Development of Artificial Neural Network-Based Prediction Model for Evaluation of Maxillary Arch Growth in Children with Complete Unilateral Cleft Lip and Palate

INTRODUCTION

Cleft lip and palate (CLP) are the most common congenital craniofacial deformities that can cause a variety of dental abnormalities in children. The purpose of this study was to predict the maxillary arch growth and to develop a neural network logistic regression model for both UCLP and non-UCLP individuals.

METHODS

This study utilizes a novel method incorporating many approaches, such as the bootstrap method, a multi-layer feed-forward neural network, and ordinal logistic regression. A dataset was created based on the following factors: socio-demographic characteristics such as age and gender, as well as cleft type and category of malocclusion associated with the cleft. Training data were used to create a model, whereas testing data were used to validate it. The study is separated into two phases: phase one involves the use of a multilayer neural network and phase two involves the use of an ordinal logistic regression model to analyze the underlying association between cleft and the factors chosen.

RESULTS

The findings of the hybrid technique using ordinal logistic regression are discussed, where category acts as both a dependent variable and as the study's output. The ordinal logistic regression was used to classify the dependent variables into three categories. The suggested technique performs exceptionally well, as evidenced by a Predicted Mean Square Error (PMSE) of 2.03%.

CONCLUSION

The outcome of the study suggests that there is a strong association between gender, age, and cleft. The difference in width and length of the maxillary arch in UCLP is mainly related to the severity of the cleft and facial growth pattern.

Clinical outcomes of implant-supported and tooth-supported fixed prostheses fabricated from digital versus analogue impression: a systematic review and meta-analysis

OBJECTIVE

To analyze the clinical outcomes of implant-supported prostheses and tooth-supported fixed prostheses, fabricated from digital and conventional impression.

MATERIALS AND METHODS

The literature search was carried out on two electronic databases (PubMed and Cochrane Library). Randomized controlled trials (RCT) published from January 2011 to September 2022 were included. The bias risk was evaluated using Cochrane Risk of Bias Tool 2.0. Further screening was done for meta-analysis according to modified Newcastle-Ottawa scoring criteria. Forest plot was generated using a statistical method of inverse variance of random effect with 95% confidence interval.

RESULTS

A total of 8 randomized controlled trials were included for systematic review out of which four studies were based on tooth-supported fixed prosthesis and remaining four were based on implant-supported prosthesis. Further screening was conducted and three studies were eligible for meta-analysis. Tooth-supported fixed prosthesis fabricated from digital impression showed no significant difference in the marginal fit in any region measured, except for occlusal region where conventional impression showed more favorable marginal fit. Implant-supported prosthesis fabricated from digital impression showed survival rates ranging from 97.3 to 100% and there was no statistically significant difference in marginal bone loss (p = 0.14).

CONCLUSION

Implant-supported prostheses fabricated from digital and conventional impressions show no significant differences in their clinical outcomes. Tooth-supported fixed prostheses fabricated from digital impression have shown favorable findings in terms of marginal fit. Despite that, there is still lack of clinical trials with larger sample size and longer follow-up periods. Future studies that fulfill these two criteria are deemed necessary.

Prosthetic management of an ocular defect utilizing a novel threaded iris fabrication technique

The conservative prosthodontic construction of an ocular prosthesis utilizing our novel threaded iris fabrication technique required high time and prosthodontic resource inputs and produced a lifelike aesthetic result.

Abstract

Patients with ocular defects frequently present with significant local anatomical deficiencies and complex histories and require extensive time and resource inputs to treat. This case report describes the conservative management of an ocular defect completed in a postgraduate prosthodontics clinical residency program utilizing a novel threaded iris fabrication technique.

Effects of Riboflavin Collagen Crosslinker on Dentin Adhesive Bonding Efficiency: A Systematic Review and Meta-Analysis

The aim of this study was to evaluate published data regarding riboflavin (RF) as a cross-linker for improved adhesive bond strength to dentin and to analyze previous studies for optimal concentration of riboflavin range suitable for dentin bond. Saliva and distilled water were used as storage media and aging time was 24 h and 6 months. Results of meta-analysis were synthesized using a statistical method of inverse variance in random effects with a 95% Confidence Interval (CI). Cochrane review manager 5.4.1 was used to determine results of the meta-analysis. In total, 3172 articles were found from search databases "PubMed", "Scopus", and "Google Scholar". Six of the fifteen studies were eligible for meta-analysis. Micro tensile strength shows significant improvement with the addition of riboflavin (p < 0.05) compared to without the addition of riboflavin from with 95% CI. A significant difference has been found in micro tensile bond strength between use of the riboflavin cross-linker and without use of the riboflavin crosslinker in the dentin adhesive system. With a 95% confidence interval (CI), the I² for micro tensile strength was 89% with strong heterogeneity, Chi² = 44.76, df = 5 (p < 0.00001), and overall effect size is Z = 2.22 (p = 0.03) after immediate aging. Chiang et al. 2013 shows maximum mean differences which is 38.50 [17.93-59.07]. After 6 months of aging in distilled water or artificial saliva micro tensile bond strength has been increased with the addition of riboflavin (p < 0.05). It can be clearly seen that pooled effect and 95% CI did not cross the line of no effect. With a 95% confidence interval (CI), the I² for micro tensile strength was 96% with strong heterogeneity, Chi² = 117.56, df = 5 (p < 0.00001), and overall effect size is Z = 2.30 (p = 0.02). Subgroup analysis proved a similar effect of distilled water and artificial saliva as storage media on micro tensile bond strength after incorporating riboflavin as a collagen crosslinker. An artificial saliva aged forest plot also showed considerable heterogeneity with I² = 96%; Tau² = 257.32; Chi² = 94.37; df = 2 (p < 0.00001); test for overall effect, Z = 1.06 (p = 0.29). Riboflavin prior to or with bonding is recommended to improve the bonding of different adhesive systems.

Clinical Applications of Artificial Intelligence and Machine Learning in Children with Cleft Lip and Palate-A Systematic Review

OBJECTIVE

The objective of this systematic review was (a) to explore the current clinical applications of AI/ML (Artificial intelligence and Machine learning) techniques in diagnosis and treatment prediction in children with CLP (Cleft lip and palate), (b) to create a qualitative summary of results of the studies retrieved.

MATERIALS AND METHODS

An electronic search was carried out using databases such as PubMed, Scopus, and the Web of Science Core Collection. Two reviewers searched the databases separately and concurrently. The initial search was conducted on 6 July 2021. The publishing period was unrestricted; however, the search was limited to articles involving human participants and published in English. Combinations of Medical Subject Headings (MeSH) phrases and free text terms were used as search keywords in each database. The following data was taken from the methods and results sections of the selected papers: The amount of AI training datasets utilized to train the intelligent system, as well as their conditional properties; Unilateral CLP, Bilateral CLP, Unilateral Cleft lip and alveolus, Unilateral cleft lip, Hypernasality, Dental characteristics, and sagittal jaw relationship in children with CLP are among the problems studied.

RESULTS

Based on the predefined search strings with accompanying database keywords, a total of 44 articles were found in Scopus, PubMed, and Web of Science search results. After reading the full articles, 12 papers were included for systematic analysis.

CONCLUSIONS

Artificial intelligence provides an advanced technology that can be employed in AI-enabled computerized programming software for accurate landmark detection, rapid digital cephalometric analysis, clinical decision-making, and treatment prediction. In children with corrected unilateral cleft lip and palate, ML can help detect cephalometric predictors of future need for orthognathic surgery.

Color variations during digital imaging of facial prostheses subjected to unfiltered ambient light and image calibration techniques within dental clinics: An in vitro analysis

Background

The study aimed to evaluate 1) the amount of color variations presents within clinical images of maxillofacial prosthetic silicone specimens when photographed under different clinically relevant ambient lighting conditions, and 2) whether white balance calibration (WBC) methods were able to mitigate variations in ambient lighting.

Methods

432 measurements were acquired from standardized images of the pigmented prosthetic silicone specimens within different ambient lighting conditions (i.e., 2 windowed and 2 windowless clinics) at noon with no light modifying apparatus. The specimens were photographed once without any white balance calibration (raw), then independently alongside an 18% neutral gray card and Macbeth color chart for calibration in a post-processing (PPWBC) software, and once after camera calibration (CWBC) using a gray card. The LAB color values were extracted from the images and color variations (ΔE) were calculated after referring to the corresponding spectrophotometric values as control.

Results

Images in windowless and windowed clinics exhibited highly significant differences (p < 0.001) with spectrophotometer (control). CWBC demonstrated no significant differences (p > 0.05) in LAB values across windowed clinics. PPWBC using Macbeth color chart produced no significant differences for a* values (p > 0.05) across all clinics while PPWBC by gray card showed no significant differences (p > 0.05) in LAB values when only similar clinics (either windowed or windowless) were compared.

Conclusion

Significant color variations were present for maxillofacial prosthetic specimens owing to natural ambient light. CWBC and PPWBC using color charts were more suitable for color correction across windowed clinics while CWBC and PPWBC using gray cards had better outcomes across windowless setups.

Current and future trends in the teaching of removable partial dentures in dental schools in Malaysia: A cross sectional study

AIMS

To investigate, using a validated questionnaire, the teaching of removable partial dentures (RPDs) in dental schools of Malaysia.

MATERIALS AND METHODS

A validated questionnaire to investigating trends in the teaching of RPDs in dental schools in Oceania was emailed (in English version form) to Heads of Restorative/Prosthodontics/course coordinators in the 13 dental schools in Malaysia. Follow-up reminders were sent and participants were given six weeks to complete and return the questionnaire. Data was entered into an Excel spreadsheet and results compiled and analyzed.

RESULTS

Completed questionnaires were received from 13 dental school - a 100% response rate. All schools (n = 13) provided a preclinical technical course in RPD design. In most schools (n = 9, 69.2%), course work was supervised by senior lecturers while rest of the institutions made use of associate professor/professors. There were significant differences (p<0.05) between dental schools in terms of the contact hours dedicated to preclinical teaching. Students received an average of 62 h of instruction. Didactic instruction was the primary focus with practical (78 h) and didactic teaching (32 h). All dental schools (n = 13) provided practical surveyor design teaching (8 h). The staff student ratio for formal lectures (1:61), tutorials (1:29) and lab demonstrations (1:12) were recorded. Majority of the schools (n = 11, 84.6%) employed paired teaching in clinical sessions. All schools (n = 13, 100%) emphasized on increased teaching of RPD design and prescription writing in future clinical RPD courses.

CONCLUSION

Teaching of RPDs in Malaysia may be considered sufficient and comparable to the teaching in other parts of the world.

CLINICAL SIGNIFICANCE

Whilst the teaching of partial dentures at Dental Schools in Malaysia provides the core competencies involved in partial denture design and construction based on sound fundamental, scientific principles they should address the challenges of teaching partial dentures and other areas of dental education including improving working conditions for dental professionals.

A 3D cone beam computed tomography (CBCT) investigation of mandibular condyle morphometry: Gender determination, disparities, asymmetry assessment and relationship with mandibular size

Objective

CBCT (cone beam computed tomography) analysis of condyle morphometry, to investigate the gender differences, symmetry and relationship with mandibular size.

Materials and methods

This is a retrospective study. 800 CBCT scan obtained for the measurement of condyle in anterior-posterior and medio-lateral aspect using OnDemand 3D software. Participants were Saudi nationals of age above 18 years. 395 Males and 405 Females with the mean age of 38.2 ± 10.5 years. Right and left anterior-posterior width and medio-lateral width of the condyle were measured. Condyles were not isolated on the CBCT for volume measurement.

Results

Mean right and anterior-posterior condyle width was 9.02 mm and 8.74 mm in males whereas in females it was 9.01 mm 8.69 mm respectively. For males mean medio-lateral width of the condyle in right and left side was 17.40 mm and 16.95 mm. For females, mean medio-lateral width of the condyle in right and left side was 17.14 mm and 16.93 mm. The prediction rate of gender was 57.2% for males and 53.3% for females. Statistically significant differences (p < 0.05) were found in the anterior-posterior and medio-lateral width of right and left condyles among males and females. Left anterior-posterior and medio-lateral width of average vs small mandible shows statistically significant difference (p < 0.05).

Conclusion

Condyle morphometry is a weak predictor for gender. Irrespective of gender, right and left condyle are asymmetrical in relation to condyle morphometry of anterior-posterior and medio-lateral aspect. Left mandibular condyle morphometry is different in relation to the mandible size.

Digital workflow and virtual validation of a 3D-printed definitive hollow obturator for a large palatal defect

This clinical report describes how a hollow obturator prosthesis was designed and fabricated for an 82-year-old partially edentulous patient with a large palatal defect. Computer-aided design (CAD) was used to design, articulate, and align the mandibular denture with the obturator prosthesis. The prosthesis was printed, adjusted chairside, rescanned, and made hollow by using a CAD software program. The prosthesis was printed in resin with a dental 3D printer. Quantitative evaluations of clinical (prosthesis dimensions, rest, and occlusal vertical dimensions) and virtual (surface area, volume, weight, interpoint mismatches, spatial overlap) parameters found that the 3D-printed prosthesis required an additional 5% chairside modification. The greatest differences in volume (24.7% less) and weight (22.2% less) were observed when the modified obturator bulb was made hollow via CAD. Hollowing the bulb, therefore, reduced the spatial overlap in volume by 16.8%.

Pulpal and Periapical Status of the Vital Teeth Used as Abutment for Fixed Prosthesis-A Systematic Review and Meta-Analysis

PURPOSE

This is a systematic review to identify the incidence of pulp necrosis and/or periapical changes among vital teeth which are used as an abutment for crown and fixed partial dentures (FPDs).

MATERIALS AND METHODS

Two reviewers independently searched two electronic databases, PubMed and Scopus. The search was complemented from references of included studies and published reviews. Studies published in the English language through January 2021 that had assessed and documented the clinical and radiographic failure of crown or FPD in vital permanent teeth due to pulpal or periapical pathology with a follow-up of at least 12 months were selected. Data screening, data collection and extraction of data was performed. Quality of studies involved was analyzed using the Newcastle-Ottawa Quality Assessment Scale for cohort studies. Meta-analysis was done using random effects model. Publication bias was assessed using funnel plots.

RESULTS

Electronic searches provided 10,075 records among which 20 studies were selected for systematic review and 7 studies were selected for meta-analysis. With respect to quality assessment, all the studies involved were considered as high quality as the score in scale ranged between 6 and 9 as per the Newcastle-Ottawa Quality Assessment Scale for cohort studies. The meta-analyses showed that there was no statistically significant difference in the incidence of the loss of pulp vitality or pulp necrosis through clinical and radiographic examination with the follow up period of 5 years: p < 0.001, 95% CI: 0.96-1.00, I² = 77.84%; 10 years: p < 0.001, 95% CI: 0.88-0.95, I² = 93.59%; 15 years: p < 0.001, 95% CI: 0.92-0.96, I² = 94.83%; and 20 years: p < 0.001, 95% CI: 0.94-0.96, I² = 95.01%.

CONCLUSIONS

The meta-analysis revealed clinical and radiographic success rate ranging between 92% to 98% at different follow up periods ranging between 5 years and 20 years. Future high-quality randomized clinical controlled trials with a larger population are required to confirm the evidence as only observational studies were considered in this paper.

The loss of an eye due to occupational injury: Two case studies of ocular prosthetic rehabilitation

BACKGROUND

Two patients received ocular injuries from rusted metallic projectiles at their industrial workplaces. Said injuries resulted in the loss of their eyes by evisceration surgeries to prevent fatal infections.

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.

Comparison of knowledge level and attitude towards obstructive sleep apnoea amongst dental and medical undergraduate students of Universiti Sains Malaysia

BACKGROUND

Sleep apnoea is a diagnosed condition in which appurtenances interrupt breathing whilst sleeping. The consequence of obstructive sleep apnoea (OSA) includes road traffic accidents due to drowsiness, systemic hypertension, heart disease, diabetes mellitus and neurocognitive disorders. This condition extends the duration of recovery phase after traumatic brain injury.

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 < 0.05 but no difference found in attitude towards OSA. However, significant difference was found towards attitude on treating OSA patients p < 0.05.

CONCLUSIONS

A difference was observed in the knowledge and attitude on OSA between dental and medical undergraduate students in USM; however, medical undergraduate students had better knowledge and attitude towards OSA than dental students.

Knowledge and awareness regarding occupational needle stick and sharp injuries among dental personnel in Malaysia

BACKGROUND

Accidental occupational injuries increase the risk of communicable diseases like hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) among dental personnel. Such occupational injuries affect healthcare quality by enhancing dissatisfaction and lack of motivation to work among dental personnel.

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 < 0.819), whereas the awareness level was significantly different between these two groups (p < 0.016).

CONCLUSIONS

There is a difference regarding awareness level on needle stick and sharp injury between dental professionals and dental supportive staff in our study but no differences were found in knowledge level between two groups.

Development and virtual validation of a novel digital workflow to rehabilitate palatal defects by using smartphone-integrated stereophotogrammetry (SPINS)

Palatal defects are rehabilitated by fabricating maxillofacial prostheses called obturators. The treatment incorporates taking deviously unpredictable impressions to facsimile the palatal defects into plaster casts for obturator fabrication in the dental laboratory. The casts are then digitally stored using expensive hardware to prevent physical damage or data loss and, when required, future obturators are digitally designed, and 3D printed. Our objective was to construct and validate an economic in-house smartphone-integrated stereophotogrammetry (SPINS) 3D scanner and to evaluate its accuracy in designing prosthetics using open source/free (OS/F) digital pipeline. Palatal defect models were scanned using SPINS and its accuracy was compared against the standard laser scanner for virtual area and volumetric parameters. SPINS derived 3D models were then used to design obturators by using (OS/F) software. The resultant obturators were virtually compared against standard medical software designs. There were no significant differences in any of the virtual parameters when evaluating the accuracy of both SPINS, as well as OS/F derived obturators. However, limitations in the design process resulted in minimal dissimilarities. With further improvements, SPINS based prosthetic rehabilitation could create a viable, low cost method for rural and developing health services to embrace maxillofacial record keeping and digitised prosthetic rehabilitation.

Percentage of mesh reduction appropriate for designing digital obturator prostheses on personal computers

STATEMENT OF PROBLEM

Computer-aided design (CAD) of maxillofacial prostheses is a hardware-intensive process. The greater the mesh detail is, the more processing power is required from the computer. A reduction in mesh quality has been shown to reduce workload on computers, yet no reference value of reduction is present for intraoral prostheses that can be applied during the design.

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<.001) in HD. The differences were, however, only found with DB1. DSC showed a progressive dissimilarity until DB25 (0.17%), after which the increase was more prominent (0.46% to 4.02%).

CONCLUSIONS

A reduction of up to 75% polygons (25% of the original mesh) was effectively carried out on simulated casts without substantially affecting the amount of similarity in volume and geometry.

Paederus Dermatitis: A severe reaction to Charlie’s kiss

Paederus dermatitis is a very painful vesicular condition which is caused by the extremely potent toxin “Pederin” released from an insect calledPaederusfuscipes but commonly known as Charlie.A 26 years old woman presented with a sudden onset of neuralgia, arthralgia of left jaw, fever, nausea and fatigue with generalized pain radiating to the neck and lower jaw as well as itch-like sensation on their left arm associated with acute inflammation which began 24-48 hours prior. The patient refused to go to the hospital due to the current pandemic situation but instead updated us daily on her conditions with photographic changes of the arm until complete resolution of symptoms. This case report accounts for the daily sequential changes experienced by a patient after severe reaction to an exposure of pederin with photographs of the affected site. While the painful lesion and all systemic conditions resolved spontaneously over time, a scar was left to mark the unpleasant period. Bangladesh Journal of Medical Science Vol.20(2) 2021 p.459-462

Effect of tropical outdoor weathering on the surface roughness and mechanical properties of maxillofacial silicones

STATEMENT OF PROBLEM

The climate of tropical Southeast Asia includes high humidity and ultraviolet radiation that reduce the lifespan of silicone prostheses by inducing changes in their mechanical properties and color stability. Studies on the surface roughness (SR) and mechanical properties of different silicone elastomers (SEs) subjected to the natural tropical weather of Southeast Asia are lacking.

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.

Sagittal Jaw Relationship of Different Types of Cleft and Non-cleft Individuals

To investigate whether the craniofacial sagittal jaw relationship in patients with non-syndromic cleft differed from non-cleft (NC) individuals by artificial intelligence (A.I.)-driven lateral cephalometric (Late. Ceph.) analysis. The study group comprised 123 subjects with different types of clefts including 29 = BCLP (bilateral cleft lip and palate), 41 = UCLP (unilateral cleft lip and palate), 9 = UCLA (unilateral cleft lip and alveolus), 13 = UCL (unilateral cleft lip) and NC = 31. The mean age was 14.77 years. SNA, SNB, ANB angle and Wits appraisal was measured in lateral cephalogram using a new innovative A.I driven Webceph software. Two-way ANOVA and multiple-comparison statistics tests were applied to see the differences between gender and among different types of clefts vs. NC individuals. A significant decrease (p < 0.005) in SNA, ANB, Wits appraisal was observed in different types of clefts vs. NC individuals. SNB (p > 0.005) showed insignificant variables in relation to type of clefts. No significant difference was also found in terms of gender in relation to any type of clefts and NC group. The present study advocates a decrease in sagittal development (SNA, ANB and Wits appraisal) in different types of cleft compared to NC individuals.

Optimization of Prosthodontic Computer-Aided Designed Models: A Virtual Evaluation of Mesh Quality Reduction Using Open Source Software

PURPOSE

Mesh optimization reduces the texture quality of 3D models in order to reduce storage file size and computational load on a personal computer. This study aims to explore mesh optimization using open source (free) software in the context of prosthodontic application.

MATERIALS AND METHODS

An auricular prosthesis, a complete denture, and anterior and posterior crowns were constructed using conventional methods and laser scanned to create computerized 3D meshes. The meshes were optimized independently by four computer-aided design software (Meshmixer, Meshlab, Blender, and SculptGL) to 100%, 90%, 75%, 50%, and 25% levels of original file size. Upon optimization, the following parameters were virtually evaluated and compared; mesh vertices, file size, mesh surface area (SA), mesh volume (V), interpoint discrepancies (geometric similarity based on virtual point overlapping), and spatial similarity (volumetric similarity based on shape overlapping). The influence of software and optimization on surface area and volume of each prosthesis was evaluated independently using multiple linear regression.

RESULTS

There were clear observable differences in vertices, file size, surface area, and volume. The choice of software significantly influenced the overall virtual parameters of auricular prosthesis [SA: F(4,15) = 12.93, R² = 0.67, p < 0.001. V: F(4,15) = 9.33, R² = 0.64, p < 0.001] and complete denture [SA: F(4,15) = 10.81, R² = 0.67, p < 0.001. V: F(4,15) = 3.50, R² = 0.34, p = 0.030] across optimization levels. Interpoint discrepancies were however limited to <0.1mm and volumetric similarity was >97%.

CONCLUSION

Open-source mesh optimization of smaller dental prostheses in this study produced minimal loss of geometric and volumetric details. SculptGL models were most influenced by the amount of optimization performed.

Plagiarism in dentistry - a systematic review

Objective Following a survey of the literature, a systematic review was carried out with the aim of answering the following questions: 1) What is 'acceptable plagiarism'?; 2) Who carries out plagiarism?; 3) What factors could encourage plagiarism?; 4) How can plagiarism be managed?Data source and selection Following PRISMA guidelines, data were gathered by searching Scopus, PubMed and Web of Science. After removal of duplicates, 345 titles were identified. Then, having satisfied a priori eligibility criteria, 29 papers were interrogated. The quality of relevant papers (n = 23) was assessed using the Joanna Briggs Critical Appraisal Tool.Data extraction There was no clear threshold as to what is 'acceptable plagiarism'. Despite this lack of clarity, it is argued consistently that males, and those who wrote in a language that is not their mother tongue, were more likely to plagiarise.Conclusion Plagiarism is all but inescapable due to various reasons: 1) there is no agreed threshold as to what is 'acceptable plagiarism'; 2) the internet; 3) institutional; and 4) societal expectations. Plagiarism could be mitigated in the student domain by grammar support and, for example, non-written submissions such as presenting work by video. Academic fraud is fundamentally undermined by valuing original and creative scholarship and sound ethical principles.

Controversies in endodontic access cavity design: A literature review

The purpose of this article is to compare and contrast the different types of endodontic access cavity designs based on the current available evidence. Four types of access cavity designs, namely, traditional endodontic access cavity design (TEC), contracted/conservative endodontic access cavity design (CEC), ultra-conservative or ninja endodontic access cavity design (NEC) and truss endodontic access cavity design (TREC) have been suggested, and the latter three are currently in the limelight. Studies in vitro have been performed comparing the TECs, CECs, TRECs and NECs; except for the TECs, the other three types have not undergone clinical trials on patients. The choice of endodontic access cavity design affects fracture strength of the tooth, but remnants of pulpal tissue, due to ineffective instrumentation, can cause root canal treatment failure.

CPD/Clinical Relevance: Root canal treatment with new access cavity designs has been proposed. However, there is lack of evidence to support such practices. It is important to consider the potential deleterious effects of such access cavity designs rather than emphasizing the preservation of tooth structure alone.

Evaluation of the Differences Between Conventional and Digitally Developed Models Used for Prosthetic Rehabilitation in a Case of Untreated Palatal Cleft

OBJECTIVE

The virtual cone beam computed tomography-derived 3-dimensional model was compared with the scanned conventional model used in the fabrication of a palatal obturator for a patient with a large palatal defect.

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.

Assessment of Parents' Oral Health Literacy and Its Association with Caries Experience of Their Preschool Children

(1) Purpose: To assess the oral health literacy (OHL) of parents and its association with the caries experience of their preschool children attending the Hospital University Sains Malaysia (HUSM), Kota Bharu, Kelantan, Malaysia. (2) Materials and Methods: This is a descriptive cross-sectional study involving a systematic random sampling method, using a sample of 230 parent/preschool child dyads. Among 230 parents, 24 were males and 206 were females (mean age 31.43 ± 5.82); among 230 children, 92 were boys and 138 were girls (mean age 4.82 ± 1.04) attending the pedodontics clinic, HUSM, who participated and met the inclusion criteria. A structured, self-administered oral health literacy questionnaire including sociodemographic factors was used in this study. A child's oral examination was performed to check the dmft (decayed, missing, filled teeth) status. Statistical analysis was done using descriptive and Spearman's correlation analysis and multivariate regression analysis. (3) Results: The mean dmft score of children in relation to the OHL level of parents showed a significant difference (p < 0.00). The mean dmft score of children in relation to the OHL level of parents showed the following relationships: Inadequate (7.49 ± 4.10) followed by marginal (3.28 ± 2.67) and then adequate (0.55 ± 1.55). The incidence of caries amongst children in relation to parental employment was more associated with unemployed parents (6.11 ± 4.43) than with employed parents (2.79 ± 3.65). The caries experience amongst children in relation to education of their parents revealed a significant difference (p < 0.001), and the mean dmft score was high amongst preschool children with primary school qualified parents (10.7 ± 4.10) followed by high school (7.04 ± 3.68), vocational (5.81 ± 3.57), diploma (2.61 ± 2.81), and university (1.29 ± 2.27), respectively. The results revealed a valid significant difference (negative correlation, rs = -0.753 **) between the OHL of parents with the dmft score of their preschool children. The age and gender of parents was not significantly associated with OHL, whereas ethnicity (positive correlation, rs = 0.283 **), education (positive correlation, rs = 0.865 **), and employment (negative correlation, rs = -0.490 **) were found to be significant. Conclusion: We conclude that there is a significant association between the OHL of parents with the dmft score of their preschool children. The logistic regression showed that after adjustment for sociodemographic factors, parents' gender (OR = 0.067, 95% CI: 0.012-0.360), parents' employment status (OR = 3.247, 95% CI: 0.897-11.754), parents' OHL score (OR = 0.042, 95% CI: 0.016-0.114), and child age (OR = 2.195, 95% CI: 1.249-3.857) were significantly associated with dental caries in children. Our study concluded that parents' employment status, age, gender, OHL, and child's age were significantly associated with the caries experience of their preschool children.

The Influence of Filler Particles on the Mechanical Properties of Maxillofacial Prosthetic Silicone Elastomers: A Systematic Review and Meta-Analysis

Although numerous studies have demonstrated the benefits of incorporating filler particles into maxillofacial silicone elastomer (MFPSE), a review of the types, concentrations and effectiveness of the particles themselves was lacking. The purpose of this systematic review and meta-analysis was to review the effect of different types of filler particles on the mechanical properties of MFPSE. The properties in question were (1) tensile strength, (2) tear strength, (3) hardness, and (4) elongation at break. The findings of this study can assist operators, technicians and clinicians in making relevant decisions regarding which type of fillers to incorporate based on their needs. The systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A total of 26 original articles from 1970 to 2019 were selected from the databases, based on predefined eligibility criteria by two reviewers. The meta-analyses of nine papers were carried out by extracting data from the systematic review based on scoring criteria and processed using Cochrane Review Manager 5.3. Overall, there were significant differences favoring filler particles when incorporated into MFPSE. Nano fillers (69.23% of all studies) demonstrated superior comparative outcomes for tensile strength (P < 0.0001), tear strength (P < 0.00001), hardness (P < 0.00001) and elongation at break (P < 0.00001) when compared to micro fillers (30.76% of all studies). Micro fillers demonstrated inconsistent outcomes in mechanical properties, and meta-analysis of elongation at break argued against (P < 0.01) their use. Current findings suggest that 1.5% ZrSiO4, 3% SiO2, 1.5% Y2O3, 2-6% TiO2, 2-2.5% ZnO, 2-2.5% CeO2, 0.5% TiSiO4 and 1% Ag-Zn Zeolite can be used to reinforce MFPSE, and help the materials better withstand mechanical degradation.

A comparative assessment of prosthetic outcome on enucleation and evisceration in three different etiological eye defects: A case series

Enucleation and evisceration are the most common surgical procedures that are performed to manage tumor, trauma, and infection. Given the consequences of surgical intervention, the conditions of the remaining eye socket may affect future prosthetic rehabilitation. A custom-made ocular prosthesis can be used to help restore the esthetics and functional defects and to improve the quality of life of patients with such conditions. An assessment must be performed on the prosthetic outcome before rehabilitation. The etiology of defect, type of surgery, condition of the remaining socket, and patient's age should all be considered. This report discusses three different etiological eye defects that have undergone enucleation and evisceration and describes the factors that have a significant role in the esthetic and functional outcome of the prosthesis. This report should serve as a helpful aid for maxillofacial prosthodontists to understand the primary objective of rehabilitating each eye defect and to meet patient expectations.

Designing 3D prosthetic templates for maxillofacial defect rehabilitation: A comparative analysis of different virtual workflows

OBJECTIVE

To design and compare the outcome of commercial (CS) and open source (OS) software-based 3D prosthetic templates for rehabilitation of maxillofacial defects using a low powered personal computer setup.

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.

A systematic review of the computerized tools and digital techniques applied to fabricate nasal, auricular, orbital and ocular prostheses for facial defect rehabilitation

A systematic review was conducted in early 2019 to evaluate the articles published that dealt with digital workflow, CAD, rapid prototyping and digital image processing in the rehabilitation by maxillofacial prosthetics. The objective of the review was to primarily identify the recorded cases of orofacial rehabilitation made by maxillofacial prosthetics using computer assisted 3D printing. Secondary objectives were to analyze the methods of data acquisition recorded with challenges and limitations documented with various software in the workflow. Articles were searched from Scopus, PubMed and Google Scholar based on the predetermined eligibility criteria. Thirty-nine selected papers from 1992 to 2019 were then read and categorized according to type of prosthesis described in the papers. For nasal prostheses, Common Methods of data acquisition mentioned were computed tomography, photogrammetry and laser scanners. After image processing, computer aided design (CAD) was used to design and merge the prosthesis to the peripheral healthy tissue. Designing and printing the mold was more preferred. Moisture and muscle movement affected the overall fit especially for prostheses directly designed and printed. For auricular prostheses, laser scanning was most preferred. For unilateral defects, CAD was used to mirror the healthy tissue over to the defect side. Authors emphasized on the need of digital library for prostheses selection, especially for bilateral defects. Printing the mold and conventionally creating the prosthesis was most preferred due to issues of proper fit and color matching. Orbital prostheses follow a similar workflow as auricular prosthesis. 3D photogrammetry and laser scans were more preferred and directly printing the prosthesis was favored in various instance. However, ocular prostheses fabrication was recorded to be a challenge due to difficulties in appropriate volume reconstruction and inability to mirror healthy globe. Only successful cases of digitally designed and printed iris were noted.

Custom made ocular prosthesis for acquired eye defect:Adefinitive option of rehabilitation

Objective:This case report describes the rehabilitation process of a case of acquired eye defect with patient specific or custom made ocular prosthesis for a patient who had her left eye surgically enucleated as a treatment step for retinoblastoma. Method: After primary evaluations, an intraorbital impression was taken while reproducing natural eye movements to ensure accuracy of the impression. The impression was cast and a transparent acrylic conformer was made from the mould in the cast. The conformer was adjusted as required and Iris position determined. The conformer was then used to cast the final custom ocular prosthesis. The patient was then instructed on its usage and maintenance. Result: A custom made ocular prosthesis was provided to the patient and it was to her satisfaction. Conclusion: Custom made ocular prosthesis is highly recommended in rehabilitation of facial defects of a co-operative patient as it does not have most of the limitations which a stock ocular prosthesis does. Bangladesh Journal of Medical Science Vol.18(4) 2019 p.823-826

Measuring Health related Quality of life and its determinants among physically disabled adults in Bangladesh

The prime purpose of the study was to assess the quality of life of physically disabled adults attending at rehabilitation center in Dhaka city, Bangladesh and to determine the relationship of the type of disability, educational level and relationship with the family with quality of life.Participants were 500 adults with physical disabilities. Thestructured questionnaire consist of WHOQOL-BREF were used as research instruments. When dividing the participants into three groups according to the level of total QOL score, in physical domain majority (96.2%) had fair level QOL score. In psychological domain veryfew(5.4%) had poor level and more than half (53.2%) had fair level QOL score and rest of them had good QOL score (41.4%). more than one third (37.2%) and nearly half(47.0%) had fair and good level respectively whereas rest of them (15.8%) had poor level of QOL in Social domain. In environmental domain a minimum number(3.8%) had poor QOL score but almost half (43.6%) and more than half (52.6%) had fair and good level of QOL score. The Cronbach’s alpha coefficient of WHOQOL-BREF was adequate (0.914) for all 26 questions and for each domain the values are: Physical health domain (0.812), Psychological health domain (0.831), Social relationship domain (0.68) and Environmental health domain (0.78). Statistically significant correlations present between all domains. Mean and percentage of satisfaction rating in DOM1, DOM2 and DOM3 and DOM4 was higher in males than females. There were significant differences found in WHOQOL-BREF score between different education level group, different marital statusgroup,different employment statusgroup, differentincome level group, relationship with family, utilization of primary rehabilitation in four domains and total of WHOQOL-BREF (P < 0.05). multiple linear regression observed that education level and utilization of primary rehabilitation center is most important factor that affects QOL of study population in total and four domains of WHOQOL.The findings from this study confirm that the WHOQOL-BREF questionnaire is a reliable instrument to measure quality of life in disable adults. From the data, it appears that Bangladeshi disable adults have WHOQOL-BREF scores that might be considered to indicate a fair level of quality of life. Bangladesh Journal of Medical Science Vol.18(3) 2019 p.607-614

Prosthetic rehabilitation of a microtia patient by adhesive retained auricular prosthesis: A dental technique

Introduction: Auricular deformity can be emotionally traumatising and affects social behavior of an individual. In such cases, aesthetically acceptable prosthesis serves as a viable alternative technique to surgical reconstruction. Case description: Impression of the auricular defect was taken by light and regular body of poly vinyl siloxane impression material. Wax sculpting was challenging due to the bulgy remnant of the defected ear. The wax pattern was made very thin to accommodate and mask the remnant without compromising the aesthetic. Trial on the patientwas done for correction of the contours, angulation, height and width according to the normal contralateral ear. The intrinsic coloration of a Room Temperature Vulcanizing silicone was done and poured in a custom-made three-piece mold. Before the final issue of the auricular prosthesis, extrinsic coloration was done based on the surrounding area of the defect. Discussion: Fabrication of adhesive retained prosthesis is challenging in patients with large deformed soft tissue who refuse to undergo surgical repair. A modified wax sculpting was done to overcome this challenge. Medical grade silicone was the choice of material because of its flexibility, biocompatibility and life like appearance. Conclusion: Replacement of missing ear is a difficult and multi-step task in which extensive array of materials and techniques need to be employed. This fabrication technique is alternative to surgical repair with the utilization of available and economical materials. Bangladesh Journal of Medical Science Vol.18(2) 2019 p.437-439

Combination of skin flap and silicone prosthesis for rehabilitation of a large orbital defect: A case report

Exenteration surgery greatly affects a person in terms of function, esthetics, and psychological trauma. In such cases, restoration by silicone orbital prosthesis is a well-accepted treatment option. However, this is a difficult task, necessitating personalized design of method for each patient. This case report describes the technique for fabrication of a silicone orbital prosthesis for a male patient with left orbital defect due to exenteration of a Grade 3 squamous cell carcinoma of the left eye and surrounding tissues. The patient was delivered with a satisfactory silicone orbital prosthesis having good retention and finish. Multidisciplinary management and team approach are crucial in providing precise and effective rehabilitation for improving the patient's quality of life and help them return to their normal social life.

A modified way of the posterior palatal seal transfer in the fabrication of the complete denture

Abstract not availableBangladesh Journal of Medical Science Vol.16(2) 2017 p.185-187

The Prevalence of Computer Related Musculoskeletal Disorders Among Bankers of Dhaka City

Introduction: Bangladesh is a developing country and the industrialization process is also getting momentum. Due to rapid industrialization and mechanization, use every day more people are coming in contact with the information technology, consequently computer use which may enhance sufferings of people by causing musculoskeletal disorders.Objective: to find out among bankers (a) the prevalence of musculoskeletal disorder and (b) the association between musculoskeletal pain and computer use.Methods: This descriptive type of cross sectional study was conducted to see the pattern of musculoskeletal disorders among the computer users in three selected banks of Dhaka city with a sample of 400.Results: More than half of the respondents (59.8%) were married, more than two-third (69.2%) was male. Majority of the respondents (58.25% and 33.0%) belonged to the level of education was graduate and post graduate. Statistically significant association found between duration of computer used in years and severity of pain. (P- Value was 0.019).Conclusion: A high proportion of Bangladeshi computer users among bankers reported musculoskeletal disorder at some body site in their occupational lives with the neck and back being injured most often. Education program on prevention and coping strategies for musculoskeletal disorders are recommended for computer users in order to reduce the rate of occupational hazards.Chatt  Shi Hosp Med Coll J; Vol.15 (1); Jan 2016; Page 40-44

Combined Mandibular Guidance Therapy in the Management of a Hemimandibulectomy Patient

This case history report describes two different devices, maxillary ramp prostheses (MRP) and mandibular guide flange prostheses (MGFP), prescribed for managing a hemimandibulectomy patient's deviated mandible. The patient was given muscle reprogramming exercises with coordinated use of both guidance prostheses for 2 months, leading to improvements in both postsurgical mandibular deviation and occlusal equilibration. A successful intercuspal position was eventually accomplished through the use of the combination therapy. MRP and MGFP can be a useful approach to avoid mandibular deviation and compromised function following a partial mandibular resection.

Knowledge, Attitude and Practices related to AI among poultry workers of Bangladesh

Background: AI (Avian influenza) refers to a large group of different influenza viruses that primarily affect birds. On rare occasions, these bird viruses can infect other species, including pigs and humans. The vast majority of avian influenza viruses do not infect humans. Objective: To assess knowledge, attitude and practices related to AI among poultry workers. Methodology: A descriptive cross sectional study was designed to conduct in Bangladesh with a pretested modified questionnaire by face to face interview. Result: Current study revealed that nearly one third of the respondents were belonged to age group 26-30 years (39.17%) with the mean age 32.18±6.65 years. Majority of the respondents were male (70%). Nearly two thirds (80%) were owners of poultry farms. Half of them (49.67%) got information regarding AI by electronic media. Nearly one third of the study respondents (34.17%) replied that hand washing after poultry care and less than one third of the respondents (31.67%) said by using PPE (Personal Protective Equipment) during poultry care can prevent AI. Most of the participant said that they informed Rapid Response Team (RRT) for management of sick or dead poultry. More than half of the respondents (57.5) were using PPE. Association found between Socio-demographic variable (Age) and Knowledge on preventing avian influenza among the respondents where p-value=0.001. Conclusion: Knowledge and practices about AI disease among the poultry workers was moderate, but their attitudes were positive. Therefore, designing and implementing health educational programs and ensure proper training for poultry workers about AI to improve preventive practices should have the priority to eliminate the disease. DOI: http://dx.doi.org/10.3329/bjms.v14i1.21558 Bangladesh Journal of Medical Science Vol.14(1) 2015 p.26-31