Turkish Journal of Orthodontics最新文献

Objective: This retrospective study aimed to assess the presence and amount of external apical root resorption (EARR) in endodontically treated teeth (ETT) and contralateral teeth with vital pulp (VPT) following orthodontic treatment.

Methods: The study sample included panoramic radiographs of 503 patients (314 females and 189 males; 16.29 years±3.98) with 620 ETT and 580 VPT. The tooth length was measured on digital panoramic radiographs, which were collected at the beginning and end of the orthodontic therapy for each subject. The pre- and post-orthodontic treatment radiographic evaluation included the percentage of EARR in ETT and contralateral VPT for all tooth types. Any relationship between EARR and orthodontic treatment type (one- and two-phase; extraction and non-extraction), duration, and patients' age and gender were investigated. Mann-Whitney U, Wilcoxon signed rank, Kruskal-Wallis and Spearman correlation tests were applied for comparisons and to test the correlations.

Results: A statistically significant difference was observed in all orthodontic treatment groups when ETT and VPT were compared in terms of EARR (p<0.05). EARR was positively correlated with orthodontic treatment duration and type (p<0.05) but was not influenced by patient age or gender. Statistically significant EARR was observed in the two-phase extraction orthodontic treatment group for both ETT and VPT. In VPT, a statistically significant EARR was found in the one-phase extraction treatment group compared with the non-extraction treatment group, whereas no significant difference was found in ETT.

Conclusion: ETT showed significantly lower EARR than VPT. ETT can therefore be moved safely during orthodontic treatment.

Objective: This study aims to compare the impact of titanium and stainless steel (SS) retainer wires on lower incisor stability and periodontal health.

Methods: Fifty patients between the ages of 14.1 and 29.5 years were recruited for the study. The impact of 0.027x0.011-inch rectangular titanium dead-soft wire retainers was compared with that of 0.0215-inch six-stranded SS wire retainers. The retainers were bonded to the mandibular arch, and 3D models were evaluated after completion of the orthodontic treatment (T1), at the third month (T2), and at the sixth month (T3). Little's irregularity index (LII), the intercanine width, the pocket depth, the plaque index, bleeding on probing, and retainer survival were analyzed. The generalized linear model method was used to compare scores on LII, the intercanine width, the pocket depth, and plaque index values. Cochran's Q test was used to compare intragroup bleeding.

Results: A significant increase was found in the irregularity index parameter according to time (p=0.004) but no statistically significant difference was found between groups in terms of the LII according to material and time (p=0.826). No significant difference was found in intercanine width parameters between the groups according to material and time (p=0.977). No statistically significant difference was found between the groups in terms of pocket depth and plaque index scores, according to material and time. No retainer failure was observed in either group.

Conclusion: Both retainer wires offer successful results in terms of stability parameters and periodontal parameters after six months.

Objective: This study aimed to evaluate the skeletal, dental, and soft tissue effects of the nickel titanium memory Leaf Expander in a growing sample of patients with unilateral posterior crossbite compared with a control group using digital models and lateral cephalometric radiographs.

Methods: The research included a total of 24 patients, 12 of whom were treated and 12 untreated. The Leaf Expander group consisted of 4 males and 8 females (mean age= 8.6±10.7 years), and the control group consisted of 5 males and 7 females (mean age: 9.2±0.8 years). Changes during the observation period in both groups were evaluated using the Wilcoxon signed-rank test. We used the Mann-Whitney U test to compare the data between the groups.

Results: There was a significant increase in the values indicating the vertical position of the maxilla and mandible in the treatment group. The palatal surface area increased significantly in both groups, but the increase was significantly higher in the treatment group than in the control group. In addition, intermolar width and arch perimeter measurements were significantly higher in the treatment group than in the control group.

Conclusion: With the advantage that this device does not require parent compliance, the possibility of incorrect activation was eliminated, and effective expansion using the Leaf Expander was achieved in patients with unilateral crossbite.

Objective: To evaluate the effect of emotional states on reproducibilities of rest position, social and spontaneous smiles, and speech.

Methods: A total of 30 individuals aged 18-22 years were included (mean age; 19.03 years ±1.03). Three emotional states were determined: amusing, sadness, and neutral. The participants watched three different videos in 3 sessions on the same day. After each video, the participants completed a questionnaire to assess their mood. The rest position, social and spontaneous smiles, and speech recordings were gathered from the participants using videographic method. Measurements were made for each function. The Friedman test, One-Way ANOVA, Kruskal-Wallis test was performed for statistical evaluations, and intra-observer correlation coefficients and Bland-Altman Limits of Agreement were calculated.

Results: In spontaneous smiles, there were significant differences between amusing and sadness in the smile height (p=0.020); amusing and sadness in the lower lip thickness (p=0.029). In social smiles there was a significant difference between amusing and sadness in the maxillary incisor display (p=0.006). There were no statistically significant differences in the rest position, but clinically significant differences were observed in some participants. In speech, a significant difference was found between amusing and sadness in the distance between the upper lip and subnasal (p=0.035).

Conclusion: The reproducibility of social and spontaneous smiles was influenced by various emotional states. However, the rest position exhibits higher reproducibility than social and spontaneous smiles in all emotional states.

Objective: This study aimed to compare the manufacturing accuracy of different printing techniques - Stereolithography (SLA), Digital Light Processing (DLP), and PolyJet-using digital dental models.

Methods: The study included cast models of 30 patients aged between 12 and 20 years. The selected models were scanned using an intraoral scanner, and surface topography format files were obtained. The models were produced from 3D printers with SLA, DLP, and PolyJet technology and scanned with an intraoral scanner. The digital files of the reference and printed models were superimposed with reverse engineering software. Root mean squared (RMS) values and point registration differences were evaluated. Furthermore, digital mesiodistal measurements of the teeth were taken to determine the point registration deviation values. Descriptive statistics were used to evaluate the measurements. ANOVA was used to evaluate differences between normally distributed data. In addition, a box plot was used to show the variability in the measurements, and the Bland-Altman test was used to examine the agreement between the measurements.

Results: According to the digital superimposition data of DLP-SLA-PolyJet technologies, PolyJet had the smallest RMS (0.145±0.10 mm), followed by DLP and SLA (0.161±0.12 mm and 0.345±0.23 mm, respectively). In the mesiodistal dimensional measurement evaluations, there was no statistically significant difference (p>0.05) between the averages of the main reference and DLP, PolyJet, and SLA measurements for all teeth.

Conclusion: According to the results of this study, all three production technologies are clinically usable at the model production stage. However, SLA was found to be less accurate than DLP and PolyJet.

Objective: The aim of this retrospective study was to compare the effects of the Twin block and Herbst appliances on the mandibular trabecular pattern using fractal dimension analysis (FDA) of panoramic radiographs (PRs).

Methods: The PRs of 50 subjects with skeletal Class II malocclusion who underwent the Twin block (T-group, average age: 11.63±0.87; 25 girls, 25 boys), 50 subjects with skeletal Class II malocclusion who underwent the Herbst (H-group, average age: 11.72±0.91; 27 girls, 23 boys), and 50 controls (C-group average age: 11.67±0.83; 24 girls, 26 boys) were selected. The condyle, corpus, and angulus regions of all groups in the mandible were examined using FDA.

Results: The condylar region (p≤0.001) and corpus mandible in the treatment groups (T-group: right, p≤0.05, left, p≤0.01; H-group: p≤0.05), as well as the left and right condylar region (p≤0.001) and left corpus mandible (p≤0.05) in the C-group, all indicated substantial increases in FDA between T0 and T1. Inter-group comparisons indicated that the T-group had greater variances in the condyle (p≤0.001) compared to the H group.

Conclusion: As the findings revealed both Twin block and Herbst appliances not only contributed to the dentoalveolar structure but also provided remodeling of the mandibular trabecular structure. Consequently, the null hypothesis was rejected.

Objective: The aim of this study was to evaluate and compare microleakage under the conventional and flash-free ceramic brackets bonded with different agents.

Methods: Forty extracted human maxillary premolar teeth were randomly divided into five groups. According to the groups, adhesive coated and conventional bracket systems were bonded to the tooth surfaces with the specified adhesive agents. To simulate a six-month oral environment, all teeth were subjected to a thermal cycle procedure. Micro-computed tomography (micro-CT) was used to view and measure the microleakage. Kruskal-Wallis test was used to compare the parameters and Mann-Whitney U test was used for the determination of the group that caused the difference. For intragroup comparisons Wilcoxon signed-rank test was used.

Results: Microleakage volume (mm³) and microleakage percentage (%) measured in Blugloo™ group was found significantly lower (p<0.05) then other groups. There was no significant difference in microleakage volume (mm³) and percentage (%) in comparison of gingival and occlusal regions (p>0.05).

Conclusion: Adhesive precoated flash-free brackets were not shown a significant difference compared to their conventional equivalent for microleakage volume. The brackets bonded with Blugloo™ adhesive were showed significant less microleakage than the other groups.

Objective: To investigate the effect of deferred timing of therapeutic extraction on the rate of space closure during en masse anterior retraction.

Methods: Twenty-six patients (aged 16-24 years) with bimaxillary protrusion, crowding <3 mm, requiring bilateral extraction of four first premolars were recruited. Permuted block randomization was done. Allocations were concealed in opaque envelopes which were numbered and sealed. Each patient's right and left quadrant was randomly assigned for premolar extraction. The extraction of the contralateral side was deferred until the commencement of retraction. The primary outcome was the rate of space closure, and the secondary outcomes were anchorage loss and canine rotation. Blinding was applied only during the outcome assessment. The independent t-test and Intraclass correlation tests were used for statistical evaluation.

Results: Twenty-four patients completed the study. The mean rate of space closure over a period of 4 months was found to be significantly higher for the recently extracted site (0.818±0.208) when compared with healed site(0.426±0.184)(p<0.001). The tipping of the canine was also significantly higher for the former (6.042°±1.398°) than the latter (5.125°±1.035°) (p<0.05). However, the amounts of anchorage loss and canine rotation were insignificant. No adverse effects were noted.

Conclusion: The rate of space closure at the recent extraction site was faster than that at the healed site. There was no significant difference in the mesial movement of anchorage molars or rotation of canines into the extraction site. The tipping of canines was significantly greater in the recent extracted quadrant. The results of this trial indicate a clinical recommendation to initiate orthodontic retraction immediately following therapeutic extractions and offer a practical, non-invasive, safe procedure for increasing the rate of tooth movement.

Objective: The purpose of this study was to compare the effects of cherry juice, coffee, coke, gastric acid, and the thermo-aging procedure (TAP) on the shear bond strength (SBS) of APC II, APC flash-free, and conventional ceramic brackets.

Methods: A total of 180 human premolar teeth were randomly divided into three major groups according to the type of ceramic bracket. Then, six subgroups (n=10) were established from each major group: Group 1: control; Group 2: only TAP; Group 3: 72 hours of cherry juice exposure + TAP; Group 4: 72 hours of coffee exposure + TAP; Group 5: 72 hours of coke exposure + TAP; and Group 6: 24 hours gastric acid exposure + TAP. SBS was assessed for each specimen using a universal test device, and the adhesive remnant index (ARI) was scored under a light microscope. Kruskal-Wallis and post-hoc Tamhane tests were used to analyze the data.

Results: Among the control groups, the highest SBS value belonged to conventional ceramic brackets (p<0.01). SBS values for all groups decreased as a result of each liquid and TAP. Gastric acid and coke had the greatest detrimental effects on SBS, while TAP had the least negative effects. The SBS values of APC II, APC flash-free, and conventional brackets were found to be statistically insignificant after different liquid exposures and TAP.

Conclusion: TAP and various fluids had a negative impact on the SBS value of ceramic brackets. SBS values, however, were still higher than clinically acceptable (8-9 MPa) values, even after exposure to gastric acid and coke.