Sex Determination Using a Discriminant Analysis of Maxillary Sinuses and Three-Dimensional Technology / 치위생과학회지

Background@#Sexual dimorphism is important for sex determination in the field of forensics. However, sexual dimorphism is commonly assessed using cone beam computed tomography (CBCT) rather than three-dimensional (3D) modeling software; therefore, studies using a more accurate measurement approach are necessary. This study assessed the sexual dimorphism of the MS using a 3D modeling program to obtain information that could contribute to the fields of surgery and forensics. @*Methods@#The CBCT data of 60 patients (age, 20∼29 y; 30 males and 30 females) admitted to the Department of Orthodontics at the Dankook University School of Dentistry were provided in Digital Imaging and Communications in Medicine (DICOM) format.The left MS and right MS were modeled based on the DICOM files using the Mimics (version 22; Materialise, Leuven, Belgium) 3D program and converted to stereolithography (STL) files used to measure the width, length, and height of the MS, infraorbital foramen (IOF), right MS, and left MS. The average of three repeated measurements was calculated, and a reliability test was performed to ensure data reliability (Cronbach’s α =0.618). A canonical discriminant analysis was performed using a standard approach (left: Box’s M=0.096; right: Box’s M=0.115). @*Results@#Males had greater values for all parameters (MS width, MS length, MS height, IOF, right MS, left MS) than females. The discriminant analysis identified six independent variables (MS width, MS height, MS length, IOF, right MS, left MS) that could identify sex. The left MS and right MS correctly identified the sex of 81.7% and 71.7% of the patients, respectively, with the left MS having higher accuracy. @*Conclusion@#This study confirmed that, for Korean individuals, the left MS has a better ability to identify sex than the right MS. These results may contribute to sex identification in the fields of surgery and forensics.

Possibility of a Standardized System for Task-Related Hierarchal Positions of Dental Hygienists / 치위생과학회지

Background@#Despite the demand for greater competence of dental hygienists in recent times, and the consequent standardization of systems in the organizations, there is a lack of a proper system for hierarchal positions of dental hygienists.The aim of this study was to identify the tasks performed by Korean dental hygienists in various work settings and hierarchal positions to suggest a standardized system for task-related hierarchal positions. @*Methods@#A survey was conducted by sending questionnaires to 966 dental hygienists, and responses from 757 participants were included in the final analysis. The survey comprised questions regarding participants’ general characteristics, tasks, current positions, and the internal policies or standards of the respective organizations to define these positions. The participants’ positions were analyzed as frequency and cross-sectional analysis with respect to their general characteristics, their place in the organizational charts, the size of their workplaces, and differences in the tasks performed. @*Results@#Data showed that 82.6% of the hospitals and clinics in Korea have organizational systems to determine the positions, and there was a significant difference in the systems according to the size of the health facility (p＜0.05). The standards or policies used to define positions within general or university hospitals were determined by internal regulations or bylaws, whereas work experience was the major determinant of positions in smaller dental hospitals or clinics. The main tasks performed by dental hygienists in Korea were dental assistance (81.2%), routine dental hygiene tasks (53.4%), and administrative tasks, such as reception and billing (46.1%). @*Conclusion@#Most dental hygienists in Korea are actively involved in dental assistance. Therefore, their specific tasks and responsibilities should be standardized more effectively. The data obtained from this study can be used to establish a standardized position system.

Antibacterial Effect of Tea Tree Ingredient for Denture Cleaners / 치위생과학회지

The purpose of this study was to evaluate the antibacterial effect of tea tree oil in denture cleaners. A self-curing denture resin was used to make the experimental specimen (12 mm×2 mm). A saline solution was used as the control. To observe surface changes after cleaning, the microhardness and color of the experimental specimen's surface were analyzed. For the antibacterial activity test, Candida albicans was used. The microhardness and color of the surface remained unchanged after cleaning. The result of the antibacterial activity test revealed that the tea tree oil-containing solutions had a more enhanced antibacterial effect than did the saline solution. Therefore, these results suggest that the tea tree oil-containing solution is a promising denture cleaners.

The Dental Hygienists' Perception of the National Practical Examination / 치위생과학회지

The purpose of the present study was to examine dental hygienists' perception of the current national practical examination. This research was performed using 199 self-reported surveys answered by professors of dental hygiene studies and clinical dental hygienist. Frequency analysis, chi-square tests, and analysis of variance were performed by using IBM SPSS Statistics ver. 20.0. The results revealed that many of the respondents consider the current national practical examination to be neutral. They did not think that the current national practical examination questions are useful for assessing occupation-centric integrated clinical practice ability and counseling techniques for patient intervention. The professors of dental hygiene studies believed that among the research tasks required as mentioned in the national practical examination questions, dental polishing and tooth brushing education are of paramount importance, whereas clinical dental hygienists believed that ultrasonic scaling is the most important (p<0.05). Most of the professors of dental hygiene studies reported that they conducted skills education for dental polishing and tooth brushing education, while most of the clinical dental hygienists reported that tasks actually performed in the clinic included impression taking, model fabrication, ultrasonic scaling, and explaining treatment precautions (p<0.05). Therefore, these tasks can be effectively carried out with the improvement of the national dental hygienist practical examination.

Color Stability of Self-Cured Temporary Crown Resin according to Different Surface Treatments / 치위생과학회지

In this study, the surface treatment of a self-cured temporary crown was polished using a denture bur, silicone bur, or pumice. The color stability of the temporary crown resin specimen was evaluated by immersing it in coffee, and cola, wine, beer, red pepper paste, or soybean paste. Two-hundred eighty-five identical resin specimens with six types of staining solution and three types of surface treatment were placed in a shaking incubator at 37℃. The degree of discoloration was observed using a time-lapse recording of days 1, 5, and 7. L*, a*, and b* were measured using a spectrophotometer, which shows the quantitative value of discoloration, and statistically processed after calculating ΔE*. The results show that as time passed, all the specimens showed a color change (p<0.001). The amount of color change was the greatest in in crowns with denture bur polishing on the day 1, 5, and 7. As the precipitation time increased, the ΔE* value was also increased. Of the specimens immersed on day 1, the greatest color change in crowns polished with denture bur was observed in those immersed in red pepper paste, while the smallest color change was observed in those immersed in cola. On days 5 and 7, the greatest color change in crowns polished with denture bur was observed in those immersed in red wine. Crowns polished with silicone bur and immersed in soybean paste exhibited the smallest color change. Based on the results, compared to pumice polishing, silicone bur polishing results in better color stability, saves time and money, and is recommended for patients with temporary crowns.

A Biocompatibility Evaluation of Hydroxyapaite·Titania Surface for Dental Implant / 치위생과학회지

The objective of this study was to fabricate hydroxyapatite (HA) containing titania layer by HA blasting and anodization method to obtain advantages of both methods and evaluated biocompatibility. To fabricate the HA containing titania layer on titanium, HA blasting treatment was performed followed by microarc oxidation (MAO) using the electrolyte solution of 0.04 M β-glycerol phosphate disodium salt n-hydrate and 0.4 M calcium acetate n-hydrate on the condition of various applied voltages (100, 150, 200, 250 V) for 3 minutes. The experimental group was divided according to the surface treatment procedure: SM (simple machined polishing treatment), HA, MAO, HA+MAO 100, HA+MAO 150, HA+MAO 200, HA+ MAO 250. The wettability of surface was observed by contact angle measurement. Biocompatibility was evaluated by cell adhesion, and cell differentiation including alkaline phosphatase activity and calcium concentration with MC3T3-E1 cells. The porous titanium oxide containing HA was formed at 150 and 200 V. These surfaces had a more hydrophilic characteristic. Biocompatibility was demonstrated that HA·titania composite layer on titanium showed enhanced cell adhesion, and cell differentiation. Therefore, these results suggested that HA containing titania layer on titanium was improved biological properties that could be applied as material for dental implant system.

Knowledge and Ability Toward CPR in Metropolitan Dental Hygienists

PURPOSE: The purpose of this study was to evaluate Cardiopulmonary Resuscitation ability and level of knowledge among certain dental hygienists in Seoul and Gyeonggi-do. METHODS: We surveyed ability and knowledge of CPR among dental hygienists working at dental offices and dental hospitals located in Soul and Gyeonggi-do from September 18, 2010 to October 16, 2010. Data acquired from dental hygienists who had completed the questionnaire that we designed were used in the analysis. Uni- and bi-variate analysis and Chi-square test were performed using SAS 9.2. RESULTS: According to our findings, among respondents, approximately 14.29% of dental hygienists had a CPR license. Their CPR licenses are affected by working period, job position, and level of education (p<.05). Factors including working period, type of CPR license, and CPR license renewal were indicators of CPR knowledge level (p<.05). Significant differences were observed among dental hygienists with regard to subjective CPR abilities, which is dependent on obtaining a CPR license, CPR knowledge level, and education channel for CPR (p<.05). CONCLUSION: CPR ability and knowledge level among dental hygienists were not sufficient to save emergency people in the dental clinic. In order to save emergency patients patients, implementation of a CPR education and renewal program for dental hygienists is recommended.

Effects of Rating Training on Inter-Rater Consistency for Developing a Dental Hygiene Clinical Rater Qualification System / 보건의료교육평가

We tried to develop itemized evaluation criteria and a clinical rater qualification system through rating training of inter-rater consistency for experienced clinical dental hygienists and dental hygiene clinical educators. A total of 15 clinical dental hygienists with 1-year careers participated as clinical examination candidates, while 5 dental hygienists with 3-year educations and clinical careers or longer participated as clinical raters. They all took the clinical examination as examinees. The results were compared, and the consistency of competence was measured. The comparison of clinical competence between candidates and clinical raters showed that the candidate group's mean clinical competence ranged from 2.96 to 3.55 on a 5-point system in a total of 3 instruments (Probe, Explorer, Curet), while the clinical rater group's mean clinical competence ranged from 4.05 to 4.29. There was a higher inter-rater consistency after education of raters in the following 4 items: Probe, Explorer, Curet, and insertion on distal surface. The mean score distribution of clinical raters ranged from 75% to 100%, which was more uniform in the competence to detect an artificial calculus than that of candidates (25% to 100%). According to the above results, there was a necessity in the operating clinical rater qualification system for comprehensive dental hygiene clinicians. Furthermore, in order to execute the clinical rater qualification system, it will be necessary to keep conducting a series of studies on educational content, time, frequency, and educator level.