• Restorative Dentistry and Endodontics
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• v.20 no.2
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• pp.843-855
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• 1995

Occupational Dentistry was introduced in Korea about 70 years ago. During the colonial period occupied by Japan till 1945, there were few documents about industrial dentistry, furthermore most cases of occupational diseases and accidents might have been concealed intentionally by the colonial government. After being an independent country, several dentists made efforts to set up 'Preventive Dentistry for Workers' performing specific oral health surveys, even though which were stopped by Korean War. In 1960s' and 1970s', some investigations of oral status were carried out intermittently for specific small groups;white-collar workers, mentally retarded person, buddhist monks and crews of ocean liners. At the same time there was important study in Korean history of occupational dentistry, which was 'a comparison of the oral hygiene conditions in the female workers of a spinning factory at intervals of 30 years.' In 1980s', young researchers began to give attention to erosion of the teeth due to sulphuric acid in the acid-related industry and dental caries due to sugar and flour in the sweets industry. After being democratic labor union movement activated in 1987, hidden and suppressed occupational diseases under the military dictatorship were exposed and flushed in the newspapers. It was shocking for all people that 15-year old boy had been dead due to mercury intoxication after 3-month employment in 1988. In 1990s', the activity for studying oral status of workers in their workplaces was launched and 'Occupational Accidents and Diseases in Oral and Maxillofacial Field' was published. And also The Korean Association of Occupationl Dentistry was established. Oral health examination of workers at the time of employment and of workers exposed to 5 special chemicals at the time of routine special health examination was adopted in 1992, and epocally oral health examination was also included in periodic routine examination of workers' health in 1995. So, occupational dentistry in Korea should cope with the changing needs of working environment and the altering scheme of health examination.

• Journal of Korean Neurosurgical Society
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• v.62 no.6
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• pp.661-670
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• 2019

Objective : Rheumatoid arthritis (RA) is known to involve the cervical spine up to 86%. It often causes cervical instability like atlantoaxial subluxation (AAS), subaxial subluxation, and vertical subluxation (VS). In order to find the relation between RA and cord compression, we will evaluate the characteristics and risk factors of basilar invagination (BI) and cervicomedullary junction (CMJ) compression. Methods : From January 2007 to May 2015, 12667 patients administrated to Hanyang University Medical Center. Four thousand three hundred eighty-six patients took cervical X-ray and 250 patients took cervical computed tomography or magnetic resonance imaging. Radiologic parameters, medication records were obtained from 242 patients. Multivariate logistic regression analysis was performed with correlation of CMJ compression, basin-dental interval (BDI), basin-posterior axial line interval (BAI), pannus formation, BI, and AAS. Results : In the point of CMJ compression, atlantodental interval (ADI), posterior-atlantodental interval, BAI, AAS, and BI are relatively highly correlated. Patients with BI have 82 times strong possibility of radiologic confirmed CMJ compression, while AAS has 6-fold and pannus formation has the 3-fold possibility. Compared to the low incidence of BI, AAS and pannus formation have more proportion in CMJ compression. Furthermore, wrist joint erosion was correlated with VS and AAS. Conclusion : BI has a very strong possibility of CMJ compression, while AAS and pannus formation have a high proportion in CMJ compression. Hence bilateral wrist joint erosion can be used as an indicator for the timing of screening test for cervical involvement. We suggest the early recommendation of cervical spine examination for the diagnosis of cervical involvement in order to prevent morbidity and mortality.

• Imaging Science in Dentistry
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• v.54 no.1
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• pp.71-80
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• 2024

Purpose: This study aimed to evaluate age-stratified radiographic features in temporomandibular joint osteoarthritis using cone-beam computed tomography. Materials and Methods: In total, 210 joints from 183 patients(144 females, 39 males, ranging from 12 to 88 years old with a mean age of 44.75±19.97 years) diagnosed with temporomandibular joint osteoarthritis were stratified by age. Mandibular condyle position and bony changes (flattening, erosion, osteophytes, subchondral sclerosis, and subchondral pseudocysts in both the condyle and articular eminence, thickening of the glenoid fossa, joint space narrowing, and joint loose bodies) were evaluated through cone-beam computed tomography. After adjusting for sex, the association between age groups and radiographic findings was analyzed using both a multiple regression model and a multinomial logistic regression model(α=0.05). Results: The prevalence of joint space narrowing and protruded condyle position in the glenoid fossa significantly increased with age (P<0.05). The risks of bony changes, including osteophytes and subchondral pseudocysts in the condyle; flattening, erosion, osteophyte, and subchondral sclerosis in the articular eminence; joint loose bodies; and thickening of the glenoid fossa, also significantly rose with increasing age (P<0.05). The number of radiographic findings increased with age; in particular, the increase was more pronounced in the temporal bone than in the mandibular condyle (P<0.05). Conclusion: Increasing age was associated with a higher frequency and greater diversity of bony changes in the temporal bone, as well as a protruded condyle position in the glenoid fossa, resulting in noticeable joint space narrowing in temporomandibular joint osteoarthritis.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.4
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• pp.555-563
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• 2004

The pH of beverages is known to be low and have, therefore, been implicated in the increasing incidence of erosion. Erosion is believed to be the predominant cause of teeth wear in children and young adults, although there will always be a contribution from attrition and abrasion. The aim of the present study was to evaluate the effect of yogurt on the progression of erosive demineralization in human enamel using demineralization model in vitro. In 4 yogurts, available on the market, pH, buffering capacity and the concentrations of calcium, phosphate and fluoride were determined. The buffering effect was determined by titration with NaOH. 50 milliliters of each drink was then titrated with 1M sodium hydroxide, added in 0.5 milliliters increments, until the pH reached about 7. Human deciduous enamel(n=40) samples were divided into four groups and exposed to 80ml of the yogurt for 30,60, 90 and 120min. Enamel surface microhardness(VHN) was examined before and after each exposure. 1. The average PH of fermented milk was 3.77 and this pH value was acidic enough to cause tooth erosion. 2. All of the fermented milks were found to be erosive(p<0.05) 3. The teeth exposed to the fermented milk all showed erosion like lesions and microhardness measurements showed that enamel surface hardness decreased proportionately with increased time of immersion in all tooth specimen groups. 4. After immersion for 30 and 60 minutes, reduction rate of microhardness values was not significantly different between the groups(p>0.05). However, after 90 and 120 minutes, reduction rate of each group was significantly different(p<0.05).

• Journal of Dental Rehabilitation and Applied Science
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• v.39 no.4
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• pp.222-228
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• 2023

Attrition is the loss of tooth hard tissue due to contact between teeth, and in severe cases, dentin is exposed, accompanied by selective corrosion and excessive wear of teeth, which is called cupping. If these lesions are left untreated, the size of the lesion gradually increases, breaking the unsupported enamel, resulting in a decrease in aesthetics and chewing function. In this case report, patients with cupping and enamel fracture due to severe attrition were directly restored using a resin with soft properties containing organic fillers. In the follow-up observation six years later, most of the filling of the occlusal surface was eliminated, but the filling on the buccal surfaces remained relatively intact, and it was confirmed that this type of resin was suitable for the area where the occlusal force was relatively weak rather than the area where the occlusal force was greatly applied.

• Journal of dental hygiene science
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• v.5 no.4
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• pp.199-204
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• 2005

Background : Oral leukoplakia(OL) and lichen planus(LP) are common soft tissue lesions characterized by white plaque or striae with erosion. The clinical characteristics of these diseases are similar but the cause and clinical course of them are very different. I compared OL with LP by analysizing clinical and histopathological characteristics and follow up study. Patients and methods : The clinical analysis of 200 patients with OL and LP was performed by review of dental and medical charts. And H/E slides were examined under the light microscope. we examined H/E slides by the light microscope. The follow up study of patients was performed. Statistical analysis was done using the SPSS/PC WINDOWS (version 13.0). Results : The age distribution of OL was in the range of 13-75 years old being most prevalent in the 5th decade and there was a tendency of male prevalent. The age distribution of LP was in the range of 20-79 years old being most prevalent in the 4th decade and there was a tendency of female prevalent. The most common site of involvement was the buccal mucosa in both diseases. The most common clinical features of OL and LP were white plaque type and white lesion with striae, respectively. In case of LP, the most common clinical sign was tenderness to palpation. Fifteen cases of OL and eight cases of LP showed epithelial dysplasia. Twelve cases of OL recurred after surgery of oral squamous cell carcinoma and 2 cases of LP were transformed into oral squamous carcinoma. Conclusion : There was statistically significant difference in age, sex, clinical signs of patients, frequency of epithelial dysplasia between OL and LP. The Pearson coefficient correlation efficient was 0.51(p < 0.05). The knowledge of the difference between OL and LP can help understand these diseases.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.739-744
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• 2020

This study evaluates the erosive potential and effects of mixed alcohols by analyzing the pH, titratable acidity, and fluorescence loss degree (△F). Following alcohol groups were investigated: Soju, Calamansi+soju, Yakult+soju, Cola+soju, and Energy drink+soju. The ratio of soju:beverage in the alcohol mixtures was 7:3. Ed. Notes: The sentence lacks clarity. Please review if the edit correctly portrays the meaning. If not, please revise appropriately. Measurement of the pH and titratable acidity (the amount of 1M NaoH solution required to raise to pH 5.5 (TA5.5) and 7.0 (TA7.0)) of alcohols was achieved by stirring with pH meter. The erosive effect of the alcohol mixtures on bovine tooth (△F) after 1, 2, 4, and 6 hours exposure were analyzed by quantitative light-induced fluorescence (QLF-D). All the mixed alcohols in this study showed an acidic pH, lower than 4.5. The average pH of mixed alcohols was 3.17 ± 0.50 whereas the pH of Soju was 8.6 ± 0.01. The TA5.5 and TA7.0 values of the mixed alcohols were 0.5~18 and 0.5~23.5, respectively. △F of the three tested mixed alcohol groups (except yakult+soju group) were observed to increase in a time-dependent manner. The calamansi mixed alcohol had the highest acidity potential and erosive effect among the tested groups. Taken together, the results indicate that the mixed alcohols have a strong erosive effect and potential on dental enamel.

• Journal of Dental Rehabilitation and Applied Science
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• v.26 no.4
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• pp.455-462
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• 2010

Patients often seek rehabilitative treatment for severely worn dentition. The etiology of noncarious tooth wear due to attrition, abrasion, and erosion is multifactorial. To treat the worn dentition, it is important to identify and eliminate and/or control the factors that contribute to excessive wear. Many situations requiring complete mouth rehabilitation present with the challenge of a lack of restorative space. To establish a correct occlusal plane and space for prostheses, it is necessary to increase vertical dimension. This may require an increase in occlusal vertical dimension. Also clinicians should be able to choose the appropriate restorative materials to achieve excellence in natural esthetics as well as proper biomechanics and durability. This article presents a method for altering occlusal vertical dimension to restore dentitions with limited restorative space due to loss of tooth structure.

• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.4
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• pp.719-726
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• 1997

The aim of this study was to evaluate the in vitro effects of exposure to acidic beverages on microhardness of enamel and dentin. Thirty enamel specimens and thirty dentin specimens were obtained from extracted bovine maxillay incisiors. Enamel and dentin specimens were divided into three groups and treated with acidic beverages as follows; Group 1 : cola(pH 2.52), Group 2 : plain soda water(pH 2.93) and Group 3 : orange juice(pH 3.75). Erosive treatment was performed by storing each specimens for 5 min in 50ml solution of cola, soda water and orange juice. Average microhardness values(VHN) were determined before and after erosive treatment. All beverages produced significant loss of microhardness of enamel and dentin. Microhardness of enamel was reduced in the following order: Group 1 : $42.71{\pm}4.36(%)$, Group 2 : $37.09{\pm}6.25(%)$, Group 3 : $35.46{\pm}4.98(%)$. Microhardness of dentin was reduced in the following order: Group 1 : $17.14{\pm}3.42(%)$, Group 2 : $13.89{\pm}3.18(%)$, Group 3 : $13.82{\pm}3.50(%)$. The differences between group 1 and group 2, 3 were statistically significant(p< 0.05).

• Journal of Oral Medicine and Pain
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• v.48 no.3
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• pp.118-122
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• 2023

In this study, we investigate the emergence of bullous pemphigoid (BP) after the administration of the Severe Acute Respiratory Syndrome-Coronavirus Disease 2019 (SARSCOVID-19) vaccine. The study presents two cases of women, aged 47 and 53, diagnosed with BP following SARS-COVID-19 vaccination. BP is a common autoimmune blistering disorder prevalent among older populations, with an incidence rate ranging from 2 to 40 cases per million individuals. This condition arises when autoantibodies target adhesive proteins in the skin, resulting in blister formation and mucosal erosion. Drug-induced bullous pemphigoid (DIBP) shares similarities with the classic form of BP but may be influenced by medication usage. Notably, DIBP exhibits distinct characteristics, such as affecting a younger demographic and involving mucosal regions more prominently than classic BP. The growing incidence of BP is linked to factors such as an aging population and the rise of drug-induced cases. This case report provides valuable insights into comprehending DIBP, elucidating post-vaccination discomforts, particularly those related to oral lesions and the exacerbation of existing lesions. By elucidating these aspects, we aim to advance the understanding of DIBP within the medical community.