Digital comparative analysis in three dimensions of two impression techniques for the bilateral distal extension of partially edentulous mandibular arches: A pilot clinical study

STATEMENT OF PROBLEM

The stability of mandibular removable partial dentures with bilateral distal extensions may be improved with the controlled tissue support achieved by using the altered cast impression technique, although this process is time-consuming and technique-sensitive.

PURPOSE

The purpose of this pilot clinical study was to compare casts generated from a conventional definitive impression with casts generated from an altered cast impression using a 3-dimensional (3D) analysis software program.

MATERIAL AND METHODS

Three partially edentulous participants with mandibular Kennedy Class I were enrolled, and impressions were made with the 2 techniques and poured in stone. The casts were scanned, aligned, and superimposed by using a 3D analysis software program. Surface deviations were measured to evaluate the differences in displacement induced by the impression on the tissue surface. Five observations were made in 4 different areas on each partially edentulous side. Means from these observations were generated, and the Wilcoxon and Mann Whitney tests were performed for all data to assess the differences between the right and left sides in the same participant and among the 3 participants (α=.05).

RESULTS

The casts made from the altered cast impression had an overall mean ±standard deviation displacement of -0.05 ±1.25 mm on the right and left sides of the mandibular buccal shelf area. Moreover, the greatest overall difference of about 0.45 ±0.41 mm occurred on the lingual slope of the residual ridge, and the differences in the other areas were 0.10 ±0.99 mm (crest of the residual ridge) and 0.16 ±0.66 mm (buccal slope of the residual ridge). The overall differences varied statistically between significance and nonsignificance for the same participant and among the 3 participants.

CONCLUSIONS

A digital comparative analysis of the conventional and altered cast methods of recording the bilateral distal extension areas in partially edentulous participants showed that the altered cast method exhibited more displacement on the buccal vestibule or buccal shelf area compared with other examined areas. The differences between the 2 impression methods in the displacement values among the examined areas were minimal and in close proximity, and such differences may lack clinical significance.

Three-dimensional analysis of reconstructed skulls using three different open-source software versus commercial software

This study aimed to compare the 3D skull models reconstructed from computed tomography (CT) images using three different open-source software with a commercial software as a reference. The commercial Mimics v17.0 software was used to reconstruct the 3D skull models from 58 subjects. Next, two open-source software, MITK Workbench 2016.11, 3D Slicer 4.8.1 and InVesalius 3.1 were used to reconstruct the 3D skull models from the same subjects. All four software went through similar steps in 3D reconstruction process. The 3D skull models from the commercial and open-source software were exported in standard tessellation language (STL) format into CloudCompare v2.8 software and superimposed for geometric analyses. Hausdorff distance (HD) analysis demonstrated the average points distance of Mimics versus MITK was 0.25 mm. Meanwhile, for Mimics versus 3D Slicer and Mimics versus InVesalius, there was almost no differences between the two superimposed 3D skull models with average points distance of 0.01 mm. Based on Dice similarity coefficient (DSC) analysis, the similarity between Mimics versus MITK, Mimics versus 3D Slicer and Mimics versus InVesalius were 94.1, 98.8 and 98.3%, respectively. In conclusion, this study confirmed that the alternative open-source software, MITK, 3D Slicer and InVesalius gave comparable results in 3D reconstruction of skull models compared to the commercial gold standard Mimics software. This open-source software could possibly be used for pre-operative planning in cranio-maxillofacial cases and for patient management in the hospitals or institutions with limited budget.

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.

Effects of Low-Level Laser Therapy and Bracket Systems on Root Resorption during Orthodontic Treatment: A Randomized Clinical Trial

This study aimed to assess the outcomes of low-level laser therapy (LLLT) with the conventional bracket (CB) and self-ligating (SL) bracket systems on root resorption (RR) during orthodontic treatment. A total of 32 patients were included in this randomized clinical trial. All the patients were randomly divided into four individual groups (SLL: self-ligating laser, CBL: conventional bracket laser, SLNL: self-ligating non-laser, CBNL: conventional bracket non-laser). RR was measured from the cone-beam computed tomography (CBCT) radiographs which were taken at two stages of the orthodontic treatment: pre-treatment (T1) and after leveling and alignment stage (T2). Wilcoxon rank test for the comparison was conducted to compare the RR at T1 and T2 stages within each group and showed a significant difference (p < 0.05) for various variables. Mann Whitney test compared the RR in laser and non-laser groups irrespective of the bracket systems and exhibited no significant differences except the left lateral incisor. Moreover, CB and SL groups showed no significant difference in RR among any tooth. Kruskal Wallis test was performed to compare the RR among all groups which presented no significant differences. LLLT and bracket systems have no consequences on RR until the leveling and alignment stage of orthodontic treatment.

Upscaling of CaO Derived from Cockle Shells as Stabilizer for Zirconia with Improved Properties for Dental Applications

The aim of this study was to upscale the production of calcium oxide (CaO) derived from cockle shells using an improved protocol and determine its purity, as well as to study the hardness of the new, improved calcia stabilized zirconia (Ca-SZ). A mixture of diluted cockle shells powder with hydrochloric acid solutions (HCl) was stirred to obtain calcium chloride (CaCl2). The homogenous CaCO3 solutions were obtained by mixing CaCl2 solution with potassium carbonate (KCO3) using upscaled mechanochemical synthesis process. Then, CaCO3 powder underwent calcination process at a temperature in range of 300°C – 550°C to obtain CaO powders. CaO showed the result under FESEM analysis as a spherical shape with crystal-like structure as well dispersed with no visible agglomeration. The yield production of CaO obtained was approximately about 5.0g which was upgraded from a previous study. The morphologies of Ca-SZ were observed at three different sintering temperatures at 1200°C, 1300°C and 1400°C were selected in order to understand the morphological and mechanical properties of Ca-SZ after incorporating 8wt% of CaO powders derived from cockle shells. The Ca-SZ pellets were then characterized using Field Emission Scanning Electron Microscopy (FESEM) and Vickers Hardness Test to ensure the effectiveness of CaO powder in fabricating Calcia-Stabilized Zirconia (Ca-SZ). As a result, sintered Ca-SZ at 1400°C showed the most promising performance for nano-CaO act as a stabilizer as it has the highest hardness at 590.03MPa with significantly difference (p<0.05) among all sintered Ca-SZ specimens. Therefore, these findings revealed that by adjusting the previous protocol, upscaling of a pure CaO may be synthesized using natural Ca source from cockle shells. The fabricated Ca-SZ showed a significantly lower hardness when sintered at 1400°C, which may be easier for machining.

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.

A Randomized Controlled Trial Evaluating the Levels of the Biomarkers hs-CRP, IL-6, and IL-8 in Patients with Temporomandibular Disorder Treated with LLLT, Traditional Conservative Treatment, and a Combination of Both

Temporomandibular disorders (TMDs) are a type of idiopathic orofacial pain. Inflammation, particularly elevated circulating levels of high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), and interleukin-8 (IL-8), has been linked to pain symptoms. The purpose of this study was to compare hs-CRP, IL-6, and IL-8 biomarkers and pain intensity with different treatment strategies (LLLT, standard conservative treatment, and combination) for TMD patients. Methods: A total of 32 participants were randomly included in the study and divided into three groups (Group I, Group II, and Group III) referred from the Dental Clinic, School of Dental Science, HUSM. Patients received LLLT (Groups II and III) in five sessions for the duration of 10 days. Patients in Groups I and III received standard conservative TMD treatment (diet and stress counseling, jaw exercises, physical therapy, which was a hot towel application) by the principal investigator. All blood samples for biomarkers were performed before starting treatments and directly after finishing the treatment protocols, where all results were recorded. Results: The result showed a significant difference in the mean IL-8 (p = 0.001) between the three intervention groups (LLLT, standard treatment, and combined treatment). IL-6 showed an increase in the mean of IL-6 levels from baseline to post-treatment with a better mean in the LLLT treatment group without any significant differences. Additionally, there were no significant mean differences found between the groups and in the group for the hs-CRP biomarker. Conclusions: A statistically non-significant difference was found in hs-CRP and IL-6 before and after LLLT, conservative, and combined treatment strategies of TMD. A statistically significant difference was observed in the mean levels of IL-8 between the LLLT intervention group and the combined treatment group. Although there was no statistically significant correlation between pain intensity and biomarkers, a statistically significant difference was found in pain intensity before and after LLLT, conservative, and combined treatment strategies. TMJ degeneration could be exacerbated by elevated IL-8 levels. Thus, this can be an important biomarker to mark or identify the painful condition of TMJ.

Osteoblastic Cell Responses of Copper Nanoparticle Coatings on Ti-6Al-7Nb Alloy Using Electrophoretic Deposition Method

Aim

To investigate and compare the cell cytotoxicity, proliferation, cell attachment, and morphology of human fetal osteoblasts (hFOB) cells of coated samples (titanium nanocopper (Ti Cu), titanium nanohydroxyapatite (Ti HA) and titanium nanocopper ion doped hydroxyapatite (Ti Cu/HA) and uncoated samples (Ti) in order to assess the suitability of these surface modifications on Ti-6Al-7Nb for dental implant application.

Materials and Methods

The cytotoxicity was studied by examining the hFOB cell response by MTT assessment. The cell morphology was evaluated by inverted microscopy and observed under scanning electronic microscopy (SEM).

Results

MTT assay results displayed that the Cu content on the surface of Ti-6Al-7Nb alloys did not produce any cytotoxic effect on cell viability. The cell viability rate in all samples ranges from 97% to 126%, indicating that hFOB cells grew at a high proliferation rate. However, no significant differences in cell viability were observed between Ti and Ti Cu and between Ti HA and Ti Cu/HA groups. Microscopic examination demonstrated no difference in the cell morphology of hFOB among all samples. In addition, SEM observation indicated favorable adhesion and spreading of the cells on the coated and uncoated samples.

Conclusions

The surface modification of Ti-6Al-7Nb alloy with Cu, HA, and Cu/HA exhibits good cell biocompatibility, and the Cu has no influence on the cell proliferation and differentiation of hFOB.

A Global Survey of COVID-19 Vaccine Acceptance Among Healthcare Workers

Objectives

Even though several effective vaccines are available to combat the COVID-19 pandemic, wide disparities in vaccine distribution, and vaccine acceptance rates between high- and low-income countries appear to be major threats toward achieving population immunity. Our global descriptive study aims to inform policymakers on factors affecting COVID-19 vaccine acceptance among healthcare workers (HCWs) in 12 countries, based on income index. We also looked for possible predictors of vaccine acceptance among the study sample.

Methods

A structured questionnaire prepared after consultation with experts in the field and guided by the “Report of the SAGE working group on vaccine hesitancy” was administered among 2,953 HCWs. Upon obtaining informed consent, apart from demographic information, we collected information on trust in vaccines and health authorities, and agreement to accept a COVID-19 vaccine.

Results

Although 69% of the participants agreed to accept a vaccine, there was high heterogeneity in agreement between HCWs in low and lower-middle income countries (L-LMICs) and upper-middle- and high-income countries (UM-HICs), with acceptance rates of 62 and 75%, respectively. Potential predictors of vaccine acceptance included being male, 50 years of age or older, resident of an UM-HIC, updating self about COVID-19 vaccines, greater disease severity perception, greater anxiety of contracting COVID-19 and concern about side effects of vaccines.

Conclusions

COVID-19 vaccine acceptance among HCWs in L-LMICs was considerably low as compared to those from UM-HICs. The lowest vaccine acceptance rates were among HCWs from the African continent. This underlines the need for the implementation of country-specific vaccine promotion strategies, with special focus on increasing vaccine supply in L-LMICs.

Minimum Intervention in Managing Two Cases of Tetracycline Staining of Different Severity

Patient dissatisfaction with tooth discoloration as a result of tetracycline therapy is not uncommon. To address patients' aesthetic demands, conservative bleaching treatments were considered before more invasive, irreversible treatments such as dental veneers or crowns. Bleaching is a relatively non-invasive, safe, and cost-effective method of achieving a desirable result. However, due to many limiting variables, including the extended duration of active bleaching, tetracycline-stained teeth are one of the most challenging cases to obtain satisfactory bleaching outcomes. This clinical report presents two cases of management of tetracycline staining of the teeth with varying degrees of severity.

Biomechanical Stress in Obturator Prostheses: A Systematic Review of Finite Element Studies

AIM

This systematic review is aimed at investigating the biomechanical stress that develops in the maxillofacial prostheses (MFP) and supporting structures and methods to optimize it. Design and Methods. A literature survey was conducted for full-text English articles which used FEA to examine the stress developed in conventional and implant-assisted MFPs from January 2010 to December 2020.

RESULTS

87 articles were screened to get an update on the desired information. 74 were excluded based on a complete screening, and finally, 13 articles were recruited for complete reviewing. Discussion. The MFP is subjected to stress, which is reflected in the form of compressive and tensile strengths. The stress is mainly concentrated the resection line and around the apices of roots of teeth next to the defect. Diversity of designs and techniques were introduced to optimize the stress distribution, such as modification of the clasp design, using materials with different mechanical properties for dentures base and retainer, use of dental (DI) and/or zygomatic implants (ZI), and free flap reconstruction before prosthetic rehabilitation.

CONCLUSION

Using ZI in the defective side of the dentulous maxillary defect and defective and nondefective side of the edentulous maxillary defect was found more advantageous, in terms of compression and tensile stress and retention, when compared with DI and free flap reconstruction.

Expression map of entry receptors and infectivity factors for pan-coronaviruses in preimplantation and implantation stage human embryos

PURPOSE

To predict if developing human embryos are permissive to multiple coronaviruses.

METHOD

We analyzed publicly available single-cell RNA-seq datasets of human embryos for the known canonical and non-canonical receptors and spike protein cleavage enzymes for multiple coronaviruses like SARS-CoV, SARS-CoV-2, MERS-CoV, hCoV-229E, and hCoV-NL63. We also analyzed the expression of host genes involved in viral replication, host proteins involved in viral endosomal sorting complexes required for transport (ESCRT), genes of host proteins that physically interact with proteins of SARS-CoV-2, and the host genes essential for coronavirus infectivity.

RESULTS

Of the known receptors of SARS viruses, ACE2, BSG, GOLGA7, and ZDHHC5 were expressed in different proportions in the zygote, 4-cell, 8-cell, morula, and blastocysts including the trophectoderm. The MERS-CoV receptor, DPP4, and hCoV-229E receptor, ANPEP, were expressed mainly from the compact morula to the blastocyst stages. Transcripts of the MERS-CoV alternate receptor LGALS1 were detected in most cells at all stages of development. TMPRSS2 transcripts were detected in the epiblast, primitive endoderm, and trophectoderm, while transcripts of the endosomal proteases CTSL, CTSB, and FURIN were expressed in most cells at all stages of development. ACE2 and TMPRSS2 were co-expressed in a proportion of epiblast and trophectoderm cells. The embryonic cells expressed genes involved in ESCRT, viral replication, SARS-CoV-2 interactions, and coronavirus infectivity. The ACE2 and TMPRSS2 co-expressing cells were enriched in genes associated with lipid metabolism, lysosome, peroxisome, and oxidative phosphorylation pathways.

CONCLUSION

Preimplantation and implantation stage human embryos could be permissive to multiple hCoVs.

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.

Biomarkers for Temporomandibular Disorders: Current Status and Future Directions

Numerous studies have been conducted in the previous years with an objective to determine the ideal biomarker or set of biomarkers in temporomandibular disorders (TMDs). It was recorded that tumour necrosis factor (TNF), interleukin 8 (IL-8), IL-6, and IL-1 were the most common biomarkers of TMDs. As of recently, although the research on TMDs biomarkers still aims to find more diagnostic agents, no recent study employs the biomarker as a targeting point of pharmacotherapy to suppress the inflammatory responses. This article represents an explicit review on the biomarkers of TMDs that have been discovered so far and provides possible future directions towards further research on these biomarkers. The potential implementation of the interactions of TNF with its receptor 2 (TNFR2) in the inflammatory process has been interpreted, and thus, this review presents a new hypothesis towards suppression of the inflammatory response using TNFR2-agonist. Subsequently, this hypothesis could be explored as a potential pain elimination approach in patients with TMDs.

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.

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.

Effect of low level laser and low intensity pulsed ultrasound therapy on bone remodeling during orthodontic tooth movement in rats

BACKGROUND

Quality bone regeneration, which leads to the improvement of bone remodeling, is essential for orthodontic treatment. In order to improve bone regeneration and increase the amount of tooth movement, different techniques have been implemented. The object of this study is to compare the effects of low-level laser therapy (LLLT), low-intensity pulsed ultrasound (LIPUS), and their combination on bone remodeling during orthodontic tooth movement.

METHODS

Eighty (80) male, 6-week-old Sprague Dawley rats were grouped in to four groups, the first group was irradiated with (940 nm) diode laser, second group with LIPUS, and third group with combination of both LLLT and LIPUS. A forth group used was a control group in an incomplete block split-mouth design. The LLLT and LIPUS were used to treat the area around the moving tooth once a day on days 0-7, then the experiment was ended in each experimental endpoint (1, 3, 7, 14, and 21 days). For amount of tooth movement, models were imaged and analyzed. Histological examination was performed after staining with (hematoxylin and eosin) and (alizarin red and Alcian Blue) stain. One step reverse transcription-polymerase chain reaction RT-PCR was also performed to elucidate the gene expression of RANK, RANKL, OPG, and RUNX-2.

RESULTS

The amount of tooth movement, the histological bone remodeling, and the RT-PCR were significantly greater in the treatment groups than that in the control group. Among the treatment groups, the combination group was the highest and the LIPUS group was the lowest.

CONCLUSION

These findings suggest that LLLT and LIPUS can enhance the velocity of tooth movement and improve the quality of bone remodeling during orthodontic tooth movement.

Cytotoxicity of gypsum-based biomaterial for direct pulp capping using stem cells from human exfoliated deciduous teeth

Aim:

The aim of this study was to evaluate the cytotoxicity effects of experimental gypsum-based biomaterial prepared with various concentrations of chitosan (Gyp-CHT).

Materials and Methods:

The study was performed using cell viability assay for mitochondrial dehydrogenase activity in stem cells from human exfoliated deciduous teeth (SHED), after 1, 2, and 3 days of exposure to the biomaterial extracts of varying concentrations. Differences in mean cell viability values were assessed by one-way analysis of variance, followed by Dunnett T3 post hoc test for multiple comparisons (P < 0.05).

Results:

The cell viability to Gyp-CHT in low extract concentrations was statistically similar to that of the control and different from that of high extract concentrations. Gyp-5% CHT showed the highest percentage of cell viability with 110.92%, 108.56%, and 109.11%. The cell viability showed a tendency toward increment with low extract concentration and no constant effect of CHT on cell viability toward higher or lower.

Conclusions:

Gyp-CHT biomaterial has no cytotoxic effects on the cultured SHED.

Association between muscle activity and overjet in class II malocclusion with surface electromyography

OBJECTIVES

The aim of the study was to assess the association and correlation between the overjet and muscle activity (the masseter and temporalis muscles) in patient with Class II malocclusion in different genders using surface electromyography (sEMG).

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.

Effects of low-level laser irradiation on the rate of orthodontic tooth movement and associated pain with self-ligating brackets

INTRODUCTION

The aim of this study was to evaluate the effect of low-level laser irradiation applied at 3-week intervals on orthodontic tooth movement and pain associated with orthodontic tooth movement using self-ligating brackets.

METHODS

Twenty-two patients (11 male, 11 female; mean age, 19.8 ± 3.1 years) with Angle Class II Division 1 malocclusion were recruited for this split-mouth clinical trial; they required extraction of maxillary first premolars bilaterally. After leveling and alignment with self-ligating brackets (SmartClip SL3; 3M Unitek, St Paul, Minn), a 150-g force was applied to retract the canines bilaterally using 6-mm nickel-titanium closed-coil springs on 0.019 x 0.025-in stainless steel archwires. A gallium-aluminum-arsenic diode laser (iLas; Biolase, Irvine, Calif) with a wavelength of 940 nm in a continuous mode (energy density, 7.5 J/cm²/point; diameter of optical fiber tip, 0.04 cm²) was applied at 5 points buccally and palatally around the canine roots on the experimental side; the other side was designated as the placebo. Laser irradiation was applied at baseline and then repeated after 3 weeks for 2 more consecutive follow-up visits. Questionnaires based on the numeric rating scale were given to the patients to record their pain intensity for 1 week. Impressions were made at each visit before the application of irradiation at baseline and the 3 visits. Models were scanned with a CAD/CAM scanner (Planmeca, Helsinki, Finland).

RESULTS

Canine retraction was significantly greater (1.60 ± 0.38 mm) on the experimental side compared with the placebo side (0.79 ± 0.35 mm) (P <0.05). Pain was significantly less on the experimental side only on the first day after application of LLLI and at the second visit (1.4 ± 0.82 and 1.4 ± 0.64) compared with the placebo sides (2.2 ± 0.41 and 2.4 ± 1.53).

CONCLUSIONS

Low-level laser irradiation applied at 3-week intervals can accelerate orthodontic tooth movement and reduce the pain associated with it.

Surface Coating of Gypsum-Based Molds for Maxillofacial Prosthetic Silicone Elastomeric Material: Evaluating Different Microbial Adhesion

PURPOSE

To compare the adhesion of three microorganisms on modified and unmodified silicone elastomer surfaces with different surface roughnesses and porosities.

MATERIALS AND METHODS

Candida albicans, Streptococcus mutans, and Staphylococcus aureus were incubated with modified and unmodified silicone groups (N = 35) for 30 days at 37°C. The counts of viable microorganisms in the accumulating biofilm layer were determined and converted to cfu/cm² unit surface area. A scanning electron microscope (SEM) was used to evaluate the microbial adhesion. Statistical analysis was performed using t-test, one-way ANOVA, and post hoc tests as indicated.

RESULTS

Significant differences in microbial adhesion were observed between modified and unmodified silicone elastomers after the cells were incubated for 30 days (p < 0.001). SEM showed evident differences in microbial adhesion on modified silicone elastomer compared with unmodified silicone elastomer.

CONCLUSIONS

Surface modification of silicone elastomer yielding a smoother and less porous surface showed lower adhesion of different microorganisms than observed on unmodified surfaces.

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.

Gypsum-based biomaterials: Evaluation of physical and mechanical properties, cellular effects and its potential as a pulp liner

This in vitro study aimed to evaluate setting time and compressive strength of gypsum-based chitosan biomaterials and its effect on proliferation of stem cells from human exfoliated deciduous teeth (SHED) and alkaline phosphatase (ALP) activity. Pure-GYP was mixed with water (2.5 g: 1.9 mL); Gyp-CHT was prepared with gypsum, chitosan, and water (2.5 g: 0.285 g: 1.9 mL). Cell viability and ALP activity were assessed at different periods. Data were analyzed using SPSS (p<0.05). The setting times were 2.7 min and 2.8 min for pure-GYP and Gyp-CHT, respectively. Significantly higher compressive strength was observed with Gyp-CHT. SHED treatments with both materials were not cytotoxic. ALP was consistently higher in the treated groups compared with the control. Cellular attachments were evident with SEM. Excellent cellular viability with pure-GYP and Gyp-CHT, as well as increased ALP activities, suggested the possibility of tertiary dentin formation. Further studies are necessary to evaluate the biomaterials for its pulp protective potentialities.

Surface Coating of Gypsum-Based Molds for Maxillofacial Prosthetic Silicone Elastomeric Material: The Surface Topography

PURPOSE

This study aimed to compare the surface roughness of maxillofacial silicone elastomers fabricated in noncoated and coated gypsum materials. This study was also conducted to characterize the silicone elastomer specimens after surfaces were modified.

MATERIALS AND METHODS

A gypsum mold was coated with clear acrylic spray. The coated mold was then used to produce modified silicone experimental specimens (n = 35). The surface roughness of the modified silicone elastomers was compared with that of the control specimens, which were prepared by conventional flasking methods (n = 35). An atomic force microscope (AFM) was used for surface roughness measurement of silicone elastomer (unmodified and modified), and a scanning electron microscope (SEM) was used to evaluate the topographic conditions of coated and noncoated gypsum and silicone elastomer specimens (unmodified and modified) groups. After the gypsum molds were characterized, the fabricated silicone elastomers molded on noncoated and coated gypsum materials were evaluated further. Energy-dispersive X-ray spectroscopy (EDX) analysis of gypsum materials (noncoated and coated) and silicone elastomer specimens (unmodified and modified) was performed to evaluate the elemental changes after coating was conducted. Independent t test was used to analyze the differences in the surface roughness of unmodified and modified silicone at a significance level of p < 0.05.

RESULTS

Roughness was significantly reduced in the silicone elastomers processed against coated gypsum materials (p < 0.001). The AFM and SEM analysis results showed evident differences in surface smoothness. EDX data further revealed the presence of the desired chemical components on the surface layer of unmodified and modified silicone elastomers.

CONCLUSIONS

Silicone elastomers with lower surface roughness of maxillofacial prostheses can be obtained simply by coating a gypsum mold.

Prevalence of torus palatinus and torus mandibularis among Malay population

The aims of this study were to determine the prevalence, size, shape, and location of torus palatinus (TP) and torus mandibularis (TM), and to assess their sex-related and age-related differences in the Malay population. Sixty-five subjects were assessed for the presence of both tori at the School of Dental Sciences University Sains Malaysia. The prevalence of TP was 38–63% and that of TM was 1–10%. TP was frequently more common in females than males (90.9% versus 9.1%; P < 0.05) and was frequently found in medium sizes, spindle shaped, and was often located at the combined premolar to molar areas. The prevalence of TM was not significantly different in males and females (33.3% versus 66.7%; P = 0.523), occurred most commonly in bilateral multiple form, and was often located at the canine to premolar area.

Effect of 940 nm low-level laser therapy on osteogenesis in vitro

Bone regeneration is essential in medical treatment, such as in surgical bone healing and orthodontics. The aim of this study is to examine the effect of different powers of 940 nm diode low-level laser treatment (LLLT) on osteoblast cells during their proliferation and differentiation stages. A human fetal osteoblast cell line was cultured and treated with LLLT. The cells were divided into experimental groups according to the power delivered and periods of exposure per day for each laser power. The (3-(4,5-dimethylthiazol-2yl)-2,5 diphenyl tetrazolium bromide) (MTT) assay was used to determine cell proliferation. Both alkaline phosphatase and osteocalcin activity assays were assessed for cell differentiation. All treatment groups showed a significant increase in cell proliferation and differentiation compared to the control group. Regarding the exposure time, the subgroups treated with the LLLT for 6 min showed higher proliferation and differentiation rates for the powers delivered, the 300-mW LLLT group significantly increased the amount of cell proliferation. By contrast, the 100 and 200 mW groups showed significantly greater amounts of cell differentiation. These results suggest that the use of LLLT may play an important role in stimulating osteoblast cells for improved bone formation.

Dental Education: Restorative dentistry in Malaysia

Objectives: The aim of this study was to identify the requirements in restorative dentistry that undergraduate dental students have to fulfill in order to sit for final examinations in dental schools in Malaysia and to compare those requirement with the competencies stipulated by the Malaysian Qualification Agency (MQA). Materials and Methods: Questionnaire from a study done previously was modified and used in this study. All questionnaires were sent by post with a reply envelope. Eight dental schools had responded (72%) to the survey and the results showed that although dental schools may differ in the number of numerical requirements, their assessments were quite similar. One school does not practice numerical requirements at all. Results: In term of requirement for full crown, majority of the schools (88%) agreed that porcelain bonded to metal crown should be included in the numerical requirement. In contrast, majority of the schools (88%) did not include inlay/onlay in their numerical requirements. For plastic restorations like composite resin, amalgam and glass ionomer, majority of the schools (88%) used numerical requirements. Majority of the schools also agreed on numerical requirements for conventional bridge (88%) and incisor to molar endodontics (88%), but not for resin bonded bridge (75%). Conclusion: This study shows that there is a disparity among institutions in Malaysia in terms of finals requirement in restorative dentistry. Ideally, all requirements should be similar among institutions and should closely follow the guidelines provided by the MQA. DOI: http://dx.doi.org/10.3329/bjms.v12i1.13352 Bangladesh Journal of Medical Science Vol. 12 No. 01 January’13 pp.55-62

An In Vitro study of Fracture Resistance of Weakened Tooth Roots Reinforced with Two Types of Adhesive Restorative Materials

Introduction: Composite resin (CR) is among the commonly used material for intraradicular reinforcement of weakened tooth roots. Purpose: This study was to compare the fracture resistance of experimentally weakened tooth roots reinforced using auto-polymerized composite resin and light-polymerized composite resin. Materials and Methods: Fifty-six extracted human maxillary incisors were divided into 2 groups (n = 28) and the root canals were over prepared to weaken it. The samples in Group Awere restored using lightcured CR Z100 and light-transmitting polymerizing post (Luminex), whereas Group B using auto-cured CR Alpha-dent. Both groups were placed with metal parapost cemented with a resin luting cement (Nexus 2). Specimens were subjected to compressive load (N) using Instron machine until fracture. Data were submitted to independent t test analysis of variance (p < 0.05). Results: There was no significant difference (p = 0.233) in fracture resistance between the teeth reinforced with light-polymerizing and auto-polymerizing CR are 549.3 (± 95.44) and 490.7 (± 110.37) respectively. Conclusion: The use of less technique sensitive autopolymerizing CR give equivalent benefit effect on reinforcing weakened roots, as the more commonly lightpolymerized composite resin. DOI: http://dx.doi.org/10.3329/bjms.v12i1.13353 Bangladesh Journal of Medical Science Vol. 12 No. 01 January’13 pp.63-67

Sealing ability of various restorative materials as coronal barriers between endodontic appointments

AIM

To evaluate and compare the microleakage of various restorative materials used as coronal barriers between endodontic appointments.

MATERIALS AND METHODS

Eighty extracted human permanent posterior teeth were prepared for standardized access cavities with dimensions of 4 × 4 × 4 mm. The teeth were then randomly divided into four groups; Kalzinol, Caviton, GC Fuji IX and GC Fuji II LC. After incubation, the samples were immersed in 2% methylene blue for 7 days. The depth of penetration was measured using a digital macroscope after longitudinal sectioning of each tooth. Kruskal-Wallis (p < 0.05) and multiple Mann-Whitney test with Bonferroni correction (p < 0.008) were used for data analysis.

RESULTS

The degree of microleakage varied at the material/ tooth interface among the test materials, and the difference was statistically significant (p < 0.05). GC Fuji II LC group showed the least median microleakage value (0.8105 ± 0.305), followed by Caviton (1.1885 ± 0.396), GC Fuji IX (3.3985 ± 0.305) and Kalzinol (4.161 ± 0.853).

CONCLUSION

Within the limitations of this study, GC Fuji II LC exhibited the best marginal seal, and has the potential to be used as a suitable coronal barrier between endodontic appointments.

CLINICAL SIGNIFICANCE

Given the prime importance that dental practitioners should thoroughly restore any tooth with a suitable coronal barrier between endodontic appointments, this study shows that Fuji II LC has the ability to maintain a hermetic seal for 7 days.

The effect of different sealer placement techniques on sealing Ability: An in vitro study

Aim:

The aim of this in vitro study was to evaluate the sealing ability of an endodontic sealer following different techniques of its placement.

Materials and Methods:

A total of 119 permanent human anterior teeth were prepared by using manual Protaper^® and randomly divided into three equal groups of 33 teeth each. The teeth were obturated with the cold lateral condensation technique and AH26 sealer which was placed by using the following: G1: rotary lentulo spiral; G2: manual lentulo spiral; and G3: master gutta-percha coating. The remaining 20 teeth served as positive and negative controls. The samples were immersed in the methylene blue solution for 3 days and longitudinally sectioned for dye penetration assessment and analyzed using a stereomicroscope.

Results:

There was no statistically significant difference (P = 0.305) among the three groups. However, the rotary lentulo spiral technique and the master gutta-percha coating technique showed the highest (4.5 mm) and the lowest (3.8 mm) microleakage values, respectively.

Conclusion:

Different techniques of sealer placement used in this study provided a comparable seal. However, the master gutta-percha coating technique might be preferable because of its ease of use.

Different surface preparation techniques of porcelain repaired with composite resin and fracture resistance

Background:

Porcelain from prosthesis such as crown or bridge can be fractured if exposed to trauma; and, can be repaired at chairside using composite resin.

Aim:

To investigate the fracture resistance of few techniques of surface preparation in repairing fractured porcelain using composite resin.

Materials and Methods:

Eighty samples of porcelain blocks were divided into 4 groups for different surface preparations, such as, Cimara repairing kit; porcelain etch kit containing hydrofluoric acid; Panavia F resin cement; and, sandblasting using aluminium oxide, before composite resin (Filtek Z250, 3M ESPE) was bonded to the prepared porcelain blocks. Twenty others samples in the control group comprised of pure porcelain blocks. The fracture resistance of each sample was tested using Instron machine (UK).

Results:

With the exception of the group repaired using hydrofluoric acid (3.04±1.04 Mpa), all the other groups showed significant difference in the fracture resistance values when compared to the control group (3.05 ± 1.42 MPa) at P<0.05.

Conclusions:

Etching of the porcelain blocks with hydrofluoric acid holds promise in the repair of fractured porcelain with composite resin at chairside.

Lymphatic vessel density is not associated with lymph node metastasis or survival in non-small cell lung carcinoma (NSCLC)

18008

Background: Angiogenesis is accepted as being essential for tumors to grow and metastasize to distant sites. Lymphatic metastasis is also an important means of tumor spread. Vascular endothelial growth factor C (VEGF-C) plays and important role in lymphangiogenesis and activates VEGFR (VEGF receptor)-3. Numerous studies suggest that tumor expression of VEGF-C is a significant prognostic factor in NSCLC. In non-small cell lung carcinoma (NSCLC), the relationship of lymphangiogenesis with lymph node metastasis and patient prognosis is unknown. Methods: A retrospective analysis of 78 patients who were diagnosed with NSCLC from 1987 to 2004 were analyzed for lymphatic vascular density (LVD). LVD was measured by use of D2–40 monoclonal antibody staining. Survival was assessed and Mantel-Cox and Wilcoxon signed rank tests were used for statistical analysis. Results: Intratumoral and peritumoral LVD was significantly higher than in the uninvolved adjacent lung, but showed no significant association with lymph node status at the time of tumor resection. Variables which appeared to affect survival in our study were the presence of lymph node metastasis (median survival 1,425 vs absence 467 days, p=0.002). The presence of VEGF staining inversely affected median survival (present 757 vs absent 1,944 days, p= 0.014). LVD ≤ 53 events per field 895 days vs >53 median survival 1,302 days, p+0.867. Survival appeared to not be affected by LVD. Conclusions: These data suggest that although lymphangiogenesis occurs in association with NSCLC, it may not be an important factor in lymph node metastasis or in survival. In fact, there is a suggestion that the number of lymphatics that a patient inherently has appears to be more important than lymphangiogenesis when it comes to the development of lymph node metastasis.

No significant financial relationships to disclose.

Indirect resin-bonded fibre-reinforced composite anterior bridge: A case report

In recent years fibre-reinforced resin composites (FRCs) have gained increasing acceptance in mainstream prosthodontics as viable alternatives to alloy-based restorations. A combination of good aesthetics and fracture toughness validates their use in a diverse range of clinical applications. In this case report an indirect resin-bonded fibre-reinforced composite anterior bridge incorporating a novel design is described. At 24-months recall the prosthesis was problem free and the patient was very happy with the treatment outcome. While definitive long-term data about their clinical performance is scarce, fibre-reinforced resin composite prostheses appear to have a worthwhile role in the conservative treatment of short edentulous spaces.

Evaluation and improvement of parasitological tests for Trypanosoma evansi infection

Research was undertaken to critically evaluate parasitological tests for the detection of Trypanosoma evansi in blood. The relative sensitivity of mouse inoculation (MI), the haematocrit centrifugation technique (HCT) and a modified miniature anion-exchange centrifugation technique (MAECT) were compared using blood and buffy coat. The effect that storage of blood prior to inoculation into mice has on the reliability of the MI test was also evaluated. The tests may be ranked in increasing order of sensitivity: HCT, MAECT with whole blood, MI with whole blood, MAECT with buffy coat and MI with buffy coat. The latter was able to detect 1.25 T. evansi per 4ml of blood. The reliability of the MI test was not reduced with storage of blood containing at least 25 T. evansi per ml for up to 21h prior to inoculation into mice. These results demonstrate that sensitivity of the MI and MAECT are increased approximately 10-fold through the use of buffy coat in place of whole blood. Although, the MI is marginally more sensitive MAECT is better suited to field use.

The susceptibility of two species of wallaby to infection with Trypanosoma evansi

OBJECTIVE

To determine the susceptibility of the agile wallaby (Macropus agilis) and the dusky pademelon (Thylogale brunil) to infection with Trypanosoma evansi.

METHOD

Two agile wallabies and three dusky pademelons were experimentally infected with between 5 x 10(4) and 10 x 10(4) T evansi from a cryopreserved stabilate isolated from an indonesian buffalo. Animals were observed twice daily for clinical signs and blood was collected every 3 days to determine parasitaemia. Necropsy was conducted on animals that died or were euthanised when in extremis and representative tissue sections examined.

RESULTS

All wallabies developed a high parasitaemia by 6 days after infection, which persisted until death or euthanasia in extremis, between days 8 and 61. Clinical signs included anorexia, weakness and ataxia. Anaemia occurred in one wallaby that survived for 61 days. Gross pathological changes varied between animals. They included pericarditis, serous atrophy of fat, splenomegaly, ulcerative gastritis and enteritis. Histological changes were characterised by a mononuclear cell infiltration of the connective tissue of most organs with little cellular destruction. Striking lesions were seen in the choroid, heart, stomach and small intestine.

CONCLUSION

Agile wallabies and pademelons are highly susceptible to infection with T evansi. Wallabies, therefore, have the potential to spread T evansi within New Guinea and Australia if infection is introduced. Mortality is likely to be high thereby acting as an indicator of recent introduction. Histological changes seen in wallabies infected with T evansi are diagnostic for infections occurring in Australia and Papua New Guinea.

The occurrence of Trypanosoma evansi in buffaloes in Indonesia, estimated using various diagnostic tests

The prevalence and incidence of Trypanosoma evansi infections in village buffaloes in Central Java were estimated using parasitological tests, two antigen-detection ELISAs (2G6 Ag-ELISA and Tr7 Ag-ELISA), an antibody-detection ELISA (IgG ELISA) and a card agglutination test (CATT). Of 2387 village buffaloes tested in five districts, 4 % (95 % confidence interval [CI]: 3 %, 5 %) were positive with the microhaematocrit test (MHCT), 58 % (95 % CI: 56 %, 60 %) were positive with the 2G6 Ag-ELISA and 70 % (95 % CI: 68 %, 72 %) were positive with the Tr7 Ag-ELISA. An increasing prevalence with age was found and the proportion of positive buffaloes was highest in the over 84 months-old age-group (68 %) with the 2G6 Ag-ELISA and in the 37-60 months-old age-group (78 %) with the Tr7 Ag-ELISA. Parasitaemic buffaloes were found in more than half of the villages visited. Corrected village-specific prevalence values obtained with the two Ag-ELISAs ranged from 0% to over 100%, and prevalence differed significantly (P < or = 0.0001) between villages in four of the five districts. Overall, 10% of buffaloes tested in markets were found to be parasitaemic and 39, 56 and 47 % were found positive with the 2G6 Ag-ELISA, IgG ELISA and CATT, respectively. Incidence rates varied according to the test used and ranged from 0.22 (95 % CI: 0.09, 0.44) to 0.44 (95 % CI: 0.24, 0.76), per animal-year at risk, in two villages. The results highlight the importance of using validated diagnostic tests to obtain accurate estimates of prevalence and incidence. These parameters are needed, for example in mathematical models, for the development and evaluation of different control strategies for T. evansi infections in buffaloes.

Evaluation of antigen detection and antibody detection tests for Trypanosoma evansi infections of buffaloes in Indonesia

Two Ag-ELISAs, an IgG-specific antibody detection ELISA (IgG ELISA) and a card agglutination test (CATT) for the detection of Trypanasoma evansi infections in buffaloes in Indonesia, were compared. Diagnostic sensitivity estimates were obtained by testing sera from 139 Indonesian buffaloes which had been found to be infected by parasitological tests. Diagnostic specificity was estimated by testing sera from 263 buffaloes living in Australia. Response-operating characteristic curves were constructed, and optimal ELISA cut-off values, which minimized the number of false-negative and false-positive results, were chosen. The IgG ELISA had the highest sensitivity (89%) and the CATT had the highest specificity (100%). There was a significant difference between the sensitivities (71 and 81%), but not between the specificities (75 and 78%), of the two Ag-ELISAs. The four tests were further compared by calculation of post-test probabilities of infection for positive and negative test results using a range of prevalence values, and likelihood ratios. The results suggested that the CATT was the best test to 'rule-in' infection (i.e. the highest probability of infection in test-positive animals) and the IgG ELISA was the best test to 'rule-out' infection (i.e. the lowest probability of infection in test-negative animals).

A possible role for rusa deer (Cervus timorensis russa) and wild pigs in spread of Trypanosoma evansi from Indonesia to Papua New Guinea

Movement of transmigrants and livestock from western Indonesia to southeastern areas of Irian Jaya near the border with Papua New Guinea may pose a risk of introducing Trypanosoma evansi into Papua New Guinea via feral Rusa deer (Cervus timorensis russa) and wild pigs which inhabit these areas in large numbers. Pilot experimental studies were conducted to observe infection in pigs and Rusa deer with a strain of T. evansi isolated in Indonesia. Parasitaemia and signs of clinical disease were monitored each second day for 120 days. Trypanosomes were observed in haematocrit tubes at the plasma-buffy coat interface of jugular blood of deer and pigs on 86% and 37% of sampling occasions respectively. Parasitaemia was at a high level in deer for 35% of the time but for only 11.5% of the time in pigs. Results indicate that both Rusa deer and pigs have a high tolerance for infection with T. evansi. The deer suffered mild anaemia evidenced by a 25% reduction in packed cell volume (PCV) 14 days after infection which coincided with the initial peak in parasitaemia. However, PCV had returned to pre infection values by the end of the experiment. The pigs showed no change in PCV. There were no visual indications of disease in either species and appetite was not noticeably affected. It was concluded that both Rusa deer and pigs were capable reservoir hosts for T. evansi but that Rusa deer, with their more persistent higher levels of parasitaemia, have more potential to spread T. evansi into Papua New Guinea from West Irian than pigs.