Angle Orthodontist最新文献

Objectives: To investigate whether the predicted changes in overbite (OB) and overjet (OJ) in Align Technology's (Santa Jose, Calif) digital treatment plan for the prescribed course of treatment with the Invisalign appliance were consistent with those same changes in OB and OJ measured with the Geomagic Control X (Geomagic US, Research, Triangle Park, NC) metrology software system.

Materials and methods: Geomagic Control X software was used to determine OB and OJ differences between the pretreatment and predicted outcome. STL files for patients satisfying inclusion criteria and undergoing nonextraction orthodontic treatment with the Invisalign appliance. The differences were compared, using the Bland-Altman analysis, to the corresponding data provided by Align Technology's digital treatment-planning interface, ClinCheck.

Results: Data regarding 76 adult patients who satisfied strict inclusion criteria were assessed. The Shapiro-Wilks test indicated normality (P > .05). The Bland-Altman analysis showed high levels of agreement between the two measurements, with a bias range of -0.131 to 0.111 for OB and -0.393 to 0.03 for OJ recorded.

Conclusions: Clinicians and researchers can be confident that measurement data provided by Invisalign's ClinCheck digital treatment-planning facility concerning OB and OJ changes from the initial to the predicted treatment outcome are valid.

Objectives: To introduce and validate newly designed computer software to aid in the diagnosis of anterior open bite (AOB).

Materials and methods: The software was constructed based on the algorithm of a standardized open bite checklist, which considered skeletal, dental, and soft tissue components, as well as smile characteristics. Feeding the software with this input yielded a digital form output (DFO) in the guise of a diagnostic report characterizing the AOB phenotype, contributing components, severity, associated problems, and functional factors. For validation, DFO was compared to a conventional form output (CFO), created in a standardized manner according to expert opinions. Agreement between the DFO and CFO in terms of AOB phenotype was the primary outcome, while the secondary outcome was the number of missing diagnostic components in either method.

Results: Percentage of agreement between CFO and DFO was 82.2%, with a kappa coefficient of 0.78, which is considered a good level of agreement. There was a statistically significant relationship between the number of missing diagnostic components in CFO and level of disagreement, which rendered the DFO more reliable.

Conclusions: Newly constructed software represents an efficient and valid diagnostic tool for AOB and its contributing components. There was good agreement between CFO and DFO, with the latter being more comprehensive and reliable. The algorithm built in the software can be used as the basis for a future artificial intelligence model to aid in the diagnosis of AOB.

Objective: To assess differences in root development between the cleft side (CS) and noncleft side (NCS) for permanent maxillary central incisor and canine longitudinally in patients with nonsyndromic complete unilateral cleft lip and palate (cUCLP) who received secondary alveolar bone grafting (SABG) and to evaluate the effects of SABG on the acceleration of root development of these teeth.

Materials and methods: Permanent maxillary central incisors and canines of 44 subjects with nonsyndromic cUCLP who had all their cleft-related surgeries performed by the same surgeon were analyzed retrospectively from chart notes and radiographs. Panoramic and periapical radiographs at time point 1 (T1) (age, 7.55 years), at SABG (time point 2 [T2], 10.13 years), and a minimum of 2 years after SABG were studied. Root development rating scores on the NCS and CS were compared using paired t-tests and analyses of proportions.

Results: Mean root development score differences (NCS - CS) for canines and central incisors were greatest at T2 but diminished at time point 3 (T3). A larger proportion of teeth on the CS trailed the teeth on the NCS by at least 1 point at T2 than at T1 or T3, with the smallest proportion being observed at T3. The change in root development scores from T1 to T2 and from T2 to T3 showed relative CS acceleration from T2 to T3, indicating a catch-up of root development of cleft-adjacent teeth after SABG.

Conclusions: Root development of cleft-adjacent central incisors and canines is slow in comparison with their noncleft analogs. Root development of these teeth accelerates following SABG.

Objectives: To study whether and how the clinical experience of the operator affects the accuracy of bracket placement using guided bonding devices (GBDs) in vitro.

Materials and methods: Five resin models were bonded virtually with brackets, and the corresponding GBDs were generated and three-dimensionally printed. Nine operators, which included three dental students, three orthodontic students, and three orthodontists, bonded the brackets on the resin models using GBDs on a dental mannequin. After being bonded with brackets, the models were scanned, and the actual and designed positions of the brackets were compared.

Results: There was no immediate debonding. The orthodontists spent a significantly shorter time (22.36 minutes) in bracket bonding than the dental students (24.62 minutes; P < .05). The brackets tended to deviate to the buccal side in the dental student group. Linear deviations tended to be smallest in the orthodontic student group, but no significant difference was found among operators with different clinical experience (P > .5). All linear and angular deviations in each group were under 0.5 mm and 2°, respectively.

Conclusions: Clinical experience was positively related to the bonding accuracy using GBDs, especially in the buccolingual dimension. Inexperience also led to longer bonding duration. However, bonding accuracy was clinically acceptable in general.

Objectives: To evaluate the change in overbite within an untreated cohort from 9 to 18 years of age and to compare age-related changes in overbite depth based on vertical skeletal proportion.

Materials and methods: Lateral cephalograms were obtained from the American Association of Orthodontists Foundation (AAOF) Craniofacial Growth Legacy Collection Project. All cephalometric outcome measures were assessed at ages 9-11 (T1), 13-15 (T2), and 17-19 (T3) years. Generalized estimating equation (GEE) regression models were fit to examine the effect of MP-SN on overbite adjusted for age and gender.

Results: A total of 130 subjects from the Denver, Bolton Brush, and Oregon Growth Studies were included. Overbite was relatively constant from T1 to T3 irrespective of facial type, with a minor decrease (0.15 mm) being observed overall. There was a transient increase between T1 and T2 (0.31 mm) that was canceled out by changes during later adolescence. Based on the GEE regression model adjusted for time and gender, a minor but statistically significantly greater reduction in overbite arose as MP-SN increased (coefficient = -0.080; 95% confidence interval -0.12, -0.04; P < .01).

Conclusions: In hyperdivergent subjects, a marginal decrease in overbite was observed from 9 to 18 years of age, with a transient increase from the period spanning 9-11 years to 13-15 years, which was negated in later adolescence. There are limited data to suggest that observation of vertical growth is required in most patients with marginally increased vertical facial proportions in the juvenile and pubertal phases.

Objective: To evaluate the responsiveness of three cone-beam computed tomography (CBCT) transverse analyses (University of the Pennsylvania [UPenn] analysis, Boston University analysis and Yonsei University [YU] analysis).

Materials and methods: A consecutive cohort sample of patients was retrospectively reviewed for eligibility. CBCT records before treatment (T0) and immediately after maxillary expansion (T1) of 71 patients receiving tooth-supported rapid maxillary expansion (RME) and 57 patients receiving mini-screw-assisted RME (MARME) were finally analyzed. Responsiveness was assessed by comparing changes of measures (T1-T0) to mid-palatal suture opening distance (MSOD) at T1. Correlational responsiveness was assessed by Pearson correlation coefficient (r). Absolute agreement responsiveness was assessed by Bland-Altman analysis. A specialized intraclass correlation coefficient (ICC) was selected to assess responsiveness combining correlation and absolute agreement.

Results: Changes of all three measures were moderately to strongly correlated to MSOD (r > 0.5). The highest correlation coefficient (0.79) was found between the YU analysis and MSOD. When exploring absolute agreement responsiveness, the smallest deviation (0.14 mm) was observed in the UPenn analysis. For ICC, the highest ICC value (0.63) was observed when the YU analysis was used. In addition, all three measurements were more responsive to MSOD in the MARME group than to those in RME group.

Conclusions: All three transverse measurements responded well to true changes of maxillary transverse deficiency during both tooth-supported and mini-screw-assisted RME. Deviations of responsive properties of these measurements from true skeletal changes were below a clinically meaningful level (1 mm).

Objectives: To evaluate the force required to promote the failure of fixed orthodontic retainers with different adhesive (composite) coverage and to assess the presence and extent of force propagation with two different orthodontic retainer wires.

Materials and methods: Ortho-FlexTech and Ortho-Care Perform (0.0175 inches), each of 15-cm length, were bonded on acrylic blocks with different adhesive surface diameters (2 mm, 3 mm, 4 mm, and 5 mm). The samples (n = 160) were subjected to a tensile pull-out test, and debonding force was recorded. Fixed retainers using two different wires and 4-mm adhesive diameter were bonded on acrylic bases resembling a maxillary dental arch (n = 72). The retainers were loaded occluso-apically until the first sign of failure while being video recorded. Individual frames of the recordings were extracted and compared. A force propagation scoring index was developed to quantify the extent of force transmission under load.

Results: A 4-mm adhesive surface diameter required the highest debonding force for both retainer wires with significant differences compared with 2 mm (P < .001; 95% confidence interval [CI]: 8.69, 21.69) and 3 mm (P = .026; 95% CI: 0.60, 13.59). Force propagation scores were significantly higher for Ortho-Care Perform.

Conclusions: Based on this laboratory-based assessment, consideration should be given to the fabrication of maxillary fixed retainers using a minimum of 4-mm diameter composite coverage on each tooth. Force appeared to propagate more readily with Ortho-Care Perform than with a flexible chain alternative. This may risk stress accumulation at the terminal ends with potential for associated unwanted tooth movement in the presence of intact fixed retainers.

Objective: This case report describes the successful treatment of a patient with Crouzon syndrome with severe midfacial deficiency and malocclusion, including reverse overjet.

Materials and methods: In Phase I treatment, maxillary lateral expansion and protraction were performed. In Phase II treatment, after lateral expansion of the maxilla and leveling of the maxillary and mandibular dentition, an orthognathic approach including simultaneous Le Fort I and III osteotomies with distraction osteogenesis (DO) was used to improve the midfacial deficiency.

Results: After DO, 12.0 mm of the medial maxillary buttress and 9.0 mm of maxillary (point A) advancement were achieved, which resulted in a favorable facial profile and stable occlusion.

Conclusion: Even after 8 years of retention, the patient's profile and occlusion were preserved without any significant relapse.

Objective: To assess soft tissue differences between monozygotic twins (MZ) for the total face and between facial regions using three-dimensional (3D) stereophotogrammetry and quantitative surface-based 3D deviation analyses.

Materials and methods: The study sample consisted of 14 untreated MZ twins (6 males, 8 females, mean age: 14.75 years) from the archive of Marmara University, Department of Orthodontics. The images were taken by the 3dMDface system, and 3dMDvultus software was used for removal of undesired areas and approximation of the images. Then, stereolithography (.stl) format images were superimposed using the best-fit algorithm using 3-matic software. The face was divided into facial thirds, and upper lip and lower lip + chin regions were created. For the comparison, 3D deviation analyses were performed, and a color map and histogram were created. The data were presented as mean deviation, root mean square (RMS), median, and interquartile range.

Results: Between the facial thirds, there was no significant difference in soft tissue differences for mean deviation. A statistically significant difference was found between the upper and lower face for the RMS value. For the comparison of upper lip and lower lip + chin region, the only significant difference was for the RMS. When the data were presented as median and interquartile range, there were no statistically significant differences between any facial regions.

Conclusions: Lower facial third and lower lip + chin regions had the greatest differences within MZ twin pairs. The genetic and environmental influences might not be the same for different parts of the face.

Objectives: To evaluate the bisphenol release of different brands of clear aligner materials.

Materials and methods: Six different clear aligner materials were used in this study: Duran (Scheu-Dental GmbH, Iserlohn, Germany), Zendura Flx (Bay Materials LLC, Fremont, CA, USA), Zendura A (Bay Materials), Essix (Raintree Essix Inc., Metairie, LA, USA), Taglus Premium (Laxmi Dental Export Pvt. Ltd, Mumbai, India), and Smart Track (Align Technology, San Jose, CA, USA). The samples were kept in saline solution for 8 weeks in airtight test tubes at 37°C. The ratio between the weights of the samples and the volumes of the dilutions was prepared as 0.1 g/mL as suggested by International Standards Organization parameters. To evaluate the bisphenol release of materials, liquid chromatography-mass spectrometry/mass spectrometry analysis was performed. Data were analyzed with the Kruskal-Wallis test (α = 0.05).

Results: Bisphenol A (BPA) values in Smart Track were found to be significantly higher than the Zendura A and Zendura Flx groups (P = .02, P = .03, respectively). There was no statistically significant difference among the samples in terms of Bisphenol F (BPF) values (P = .108). In terms of Bisphenol S (BPS) values, a statistically significant difference was found (P = .002) indicating that Smart Track released significantly more BPS than Zendura A (P = .001).

Conclusions: Under the test conditions, the amounts of leached BPA, BPF, and BPS were less than the reference dose for daily intake. However, the cumulative effect of these appliances should not be underestimated.