The Angle orthodontist最新文献

Objective: To compare the accuracy of mandibular incisor intrusion with Invisalign (Align Technology, Santa Clara, Calif) in adolescents to that in adults.

Materials and methods: This prospective clinical study included 58 patients treated with either Invisalign Teen or Invisalign Full. Mandibular central and lateral incisors were measured on digital models created from intraoral scans. Predicted values were determined by superimposing the initial and final ClinCheck models, and achieved values were determined by superimposing the initial ClinCheck models and the digital models from the final scans. Individual teeth were superimposed with a best-fit analysis and measured using Compare software (version 8.1; GeoDigm, Falcon Heights, Minn).

Results: The mean accuracies of mandibular incisor intrusion were 63.5% in adolescents and 45.3% in adults, and this difference was statistically significant. The amounts of achieved intrusion were 1.7 mm in adolescents and 0.9 mm in adults, and this difference was also statistically significant. Overall, there was a weak negative correlation between age and accuracy; as age advanced, the accuracy of mandibular incisor intrusion diminished slightly.

Conclusions: Mandibular incisor intrusion with Invisalign is significantly more accurate in adolescents than in adults. Orthodontists could contemplate reducing the degree of overcorrection for mandibular incisor intrusion in adolescents with deep overbites undergoing Invisalign Teen but still implementing the reverse curve of Spee mechanics.

Objectives: To compare facial growth prediction models based on the partial least squares and artificial intelligence (AI).

Materials and methods: Serial longitudinal lateral cephalograms from 410 patients who had not undergone orthodontic treatment but had taken serial cephalograms were collected from January 2002 to December 2022. On every image, 46 skeletal and 32 soft-tissue landmarks were identified manually. Growth prediction models were constructed using multivariate partial least squares regression (PLS) and a deep learning method based on the TabNet deep neural network incorporating 161 predictor, and 156 response, variables. The prediction accuracy between the two methods was compared.

Results: On average, AI showed less prediction error by 2.11 mm than PLS. Among the 78 landmarks, AI was more accurate in 63 landmarks, whereas PLS was more accurate in nine landmarks, including cranial base landmarks. The remaining six landmarks showed no statistical difference between the two methods. Overall, soft-tissue landmarks, landmarks in the mandible, and growth in the vertical direction showed greater prediction errors than hard-tissue landmarks, landmarks in the maxilla, and growth changes in the horizontal direction, respectively.

Conclusions: PLS and AI methods seemed to be valuable tools for predicting growth. PLS accurately predicted landmarks with low variability in the cranial base. In general, however, AI outperformed, particularly for those landmarks in the maxilla and mandible. Applying AI for growth prediction might be more advantageous when uncertainty is considerable.

Inadequate maxillary incisor display can negatively impact facial esthetics. Various treatment options exist depending on the underlying cause and severity of the condition. Skeletal anchorage was used to extrude the maxillary dentition and rotate the mandible backward, enhancing visibility of the maxillary incisors. An extrusion assembly was introduced to achieve orthodontic extrusion. Use of bite raisers and interarch elastics was also discussed. Treatment results demonstrated successful achievement of the treatment goals. In addition to optimal occlusion, the patient's facial profile improved with increased lip fullness. There was an increase in vertical facial height, and maxillary incisor display was significantly improved, resulting in a more pleasant smile. Two-year postretention records evidenced the stability of total arch extrusion to improve maxillary incisor display.

Objective: To examine whether patients with different blood glycemic levels undergoing fixed orthodontic therapy demonstrate changes in the biochemical profiles of crevicular fluid and salivary advanced glycation end products (AGEs) and proinflammatory cytokine levels in comparison with nondiabetic healthy subjects.

Materials and methods: Prediabetic subjects, subjects with type 2 diabetes mellitus (T2DM), and subjects without a diabetes mellitus diagnosis undergoing fixed orthodontic therapy with MBT prescription brackets (0.022-inch brackets and 0.019 × 0.025-inch stainless steel archwires) were included in the study. The following clinical periodontal parameters were evaluated: (1) plaque score (PS), (2) probing depth (PD), (3) bleeding on probing (BOP), and (4) clinical attachment loss. Crevicular fluid and saliva specimens were collected during regular orthodontic visits. Salivary and crevicular fluid tumor necrosis factor alpha, interleukin-6, ghrelin, resistin, AGEs, and receptor activator of nuclear factor κΒ ligand were evaluated using a human magnetic Luminex multiplex assay.

Results: BOP scores were significantly higher among T2DM subjects (19.2%) than among nondiabetic subjects (11.2%) and prediabetic subjects (15.9%). Comparable values were demonstrated by all three study groups regarding PD scores and PSs. T2DM subjects demonstrated higher scores for gingival crevicular fluid (GCF) chemokines than nondiabetic and prediabetic subjects. A statistically significant difference was found in the levels of AGEs and resistin among the three study groups. The scores revealed for the levels of GCF resistin and AGEs versus periodontal BOP demonstrated a significant positive association by the Pearson correlation test.

Conclusions: T2DM patients demonstrated significantly higher levels of GCF resistin and AGEs during fixed orthodontic therapy. Chronic hyperglycemic patients undergoing orthodontic therapy demonstrated a proinflammatory response.

Objectives: To investigate the difference in labial and palatal alveolar bone thickness and height during the retention period after incisor retraction treatment with microimplant.

Materials and methods: A sample of 21 patients (mean age: 17.80 ± 4.38 years) who underwent incisor retraction treatment using microimplants after premolar extraction was investigated. The cone-beam computed tomography images at pretreatment, posttreatment, and retention were used to measure anterior alveolar bone thickness (labial, palatal, and total; at three vertical levels) and height (labial and palatal) and differences in the incisor position during treatment or retention. Repeated-measures analysis of variance with Bonferroni correction was performed to compare the variables at T0, T1, and T2.

Results: The maxillary central incisor moved posteriorly by approximately 8.0 mm along with intrusive movement of 1.8 mm after treatment. The alveolar bone thickness significantly decreased on the palatal side and increased on the labial side after treatment. Thereafter, the palatal bone thickness significantly increased and labial bone thickness decreased during the retention period. The palatal interdental bone depressed by incisor retraction showed substantial bone deposition after retention.

Conclusions: Radiographic palatal bone dehiscences on the incisor root and palatal bone depression between the incisor roots were apparent after treatment. This palatal bone loss around the incisor roots noticeably recovered with newly formed bone during retention.

Objectives: To develop a photochromic bracket adhesive (PCA) with modification using photochromic material and evaluate the biocompatibility, bond strength, photochromic property, and adhesive removal efficiency.

Materials and methods: The resin-modified glass ionomer powder was mixed with the photochromic material and then blended with the liquid agent to form PCA. Biocompatibility was evaluated by CCK-8 kit, and shear bond strength (SBS) was measured. Stereoscopic microscopy and quantitative color analysis were used to assess the photochromic property. Bracket bonding and debonding procedures were performed on a head simulator with the assistance of an ultraviolet radiator. The effectiveness of adhesive removal during bonding and debonding procedures was assessed using a stereomicroscope. Removal time was recorded, and the enamel damage index after debonding was analyzed.

Results: CCK-8 assay and SBS test indicated that 5wt.% mixing ratios of the photochromic material did not compromise the biocompatibility and SBS of the adhesive (PCA5). PCA5 showed photochromic properties and could help the operator remove adhesive more thoroughly without increasing enamel damage.

Conclusions: Photochromic adhesive (PCA5) can be good for orthodontic adhesive removal and therefore has good clinical translation potential.

To survey treatment-planning practices of orthodontists related to the Invisalign Lite clear aligner appliance (Align Technology, San Jose, Calif).

Patients satisfying inclusion and exclusion criteria and treated with Invisalign Lite were selected from a database containing more than 17,000 patients. Relevant data regarding treatment-planning practices were obtained from Align Technology’s treatment-planning facility, ClinCheck, and evaluated.

Most (n = 135; 79.9%) patients were female and had a median (interquartile range [IQR]) age of 30.5 (23.8, 43.1) years. The median (IQR) number of aligners for the sample was 23.0 (14, 28) for the maxilla and 24 (14, 28) for the mandible. Most (n = 122; 72.2%) patients required at least one additional series of aligners. More locations for interproximal reduction (IPR) were prescribed in the mandible (mean 1.91 [1.78]) than in the maxilla (1.03 [1.78]; P < .024) in the initial accepted plan of all patients. More teeth were prescribed composite resin (CR) attachments in the maxilla (P < .0001) in the initial accepted plan of all patients. Issues regarding tooth position protocols (n = 50; 53.3%) and requirement for additional IPR (n = 68; 45.3%) were reasons for treatment plan changes before acceptance of the initial treatment plan by orthodontists.

More than 7 of 10 patients required at least one additional series of aligners after the initial series of Invisalign Lite aligners was completed. Prescription of IPR was more common in the mandible, and prescription of CR attachments was more common in the maxilla.

To assess the quality and accuracy of information contained within the websites of providers of marketed orthodontic products.

Twenty-one websites of orthodontic appliance and adjunct (product) providers were identified. The website content was assessed via two validated quality-of-information instruments (DISCERN and the Journal of the American Medical Association [JAMA] benchmarks) and an accuracy-of-information instrument. Website content was qualitatively analyzed for themes and subthemes.

More than half (n = 11; 52.3%) of the assessed websites contained clinician testimonials. The mean (SD) DISCERN score was 33.14 (5.44). No website recorded the minimum of three JAMA benchmarks required to indicate reliability. The most common content themes related to quality-of-life impact and treatment duration. Just 8% of the statements within the websites were objectively true. The Pearson correlation coefficient indicated that the DISCERN scores were correlated with the accuracy-of-information scores (r = .83; P < .001).

The quality and accuracy of information contained within the websites of the providers of marketed orthodontic products was poor. The combined use of DISCERN and the accuracy-of-information instrument may help overcome the shortcomings of each. Clinicians should check the accuracy of information on orthodontic product provider websites before adding links to those websites on their own sites.

Objective: To evaluate the effectiveness of micro-osteoperforation (MOP) on the rate of piezocision-aided canine retraction (CR).

Materials and methods: The split-mouth study included 25 participants at the stage of commencing CR. The participants received flapless piezocision bilaterally at T0 (0 months) and MOP only on one side at T3 (3 months). The quadrant that received MOP at T3 served as the intervention, whereas the other quadrant served as the control. The primary outcome was the rate of CR, assessed using digital models. The angular change (AC) of the canine and the change in the buccal cortical bone thickness (BCBT) from before to after CR were also assessed using cone beam computed tomography.

Results: The rate of CR was 0.82 ± 0.39 mm/month in the control quadrant vs 0.75 ± 0.44 mm/month in the intervention quadrant (P > .05). The AC of the canine was 2.00° ± 0.88° in the control quadrant vs 1.98° ± 0.86° in the intervention quadrant (P > .05). The crestal bone gain was 0.50 mm in the control quadrant vs 0.28 mm of bone loss in the intervention quadrant. The bone thickness at a 3-mm height was increased by 0.11 mm in the control quadrant vs a 0.29-mm decrease in the intervention quadrant. The bone thickness at a 6-mm height was decreased by 0.12 mm in the control quadrant vs a 0.15-mm decrease in the intervention quadrant. However, none of the changes or group differences in bone height or thickness were statistically significant (P > .05).

Conclusions: The periodic activation of a piezocision-aided CR site using MOP had no significant positive effect on the rate of CR, angulation of the canine, or changes in BCBT.

Objectives: To determine the optimal settings for reconstructing the buccal surfaces of different tooth types using the virtual bracket removal (VBR) technique.

Materials and methods: Ten postbonded digital dentitions (with their original prebonded dentitions) were enrolled. The VBR protocol was carried out under five settings from three commonly used computer-aided design (CAD) systems: OrthoAnalyzer (O); Meshmixer (M); and curvature (G2), tangent (G1), and flat (G0) from Geomagic Studio. The root mean squares (RMSs) between the reconstructed and prebonded dentitions were calculated for each tooth and compared with the clinically acceptable limit (CAL) of 0.10 mm.

Results: The overall prevalences of RMSs below the CAL were 66.80%, 70.08%, 62.30%, 94.83%, and 56.15% under O, M, G2, G1, and G0, respectively. For the upper dentition, the mean RMSs were significantly lower than the CAL for all tooth types under G1 and upper incisors and canines under M and G2. For the lower dentition, the mean RMSs were significantly lower than the CAL for all tooth types under G1 and lower incisors and canines under M, G2, and G0 (all P < .05). Additionally, the mean RMSs of all teeth under G1 were significantly lower than those under the other settings (all P < .001).

Conclusions: The optimal settings varied among different tooth types. G1 performed best for most tooth types compared to the other four settings.