DESIGN: A digitally derived 3-dimensional maxillary model incorporating the palatal defect was generated from the patient's existing cone beam computerized tomography data and compared with the scanned cast from the conventional impression for linear dimensions, area, and volume. The digitally derived cast was 3-dimensionally printed and the obturator fabricated using traditional techniques. Similarly, an obturator was fabricated from the conventional cast and the fit of both final obturator bulbs were compared in vivo.
RESULTS: The digitally derived model produced more accurate volumes and surface areas within the defect. The defect margins and peripheries were overestimated which was reflected clinically.
CONCLUSION: The digitally derived model provided advantages in the fabrication of the palatal obturator; however, further clinical research is required to refine consistency.
PURPOSE: The purpose of this in vitro study was to evaluate the SR, tensile strength (TS), and percentage elongation (% E) of different SEs subjected to outdoor weathering in the Malaysian climate.
MATERIAL AND METHODS: Type-II dumbbell-shaped specimens (N-120) (nonweathered=15, weathered=15) were made from 3 room-temperature vulcanized (A-2000, A-2006, and A-103) and 1 heat-temperature vulcanized (M-511) silicone (Factor II). For 6 months, weathered specimens were subjected to outdoor weathering inside a custom exposure rack. Simultaneously, the nonweathered specimens were kept in a dehumidifier. Subsequently, the SR was measured with a profilometer; TS and % E were measured by using a universal testing machine. Two-way ANOVA was used to compare the means of the tested properties of the nonweathered and weathered specimens, and pairwise comparison was carried out between the silicones (α=.05).
RESULTS: After outdoor weathering, the SR, TS, and % E were adversely affected by weathering in the Malaysian environment. Among the silicone materials, A-2000 showed the least TS changes (2.51 MPa), while A-2006 demonstrated significant changes in percentage elongation after outdoor weathering (266.5%). M-511 exhibited the highest mean value (2.50 μm) for SR changes. In addition, A-103 SE showed statistically significant differences in most pairwise comparisons for all 3 dependent variables.
CONCLUSIONS: Based on the evaluation of mechanical properties, A-103 can be suggested as a suitable silicone for maxillofacial prostheses fabricated for tropical climates. However, A-2000 can be a suitable alternative, although significant changes to surface roughness were detected after outdoor weathering.
PURPOSE: The purpose of this simulation study was to establish a reference percentage value that can be used to effectively reduce the size and polygons of the 3D mesh without drastically affecting the dimensions of the prosthesis itself.
MATERIAL AND METHODS: Fifteen different maxillary palatal defects were simulated on a dental cast and scanned to create 3D casts. Digital bulbs were fabricated from the casts. Conventional bulbs for the defects were fabricated, scanned, and compared with the digital bulb to serve as a control. The polygon parameters of digital bulbs were then reduced by different percentages (75%, 50%, 25%, 10%, 5%, and 1% of the original mesh) which created a total of 105 meshes across 7 mesh groups. The reduced mesh files were compared individually with the original design in an open-source point cloud comparison software program. The parameters of comparison used in this study were Hausdorff distance (HD), Dice similarity coefficient (DSC), and volume.
RESULTS: The reduction in file size was directly proportional to the amount of mesh reduction. There were minute yet insignificant differences in volume (P>.05) across all mesh groups, with significant differences (P
Materials and Methods: At the first stage, all the selected variables will be a screen for their clinical important point of view, and it was found that creatinine has a significant relationship to the level of urea reading, a total of cholesterol reading, and the level of uric acid reading. By considering the level of significance, α = 0.05, these three variables are being selected and used for the input of the MLP model. Then, the MLR is being applied according to the best variable obtained through MLP process.
Results: Through the testing/out-sample mean squared error (MSE), the performance of MLP was assessed. MSE is an indication of the distance from the actual findings from our estimates. The smallest MSE of the MLP shows the best variable selection combination in the model.
Conclusion: In this research paper, we also provide the R syntax for MLP better illustration. The key factors associated with creatinine were urea, total cholesterol, and uric acid in patients with dyslipidemia and type 2 diabetes mellitus.
METHOD: Medical image data for five types of defects were selected, segmented, converted and decimated to 3D polygon models on a personal computer. The models were transferred to a computer aided design (CAD) software which aided in designing the prosthesis according to the virtual models. Two templates were designed for each defect, one by an OS (free) system and one by CS. The parameters for analyses were the virtual volume, Dice similarity coefficient (DSC) and Hausdorff's distance (HD) and were executed by the OS point cloud comparison tool.
RESULT: There was no significant difference (p > 0.05) between CS and OS when comparing the volume of the template outputs. While HD was within 0.05-4.33 mm, evaluation of the percentage similarity and spatial overlap following the DSC showed an average similarity of 67.7% between the two groups. The highest similarity was with orbito-facial prostheses (88.5%) and the lowest with facial plate prosthetics (28.7%).
CONCLUSION: Although CS and OS pipelines are capable of producing templates which are aesthetically and volumetrically similar, there are slight comparative discrepancies in the landmark position and spatial overlap. This is dependent on the software, associated commands and experienced decision-making. CAD-based templates can be planned on current personal computers following appropriate decimation.
OBJECTIVE: This study was intended to assess the knowledge and attitude towards OSA and compare it among dental and medical undergraduate students of University Sains Malaysia (USM).
METHODS: In this study, a total of 216 clinical undergraduate students (36 from each year; 108 from medical and 108 from dental school) of University Sains Malaysia (USM) Health campus were recruited for the study by non-probability stratified random sampling method. Total study period was October 2017 to October 2018. A self-administered questionnaire was used to assess the sociodemographic status and OSAKA questionnaire was used to assess knowledge and attitude regarding sleep apnoea of the respondents. Descriptive analysis was carried out to assess the knowledge and attitude of OSA amongst dental and medical undergraduate students of USM. The Mann-Whitney U test was carried out to compare the knowledge and attitude of OSA amongst dental and medical undergraduate students of USM.
RESULTS: Our study findings revealed that 0.9 %and 6.5 %of the dental undergraduate students and medical undergraduate students could answer all the questions correctly regarding knowledge of OSA. Based on the assessment of the difference between medical and dental students in terms of knowledge towards OSA patients, significant difference was observed at the significance level of 95%, where p
Results: A significant difference (p < 0.001) of mean debonding force was found between different types of teeth in vivo. Clinically, ARI scores were not significantly different (p = 0.921) between different groups, but overall higher scores were predominant.
Conclusion: Bracket debonding force should be measured on the same tooth from the same arch as the significant difference of mean debonding force exists between similar teeth of the upper and lower arches. The insignificant bracket failure pattern with higher ARI scores confirms less enamel damage irrespective of tooth types.
OBJECTIVE: The present study aims to assess knowledge and awareness regarding needle stick and sharp injury among dental personnel and compared the knowledge and awareness level about needle stick injuries between dental professionals and dental supporting staff working at the School of Dental Sciences, Universiti Sains Malaysia.
METHODS: This cross-sectional study was conducted from March 2016 to March 2017. The total sample included 112 registered dental personnel including dental professionals (lecturers, dental officers, and postgraduate students) and dental supportive staff (including staff nurses and dental surgery assistant) who were selected from the School of Dental Sciences, Universiti Sains Malaysia at Kelantan District of Malaysia. Data were collected by a structured questionnaire.
RESULTS: In our study 60.7% respondents answered correctly for all the statements regarding knowledge and 51.8% of the respondents answered correctly for the statements regarding awareness on needle stick and sharp injury. No significant difference of knowledge level has been observed between the dental professionals and dental supportive staff (p
Method: Scopus, PubMed, and Web of Science (all databases) were searched by 2 reviewers until 29th October 2020. Articles were screened and narratively synthesized according to PRISMA-DTA guidelines based on predefined eligibility criteria. Articles that made direct reference test comparisons to human clinicians were evaluated using the MI-CLAIM checklist. The risk of bias was assessed by JBI-DTA critical appraisal, and certainty of the evidence was evaluated using the GRADE approach. Information regarding the quantification method of dental pain and disease, the conditional characteristics of both training and test data cohort in the machine learning, diagnostic outcomes, and diagnostic test comparisons with clinicians, where applicable, were extracted.
Results: 34 eligible articles were found for data synthesis, of which 8 articles made direct reference comparisons to human clinicians. 7 papers scored over 13 (out of the evaluated 15 points) in the MI-CLAIM approach with all papers scoring 5+ (out of 7) in JBI-DTA appraisals. GRADE approach revealed serious risks of bias and inconsistencies with most studies containing more positive cases than their true prevalence in order to facilitate machine learning. Patient-perceived symptoms and clinical history were generally found to be less reliable than radiographs or histology for training accurate machine learning models. A low agreement level between clinicians training the models was suggested to have a negative impact on the prediction accuracy. Reference comparisons found nonspecialized clinicians with less than 3 years of experience to be disadvantaged against trained models.
Conclusion: Machine learning in dental and orofacial healthcare has shown respectable results in diagnosing diseases with symptomatic pain and with improved future iterations and can be used as a diagnostic aid in the clinics. The current review did not internally analyze the machine learning models and their respective algorithms, nor consider the confounding variables and factors responsible for shaping the orofacial disorders responsible for eliciting pain.
CASE DESCRIPTION: The first case, a man in his twenties, received a stock conformer immediately after surgery and started prosthetic therapy within 2 months. The second case, a man in his forties, started prosthetic therapy after 10 years. Definitive custom ocular prostheses were fabricated and relined according to conventional protocol.
RESULTS: On issue of the prosthesis, there was adequate retention, aesthetics and stability to extra-ocular movements and treatment was considered successful for both cases. However, follow-ups showed noticeable prosthetic eye movements for case 1 which, to some extent mimicked the physiologic movement of its fellow natural eye. Case 1 adjusted to his prosthesis better while case 2 was still adjusting with little to no physiologic movement.
CONCLUSION: Prosthetic rehabilitation should be started as early as possible to obtain optimum rehabilitative results.
Results: The mean age of patients in group 1 was 6.8 ± 2.1 years, group 2: 8.15 ± 2.27 years, group 3: 7.5 ± 2.3 years, and group 4: 7.27 ± 1.68 years. The intragroup comparisons of heart rate and facial image scores have shown a significant difference in before and after dental treatment procedures. Marked reduction in heart rate and facial image scale scores were found in patients belonging to group 1 (mobile applications) and group 2 (dental video songs). An increase in heart rate and facial image scale scores was seen in group 3 (tell-show-do) and the control group.
Conclusion: The paediatric dental anxiety is a common finding in dental clinics. Behavior modification techniques like smartphone applications, "little lovely dentist," and "dental songs" can alleviate dental anxiety experienced by paediatric patients. The "tell-show-do" technique although most commonly used did not prove to be beneficial in the reduction of the anxiety levels.
Materials and Methods: The present systematic review was carried out according to PRISMA guidelines. The search was carried out on PubMed/MEDLINE, Cochrane collaboration, Science direct, and Scopus scientific engines using selected MeSH keywords. The articles fulfilling the predefined selection criteria based on the fit and accuracy of removable partial denture (RPD) frameworks constructed from digital workflow (CAD/CAM; rapid prototyping) and conventional techniques were included.
Results: Nine full-text articles comprising 6 in vitro and 3 in vivo studies were included in this review. The digital RPDs were fabricated in all articles by CAD/CAM selective laser sintering and selective laser melting techniques. The articles that have used CAD/CAM and rapid prototyping technique demonstrated better fit and accuracy as compared to the RPDs fabricated through conventional techniques. The least gaps between the framework and cast (41.677 ± 15.546 μm) were found in RPDs constructed through digital CAD/CAM systems.
Conclusion: A better accuracy was achieved using CAD/CAM and rapid prototyping techniques. The RPD frameworks fabricated by CAD/CAM and rapid prototyping techniques had clinically acceptable fit, superior precision, and better accuracy than conventionally fabricated RPD frameworks.
MATERIALS AND METHODS: The overjet (measured clinically) and electromyographical activity (rest, chew, post chew rest, clench and post clench rest) of the masseter and temporalis muscle of class II malocclusion patient were assessed in 18 patients (3 males and 15 females) from the School of Dental Science, Hospital University Sains Malaysia.
RESULTS: The results were compared by simple linear regression test to evaluate the association between overjet and muscle activity in different genders. Class II malocclusion patients with increased overjet group showed significant association with masseter muscle activity on chewing stage (P = 0.005, F = 6.081 and adj-R2 = 0.473). Left temporalis muscle in class II malocclusion showed a significant linear association (P = 0.014, F = 0.812 and adj-R2= -0.034) with gender during clench.
CONCLUSION: In conclusion, class II malocclusion patient with increased overjet can affect masticatory muscle function and as well as clench force may differ in gender.
METHODS: Relevant articles written in English only, before January 15, 2017, were identified using an electronic search in the PubMed, Scopus, and Google Scholar databases. Furthermore, a manual search of the related major journals was also conducted to identify more pertinent articles. The relevancy of the articles was verified by screening the title, abstract, and full text if they met the inclusion criteria. A total of 37 articles satisfied the criteria, from which data were extracted for qualitative synthesis.
RESULTS: Among the 37 included articles, 14 were without aging, 15 were natural or artificial accelerated aging, 7 were outdoor weathering, and 1 contained both artificial aging and outdoor weathering. Only 4 studies out of the 14 without aging had significant observations; whereas 9 articles with natural or artificial aging published significant results, and 3 out of 7 outdoor weathering articles showed significant changes in the evaluated silicone elastomers.
CONCLUSIONS: Despite the varying research, it seems that the single "ideal" maxillofacial prosthetic material that can provide sufficient resistance against different aging conditions is yet to be identified. Therefore, it is imperative for standardization organizations, the scientific community, and academia to develop modified prosthetic silicones possessing improved physical properties and color stability, limiting the clinical problems regarding degradation of maxillofacial prostheses.
MATERIALS AND METHODS: A total of 370 orthodontic records including their pre-treatment orthopantomographs (OPG) and study models of orthodontic patients in permanent dentition who attended dental clinic were assessed for impaction, hypodontia, supernumerary, supraocclusion, infraocclusion, and any other anomalies excluding the third molars. The association of anomalies with gender status and racial status was analyzed using Pearson's Chi-square test. A P value of <0.05 is considered as significant. The confidence interval at 95% (CI) was set.
RESULTS: Among the 370 subjects, 105 (28.4%) presented with at least one anomaly. Eighty-five (23%) demonstrated a single anomaly and 20 (5.4%) with more than one anomaly. The most prevalent anomaly was impaction (14.32%), followed by hypodontia (7.03%). The less common anomalies were microdontia (1.08%), dilacerations (0.27%), and generalised enamel hypoplasia (0.27%). Maxillary right lateral incisors and canines were the most common affected teeth and these are located on the maxillary right quadrant. It was evident that dental anomalies were statistically dependant on race (P = 0.025), but independent of gender. The most common treatment planned for these patients was fixed appliance.
CONCLUSIONS: Impaction was predominant among 28.4% subjects observed with anomaly and most patients with anomaly are treated with fixed appliances (49%).
CLINICAL RELEVANCE: These anomalies play a great role in occlusion and alignment in treatment planning and relapse for orthodontic treatment.