The Angle orthodontist最新文献

Objectives: To compare planned and achieved outcomes for an initial series of Invisalign Lite (Align Technology, Santa Clara, Calif) aligners regarding overjet, overbite, arch depth, and incisor labiolingual inclination.

Materials and methods: Relevant data from adult patients satisfying inclusion criteria regarding overjet and overbite were obtained from the Align Technology treatment planning application. Metrology software was employed to calculate pretreatment, planned, and achieved arch depth and labiolingual measurements of maxillary and mandibular central incisors. Bland-Altman plots were used to demonstrate findings.

Results: Most (n = 95; 79.5%) of 122 patients satisfying selection criteria were female. For overjet, mean differences were + 0.183 mm (SD: 0.557). P values (both = 1.000) indicated that differences did not lie outside the clinically acceptable interval ± 0.5 mm. For overbite, with a mean difference of + 0.746 mm (SD: 0.857), Bland-Altman plot showed a potential proportional bias, with discrepancies increasing as initial overbite increased. Across all arch depth subgroups, differences remained within an acceptable range, and no differences (P > .05) were detected between planned and achieved outcomes. Achieved mandibular incisor labiolingual inclination outcomes closely matched those planned with a mean difference of -1.088° (SD = 2.78°), whereas corresponding outcomes in the maxilla (-2.905° [SD = 2.671°]) indicated a consistent tendency for achieved to be lower than planned.

Conclusions: Although achieved overjet, arch depth and mandibular incisor labiolingual inclination measurements closely matched those planned, there were significant statistical and clinical differences between planned and achieved overbite and maxillary incisor labiolingual inclination measurements.

Objectives: To evaluate the accuracy of clear aligner attachments and quantify excess composite volume when using flowable composite resins with different viscosities in an in vitro setting. The null hypothesis was that viscosity would not significantly impact accuracy or excess.

Materials and methods: A total of 120 samples was evaluated. Four attachment types: ellipsoid (EA), rectangular (RA), beveled (BA), and half-moon (HMA), were applied using three flowable composites: Estelite Universal Flow High (HF), Medium (MF), and Super-Low (SLF) viscosity (Tokuyama Dental, Japan). Attachments were bonded on three-dimensionally printed typodont models and digitally scanned. Digital scans were aligned with reference models using local best-fit analysis. Surface deviation was measured at five points, and overall deviation was represented by arithmetic mean and standard deviation (sigma) values. Excess composite area and volume were calculated. The data were nonnormally distributed, so nonparametric tests were used: Kruskal-Wallis for group comparisons and Mann-Whitney U for pairwise analyses (P < .05).

Results: Significant differences in attachment accuracy and excess composite were observed among viscosity groups. In EA and RA groups, HF composite showed significantly greater accuracy than MF and SLF (P = .016, P = .018). In BA, SLF exhibited lower accuracy than HF and MF (P = .005). Excess composite volume was significantly higher in EA and HMA with HF composite (P = .011 and P = .002, respectively).

Conclusions: Composite viscosity and attachment shape influence accuracy and excess. High-viscosity resins improve precision but increase excess; low-viscosity resins reduce excess but may compromise accuracy. Both material and attachment design should guide clinical choices in clear aligner treatment.

Objectives: To elucidate the retraction effectiveness of extra-alveolar mandibular buccal shelf (MBS) bone screws anchorage relative to the presence of mandibular third molars and ANB angle in Class III patients.

Materials and methods: This retrospective study included 45 patients (mean age = 22.2 ± 6.7 years) treated with bilateral MBS stainless steel bone screws (2 × 12 mm). Patients were subgrouped based on mandibular third molar status and ANB angle (≤-2° vs > -2°). Pretreatment and posttreatment cephalograms were superimposed and analyzed. Statistical tests included analysis of variance, paired and independent t-tests, and linear regression.

Results: Mean retraction of mandibular first molars and incisors was 1.86 ± 1.36 mm and 2.89 ± 1.64 mm, respectively, over an average of 9.0 months. Retraction ≥ 3 mm was significantly associated with treatment durations ≥ 12 months (P < .001). No significant differences in retraction outcomes were found among third molar subgroups. The severe malocclusion group (ANB ≤ -2°) showed greater molar retraction and overjet increase. A moderate positive correlation was found between molar crown retraction and retraction duration (R2 = 0.282, P < .001).

Conclusions: MBS bone screws provide effective, minimally invasive anchorage for mandibular whole-arch retraction in Class III patients. Treatment outcomes are not hindered by third molars in adolescents, and longer retraction duration enhances distal movement.

Objectives: To compare the susceptibility of enamel to white spot lesion formation following the application of two orthodontic bonding protocols: a conventional three-step adhesive system and a two-step self-adhesive system with primer integrated into the resin.

Materials and methods: Thirty extracted premolars were randomly allocated to two groups: Transbond XT (three-step system) and GC Ortho Connect (two-step self-adhesive system). After 7-day pH cycling, demineralization was assessed using Witec a300R confocal Raman microscopy. Phosphate intensity at 960 cm-1 was measured along a 130-µm enamel profile and normalized.

Results: Measurements by two operators showed high intraoperator and interoperator reliability (intraclass correlation coefficient = 0.82-0.92). GC samples exhibited a continuous decline in phosphate intensity, indicating extensive demineralization, while XT samples showed a midenamel plateau, suggesting mineral preservation. Spline modeling confirmed significantly higher phosphate retention in the XT group at middepth (P < .001), with both groups showing surface demineralization near 130 µm (P = .005).

Conclusions: The three-step adhesive system (Transbond XT) showed greater resistance to subsurface enamel demineralization than the self-adhesive system (GC Ortho Connect). These results suggest that using a separate primer may better protect enamel beyond the immediate bracket interface.

Objectives: To determine the most effective ways to correct lower lip sucking in preschool children, minimizing impacts on their Oral Health-Related Quality of Life (OHRQoL) and improving malocclusion.

Materials and methods: 83 children aged 3-6 years were divided into behavioral therapy (Group A, n = 27), lip bumper therapy (Group B, n = 27), and Twin Block therapy (Group C, n = 29) groups. After 6 months of treatment, oral exams, model analysis, cephalometrics, and the Early Childhood Oral Health Impact Scale (ECOHIS) were used for assessment.

Results: Success rates in Groups A, B, and C were 33.33%, 73.08%, and 96.43%, respectively (P < .05). Groups A and B had no significant measurement differences (P > .05). Group C showed significant changes in overjet, SNA, SNB, ANB, U1SN, and L1MP (P < .05). The ECOHIS scores of all groups first rose, then fell (P < .05).

Conclusions: Twin Block appliances are highly effective for correcting lower lip sucking. They have a higher success rate than other methods and can reduce skeletal malocclusion severity in children with specific dental conditions.

Objectives: To determine if adhesive remnants and enamel loss after debonding and cleanup with a finishing bur were affected by hardness properties of the adhesive resins.

Materials and methods: Stainless steel orthodontic brackets (American Orthodontics, Mini Master series) were bonded on facial surfaces of extracted premolars using a relatively soft bioactive resin (ACTIVA BioACTIVE-Restorative, Pulpdent) or harder traditional adhesive (Transbond XT, 3M; N = 20/group). Bracketed teeth underwent 5000 thermocycles before brackets were debonded. Debonding surfaces were examined qualitatively and categorized by three examiners. Remaining adhesive was removed with a carbide finishing bur. Teeth were scanned with an optical scanner before brackets were bonded (baseline), after debonding, and after cleanup. Surface changes (mean thickness or depth, affected surface area, and volume) were calculated quantitatively after aligning scans to the baseline. Differences between the two groups were analyzed statistically with Mann-Whitney U-test or pairwise comparison at a significance level of 0.05.

Results: Qualitative examination of debonded surfaces did not show a significant difference (P = .7949) in adhesive remnants between groups, which was confirmed by quantitative evaluation (P > .05). After cleanup, enamel loss was significantly higher in the softer bioactive resin group (mean depth = 91 ± 16 µm, area = 24.48 ± 9.88 mm2) than the harder traditional adhesive (mean depth = 66 ± 9 µm, area = 6.34 ± 4.41 mm2; P < .0001).

Conclusions: The likelihood of adhesive remnants after debonding a bracket bonded with the bioactive resin was similar to traditional adhesive. However, enamel loss from cleaning up with a finishing bur was higher for the softer bioactive resin.

Objectives: To compare the effectiveness of clear aligner (CA) vs removable inclined plane (RP) in improving the dentofacial changes and oral health-related quality of life (OHRQoL) in children with anterior crossbite in the mixed dentition.

Materials and methods: Twenty-four pseudo-Class III patients in the mixed dentition (8-12 years) were randomly allocated into two equal groups: the CA group treated with clear aligners, and the RP group treated with removable inclined planes. Lateral cephalometric analysis and OHRQoL questionnaires were conducted immediately before and after 4 months of intervention. The primary outcome included cephalometric changes, whereas the CPQ8-10 (children's perception questionnaire) was the secondary outcome. Data analysis included paired t-tests, independent t-tests, the Shapiro-Wilk test, the Wilcoxon signed-rank test, and the Mann-Whitney test.

Results: Significant differences were observed between the two groups for changes in U1-SN, IMPA, L1-NB angles, and L1-NB (mm) (P < .05). However, there was no significant difference in improving the OHRQoL of patients between the CA and RP groups (P > .05).

Conclusions: Both treatment approaches resulted in similar improvement in the patients OHRQoL. However, the CA group resulted in more significant proclination of the upper incisors, while the RP group showed more significant retroclination of the lower incisors.

Objective: To evaluate the effects of orthodontic traction of impacted maxillary canines on treatment duration, alveolar bone levels, white spot lesions (WSLs), root resorption, and the need for auxiliary appliances.

Materials and methods: In this retrospective study, 116 patients were divided into two groups: 58 with unilaterally impacted maxillary canines and 58 controls without impaction. All patients received nonextraction treatment using labial fixed appliances. Pretreatment and posttreatment panoramic radiographs, intraoral photographs, and intraoral scans were analyzed. The collected data were used to compare the groups across five clinical parameters. Statistical analyses included the Mann-Whitney U-test, Wilcoxon signed-rank test, χ2 test, and Cochran's Q test, with significance set at P < .05.

Results: The impaction group had significantly longer treatment duration (mean = 2.64 ± 0.99 years) than controls (mean = 1.85 ± 0.60 years). Alveolar bone loss was significantly greater in teeth adjacent to the impacted canine and between the impacted and nonimpacted sides within the impaction group (P < .05). WSL incidence was higher in the impaction group, especially in posterior teeth (P = .0034). Root resorption patterns differed by region: maxillary incisors were more affected in the impaction group, whereas mandibular posterior teeth showed more resorption in controls. The use of auxiliary appliances was significantly greater in the impaction group.

Conclusions: Impacted canine treatment is associated with increased treatment time, greater alveolar bone loss, higher risk of WSLs, and distinct root resorption patterns. These findings highlight the importance of individualized treatment planning, careful biomechanical control, and preventive strategies in managing impacted canines.

Objectives: To evaluate esthetic outcomes of four treatment options for missing maxillary lateral incisors-canine substitution, canine substitution with buildup, resin-bonded fixed dental prostheses (RBFDPs), and dental implant-and to compare with a control group with sound lateral incisors after orthodontic treatment.

Materials and methods: A total of 144 digital intraoral photographs from clinical expert archives was analyzed, including the control group. Esthetic outcomes were assessed using ImageJ software based on the recurring esthetic dental (RED) proportion, vertical position, black triangles, gingival zenith, color, and apparent contact dimension (ACD). Statistical analyses were conducted to identify significant differences among groups.

Results: RED proportion was more favorable in both canine substitution groups than with RBFDPs. Vertical position favored RBFDP over canine substitution with buildup. Black triangles were less frequent in both canine substitution and the control group than with RBFDPs. Gingival zenith was less favorable in both canine substitution groups than the control and with RBFDPs. The control group showed best color outcomes, outperforming all treatment groups except for dental implant. ACD central-lateral incisors was better in the canine substitution with buildup and control group than canine substitution without buildup. ACD lateral incisor-canine was superior in both canine substitution and control groups than with RBFDPs and dental implants.

Conclusions: No single treatment excelled across all parameters, emphasizing the need for individualized treatment plans based on patient priorities. Collaborative decision-making is crucial for optimizing esthetic outcomes.

Objectives: To investigate the relationship between body dysmorphic disorder (BDD), orthodontic parameters, and the level of depression.

Materials and methods: A total of 205 adolescents (142 females, 63 males; aged 12-18) completed the Body Dysmorphic Disorder Questionnaire (BDDQ) and the Beck Depression Inventory (BDI). Orthodontic parameters, including skeletal malocclusion type, maxillary and mandibular anterior crowding, and Index of Treatment Need (IOTN) scores, were recorded. Associations were analyzed using appropriate statistical methods.

Results: BDDQ positivity was observed in 69.8% (n = 143) of participants. BDDQ-positive individuals had significantly higher BDI scores compared to BDDQ-negative individuals (P < .001). No significant group differences were found in terms of age, crowding, IOTN scores, or skeletal malocclusion type. However, correlation analysis showed a weak but statistically significant negative association between malocclusion type and BDDQ positivity (r = -0.146, P = .042), and a moderate positive correlation between BDDQ positivity and BDI scores (r = 0.317, P < .001).

Conclusions: BDD was significantly associated with depression levels. Although most orthodontic variables showed no direct relationship with BDD, malocclusion type demonstrated a weak but significant correlation.