Turkish Journal of Orthodontics最新文献

Objective: In this study, the effects of different chemical solvents such as acetone, ethanol, dimethyl sulfoxide (DMSO), peppermint oil, and hot water on the shear bond strength (SBS) of mechanically and chemically bonded ceramic brackets were examined. Their use for facilitation of the debonding process in practice was evaluated regarding the purposes of this study.

Methods: One hundred and thirty-two human premolar teeth extracted for orthodontic purposes were randomly divided into 11 groups. SBS were applied using a universal test machine. The amount of residual adhesives was determined through adhesive remnant index scoring. Scanning electron microscopy (SEM) images were examined to determine the effects of solvents on the enamel surface.

Results: In all test groups, the highest SBS values were found in the ethanol 5- and 15-minutes groups. SEM examination showed micro-cracks in all groups. Increased SBS values were also found in 5- and 15-minutes groups of hot water and DMSO, while both peppermint oil groups had similar SBS values as the control group. SBS values of both acetone 5- and 15-minutes groups were found to be lower than the control and other groups.

Conclusion: Acetone application for 5 or 15 minutes before debonding of ceramic brackets could be an alternative clinical approach to prevent enamel damage and facilitate debonding.

Objective: The goal of the current study is to compare the transfer accuracy of two different conventional indirect bonding trays with 3D-printed trays.

Methods: Twenty-two patients' upper dental models were duplicated, scanned and brackets were bonded digitally. Different indirect bonding trays (double vacuum formed, transparent silicone and 3D-printed) were prepared according to three groups. These trays were used for the transfer of the brackets to the patients' models, then models with brackets were scanned. GOM Inspect software was used for the superimposition of virtual bracket setups and models with brackets. A total of 788 brackets and tubes were analyzed. Transfer accuracies were determined according to the clinical limit of 0.5 mm for linear and 2° for angular measurements.

Results: 3D-printed trays had significantly lower linear deviation values than other trays for all planes (p<0.05). 3D-printed trays have significantly lower torque and tip deviation values than other groups (p<0.05). Transfer deviations were within the clinically acceptable limit for all transfer trays in horizontal, vertical and transverse planes. Deviation values of the molars were higher than those of the other tooth groups for all trays in the horizontal and vertical planes (p<0.05). Brackets were generally deviated toward the buccal direction in all tray groups.

Conclusion: The transfer accuracy of 3D-printed transfer trays was more successful than the double vacuum formed and transparent silicone trays in the indirect bonding technique procedure. Deviations in the molar group were greater than those in the other tooth groups for all transfer trays.

Objective: The present study aimed to find a chemical reagent that would reduce the debonding force to enable easier debonding of the ceramic brackets, thus reducing enamel damage as well as chair side time.

Methods: The study included 4 groups -control (distilled water), eucalyptus oil, glutathione and lemon essential oil for immersing teeth bonded with ceramic brackets. Samples (25 in each group), extracted first premolars, were mounted and immersed in their respective solution for a duration of 10 minutes following which they were tested to evaluate the debonding force using the INSTRON universal testing machine. The amount of adhesive left behind on the enamel surface was evaluated using adhesive remnant index (ARI) score and surface changes were checked using a scanning electron microscope.

Results: Teeth immersed in glutathione showed the greatest amount of reduction in debonding force (p=0.001) compared with other groups. ARI scores were low for specimens immersed in glutathione. SEM images showed that teeth in the glutathione group had a cleaner enamel surface, suggesting less or no adhesive was left behind and no sign of enamel damage after debonding ceramic brackets.

Conclusion: Specimens that were immersed in glutathione for a duration of 10 minutes before debonding of ceramic brackets showed the greatest reduction in debonding force compared with control and demonstrated peel off effect with no enamel damage. Glutathione can be used as an effective reagent during the clinical debonding of ceramic brackets.

Objective: To define the dental and skeletal characteristics of Class III surgery patients with ideal final soft-tissue profiles, and to compare them with those of Class I subjects. Also, to show how soft-tissues respond to surgical jaw movements and contribute to the outcome.

Methods: This short-term, retrospective study was conducted using pre-treatment (T0), pre-surgery (T1), and post-treatment (T2) records of 50 double-jaw Class III surgery patients who presented with ideal cephalometric characteristics in sagittal (Holdaway and soft-tissue convexity angles) and vertical dimensions (GoGn. SN angle and upper-to-lower face harmony) at the end of treatment, and 50 control subjects.

Results: At T2, the horizontal distance between the vertical reference plane (a perpendicular plane to the horizontal reference plane that is angulated 7° clockwise to the SN plane) and hard-tissue A, B and Pog points, lower lip, soft-tissue B, and pogonion points were greater, Wits appraisal was more negative, U1.PP was higher, IMPA was lower, and soft-tissue chin (Pog-Pog') was thicker in Group 1 when compared to Group 2 (p<0.05). Moreover, upper lip and subnasal (A-A') thicknesses were decreased, and chin thickness (Pog-Pog') was increased significantly (p<0.05).

Conclusion: Dentoskeletal characteristics of an ideally-treated Class III surgery patient differed from a Class I subject concerning a protrusive maxilla and soft-tissue pogonion, and incisors that were not fully-decompensated. Soft-tissues hindered the actual surgical correction to 66% and 73% in the mid- and lower-faces, respectively.

Objective: To systematically review the relationship between gingival biotype (GT) and malocclusion.

Methods: The review followed PRISMA standards of quality for systematic reviews and meta-analyses reporting with PROSPERO registration number CRD42020126543. The systematic database search included MEDLINE, Scopus, Embase, PsychINFO, CINAHL, and other key journals; the article search was performed until February 2020. Cochrane's risk of bias in non-randomized studies-of interventions (ROBINS-I) was used to grade the methodological quality of the included studies.

Results: The systematic search identified 105 studies, six studies satisfied the inclusion criteria for eligibility. The study participants ranged from 26 to 200 (total n=812), with a mean of 135. Study participants were aged between 14 and 32 years. Five studies were graded as the moderate risk of bias and one study as low risk of bias. Two studies showed thin GT among individuals with severe crowding compared to mild crowding. Three studies showed a thin GT with a narrow zone of the keratinized gingival width compared to a thick GT. No relationship was found between GT and Angle's classification of malocclusion.

Conclusion: No relationship was observed between Angle's classification of malocclusion and GT. Thin GT was prevalent among individuals with pro-inclination of incisors. Keratinized gingival width was narrow among individuals with thin GT.

Orthodontics stands on a junction where traditional analog appliance manufacturing slowly but steadily changes to a digital one with the use of 3D technology. The main cause of this shift was the invention and use of computers. The use of computers, computer-aided design (CAD) software, computerized machines, and newly invented materials allowed this change to occur in a relatively short time in dentistry and orthodontics. The trigger for this transformation is the ability to digitally scan the oral cavity. CAD software and 3D printers already existed. It took a few years to include this technology in orthodontics and continuously apply it in the orthodontic office. Orthodontic treatment is mainly based on the use of fixed appliances, while in the last years, thermoformed aligners have been introduced as an alternative whenever a more invisible treatment modality is preferred. Clear aligner treatment is performed using thermoformed aligner. A new aligner resin has been recently invented to allow direct aligner printing. Directly printed aligner possess many advantages compared to thermoformed one. Research has been initiated to investigate all the aspects of the workflow and aligner printing outcome. More studies must be performed to look into the various aspects of directly printed aligners.

Objective: Operator experience and scanner type may influence the time taken and obtained accuracy of intraoral scanning. This study aimed to evaluate the influence of operator experience on the scanning time and correlate the accuracy of the scans taken with two different intraoral scanners (TRIOS 3, 3Shape and i500, Medit).

Methods: In this trial, a total of 20 subjects who required intraoral scanning for orthodontic treatment were included. Intraoral scanning was done with two different scanners, TRIOS 3 and i500. One operator each with high (group 1), medium (group 2) and low (group 3) levels of experience performed intra-oral scanning with two different intraoral scanners. A One-Way ANOVA test was performed to assess the intergroup difference in scanning time and Kendall's tau's correlation test to determine the correlation between the experience of the operator and accuracy among the three groups using the two scanners. Also Independent samples t-test were performed to assess the intragroup differences in scanning time with two different scanners.

Results: The scanning time was influenced by the type of intraoral scanner and operator experience (p<0.05). No significant correlation between operator experience and scanning accuracy in the three groups was noted (p>0.05). Statistically significant intragroup differences in scanning time between the two scanners were noted (p<0.05).

Conclusion: Less experienced operators took more time to scan a subject. Accuracy of scanning among three groups using two scanners was not influenced by the experience of the operator. Scanning with i500 IOS took more time than TRIOS.

Objective: The aim of this study was to determine the effect of Forsus Fatigue Resistant Device (FRD) appliance on craniofacial structures, bite force and periodontal status in Class II malocclusion patients.

Methods: In this prospective interventional follow-up study, thirteen (13) Class II Division 1 patients in their post-adolescent age group with average age of 17.10 ± 1.63 year was treated with Forsus FRD. They were assessed for craniofacial changes, bite force and periodontal status at baseline, after alignment and leveling, after removal of FRD.

Results: Improvement in soft tissue profile was due to significant dentoalveolar changes. There were significant decreases in overjet, overbite, reference line to upper first molar, H angle (p<0.001) and significant increases in upper lip to E-line, reference line to lower molar and angular measurements like nasolabial angle, U1 to SN plane, Incisor Mandibular Plane Angle (p<0.001). The bite force was significantly decreased on the molar and the incisor region (p<0.001). A significant increase in plaque index (PI), gingival index (GI), probing pocket depth was noticed without any significant clinical attachment loss.

Conclusion: Class II correction with Forsus FRD appliance was mainly due to significant dentoalveolar changes. Skeletal changes were non-significant. A decrease in the bite force was found with FRD. The magnitude of bite force was more in males compared with females. The increase in GI, PI, pocket probing depth implies the necessity of oral hygiene and plaque control measures. However, there was no significant change in clinical attachment level.

Objective: To determine whether multiple siblings resemble one another in their craniofacial characteristics as measured on cephalometric radiographs.

Methods: This study was conducted retrospectively using the Forsyth Moorrees twin sample. A total of 32 families were included, each with ≥4 postpubertal siblings, totaling 142 subjects. Only 1 monozygotic twin was included per family. Headfilms were digitized, skeletal landmarks were located, and 6 parameters that indicated sagittal jaw relationships and vertical status were measured. Diverse statistical approaches were used. Dixon's Q-test detected outliers in a family for a given parameter. Manhattan Distance quantified similarity among siblings per parameter. Scatter plots visually displayed subject's measure relative to the mean and standard deviation of each parameter to assess the clinical relevance of the differences.

Results: A total of 11 families (34.4%) had no outliers on any parameter, 13 families (40.6%) had outliers on 1 parameter, and 8 families (25%) had outliers on ≥2 parameters. We identified 29 individuals with at least 1 outlying measure (20.4%). Among these, only 2 individuals (1.4%) were significantly different from their siblings for more than 1 measurement. Although the majority of the families did not demonstrate any statistical outlier, the ranges of the measurements were clinically relevant as they might suggest different treatment. For example, the mean range of SNB (Sella-Nasion-B point) angles was 7.23°, and the mean range of MPA was 9.42°.

Conclusion: Although families are generally not dissimilar in their craniofacial characteristics, measurements from siblings cannot be used to predict the measurements of another sibling in a clinically meaningful way.

Objective: This randomized controlled trial aimed to evaluate the role of fixed orthodontic treatment in the aggravation, precipitation, or alleviation of temporomandibular disorders in young adults.

Methods: Sixty patients were randomly assigned to 4 groups of 15 patients each (group I, orthodontic treatment in temporomandibular disorder-free orthodontic patients; group II, orthodontic treatment in patients with mild symptoms of temporomandibular disorders; group III, splint therapy accompanied by orthodontic treatment in patients with moderate symptoms; and group IV, control with no treatment). The biometric equipment used were the T-scan, to analyze the occlusal component; the BioEMG for muscular analysis; BioJVA for temporomandibular joint acoustic analysis; and JT3D for mandibular kinematic analysis. The paired t-test and ANOVA were used for intragroup and intergroup comparisons, respectively. The difference between groups was assessed using post hoc Tukey's test.

Results: Groups I and III showed significant difference in the occlusal, muscular, temporomandibular joint vibration, and kinematic mandibular assessment variables. Group II showed significant improvement in occlusal variables only. Group IV did not show improvement in any of the variables except for certain muscular components.

Conclusion: Successful practical utilization of biometric equipment revealed that fixed orthodontic treatment does not aggravate temporomandibular disorders. It was also found that temporomandibular disorders due to malocclusion can be treated successfully with orthodontic treatment, whereas temporomandibular disorders due to multifactorial temporomandibular joint and muscular components might require splint therapy before orthodontic intervention.