• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.4
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• pp.337-349
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• 2008

Despite an improved bone reactions of Mg-incorporated implants in the animals, little yet has been carried out by the experimental investigations in functional loading conditions. This study investigated the clinical and histologic parameters of osseointegrated Mg-incorporated implants in delayed loading conditions. A total of 36 solid screw implants (diameter 3.75 mm, length 10mm) were placed in the mandibles of 6 beagle dogs. Test groups included 18 Mg-incorporated implants. Turned titanium Implants served as control. Gold crowns were inserted 3 months. Radiographic assessments and stabilitytests were performed at the time of fixture installation, $2^{nd}$ stage surgery, 1 and 3 months after loading. Histological observations and morphometrical measurements were also performed. Of 36 implants, 32 displayed no discernible mobility, corresponding to successful clinical function. There was no statistically significant difference between test implants and controls in marginal bone levels (p=0.413) and RFA values. The mean BIC % in the Mg-implants was $54.4{\pm}20.2%$. The mean BIC % in the turned implant was $48.9{\pm}8.0%$. These differences between the Mg-implant and control implant were not statistically significant (P=0.264). In the limitation of this study, bone-to-implant contact (BIC) and bone area of Mg-incorporated oxidized implant were similar to machine-turned implant. The stability analysis showed no significantly different ISQ values and marginal bone loss between two groups. Considering time-dependent bone responses of Mg-implant, it seems that Mg-implants enhanced bone responses in early loading conditions and osseointegrated similarly to cp Ti implants in delayed loading conditions. However, further investigations are necessary to obtain long-term bone response of the Mg-implant in human.

• The Korean Journal of Nuclear Medicine Technology
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• v.20 no.2
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• pp.14-20
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• 2016

Purpose Tongue cancer is 1.8% of all cancer tumors occur in the tongue, it is known that the high incidence enough to account for 75% of oral cancer conducted a PET / CT examination for early diagnosis, metastasis, staging, etc. and. Tongue when PET / CT scan of a cancer patient and a Torso taken to close mouth lesions if the condition was caused due to the overlapping or corresponding artifacts are not clearly observed. The purpose of this study is to evaluate the changes that occur during PET / CT scan with open mouth and its usefulness under. Materials and Methods From June 2015 to March 2016 complained of herein by May 21 had received a diagnosis of tongue cancer underwent PET / CT scan patients were treated with a target (16 males, 5 female). The first was taken to close mouth Torso state, it was taken to add 1 bed open mouth condition. Tumor (T), measuring the Normal Tongue (NT), Lymph Node (LN) standard intake coefficient by setting a region of interest in the (standardized uptake value, SUV) SUVmean, the average value was measured SUVmax, drawn to each region of interest 3 times and Background (Carotid artery) was out of the SUV. In Chapter 3 of the slice to the tumor clearly visible by setting the region of interest to measure the change Tumor size was calculated average value. Gross Image resolution assessment were analyzed statistically through were divided into 1-5 points by the Radiation 7 people in 2, more than five years worked in specialized nuclear medicine compare to proceed with the blind test nonparametric test (wilcoxon signed rank test). (SPSS ver.18) Results $SUV_{mean}$ T's were in close mouth $5.01{\pm}2.70$ with open mouth $5.48{\pm}2.88$ (P<0.05), $SUV_{max}$ were respectively $8.78{\pm}5.55$ and $9.70{\pm}5.99$ (P<0.05). $SUV_{mean}$ in the NT were respectively $0.43{\pm}0.30$ and $0.34{\pm}0.24$ (P=0.20), $SUV_{max}$ was $0.56{\pm}0.34$ and $0.45{\pm}0.25$ (P=0.204). LN $SUV_{mean}$ were respectively $1.62{\pm}1.43$ and $1.69{\pm}1.49$ (P=0.161), $SUV_{mean}$ was $2.09{\pm}1.88$ and $1.99{\pm}1.74$ (P=0.131). Tumor size change is close mouth $4.96{\pm}4.66cm^2$ $5.33{\pm}4.64cm^2$ with 7.45% increase was (P<0.05), gross image resolution evaluation is $2.87{\pm}0.73$, $3.77{\pm}0.68$ with open mouth examinations 30.5% increase was (P<0.05). Conclusion Tumor SUV on the changes that had an increase in open mouth during inspection, the normal tongue and lymph node, but there was no significant difference in the change slightly. It is also one open mouth PET / CT scan will provide improved image to all patients with tongue cancer, but it could be confirmed that similar overall through the blind test, or tumor size changes and showing a high resolution image. It can be the perfect alternative method for problems that occur when the close mouth Open mouth PET / CT scan, but is believed to be through the open mouth to observe the boundary of overlapping or tumor of the oral cavity other structures a little more clearly. Tongue cancer patients how to recommend that the shooting further open mouth PET / CT.

• Journal of dental hygiene science
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• v.11 no.3
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• pp.173-179
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• 2011

This study identified knowledge, attitudes and behavior for radiation safety managemen of career dental hygienists and new dental hygienists. Results obtained from this study are as follows. 1. Regarding the knowledge level of radiation safety management, average score was $8.25{\pm}2.47$ for career dental hygienists and $7.42{\pm}2.77$ for new dental hygienists from 15 scale test.(p<.001). In addition, knowledge level of radiation safety management by general characteristics showed statistically significant difference according to health status(p<0.01). 2. Regarding the attitude level of radiation safety management, average score was $4.35{\pm}0.55$ for career dental hygienists and $4.19{\pm}0.60$ for new dental hygienists from 5 scale test.(p<0.01). 3. Regarding the behavior level of radiation safety management, average score was $3.14{\pm}0.98$ for career dental hygienists and $3.33{\pm}0.99$ for new dental hygienists from 5 scale test.(p<0.05). In addition, the behavior level by general characteristics showed statistically significant difference according to attendance rate of radiation safety management training (p<0.01) and defences of clinic (p<.001). 4. Based on the survey of relationship among knowledge, attitude and behavior of radiation safety management, we found that the higher the knowledge level of radiation safety management was, the higher the level of attitude was(p<.001).

• Journal of dental hygiene science
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• v.8 no.2
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• pp.73-80
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• 2008

The purpose of this study was to examine the health promotion behavior of dental hygiene students in boosting a university student health. The subjects in this study were 687 dental hygiene students in four different colleges in Gyeonggi province. A survey was conducted in September and October 2007, and the collected data were analyzed with SPSS 12.0 program. The findings of the study were as follows: 1. The he freshmen scored lowest in oral health care behavior($3.11{\pm}.57$), and the gap between them and the others was statistically significant (p < .001). 2. In regard to health promotion behavior, the students who found themselves not to be in good shape scored lower in terms of nutritional care($3.63{\pm}.63$), social support($2.43{\pm}.60$), responsibility for their own health($2.40{\pm}.68$) and esteem for their own lives($2.33{\pm}.51$). There were statistically significant differences between them and the others(p < .001, p < 0.01). 3. As to the relationship of the academic background of parents to health promotion behavior, the students whose fathers stopped at middle school($3.62{\pm}.52$) lagged behind most in terms of nutritional (p < .001), and those whose mothers stopped at middle school($2.52{\pm}.52$) were given the smallest social support. The gap between these groups and the others were statistically significant(p < .05). 4. The self-boarding students($3.66{\pm}.57$) fall behind most in the aspect of nutritional care, and there was a statistically significant gap between them and the others(p < .001). 5. The students whose monthly mean household income was one million won or less($2.42{\pm}.62$) valued their own lives least, and the gap between them and the others was statistically significant(p < .05). 6. As for correlation among the variables, stronger social support led to better reverence for life, and better esteem for life was concurrent with better stress management. There was a statistically significant relationship between those variables(p < .01).

• The korean journal of orthodontics
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• v.27 no.3 s.62
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• pp.421-430
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• 1997

Alveolar bone grows with development of tooth germs and roots; bone deposition occurs with tooth eruption. Bone components undergoes processes of resorption and deposition, and when the balance between them is disrupted, decrease in alveolar bone height or excessive bone deposition result. It has been hon that repositioning of teeth through orthodontic treatment can cause alveolar bone resorption which result in decreased alveolar bone height, and there have been many studies to evaluate such effects. X-ray films that could be replicated and standardized were chosen in clinical studies, and among them, bitewing films were used for objective evaluation of changes in alveolar bone level. Twenty subjects, 10 to 13-year- old (average 12.2) children with Cl I molar key, healthy oral condition, no congenital missing, no periodontal disease, and pre-and post-orthodontic bitewing films, were randomly selected for comparison of alveolar bone heights. Amounts of tooth and changes in alveolar bone heights were analyzed. The following results were obtained: 1. Amount of tooth movement in canine, premolar, and molar regions, changes in tooth axis, and changes in alveolar bone heights were measured, and the mean and median values were obtained. 2. When pre-and post-orthodontic alveolar bone levels were compared, larger changes were noticed in maxilla than mandible. 3. When mesio-distally compared, larger changes were observed in the distal sides of 3D3 and 4M3, mesial sides of 4M3 and 4D3, distal sides of 4D3 and 5M3, mesial sides of 5M3 and 5D3, md distal sides of 5D3 and 6M3. 4. When the amounts of tooth movements(TX, TY)and changes in tooth axis(A) were compared,34TX, 34TY, 34A of both sides in maxilla were greater, iud changes in alveolar bone level were greater than any other region.

• Journal of Oral Medicine and Pain
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• v.30 no.4
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• pp.411-426
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• 2005

The purpose of this study was to investigate the effects of occlusal condition and clenching level on the mandibular torque rotational movement. For this study, healthy 14 men without any symptoms and signs of temporomandibular disorders were selected. Mandibular torque rotational movement was observed in each circumstance of combination of three occlusal conditions such as natural dentition, with wafer of 3.6 mm thickness, and wafer with resin stop of 14 mm thickness total during hard biting of bite stick at maximum voluntary contraction(MVC) and 50% of MVC level of surface EMG activity of masseter muscle. Electromyographic activity and mandibular torque rotational movement were observed using BioEMG and BioEGN in $BioPak^{(R)}$ system. Each biting movement in each circumstance was composed of clenching one time and hard biting of wooden stick two times. The observed items were opening distance, velocity and amount of torque rotational movement in mandibular movement, and the data were statistically processed with $SPSS^{(R)}$ windows (ver.10.0). The results of this study were as follows: 1. There were no differences in the mandibular movement distance between those value in both biting sides, and between those in both clenching forces, but the mandibular velocity showed a different results by clenching force. For the amount of torque rotational movement, there were no difference in the value of the frontal plane but some significant difference was in the value of the horizontal plane by biting side. 2. The mandibular movement distance and the mandibular velocity in both planes were higher by maximum voluntary contraction than those by half maximum voluntary contraction, and amount of torque rotational movement in the horizontal plane was also increased by maximum voluntary contraction. 3. The opening distance in both planes were decreased with the increase of vertical dimension of occlusion, namely, by the occlusal appliances, and this pattern was also showed in the mandibular velocity in case of hard biting by maximum voluntary contraction. However, the amount of torque rotational movement were not different by the increase of vertical dimension of occlusion. 4. The value of angle and distance of the torque rotational movement in the hard biting of wooden stick were generally higher than those in the clenching without wooden stick in both planes without regard to occlusal conditions and/or clenching forces.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.3
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• pp.499-506
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• 1999

The odontoma is relatively a common benign odontogenic tumor and caused by overgrowth of odontogenic tissues. The recent classification by World Health Organization divides odontoma into 2 groups such as compound odontoma and complex odontoma. Compound odontoma comprises dental tissues, resembling the morphology of a tooth and has predilection for the anterior maxilla. In contrast, complex odontoma has unorganized mass, not resembling the normal tooth and has predilection for the posterior mandible. The etiology of odontoma is unknown and almost asymptomatic. So, it usually is found in routine radiographic examination, and most common presenting symptom is impacted or unerupted permanent teeth and retained primary teeth. It can occurs almost anywhere in jaws. It is desirable that odontoma should be removed by surgical enucleation including follicle and surrounding soft tissues. Considering the age and behavioral cooperation of patient, the development of permanent dentition, the location of odontoma in jaw, the need for the concomitant operative dentistry, operation is performed in outpatient department with/without sedation or under general anesthesia with endotracheal intubation. In this case report, 2 patients with compound odontoma were treated by surgical enucleation including follicle and surrounding soft tissues. One patient, about 5 years old, was treated under general anesthesia and concomitant operative dentistry was performed. The other patient, about 11 years old, was treated under local anesthesia in outpatient department. In 2 cases, after 4 months, surgical defects were filled with new bone and normalization of eruption path of impacted permanent teeth was observed.

• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.3
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• pp.242-248
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• 2012

Children usually have varying degree of caries in primary anterior teeth, and treatment planning for each case prescribed by each dentist can also be varied. This survey was conducted to compare the preferred treatment method and restorative materials between general dentists and pediatric dentists in regard to the treatment of primary incisors. The questionnaires, composed of 18 questions were sent to 45 general dentists and 50 pediatric dentists. Among which 30 and 31 questionnaires were retrieved respectively. The collected data were analyzed by rate and the results were as follows: 1. For the teeth with initial caries without cavitation, general dentists showed the tendency to prefer restorative treatment(30%) or observation without any treatment(42%), whereas pediatric dentists prefer preventive treatment(76%). 2. The primary factor in choosing restorative materials by both groups was its manipulativeness. 3. For anterior esthetic restoration, general dentists seldom use the full-coverage restoration(13%) but resin restoration(75%), whereas pediatric dentists frequently used full-coverage crow(64%). 4. In the treatment of dentinal caries, pediatric dentist did not perform the treatment lesser than 2.0 years before the exfoliation (compared to 1.2 years of general dentist). 5. In the treatment of 1 year children, both pediatric and general dentists tend to select preventive procedure as first choice of treatment(84%, 52%). When treating primary incisor caries, it is shown that pediatric dentists are more interested in restorative/preventive treatment than general dentists are.

• The korean journal of orthodontics
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• v.30 no.2 s.79
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• pp.175-183
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• 2000

The purpose of this study was to identify the compensatory adaptation of dentoalveolar structure according to the various skeletal relation through the statistical correlation between the anteroposterior, vertical skeletal and dentoalveolar relation. For this study, the sample were consisted of 101 adult subjects (51male and 50 female, mean age; male 23.6 years, female 21.5 years) who had good occlusion with the range of normal overjet and overbite and acceptable Angle's class I molar relationship which had not been related orthodontically The results were as follows : 1. Even though acceptable normal occlusion, the range of measurements which represent anteroposterior, vertical skeletal relation and dentoalveolar relation were very wide. 2. Upper and lower incisor axis were significantly correlated with anteroposterior skeletal relation, which means the mote lingual inclination of upper anterior teeth and the more labial inclination of lower anterior teeth according to the more anterior position of mandible to the maxilla (P<0.01). 3. Upper and 1ower anterior alveolar bone height was statistically correlated with the lower anterior vertical skeletal height. 4. Upper and 1ower alveolar bone height were not correlated with anteroposterior skeletal relation (P>0.05). 5. The correlation between the incisor axis and vertical skeletal was more closely related in upper anterior teeth than the lower anterior teeth. To summarize the above results, even though acceptable normal occlusion, skeletal and dentoalveolar relation was very widely ranged, and there were close relationship between the anteroposterior skeletal relation and the inclination of upper and lower anterior teeth and between the vertical skeletal relation and upper and lower anterior alveolar bone height. These finding can be concluded as compensatory adaptation to the different skeletal relationship.

• Journal of Nutrition and Health
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• v.51 no.4
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• pp.287-294
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• 2018

Purpose: This study was conducted to evaluate the association between serum 25-hydroxyvitamin D (25(OH)D) levels and dental caries experience in Korean adolescents based on the 2010 ~ 2014 Korean National Health and Nutrition Examination Surveys. Methods: The study subjects were 2,655 Korean adolescents aged 10 to 18 years. Subjects were classified into four groups according to their serum 25(OH)D levels. We used logistic regression to evaluate the relationship between vitamin D and for dental caries experience after adjusting for age, household income level, recipient of basic livelihood, tooth brushing and visiting dental clinics. Result: Multiple logistic regression analysis showed that serum 25(OH)D insufficiency (20 ng/mL ${\leq}25(OH)D$ < 30 ng/mL) was associated with increased odd ratios (ORs) for dental caries experience in boys (OR = 2.577, 95% CI = 1.013-6.557), compared with serum 25(OH)D sufficiency (25(OH)D ${\geq}30ng/mL$). Conclusion: The serum 25(OH)D levels were found to be related to risk of dental caries experience in Korean adolescent boys.