{\pm}7.2years$ at the time of operation (range, 20-76 years). The mean follow-up duration was 2.1 years (range, 0.5-5 years) after implant placement. Regarding the method of sinus elevation, only the lateral approach was included in this study. Results: Ninety-nine implants were placed in 41 patients whose sinus membranes were perforated during lateral approach. The perforated sinus membranes were repaired with a resorbable collagen membrane. Simultaneous implant placements with sinus bone grafting were performed in 37 patients, whereas delayed placements were done in four patients. The average residual bone height was $3.4{\pm}2.0mm$ in cases of simultaneous implant placement and $0.6{\pm}0.9mm$ in cases of delayed placement. Maxillary bone graft with implant placement, performed on the patients with a perforated maxillary sinus membrane did not fail, and the cumulative implant survival rate was 100%. Conclusions: In patients with perforations of the sinus mucosa, sinus elevation and implant placement are possible regardless of the location and size of membrane perforation. Repair using resorbable collagen membrane is a predictable and reliable technique.

• Korean Journal of Cleft Lip And Palate
• /
• v.4 no.1
• /
• pp.1-11
• /
• 2001

Disposable blade is widely used for palatal and oral mucosal incision in oral and maxillofadal surgery nowadays, But its design and durability need for improvement, Especially, there are so many hard tissues intraoral area, such as bone and tooth, therefor the sharpness of the surgical blade was easily destroyed, The purpose of this study was to make basic data for developing new design of surgical blade using in oral and maxillofacial area including for the patients who have cleft lip and palate deformities, Some questionnaires about the usefulness of currently used surgical blades were sent to 150 dentists, the 54 of them made a reply, Secondly, The used-once blade and fresh new blade were examined under the scanning electron microscope with the 4000-times magnification, Lastly, the tissue reaction following the surgical incision with a fresh-new and a used blade on rat buccal cheek mucosa and hard palate was evaluated with light microscope with hematoxilin-eosin staining, The time interval from the surgical trauma to taking a sample were 1 day, 3 days, 7 days, and 14 days, At each time schedule, 2 Sprague-Dawley rats were sacrificed, Many dentists were agreed to need for changing the design of the surgical blades and also demand to improve the durability of the blades, They were also eager to adopt the new design of blade if it was available, The blade used in surgical extraction procedure was heavily damaged in its sharpe edge of number 15 blade, The histological differences were not prominent, but the delayed healing was detected in buccal mucosal defects especially in the surgical group with used blade, There are slight different changes in hard palatal defects between a used and a new blade group, In this study, we could find that there are imperative demanding on improvement of surgical blade design and durability for oral and maxillofadal area, The blade currently using in surgical extraction was easily damaged, The animal model of this study was not perfect for the purpose of this study.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.32 no.1
• /
• pp.19-26
• /
• 2006

Objective: In order to elucidate the retrogressive degeneration of orofacial cleft, the fissured tissues of prenatal and postnatal cleft lip and palate were examined by histological and immunohistochemical methods. Design: Totally 42 cases of prenatal (n=17) and postnatal (n=25) cleft lip and/or palate were examined in comparison with 10 cases of normal lip and oral mucosa using immunohistochemical stainings of MMP-3, MMP-9, MMP-10, cathepsin G, PCNA, E-cadherin, TGase 2, HSP-70, vWF, and VEGF. Main Outcome Measures: In the fissured tissue the sebaceous glands were strongly positive for PCNA and grew into the underlying fibromuscular tissue (24/42). Some hyperplastic sebaceous glands of prenatal cleft lip produced infundibular follicular cyst (9/17). The skin and mucosal epithelia from the postnatal cleft lip and palate (10/25) showed severe basal hyperplasia (11/25) and melanocyte infiltration (7/25). Results: The immunostaining of MMP-3 and HSP-70 were strongly positive in the hyperplastic sebaceous glands and nearby atrophying muscle bundles of the fissured tissue, while MMP-9, MMP-10, and cathepsin G were almost negative. The immunoreactions of the other antibodies used in this study were similar between in the fissured tissues and in the normal controls. Conclusions: These data suggest that the over-expression of MMP-3 is closely related to the sebaceous gland hyperplasia, epithelial dysplasia, and the muscle degeneration, and that the over-expression of MMP-3 in the fissured tissue may continuously aggravate the cleft condition in the later life.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.2
• /
• pp.585-589
• /
• 2012

Background: Israeli Arabs are considered as a developing society characterized by poverty and high levels of smoking among men. The purpose of this study was to describe their incidence, mortality and survival rates for oral and pharyngeal cancer between the years 1970-2006. Studies such as this in the Arab world, where the population is almost the same as the Arab population in Israel, are rare. Methods: The incidence and survival data were derived from all relevant registered data at the National Cancer Registry. The group of lesions included cancer of the lips, tongue, buccal mucosa, floor of the mouth, salivary glands, gums, palate and pharynx. Morphological description was according to WHO classification. Results: Most diagnosed patients were male. The mean age was 54.4 years, and mean years of survival were 3.83. The oropharynx was the most common site (28.3%) while the palate was the least frequent (3.12%). Squamous cell carcinoma (SCC) was the most common histological feature (66.3%), while basal cell carcinoma (BCC) was the least (3.9%). The overall 5 years survival rate was 59.4%, this being highest for BCC (82.1%), while SCC was significantly lower (56.2%) (p<0.001). Lip cancers survived better than other sites. Conclusions: Data from this society are similar to other developing societies in the majority of the results. The incidence of oral and pharyngeal cancer is lower among the Arab population, in comparison to the Jewish population in Israel.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.23 no.2
• /
• pp.174-179
• /
• 2001

The authors analyzed retrospectively the 19 patients with mucoepidermoid carcinoma of salivary glands who were treated at Department of Oral and Maxillofacial Surgery, Pusan National University Hospital from June, 1986 to September, 1998. The results obtained were as follows: 1. There were 4 males(21%) and 15 females(79%). Age distribution was wide and the mean age was 45.2. 2. Of all mucoepidermoid carcinomas of salivary gonads, 4 cases arose in the major salivary glands and 15 cases in the minor salivary glands. The incidence according to the anatomic primary site for minor salivary glands was 8 cases in the palate, 2 cases each arising in the tongue and floor of mouth and 1 case each arising in the mandible, buccal mucosa and the lower lip. 3. In histopathological classification of mucoepidermoid carcinoma, 5 cases were low grade. 9 cases, intermediate grade and 5 cases, high grade. 4. Perineural invasion was observed 40%(2/5) in high grade and 22%(2/9) in the intermediate grade of mucoepidermoid carcinoma. 5. The incidence of cervical lymph node metastasis according to histopathologic grade was 40% (2/5) in high grade and 11%(1/9) in intermediate grade of mucoepidermoid carcinoma. 6. The lung was the commonest site for metastasis comprising 3 cases among 3 cases of distant spread of which 2 cases in high grade and 1 case in intermediate grade of mucoepidermoid carcinoma.

• The Journal of Advanced Prosthodontics
• /
• v.9 no.6
• /
• pp.453-462
• /
• 2017

PURPOSE. The purpose of this study was to investigate the in vitro cytotoxicity of thermoplastic denture base resins and to identify the possible adverse effects of these resins on oral keratinocytes in response to hot water/ food intake. MATERIALS AND METHODS. Six dental thermoplastic resin materials were evaluated: three polyamide materials (Smile tone, ST; Valplast, VP; and Luciton FRS, LF), two acrylic materials (Acrytone, AT; and Acryshot, AS), and one polypropylene resin material (Unigum, UG). One heat-polymerized acrylic resin (Vertex RS, RS) was chosen for comparison. After obtaining extracts from specimens of the denture resin materials (${\phi}=10$ mm and d=2 mm) under different extraction conditions ($37^{\circ}C$ for 24 hours, $70^{\circ}C$ for 24 hours, and $121^{\circ}C$ for 1 hour), the extracts (50%) or serial dilutions (25%, 12.5%, and 6.25%) in distilled water were co-cultured for 24 hours with immortalized human oral keratinocytes (IHOKs) or mouse fibroblasts (L929s) for the cytotoxicity assay described in ISO 10993. RESULTS. Greater than 70% viability was detected under all test conditions. Significantly lower IHOK and L929 viability was detected in the 50% extract from the VP ($70^{\circ}C$) and AT ($121^{\circ}C$) samples (P<.05), but only L929 showed reduced viability in the 50% and 25% extract from LF ($37^{\circ}C$) (P<.05). CONCLUSION. Extracts obtained from six materials under different extraction conditions ($37^{\circ}C$, $70^{\circ}C$, and $121^{\circ}C$) did not exhibit severe cytotoxicity (less than 70% viability), although their potential risk to oral mucosa at high temperatures should not be ignored.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.4
• /
• pp.1515-1518
• /
• 2015

Background: Leukoplakia is an asymptomatic and potentially malignant change in the oral mucosa and high frequencies have been reported among smokers. The present study concerned the prevalence of tobacco use and leukoplakia and also associations between the two. Study design: This cross sectional survey was conducted amongst the Gond tribal population of Kundam Block, Jabalpur district, Madhya Pradesh state, Central India during 2007 to 2009. Screening for leukoplakia was conducted by a medical officer with two mouth mirrors. It is only based on visual inspection and oral pathology was not performed. A semi-structured questionnaire was used to collect information on socio-demographic and smoking habits. Prevalence of leukoplakia among users and non-users of tobacco was calculated in terms of percentages. Results: Of 1,552 individuals aged more than 12 years of age who were screened, 144 (9.3%) were found to have oral leukoplakia. The prevalence of leukoplakia was significantly elevated among tobacco users as compared to non-users (11% vs 2.5%; p<0.001). The percentage of leukoplakia was almost similar in both tobacco smokers and chewers (9% vs 11%; p=0.304). However, the percentage of leukoplakia was especially high among those chewers who also smoked tobacco (21.9%). Conclusions: The findings of the present study showed a positive effect of tobacco use and prevalence of leukoplakia. Also the prevalence was very high among Gond tribe, a marginalized population living in central India. There is a need for effective screening and treatment of leukoplakia in this area.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.27 no.5
• /
• pp.424-430
• /
• 2005

The oral cavity is humid environment mainly due to the continuous salivary flow. The reaction of oral mucosa to fluid flow is important for homeostasis and pathogenesis. The objective of this study is the screening the change of gene expression after the application of fluid induced shear stress (FISS) on the gingival fibroblast using cDNA microarray assay. The immortalized human gingival fibroblasts were grown and FISS was applied using a cone viscometer at a rotational velocity of 40 rpm, respectively for periods of 2 and 4 hours. The synthesis of cDNA was done from the extracted total RNA and cDNA microarray assay was done subsequently. The genes that showed over 1.6 in the Cy3/Cy5 or the Cy5/Cy3 value were regarded as genes influenced significantly by the FISS application ion (/M/>0.7). The " RUNX-1" was increased its expression in 2 hours group and " RUN and SH3 domain containing 1" was increased its expression in 4 hours group. The "CC020415", "cyclin L1", "interferon regulatory factor1", "early growth response 1", "immediate early response 2", and "immediate early response 3" genes were increased their expression in 2 and 4 hours after FISS application. In conclusion, we could find many genes that were probably related to the FISS application. Interestingly, most of them were placed in similar molecular pathways and these findings improve the reliability of chip data and usefulness in overall screening. From this experiment, we could find many items for further study and it will make improvement in the understanding of intracellular events in response to FISS.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.28 no.5
• /
• pp.454-469
• /
• 2006

Today, there is considerable evidence to support a cause-effect relationship between microbial colonization and the pathogenesis of implant failures. The presence of bacteria on implant surfaces may result in an inflammation of the peri-implant mucosa, and, if left untreated, it may lead to a progressive destruction of alveolar bone supporting the implant, which has been named as peri-impantitis. Several maintenance regimens and treatment strategies for failing implants have been suggested. Recently, in addition to these conventional tools, the use of different laser systems has also been proposed for treatment of peri-implant infections. As lasers can perform excellent tissue ablation with high bactericidal and detoxification effects, they are expected to be one of the most promising new technical modalities for treatment of failing implants. It is introduced that Er,Cr:YSGG laser, operating at 2780nm, ablates tissue by a hydrokinetic process that prevents temperature rise. We studied the change of the titanium implant surface under scanning electron microscopy after using Er,Cr:YSGG laser at various energies, irradiation time. In this study, Er,Cr:YSGG laser irradiation of implant fixture showed different effects according to implant surface. Er,Cr:YSGG laser in TPS surface with RBM not alter the implant surface under power setting of 4 Watt(W) and irradiation time of 30sec. But in TPS surface with $Ca_3P$ coating alter above power setting of 2W and irradiation time of 10sec. TPS surface with RBM showed microfracture in 4W, 30sec and TPS surface with $Ca_3P$ coating showed destruction of fine crystalline structure, melting in excess of 2W, 10sec. We concluded that proper power setting, air, water of each implant surface must be investigated and implant surface must be irradiated under the damaged extent.