MBRU Theses & Dissertations

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Accuracy of three-dimensional printed guide plate for indirect bracket placement: one-piece verses segmented, an in Vitro study
(2022) Alyammahi, Bayan Esmaeil
Background: An accurate placement of brackets is a key element of the comprehensive treatment process of orthodontics to achieve an ideal occlusion. Orthodontic brackets can be directly placed on tooth surfaces or indirectly. Aim: To compare the accuracy of indirect bonding techniques in moderate, and severe crowding cases using three-dimensional printed one-piece transfer tray and segmented trays. Digital models with virtual brackets were considered as the control group. Four points were selected in each tooth to perform the analysis. From the midpoint of each bracket to the mesial margin (CM= center mesial), distal margin (CD =center distal), occlusal/ incisal margin (CI= center Incisal/occlusal) and gingival margin (CG= center gingival). Shapiro-Wilk was used to test the normality of continuous variables. The Mann-Whitney test, Kruskal-Wallis H test was used. A P-value of less than 0.05 will be considered significant in all statistical analyses. Results: There were statistically significant differences between models with moderate crowding bonded using full, segmented transfer trays and control for CD12, CD21, CI25 (P < 0.001). While the rest of the measurements showed no significant differences between models with moderate and severe crowding bonded using full, segmented transfer trays and control (P=1.0). Conclusion: The one-piece and the segmented indirect 3D printed transfer trays are accurate in the severe and moderate malocclusion.
Anterior teeth root inclination prediction derived from digital models: A comparative study of plaster study casts and CBCT images Mahmoud Dastoori MSc, University College London, 2007 DDS, Ajman
(2017-08) Dastoori, Mahmoud
Aim: To assess the accuracy of digital models generated using commercially available software to predict anterior teeth root inclination characteristics and compare the results to relevant data obtained from CBCT images. Materials and Methods: Following sample size calculation and after evaluation of inclusion and exclusion criteria, pre-treatment maxillary and mandibular plaster models and the corresponding CBCT scans of 31 patients attending a private orthodontic clinic in Beirut, Lebanon, were randomly selected. The subjects represented both genders (males: 10; females: 21), ranging in age from 12 to 40 years. Plaster models were scanned using the high resolution of an Ortho Insight 3D ™ scanner (Motion View Software, Chattanooga, Tennessee, USA) and CBCT scans were taken using a Kodak 9500 Cone Beam 3D System (Carestream Health, Inc., Rochester, New York, USA). Elaboration of plaster models and CBCT data were performed according to specific technical steps. The Shapiro-Wilk test was used to test normality of measurements per tooth and crosstabulation to examine the independency between categorical variables. Statistical analysis was performed using χ2 test of association. If the measurements were II normally distributed, the t-test and ANOVA were used to examine two or more continuous independent variables. In cases of non-normality of measurements, the Mann-Whitney and Kruskal-Wallis tests for multi-comparison of continuous data were employed. To evaluate the reliability and consistency of the investigator, the paired t-test was used. P-value was set as ≤ 0.05 in all statistical analyses. To determine the intra-examiner error of the measurements, records of 5 random patients were selected and all measurements were repeated twice by the author after a two week interval and the correlations computed using intra-class correlation coefficient (ICC). Results: The maximum disparity in angle between images derived from digital models and CBCT data was almost 40 degrees (upper left canine). The disparity in upper right canines was similar. The upper and lower canines produced the worst results, followed by the lower lateral incisors. The upper central incisors showed the best results, although the maximum angle of difference exceeds 20 degrees (with the median only around 8 degrees). There was no statistically significant difference in measurements of difference between long axes of the root by using the two methods in each tooth (MDBLAR) according to Angle classification. Observation of the cases showed that the software frequently estimates angulations leading to overlapping of adjacent roots; a clinically unfeasible situation in the absence of extensive root resorption or root morphology variation. Errors were higher for canines and lower for central incisors. There was no correlation of errors between teeth. Conclusions: Root morphology imaging prediction is not a primary function of this software and this study confirmed its limitation as a sole tool in routine clinical applications. At III present these predictions cannot be considered accurate or reliable unless correlated with a radiographic image.
Anterior teeth root morphology prediction as derived from digital models: A comparative study of plaster study casts and natural teeth from dry skulls
(2018) Magkavali-Trikka, Panagiota
Aim: To assess the accuracy and reliability of the digital images of dental models generated by specific commercially available software in predicting root morphology characteristics in comparison to the corresponding natural teeth. Materials and Methods: The initial sample of 56 natural teeth derived from14 dry human skulls with permanent dentition. From the 14 dry skulls, there were 11 mandibles and 3 maxillae. The inclusion criteria used in this study were that all the teeth should derive from permanent dentition of adults and should present normal crown morphology. Primary teeth, teeth with abnormal tooth morphology and restorations, and jaws resembling craniofacial anomalies or syndromes were excluded. Based on these criteria, one maxillary right lateral incisor was excluded since it had a fractured crown. Therefore, the total number of the sample of teeth used was 55. The sample size calculation required 43 teeth. Upper and lower dental arch impressions, utilizing alginate material, were taken and plaster study models were fabricated. The maxillary and mandibular plaster models were ii scanned using the Ortho Insight 3D laser scanner. Using the Ortho Insight 3D software (version 4.0.6), measurements, to the nearest 0.01 mm, were recorded by locating relevant landmarks using the intrinsic linear measurement function of the software. Based on these landmarks, the software produced virtual roots for the selected teeth. Then both the scanned casts and their root predictions were exported in stereolithography (STL) files. All corresponding 55 natural teeth were removed from the upper and lower jaws of the dry skulls and scanned using the Identica extraoral white-light scanner in order to calculate their actual root morphological characteristics. In order to acquire the whole tooth geometry, the teeth were scanned twice, once to acquire the crown and the cervical part of the root, and a second time to acquire the remaining part of the root, including the apex. The two scanned segments were joined in software by superimposing them along their common part. Finally, the accuracy of the digital models generated by the Ortho Insight 3D laser scanner in predicting root morphology characteristics was assessed by comparing these results to the corresponding measurements of the 55 natural teeth. The long axes of the tooth models obtained from the software prediction and the scanning of the actual teeth were computed and the discrepancy between them evaluated. Results: The error of the method was evaluated by repeating the measurements on 14 teeth. The differences in root mean squared error (RMSE) of superimposition of the two scanned segments (crown - root) of each tooth ranged from -0.006 to 0.010 mm. The differences in RMSE of superimposition of each tooth on its corresponding cast ranged from -0.040 to 0.057 mm. Both these error ranges showed acceptable accuracy. The error in calculating the angulation between the predicted and actual long axes ranged from -3.2 to 2.3 degrees (95% limits of agreement: -3.7 to 3.2). iii The predicted tooth angulation was found to differ significantly from the actual angulation, both statistically and clinically. The angle between the predicted and actual long axes ranged from 2.0 to 37.6 degrees (average: 9.7 degrees; median: 7.4 degrees). Conclusions: Based on the results of this study, the degree of error is higher for mandibular central incisors and maxillary lateral incisors, and lower for maxillary central incisors and mandibular lateral incisors. Further investigations and improvements of the software are needed before it can be considered clinically effective.
The anteroposterior effect of rapid maxillary expansion using bone-borne VERSUS tooth-borne expander: A comparative study
(2022) AlNashmi, Nashmi Qais
Background: In orthodontics, slow, rapid, and surgically assisted maxillary expansions are commonly performed to correct maxillary constriction, posterior crossbite, and crowding. Ideally, this treatment approach is recommended in growing (i.e., pediatric and adolescent) patients, as it requires a mid-palatal suture that is not fully fused. There is limited understanding on the relative efficacy of bone- and tooth-borne expanders for maxillary expansion. Aim: To assess and compare dentoskeletal changes in maxilla and mandible after RME using bone- and tooth-borne expanders in adolescent patients. Materials and Methods: This study compares 18 subjects (10 females and 8 males, with an average age of 14.4±1.3 years) who received tooth-borne RME; and 18 subjects (12 females and 6 males, with an average age of 14.7±1.4 years) who received bone-borne RME. Specific three-dimensional landmarks were used in order to compare skeletal and dental changes in tooth-borne and bone-borne expanders. Data was analyzed using Shapiro-Wilk, Paired t, Wilcoxon, and Mann-Whitney tests, in addition to Pearson correlation. A P-value of less than 0.05 was considered significant in all statistical analyses. Results: In the tooth-borne group the following parameters showed a significant difference after expansion (P <0.05 ): molar width, intermolar width, molar buccal tipping in the transverse plane, and Pog-FH in the vertical plane. In the bone-borne group, a significant difference after expansion (P <0.05 ) was recorded for the following parameters: linear intermolar relation, palatal bone width, intermolar width, and interpremolar width. Comparison of the post- ii expansion results of both groups revealed that the bone-borne group exhibited less molar buccal tipping. Conclusion: There was significant transverse change reported after expansion in both the bone-borne and tooth-borne groups, with less significant of dental tipping in the former. Nevertheless, both groups displayed limited sagittal and vertical changes when correlated to the transverse changes.
Are asthma and airway allergy associated with increased root resorption following orthodontic treatment? A systematic review
(2020) Al-Saqi, Reem Kais
Aim: Asthma and airway allergy have been implicated with root resorption development following orthodontic treatment. The objective of this study was to investigate systematically the relevant literature. Materials and Methods: Search without restrictions for published and unpublished literature and hand searching took place. Data on root resorption in patients with asthma or allergy having undergone comprehensive orthodontic treatment were reviewed. The risk of bias was assessed using the Newcastle-Ottawa Scale. Results: From the initially retrieved records, three cohort and two case-control studies met the inclusion criteria. The studies reported conflicting results and the risk of bias assessment revealed shortcomings in various domains. Conclusions: The information regarding the association of asthma and airway allergy with root resorption following orthodontic treatment is contradictory and further research is warranted. However, until more data become available good practice would suggest that it is important to identify patients with asthma or airway allergy and consider the possible implications.
Clinical Crown Length Changes and Gingival Recessioa Development in Anterior Teeth Associated with Orthodontic Treatment: A Systematic Review and Meta-Analysis
(2018) Bin Bahar, Budoor
AIM: To systematically investigate and appraise the quality of the available evidence regarding clinical crown length changes and gingival recession development following orthodontic treatment. MATERIALS AND METHOD: A search without restrictions for published and unpublished literature and hand searching was performed. Data on incisor clinical crown length changes and gingival recession development following orthodontic treatment were reviewed. Measurements before and after orthodontic treatment, as well as case-control studies, were considered. Relevant information was extracted, methodological quality was evaluated using the ROBINS-I tool (Risk Of Bias In Nonrandomized Studies of Interventions) and the random effects model was used to combine the retrieved data. RESULTS: Ten studies following patients for up to 6 years after orthodontic treatment were finally identified. Clinical crown length increased after orthodontic treatment and during retention. However, in general, no differences were noted iii between the groups that underwent proclination compared to the non-proclination group. Moreover, orthodontic treatment seemed to increase the odds for a patient to exhibit gingival recession in at least one tooth, compared to before treatment. In addition, orthodontic treatment seemed to increase the odds for a patient to exhibit gingival recession in at least one mandibular incisor, compared to before treatment or the untreated controls. CONCLUSIONS: The present systematic review and meta-analysis showed that some increases in gingival recession prevalence may be encountered after orthodontic treatment. Although clinical crown length increases during orthodontic treatment and retention, overall no statistically significant differences were noted between incisors having undergone proclination compared to the non-proclination group. More high quality studies are needed in order to further elucidate possible associations.
Clinical crown length, gingival recession development and sagittal inclination changes in incisors associated with orthodontic treatment: a retrospective study
(2018) Abdulkader, Shatha
AIM: To retrospectively investigate the clinical crown length changes and the development of gingival recession in the labial aspect of the maxillary and mandibular incisors associated with orthodontic treatment and relate them to the observed changes in their sagittal inclination. MATERIALS AND METHODS: Eighty-two consecutive subjects, treated by means of fixed orthodontic appliances in both dental arches, with good quality pre- and post-treatment dental casts and lateral cephalometric radiographs, were selected from the archives of a private orthodontic clinic. Incisor clinical crown length before and after orthodontic treatment, as well as the presence or absence of recession, were measured on digitized study models. Sagittal inclination changes were assessed on lateral cephalometric radiographs and categorized as proclination, retroclination or no change (±1°). Spearman’s correlation coefficient, one-way analysis of variance and chi-square tests were used for analysis. RESULTS: The mean change of clinical crown lengths for the maxillary incisors was from -0.24 to 0.01 mm, and for the mandibular, from 0.06 to 0.10 mm. The inclination changes were -1.78° and 1.03°, respectively, but no correlations were observed with changes in clinical crown length. Overall, no statistically significant differences were observed regarding clinical crown length changes and the presence of gingival recession between proclination, retroclination and no change groups. CONCLUSIONS: The change of incisor inclination during treatment did not seem to affect labial clinical crown length increases and gingival recession development in this specific sample.
Craniofacial Adaptations Following Tongue Volume Reduction Surgery: A Systematic Review
(2018) Alawadhi, Tariq
AIM: To systematically investigate the available literature regarding craniofacial adaptations after tongue volume reduction surgery and critically evaluate the quality of existing evidence. MATERIALS AND METHOD: A search without restrictions for published and unpublished literature and hand searching was performed. Data on craniofacial adaptations in patients of any age having undergone tongue volume reduction surgery were reviewed. Methodological quality was evaluated using the Robins-I tool (Risk of Bias in Non- randomized studies of intervention). RESULTS: Out of 425 initially identified unique records, only 3 articles which followed patients up to one year post-surgery fulfilled the selection criteria for inclusion in the systematic review. Two studies presented data on various functional characteristics involving the tongue. After tongue volume reduction surgery, no significant differences were noted in the rest position, or during chewing and swallowing. At the same time, minimal influence was noted on oral stereognosis and motor ability. The third study investigating the effect of tongue volume reduction on dentofacial structures after mandibular setback showed that there was no significant difference in the assessed skeletal, hyoid position and airway cephalometric variables at 1 year. Methodological quality assessment identified various flaws in the included studies. CONCLUSIONS: The present systematic review showed that, overall, no statistically significant differences were noted in terms of tongue function and dentofacial structure adaptation following tongue volume reduction surgery in the medium term. More high quality studies are needed in order to further investigate craniofacial adaptations following this procedure.
Cytotoxicity and estrogenicity of Vivera® retainers
(2016-12) Al Naqbi, Shaima
Aims: The aim of the present study is to investigate the cytotoxicity and estrogenicity of Vivera® retainers by assessing their biological behavioral effects: as-received from the manufacturers, and after retrieval from patients. The null hypothesis of this study is that Vivera® retainers, both as-received or after retrieval from patients, have no cytotoxic or estrogenic effect. Materials and Methods: The study sample consisted of six sets of Vivera® retainers, three as-received from the manufacturer and three retrieved from three consecutive patients of the Postgraduate Orthodontic Clinic, Hamdan Bin Mohammed College of Dental Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai, United Arab Emirates. All participants agreed to their inclusion in this research study. With regard to the retrieved retainers, these were retrieved from the patients after four weeks of use. All sets in the study consisted of a maxillary and a mandibular appliances. The evaluation of the cytotoxicity and estrogenicity of all retainers took place in the Laboratory of Cell Proliferation and Ageing, Institute of Biosciences and Applications, National Center for Scientific Research “Demokritos”, Athens, Greece. The retainers were transferred from Dubai to the laboratory in Athens by one member of the research team in a way that ensured that their physical condition remained unchanged from the time they were removed from the patients or delivered by the company. All retrieved retainers were divided in two equal parts randomly regardless of being upper or lower component. Each one subjected to either mode of sterilization procedures, i.e. gamma-irradiation or autoclaving. The as-received retainers were divided into three equal parts randomly as well. Two parts were sterilized, with each part using one of the above-mentioned procedures, while the third part of as-received retainers was not subjected to any sterilization mode, so as to test the effects of the sterilization procedure Subsequently, all samples were immersed in sterile normal saline (NaCl 0.9% w/v) with each sample in different container and incubated for fourteen days at 37° C. A sample of normal saline without any retainer was incubated in the same conditions in parallel with the study samples, to be used as negative control. After sterilization, all retainers, which had been treated following specific allocation and procedures of sterilization, were aliquoted and kept at -20° C to maintain its integrity until further experimental use. Samples obtained from incubation of as-received / unsterilized retainers were considered to be identical. The estrogenicity assays involved 2 cell lines, i.e. the estrogen-sensitive MCF-7 and the estrogen-insensitive MDA-MB-231 (both from human breast adenocarcinoma), in order to exclude the possibility that a decreased proliferation of cells induced by the retainer eluent would mask a potential induction of proliferation due to estrogenicity. Cells were cultured in Dulbecco’s Modified Eagle Medium (DMEM) supplemented with 10% Fetal Bovine Serum, at 37° C, in 5% carbon dioxide, in a humidified incubator. The cells were regularly subcultured by using trypsin-citrate solution. To evaluate the estrogenicity of the samples, the cells were plated in 48-well flat-bottomed microwells (10,000 cells per well) in DMEM and 10% fetal calf serum. Twenty-four hours later, the medium was changed to phenolfree DMEM supplemented with 2% fetal calf serum pretreated with dextran-coated charcoal, along with the solutions to be tested, at concentrations varying from 5% to 20% vol/vol. βEstradiol was used as positive control, and normal saline solution was used as negative control. After six days of incubation, with the medium renewed at day three, the cells were detached using trypsin-citrate solution and counted using a Z1 Beckman-Coulter counter. The assays were performed in triplicate and the results averaged. The statistical analysis of data was performed with 2-way analysis of variance (ANOVA) with appliance and concentration as predictors. Differences were further investigated with the Tukey multiple comparison test at a 0.05 level of significance. Results: An initial experiment was performed using 3 samples, corresponding to as-received retainers, to assess the effects of the two sterilization procedures and the third served as control. None of the samples, at any concentration tested, induced a proliferation of MCF-7 cells compared to the negative control. This was in contrast to the pronounced stimulation by all three β-estradiol concentrations (within the physiological limits) tested. However, after gamma-irradiation, the retainer appearance appeared altered, having acquired a yellowish color reminiscent of the effect of ultraviolet light on plastic materials. Hence, the sterilization through gamma-irradiation was considered a possible source of damage the plastic, and autoclaving was finally chosen as the preferred mode of sterilization. IV Accordingly, 3 samples, corresponding to the retrieved retainers from the three patients were evaluated, in comparison to 2 samples from as-received retainers (either autoclaved or not). No significant MCF-7 proliferation was induced by the three samples compared either to the eluents from as-received retainers or to the negative control. As expected, β-estradiol induced a potent stimulation of MCF-7 cell proliferation, while no effect was observed on MDA-MB- 231 cells. Thus, the null hypothesis was accepted meaning that Vivera® retainers, either as-received or after retrieval from patients, possess no cytotoxic or estrogenic effects. Conclusions: Based on this study, which was performed with the aim of testing the cytotoxic and estrogenic behavior of both as-received and retrieved Vivera® retainers, there was no significant release of substances with estrogenic activity after incubation in normal saline for two weeks at body temperature.
Demographic characteristics of Systematic Reviews, Meta-Analyses and Randomized Controlled Trials in non-orthodontic journals with impact factor
(2017-08) Alqaydi, Ahlam
Aim: The purpose of this study was to identify authorship characteristics of all orthodontic systematic reviews (SRs), meta-analyses (MAs) and randomized controlled trials (RCTs) published in nonorthodontic journals with Impact Factor (IF). The outcomes of this investigation will reveal authorship trends in high impact orthodontic articles published in non-orthodontic journals. Materials and methods: This study identified all SRs, MAs and RCTs published in non-orthodontic journals with IF, until December 2015. Detailed search strategies were developed for every database searched which was based on the strategy developed for MEDLINE but revised appropriately for each database to take account of the differences in controlled vocabulary and syntax rules. The following electronic databases were searched: MEDLINE via PubMed, Scopus, Web of Science™ Core Collection, Google Scholar, and Ovid database. Each database was searched individually and included all the articles published until December 2015. No restrictions were applied during the electronic search regarding language or publication status. However, articles without an abstract in English were excluded. A total of 4524 articles were found. After deleting duplicated results, letters, comments, books, and articles published in orthodontic journals 1860 articles remained. After reviewing each article we ended up with 274 articles in total (SRs: 152; MAs: 36; RCTs: 86). Results: In general, most of the articles published were SRs (55.5%) followed by RCTs (31.4%) and MAs (13.1%). North America (52.2%), European Union countries (56.7%), non-European Union countries (64.3%), and Central and South America (53.6%), all are concentrating in publishing SRs mostly followed by RCTs (North America 32.6%; European Union countries 34.6%; nonEuropean Union countries21.4%; and Central and South America 32.1%). On the other hand, authors in Asia concentrated more on SRs (56.9%) and published RCTs (21.6%) and MAs (21.6%) to almost the same extent. Similar trends applied to authors in Africa (SRs: 60%; MAs: 20%; RCTs: 20%). Oceania presented only publications of RCTs. All three kinds of articles were mostly published during the period of 2006-2015 and most of the regions presented an increase in publications in this period. It was shown that in both periods most of the articles were published in non-orthodontic dental journals (before 2006: 65.8%; during 2006-2015:64.8%). Regarding the number of authors, RCTs had mostly four or more authors (23.3%), SRs had mostly five authors (21.1%) and MAs had three authors (30.6%). It was noticed that in both periods the majority of studies had four authors (21.1% and 20.8%, respectively). Conclusions: Orthodontic literature of a high level published in non-orthodontic journals has significantly increased during the last decade (2006-2015) and has been concentrated mostly in dental journals characterized mainly by an increase in publishing SRs. During the period 2006-2015 there was a significant increase in published articles originating from Asia compared to similar contributions by European Union countries, whose output exhibited a slight decline over the period.
Do Probiotics Affect Oral Health in Patients Under Treatment with Fixed Orthodontic Appliances? A Systematic Review
(2019) Hamou, Riham
AIM: As the presence of fixed orthodontic appliances increases biofilm retention, a deterioration in periodontal clinical parameters can be observed and, under certain conditions, a cariogenic environment may develop, leading to enamel decalcification. The aim of the present review was to systematically investigate the available literature regarding the effects of probiotics on gingival inflammation and enamel decalcification development in patients under orthodontic treatment with fixed appliances. MATERIALS AND METHOD: Searches without restrictions in eight databases and hand searching were carried out. Randomized controlled studies investigating the effect of probiotics on gingival health and enamel decalcification development in patients under orthodontic treatment with fixed applianceswere reviewed. Following study retrieval and selection, relevant data were extracted and the risk of bias was assessed according to the Cochrane Collaboration guidelines. RESULTS: Out of the initially identified unique records, four studies fulfilled the selection criteria for inclusion in the systematic review. Three studies evaluating gingival inflammation after probiotic use for up to one month did not show any iii statistically significant changes. The only study investigating enamel decalcification for a mean duration of 17 months of probiotic use did not demonstrate differences in the incidence of white spot lesions between the groups at debonding. No adverse effects were reported. Various problems were noted during risk of bias assessment. CONCLUSIONS: Overall, short-term probiotic administration does not seem to exert an effect in the development of gingival inflammation and enamel decalcification in patients under treatment with fixed orthodontic appliances. More high-quality studiesinvolving different combinations of probiotic strains and of longer duration of intervention and follow-up are required.
Do the various interceptive interventions improve the position of palatally displaced permanent canines? A meta-analysis
(2021) Habib, Ahlam
Background: Extraction of maxillary primary canines (Cs) and other interceptive interventions in the mixed dentition have been suggested to increase the rate of normal eruption of palatally displaced permanent canines (PDCs). However, the information on the overall effect on PDCs position has not been yet summarized in an evidencebased manner. Objective: To assess whether this practice improves the position of PDCs and to investigate the quality of the evidence. Search methods: Unrestricted searches in 8 databases and manual searching of the reference lists in relevant studies were performed up to March 2021 (Medline via PubMed, CENTRAL, Cochrane Database of Systematic Reviews, Scopus, Web of Science, Arab World Research, ClinicalTrials.gov, ProQuest Dissertations and Theses Global). Selection criteria: We looked for data on the positional changes of PDCs (mesial ii inclination, vertical position, canine crown cusp tip to midline) from randomized controlled trials, assessing the various interceptive interventions. Data collection and analysis: Following study retrieval and selection, relevant data were extracted, and the risk of bias was assessed using the Cochrane Risk of Bias 2 Tool. Exploratory synthesis and meta-regression were carried out using the random effects model, and the overall quality of the available evidence was assessed with the Grades of Recommendation, Assessment, Development, and Evaluation approach. Results: Five studies (3 at low risk of bias) were identified, involving 238 individuals, followed for up to 18 months post-intervention with orthopantomograms or cone beam computed tomography. Exploratory data synthesis showed that PDCs’ position improved more in the extraction sites compared to non-extraction. Analysis of the studies at low risk confirmed the above observations (6 and 12 months). Improvements were observed in patients using headgear after extraction of the Cs compared to extraction alone, but not in patients with double extraction of Cs and first molars. The quality of available evidence was rated as moderate at best. Conclusions: Interceptive interventions in the mixed dentition may improve the position of PDCs. However, further studies are warranted in order to determine the clinical significance of the changes.
Effect of enamel deproteinization on bonding orthodontic brackets: A systematic review and meta-analysis
(2022) Alrai, Sami Zohdi Saleem
Background: Frequent deboning is common during orthodontic treatment. Enamel deproteinization with 5.25% NaOCl or papain has been proposed as one way to increase shear bond strength (SBS) of orthodontic brackets. Moreover, frequent appearance of white spot lesions is common yet unwanted consequence of orthodontic treatment. The use of fluoride releasing resin modified glass ionomer cements (RMGIC) as an adhesive for bonding has been proposed to help minimize white spot lesions. However, with their reduced SBS compared to resin composite, the use of RMGIC, clinically, is not highly recommended. Enamel deproteinization has been proposed as one way to increase SBS of RMGIC. Aim: to systematically review studies assessing the effect of enamel deproteinization on SBS and adhesive remnant index (ARI) of orthodontic brackets by a systematic review of the published literature Materials and Methods: Unrestricted electronic search of 5 databases and grey literature was performed. Following the preferred reporting items for systematic reviews and meta-analysis (PRISMA) statement, randomized trials using extracted human premolar teeth with intact buccal surface, no cracks, no pretreatment with chemical agents, no caries and absence of congenital or developmental conditions with at least one group using deproteinization with 5.25%NaOCl or Papain as an additional measure while bonding were included to assess the effect of deproteinization on SBS as the main outcome and on ARI as a secondary outcome . The random effect method of combining treatment effects for different groups was used. Risk of bias assessment was performed using the Cochrane’s collaboration tool risk of bias tool for randomized trials. Study selection, risk of bias assessment, and data-extraction were performed in duplicate. Results: 19 studies met the inclusion criteria and were included in this systematic review; 14 studies were included the meta-analysis. Eleven studies were at high risk of bias and 4 were at unclear risk. Very low evidence shows that 5.25%NaOCl improved the SBS 0.7(-1.86-0.47). P=0.24 and ARI 0.55 (-0.52 – 1.63) P=0.3 of brackets bonded with RMGIC to be comparable with resin composite only. However, with significantly high heterogeneity for SBS (I 2 , 90%; P <0.00 1) and ARI (I 2 , 86%; P ) respectively. Moreover, for the other comparisons, when comparing 5.25%NaOCl with resin composite to resin composite only, no improvement in SBS 0.212 MPa (-0.16- 0.6), P=0.27 nor ARI 0.14(-0.3-0.56), P=0.5was shown. Similarly, when comparing 5.25%NaOCl RMGIC to RMGIC only, no improvement in SBS 0.36MPa (-0.19-0.89), P=0.2 nor ARI 0.54 (- 0.5-0.1.62), P=0.312was shown. With regards to pretreatment with 10%Papain, a significant mean difference favoring the control group was shown for SBS 0.95MPa (0.63 – 1.26) P 0.001 and ARI 0.55 (0.23- 0.87), P<0.05. Conclusion: There is no strong evidence that enamel deproteinization improves SBS and ARI of orthodontic brackets bonded with resin composite or RMGIC.
Effect of estrus cycle on the rate of orthodontic tooth movement: A systematic review of animal studies
(2020) Almidfa, Noura Saeed Sultan
Background: As estrogen levels affect bone metabolism, the hormonal changes encountered during the estrus cycle may exert an influence on the rate of orthodontic tooth movement. Aim: To systematically investigate the available evidence from animal studies regarding the effect of estrus cycle on the rate of orthodontic tooth movement. Materials and Methods: Search without restriction for published and unpublished literature and hand searching took place. Controlled studies investigating the effect of estrus cycle on the rate of orthodontic tooth movement were reviewed. Following study retrieval and selection, relevant data was extracted and the risk of bias was assessed using the SYRCLE’s Risk of Bias Tool. Results: From the final records, 3 studies met the inclusion criteria. The rate of orthodontic tooth movement was increased during the stages of the estrus cycle when estrogen and/or progesterone levels were lower. The risk of bias in the retrieved studies was assessed to be unclear. Conclusion: Hormonal changes during the estrus cycle may affect the rate of orthodontic tooth movement. Although these animal experiment results should be approached cautiously, it could be safe practice to consider the possible impact of these physiological changes in the clinical setting until more information becomes available.
Effect of nicotine exposure on the rate of orthodontic tooth movement: a meta-analysis based on animal studies
(2020) Jyothish, Sanjay Kumar
Background: Nicotine exposure has been reported to modify bone metabolism with potential effects on the rate of orthodontic tooth movement. Aim: To systematically investigate and appraise the quality of the available evidence from animal studies regarding the effect of nicotine exposure on the rate of orthodontic tooth movement in animal subjects. Materials and methods: Search without language restriction was performed for published and unpublished studies on electronic databases. Controlled studies investigating the effect of nicotine on the rate of orthodontic tooth movement were considered. Following study retrieval and selection, relevant data was extracted, the risk of bias was assessed using the SYRCLE’s Risk of Bias Tool and the random effects method of combining treatment effects was used. Results: From the initially identified records, 5 articles meeting the inclusion criteria were selected. Overall, quantitative data synthesis showed that the rate of orthodontic tooth movement in the nicotine exposed rats was higher than in control the group animals. No effect of the concentration or the duration force application was demonstrated following employment of meta-regression techniques. Many of the risk of bias domains assessed were considered to be unclear. Conclusion: Rats administered with nicotine showed accelerated rates of orthodontic tooth movement. Although, information from animal studies cannot be fully translated to human clinical scenarios, the orthodontist should be able to identify patients exposed to nicotine and consider the possible implications for everyday clinical practice.
Effect of Ovariectomy-Induced Menopause on The Rate of Orthodontic Tooth Movement: A Systematic Review of Animal Studies
(2019) Mohammed, Ayesha Omar Hussain Abdulla
Background: The menopause may theoretically affect the biochemical events leading to orthodontic tooth movement. Aim: To systematically investigate and appraise the quality of the available evidence from animal studies regarding the effect of experimentally induced menopause on the rate of orthodontic tooth movement. Materials and Methods: Search without restriction for published and unpublished literature and hand searching took place. Controlled studies investigating the effect of ovariectomy-induced menopause on the rate of orthodontic tooth movement were reviewed. Following study retrieval and selection, relevant data was extracted and the risk of bias was assessed using the SYRCLE’s Risk of Bias Tool. Results: From the initially identified records, finally, 11 studies met the inclusion criteria. The majority of the retrieved studies were found to be of an unclear risk of bias. The rate of orthodontic tooth movement in ovariectomized animals was greater than in the control group. This difference between the two groups gradually widened as the duration of force application increased. Conclusion: Ovariectomy-induced menopause may affect the rate of orthodontic tooth movement. Although the overall quality of evidence only provides the clinician with a iii cautious perspective on the strength of the relevant recommendations, the orthodontist should be capable of identifying such patients and consider the possible implications.
Effect of supine and upright positions on airway dimensions in patients with obstructive sleep apnea
(2021) Abdullah, Maryam
Aim: The aim of the study was to assess the effect of supine vs upright imaging positions on airway dimensions in patients with obstructive sleep apnea (OSA). Materials and methods: This retrospective study included three-dimensional (3D) data of 30 subjects diagnosed with OSA. Patients’ ages ranged from 26 to 60 years (35.7 ± 2.3 years). Subjects were scanned with a low-dose multiplanar CT scanner in a supine position using X-vision EX, (Toshiba Medical Systems, Otawara-Shi, Japan) at a voxel size of 0.4 mm and a second scan in an upright position using iCAT CBCT scanner (Imaging Sciences International, Hartfield, PA) at the same voxel size. Airway volume was measured at the level of the nasal cavity, nasopharynx, oropharynx, and hypopharynx using Dolphin imaging software (version 11.5; Patterson Dental Supply, Chatsworth, CA). The differences in the measurements in both positions were compared using Student’s t-test and p ≤ 0.05 was considered statistically significant. Results: Significant statistical differences were reported between the measurements at the two positions. The nasopharynx and oropharynx area were significantly less when measured at the supine position. The airway volume measured at the nasal cavity and hypopharynx did not show significant differences between both positions. Conclusion: The patient’s position during the imaging session significantly affects the airway measurements. Airway volume measurement recorded when patient scanned in supine position shows less values than those recorded with upright scanning position.
Effect of Voxel Size on the Accuracy of Airway Volumetric Measurements Using Cone Beam Computed Tomography
(2021) Alhawi, Worod Naeem Khaled
Aim: The purpose of this retrospective study was to evaluate the accuracy and reliability of the airway volume, dental, and skeletal parameters measured digitally on cone beam computed tomography scans (CBCTs) using airway model scanned with different resolutions. Material and method: This retrospective study was performed using CBCT images obtained from an artificial model of airway made by an acrylic airway model scanned at different voxel sizes, timing, and segmentation levels. CBCT scans were divided into four groups according to the voxel size of each scan (0.2, 0.25, 0.3 and 0.4). Airway volume parameters were measured using Dolphin 3D (Dolphin Imaging & Management solutions, Chatsworth, California, USA) software version 11.95. Reliability and accuracy were assessed by using intraclass correlation and Student’s t-test. A P-value of less than 0.05 was considered significant. Results: The intra- and inter-examiner reliability were high for all measurements. Significant statistical differences were detected among airway volume measured at variable voxel size, scanning time, and segmentation level however, no significant differences were found in the skeletal and dental parameters. These results suggested that the airway measurements vary according to the voxel size, scanning time and segmentation level. Conclusion: Airway volume measurements vary depending on the voxel size, scanning time and segmentation level of CBCT scans. Clinicians and researchers should be aware of the effect of the voxel size and scanning resolution on the airway measurements since this could affect the clinical judgement of critical cases.
Effectiveness of extraction of the primary canines for the interceptive management of palatally displaced permanent canines - a meta-analysis
(2017-01) Alyammahi, Ameirah
AIM: Although extraction of primary canines in the mixed dentition has been suggested as a measure to prevent impaction of palatally displaced permanent canines (PDC), the relevant evidence has been inconclusive. The aim of this study was to investigate the effectiveness of this practice. MATERIALS AND METHOD: Search without restrictions for published and unpublished literature and hand searching took place. Data on the prevalence of physiologic PDC eruption, patient reported outcomes, adverse effects and economic evaluation data from randomized controlled trials (RCTs) that compared extraction of primary canine to no treatment (including delayed treatment) were reviewed. The random effects method of combining treatment effects was used and the individual study risk of bias and the overall quality of the available evidence (confidence in the observed effect estimates) were assessed using the Cochrane Risk of Bias Tool and Grades of Recommendation, Assessment, Development and Evaluation approach, respectively. RESULTS: We initially identified 1878 references and finally included data from 5 RCTs involving 329 patients with 479 PDC in total, following them for up to 48 months post- ii intervention. One study also presented data for the 12-month evaluation. Two studies were at low and the rest at high risk of bias. At the 12-month evaluation, extraction of the primary canine does not result in a statistically significant benefit compared to no treatment [Risk Ratio (RR): 1.537; 95% Confidence Interval (CI): 0.656 – 3.601; 1 study, n = 67 participants]. Beyond 12 months, overall, there is only low quality evidence that extraction of primary canines provides a statistically significant benefit compared no treatment or delayed treatment [RR: 1.784; 95% CI: 1.376 – 2.314; 5 studies, n = 214 participants; I2 = 0%]. Analysis of the studies at low risk of bias confirmed the abovementioned result [RR: 1.713; 95% CI: 1.226 – 2.394; 2 studies, n = 91 participants; I2 = 0%]. Moreover, the intervention did not result in a statistically significant benefit compared to no treatment regarding root resorption of adjacent permanent teeth [RR: 0.602; 95% CI: 0.277 – 1.308; p = 0.200 n = 67 participants] CONCLUSIONS: Extraction of primary canines in mixed dentition may increase the chance of subsequent successful eruption of PDC in the long term. However, better study standardization and reporting of long follow-ups are necessary.
Effectiveness of Orthodontic Procedures, Alternative or Adjunctive To Extraction of the Primary Canines, For Interceptive Management of Palatally Displaced Permanent Canines: A Systematic Review
(2018) Al Naqbi, Ibrahim
Aim: Although Rapid Maxillary Expansion (RME), Trans-Palatal Arch (TPA) and Cervical-pull Headgear (HG) have been suggested as interventions in the mixed dentition to increase the rate of normal eruption of the palatally displaced permanent canines (PDCs), existing knowledge on the subject has been inconclusive. The aim of this study was to investigate their effectiveness in an evidence-based manner. Materials and method: Search without restrictions for published and unpublished literature and hand searching took place. Data on the prevalence of physiologic PDCs eruption from randomized controlled trials (RCTs) that investigated the use of RME, TPA and HG alternatively or adjunctively to extraction of the primary canines were reviewed. The individual study risk of bias was assessed using the Cochrane Risk of Bias Tool. Results: From the initially identified records, finally, data from 5 RCTs (at high risk of bias) were included, involving the analysis of 480 PDCs in total with a follow up period of 5 years. RME, TPA and HG, used alternatively or adjunctively to extraction of primary canines, can significantly increase the rate of normal eruption of PDCs in the long term compared to no intervention, while no difference was observed in comparison to extraction. Only when HG was used after the iv extraction of the primary canine, was a statistically significant benefit shown compared to the extraction of the primary canine only group. Conclusions: RME, TPA and HG used alternatively or adjunctively to extraction of primary canines can significantly increase the rate of normal eruption of PDCs compared to no intervention. However, when compared to extraction, no differences were noted overall. Further research and better study standardization are warranted.

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