Orthodontics & Craniofacial Research最新文献

Background: Different protocols exist regarding wear time of invisible aligners. There is no study that compared the effect of different protocols. The aim of this study was to assess the effect of Invisalign aligners in four first-premolar extraction treatments in adolescents using three aligner wear protocols, every 7, 10 and 14 days.

Materials and methods: In the experimental set-up, 50 participants were divided into three distinct groups: group A, with a regimen of changing aligners every 7 days; group B, with a 10-day interval for aligner replacement; and group C, where aligners were replaced every 14 days. The evaluation of occlusal adjustments was conducted employing the Discrepancy Index (DI) and the Cast-Radiograph Evaluation (CRE), as defined by the American Board of Orthodontics for the purpose of recording orthodontic outcomes. The treatment duration, number of maxillary and mandibular Invisalign aligners, and number of Invisalign restarts were simultaneously recorded and evaluated. The data set was statistically examined using ANOVA, complemented by the F-test, least significant difference (LSD) method and Tamhane's T2 test.

Results: The final sample size for analysis is 45 cases, with five cases lost to follow-up. Before treatment, the three groups showed no significant difference in the degree of malocclusion or each item of DI (p > 0.05). Posttreatment, within groups, and regardless of the wearing protocol, the total CRE scores demonstrated no statistically significant differences (p > 0.05). For the other items, groups A and C completed occlusal relations and interproximal contacts significantly better than did group B (p < 0.05). The group C cases had the least number of Invisalign refinement (3.93 ± 0.96 vs. 4.93 ± 0.70 vs. 6.00 ± 1.25, p < 0.05), but the treatment duration and number of Invisalign aligners were not significantly different (p > 0.05).

Conclusions: The different treatment timing protocols showed equivalent effectiveness regarding treatment outcome, with significantly improved results for the 7- and 14-day protocol in terms of occlusal relations and interproximal contacts. The attainment of comparable clinical accuracy between the 7- and 14-day protocol, within a treatment duration of fewer than 3 months, indicates that the 7-day protocol can be deemed an effective treatment approach.

Objective: This retrospective study aimed to evaluate morphometric changes in mandibular condyles of patients with skeletal Class III malocclusion following two-jaw orthognathic surgery planned using virtual surgical planning (VSP) and analysed with automated three-dimensional (3D) image analysis based on deep-learning techniques.

Materials and methods: Pre-operative (T1) and 12-18 months post-operative (T2) Cone-Beam Computed Tomography (CBCT) scans of 17 patients (mean age: 24.8 ± 3.5 years) were analysed using 3DSlicer software. Deep-learning algorithms automated CBCT orientation, registration, bone segmentation, and landmark identification. By utilising voxel-based superimposition of pre- and post-operative CBCT scans and shape correspondence, the overall changes in condylar morphology were assessed, with a focus on bone resorption and apposition at specific regions (superior, lateral and medial poles). The correlation between these modifications and the extent of actual condylar movements post-surgery was investigated. Statistical analysis was conducted with a significance level of α = 0.05.

Results: Overall condylar remodelling was minimal, with mean changes of < 1 mm. Small but statistically significant bone resorption occurred at the condylar superior articular surface, while bone apposition was primarily observed at the lateral pole. The bone apposition at the lateral pole and resorption at the superior articular surface were significantly correlated with medial condylar displacement (p < 0.05).

Conclusion: The automated 3D analysis revealed distinct patterns of condylar remodelling following orthognathic surgery in skeletal Class III patients, with minimal overall changes but significant regional variations. The correlation between condylar displacements and remodelling patterns highlights the need for precise pre-operative planning to optimise condylar positioning, potentially minimising harmful remodelling and enhancing stability.

Objective: To assess the accuracy of three commercially available and one open-source deep learning (DL) solutions for automatic tooth segmentation in cone beam computed tomography (CBCT) images of patients with multiple dental impactions.

Materials and methods: Twenty patients (20 CBCT scans) were selected from a retrospective cohort of individuals with multiple dental impactions. For each CBCT scan, one reference segmentation and four DL segmentations of the maxillary and mandibular teeth were obtained. Reference segmentations were generated by experts using a semi-automatic process. DL segmentations were automatically generated according to the manufacturer's instructions. Quantitative and qualitative evaluations of each DL segmentation were performed by comparing it with expert-generated segmentation. The quantitative metrics used were Dice similarity coefficient (DSC) and the normalized surface distance (NSD).

Results: The patients had an average of 12 retained teeth, with 12 of them diagnosed with a rare disease. DSC values ranged from 88.5% ± 3.2% to 95.6% ± 1.2%, and NSD values ranged from 95.3% ± 2.7% to 97.4% ± 6.5%. The number of completely unsegmented teeth ranged from 1 (0.1%) to 41 (6.0%). Two solutions (Diagnocat and DentalSegmentator) outperformed the others across all tested parameters.

Conclusion: All the tested methods showed a mean NSD of approximately 95%, proving their overall efficiency for tooth segmentation. The accuracy of the methods varied among the four tested solutions owing to the presence of impacted teeth in our CBCT scans. DL solutions are evolving rapidly, and their future performance cannot be predicted based on our results.

Objective: To evaluate the effects of presurgical infant orthopaedics using the Modified Grayson technique and Rhinoplasty Appliance System on the maxillary alveolus and nasolabial region in infants with unilateral cleft lip and palate (UCLP).

Materials and methods: This prospective study looked at 26 patients with a mean age of 6.3 ± 1.48 days, having complete UCLP. The study sample was divided into two groups of 13 UCLP infants: Group 1, treated by the modified Grayson technique, and Group 2, treated with the Rhinoplasty Appliance System (RAS). The scanned cast parameters were assessed before and after PSIO treatment, assessing treatment changes in the alveolar arch, which was further supplemented with standardised anteroposterior, Worms-eye view and profile photographs assessing sift tissue facial parameters. Descriptive statistics were applied, and a two-tailed t-test for intergroup comparison was used to determine cast and facial parameters across the two techniques.

Results: Intra-group assessment of cast and facial parameters showed a significant difference (p < 0.005) across pre and post-treatment assessment using two different treatment modalities. However, intergroup comparison showed no significant difference (p > 0.005) between modified Grayson's and RAS techniques.

Conclusion: In infants with UCLP, both techniques significantly impacted the alveolus and nasolabial region while reducing cleft defects. However, an intergroup comparison of both the treatment modalities showed similar effects on intraoral and extraoral parameters. Integrating RAS into PSIO protocols shows promise in treating lip-and-palate cleft deformities. The study emphasises the value of digital technology in enhancing PSIO protocols, with potential benefits for treatment standardisation and improvement in patient experience.

Objective: The study compares and evaluates planned virtual outcomes with actual post-treatment outcomes to assess the accuracy and predictability of clinical results during presurgical infant orthopaedics (PSIO) with AlignerNAM in infants with unilateral cleft lip and palate.

Setting: Institutional study.

Participants: 14 UCLP patients.

Materials and methods: Digital models for infants with unilateral cleft lip and palate (UCLP) who had undergone PSIO with AlignerNAM between 1 and 6 weeks were obtained at three stages-pretreatment (T_o), planned (T_p) and post-treatment (T₁). Linear and angular measurements were made on these using the OrthoAnalyser software (3Shape, Copenhagen, Denmark). A paired t-test and Bland-Altman analysis assessed the accuracy between predicted and achieved movements, while inter- and intra-rater reliabilities were also calculated using digital records of seven patients.

Results: The study found no significant difference (p > 0.05) between the clinical outcome (post-treatment) values and the predicted values (obtained from the virtual post-treatment simulation/planned movement). The sagittal reduction in the cleft defect demonstrated the highest accuracy (97.71%), followed by the transverse reduction (95.1%). Overall, linear measurements achieved an accuracy of 94.57% and angular measurements an accuracy of 93.64%. All measurements were within the limits of agreement based on the Bland-Altman plots. The widths of limits of agreement were narrow and similar for both linear and angular measurements showing high levels of agreement.

Conclusion: AlignerNAM showed high accuracy in reducing cleft size and aligning alveolar segments in UCLP patients, achieving accuracy rates above 90% in both linear and angular dimensions. AlignerNAM appliance is a suitable alternative to conventional PSIO techniques.

Objectives: To investigate maxillary canine movement accuracy and anchorage during space closure in first premolar extraction cases (maximum anchorage) using In-House Clear Aligners (IHCAs).

Materials and methods: A randomised controlled trial with a split-mouth design recruited 16 adults in university setting. Each patient was randomly assigned by side for canine retraction using 12 IHCAs to both the experimental palatal power arm (Pa) and non-Pa control (C). Accuracy was assessed using GOM Inspect by superimposing the virtual and actual digital models between pretreatment and 12th IHCA. Paired t-test or Wilcoxon signed-rank test was used to compare virtual-power arm (VPa) versus actual-power arm (APa) and virtual-control (VC) versus actual-control (AC). Root mean square error (RMSE) was calculated.

Results: Pa displayed a significant difference in preliminary canine distalisation (VPa 2.0 mm vs. APa 2.4 mm), while the control did not differ. Both Pa and control exhibited significantly greater actual distal crown tipping than virtual movement (VPa 4.4° vs. APa -6.3°/VC 4.4° vs. AC -4.3°). AC achieved more canine rotation than VC. RMSE was slightly greater in Pa than control for canine distalisation (Pa 0.6 vs. C 0.55 mm) and distal crown tipping (Pa 10.9° vs. C 8.99°). Conversely, Pa displayed better accuracy in canine rotation. For anchorage, Pa and control exhibited significantly greater actual mesialisation and mesial tipping than virtual. RMSE for anchorage mesialisation and mesial tipping were comparable between Pa and control.

Conclusions: Preliminary canine retraction using Pa may result in greater error in distal crown tipping but less rotation than control.

Trial registration: ISRCTN 14020146 by the International Standard Randomised Controlled Trial Registry.

The primary objective was to systematically assess the prevalence, incidence and risk factors of WSLs with orthodontic treatment. The secondary objective was to compare the prevalence of WSLs between conventional fixed appliances (CFA) and other appliances, as well as with no treatment. PubMed, Scopus, Web of Science, LILACs, Virtual Health Library and Cochrane CENTRAL were searched. Risk of bias was assessed using RoB-2, ROBINS-I tool and the Joanna Briggs Institute Critical Appraisal Checklist. Random-effects meta-analyses of pooled proportions and odds ratios (OR) with 95% confidence intervals (CIs) were conducted, followed by meta-regressions, sensitivity analyses, and an assessment of the quality of evidence using GRADE. Trial Sequential Analysis (TSA) was performed to determine the conclusiveness of the evidence. Fifty-seven studies involving 9101 patients (mean age of 16.4 years, 33.5% male) were included. Among orthodontic patients, the pooled prevalence of WSLs was 55.06% (95% CI: 47.7%, 63.6%: 42 studies), incidence was 34.2% (95% CI: 27.6%, 40.6%: 44 studies) and surface prevalence was 26.9% (6 studies; 95% CI: 13.8%, 39.8%). Among non-treated patients, the pooled prevalence of WSLs was 29.1% (95% CI: 17.2%, 41.1%; 21 studies). The odds of WSLs were significantly higher, with CFA being 4.73 times greater compared to other appliances (OR = 4.7, 95% CI: 1, 19.2, p = 0.05) and seven times higher compared to no treatment (OR = 7, 95% CI: 2.6, 18.5, p = 0.001). Prevalence of WSLs increased with longer treatment duration (p < 0.001), varied with ethnicity, being highest in Africans and lowest in Americans (p < 0.05), and method of detection (p < 00.1). TSA confirmed that CFA leads to more WSLs than other appliances or no treatment, with future studies unlikely to alter the direction of the outcomes. Orthodontic treatment increases WSL prevalence, influenced by various factors. Clinicians should carefully consider the development of WSLs during orthodontic treatment and adjust treatment plans accordingly, choose appliances wisely and monitor with effective detection tools. Since one-third of untreated cases already have WSLs, proper documentation at treatment start is essential. Trail Registration: CRD42023478065.

Objectives: The aim of this study was to compare the effectiveness of different attachment shapes and locations on the extrusion of the upper left lateral incisor (UL2) using thermoplastic aligners.

Materials and methods: Seven typodonts were digitally printed with hemi-ellipsoid or rectangular attachments in the incisal, middle or cervical third of the UL2. Five clear aligners were fabricated for each typodont; each was tested twice. Forces and moments were measured with an orthodontic force tester during 0.2 mm simulated extrusion of the UL2. Analysis of variance (ANOVA) was used to determine the effects of group, tooth, and the group-by-tooth interaction on the outcomes. A two-sided 5% significance level was used for all tests.

Results: Altering attachment shape and location had a statistically significant effect on the forces and moments generated in each trial (p < 0.01), except for rectangular incisal and hemi-ellipsoid cervical (p > 0.05). The rectangular middle attachment generated the highest extrusive force (Fz = 7.498 N), followed by hemi-ellipsoid cervical (Fz = 6.338 N) and rectangular incisal (Fz = 5.948 N).

Conclusions: Varying direct attachment shape and location on the UL2 during extrusion has a significant effect on the forces and moments generated by thermoplastic aligners. The rectangular attachment located in the middle third generated the most effective extrusive force and least unwanted moment. For anchorage teeth, hemi-ellipsoid attachments located in the cervical third were found to be the most effective in minimising the reciprocal intrusive forces and unwanted moments.

Objective: The aim of this study was to examine whether ACTN3 rs1815739 polymorphism, which causes the deficiency of the alpha-actinin-3 muscle protein, is related to the formation of open bite malocclusion.

Materials and methods: Fifty-eight participants (18.5 ± 3.6 years old) with anterior open bite (n = 29) and normal overbite (n = 29) who presented to Marmara University, Department of Orthodontics for treatment were included in the study. Initial cephalometric radiographs were used for the diagnosis of malocclusion. The case group was divided into three subgroups according to degree of open bite. For DNA isolation, oral epithelial cells were collected with buccal swabs (Van Allen Way, Carlsbad, USA), and the real-time PCR method was used for the genotyping of all polymorphisms. The results were statistically analysed, and the threshold for statistical significance was set at p < 0.05.

Results: The frequencies of RR, RX and XX genotypes of ACTN3 rs1815739 polymorphism were found as 6 (20.7%), 14 (48.3%) and 9 (31.0%) in the control group and 8 (8%), 9 (31.0%) and 12 (41.4%) in the case group, respectively. There was no statistically significant difference between the groups in terms of the presence of the examined polymorphism (p > 0.05). However, the intra-group evaluation of case group revealed a significant difference in the prevalence of XX genotype (83.3%) for the subgroup with an open bite of -5 mm or above.

Conclusion: Although no significant difference was observed between the case and control groups, a possible association was identified between ACTN3 rs1815739 polymorphism and an increased severity of open bite malocclusion.