Progress in Orthodontics最新文献

Background: This cross-sectional observational study seeks to determine the clinical differences in eruption failure of permanent first molars presenting in cases of ankylosis, failure due to mechanical obstruction (MFE), and failure due to genetic causes (PFE). A total of 34 patients between 7 and 12 years old (mean ± SD: 9.3 ± 1.28 years), with anomalies in the eruption of the first permanent molars, were selected based on clinical observation, the evaluation of orthopanoramic radiographs, and intra- and extra-oral photographs. Genetic testing was also conducted to identify variants of the PTH1R gene in 27 patients with clinical signs of PFE. The familial nature of the condition was investigated through anamnesis of the first-degree relatives.

Results: Out of the 34 patients, 3 were diagnosed with PFE, confirmed by the presence of PTH1R variants. Twelve patients showed clinical signs suggestive of MFE diagnosis. The remaining 19 cases, in which no variants of the PTH1R gene were found, were considered cases of ankylosis. Roots in ankylosed teeth were located in the basal bone and often dilacerated. The reduction of vertical growth of the alveolar bone was present in both PFE and ankylosis cases, but teeth were nearer to the basal bone in ankylosis cases. Infraocclusion of deciduous teeth was present in PFE and MFE cases. Asymmetry due to bilaterally unbalanced eruption of the teeth was present in six cases with ankylosis. Bilateral affection was noticed in one PFE case and 6 MFE cases. A descriptive statistical analysis using Fisher's exact test was employed to evaluate the significant association between variables.

Conclusions: The study highlighted some characteristic signs that help in early diagnosis of cases of PFE, MFE, and ankylosis. However, genetic testing remains necessary to understand the nature of the most dubious cases.

Background: The aim of this study was to investigate if there is a significant difference in the incidence of buccal gingival recession after non-surgical transversal dentoalveolar compensation with completely customized lingual appliances (DC-CCLA) versus surgically assisted rapid palatal expansion (SARPE).

Methods: This cohort study included 81 adult patients with posterior crossbite. The DC-CCLA group (n = 38; f/m 25/13; mean age 30.3 ± 13.0 years) was treated with dentoalveolar compensation using completely customized lingual appliances. The SARPE-group (n = 43; f/m 19/24; mean age 28.2 ± 9.4 years) was treated with SARPE and buccal straight wire appliances. The number of buccal gingival recessions was recorded on digital models before treatment (T0) and after removal of fixed appliances (T1). Statistical analyses included Fisher's exact tests, Chi-squared tests, Mann-Whitney U tests and mixed-effects logistic regression to evaluate the influence of various variables on the incidence of gingival recession.

Results: In 3976 teeth evaluated, the incidence of developing gingival recessions was 8.1% with DC-CCLA (n = 77) and 5.8% with SARPE (n = 60). This difference was not statistically significant (p > 0.05). Age was a significant factor for the incidence of gingival recession and recessions were more likely to occur in males and in the maxillary posterior region.

Conclusions: There was no statistically significant difference in the incidence of gingival recessions between dentoalveolar compensation with CCLAs and SARPE after debonding, with some degree of gingival recession being inevitable with both treatment approaches.

Objectives: This study aimed to compare the designed and achieved maxillary teeth movements in patients undergoing first premolar extraction after the initial series of Invisalign^® treatment using a 3D whole-tooth (crown with root) model and research the related influencing factors.

Materials and methods: Thirty-three consecutive adult patients (Class I with crowding or bimaxillary protrusion) from a single clinical division who completed the first series of aligners after first premolar extractions were included in this retrospective study. The pretreatment, designed, and post-first series treatment teeth (crowns, roots, and bone) models were exported from ClinCheck^® software (Align Technology). The superimposition of the models and 3D tooth movement measurements were constructed using Geomagic Studio Software 2014 (Raindrop Geomagic Inc., USA). Descriptive and analytical statistics were performed, and a P-value < 0.05 was considered statistically significant.

Results: Significant discrepancies were observed between the designed and achieved maxillary tooth movements, particularly in mesiodistal (except U1) and buccolingual (except U6) angular tooth movements (P < 0.05). In contrast, non-significant discrepancies were observed in linear buccolingual movements (P > 0.05). Significant discrepancies in mesiodistal (all teeth) and vertical (U1, U5, U6) tooth movements were more pronounced (P < 0.05). Key influencing factors included the usage of TADs, aligner generation (G6), attachment design, overbite, and gender (P < 0.05).

Conclusions: This study highlights significant deviations between the designed and achieved maxillary teeth (crowns with roots) movements following the first premolar extractions in the initial series of Invisalign^®treatment. Key findings demonstrate significant mesiodistal (except U1) and buccolingual (except U6) angular movement deviations. While linear buccolingual movements were well-controlled, mesiodistal and vertical (U1, U5, U6) discrepancies were more pronounced, influenced by factors such as TADs usage, aligner generation (G6), attachment design, overbite, and gender. These findings may provide further evidence for virtual design during clear aligner treatment.

Background: Mechanical stress triggers an increase in cellular reactive oxygen species (ROS), which is associated with the impairment of osteogenesis. During orthodontic treatment, bone marrow mesenchymal stem cells (BMSCs) experience mechanical stress, yet the oxidative profile and redox regulatory mechanisms under such stress, especially involving Nicotinamide adenine dinucleotide (NAD⁺), are not well understood, necessitating further research into their roles in orthodontic therapies.

Methods: The Tension System was established to detect ROS changes in BMSCs under cyclic stretch stress, with H₂O₂ simulating uncontrolled ROS. Flow cytometry and fluorescence staining measured ROS, while an NAD⁺/NADH assay kit assessed NAD⁺ levels. qRT-PCR and Western blotting analyzed expression of NAD⁺ synthesis and consume enzymes. Osteogenic potential was evaluated by qRT-PCR, Western blotting, and Alkaline phosphatase (ALP) staining. Loss-of-function and supplementation assays explored role of NAD⁺ in oxidative stress and Nrf2 regulation, with localization assessed by immunofluorescence and Western blotting. In vivo osteogenic effects were confirmed using an orthodontic tooth movement (OTM) model, with osteogenesis assessed by immunohistochemistry and microCT for OTM measurements.

Results: Cyclic stretch stress increased ROS in BMSCs over 24 h and boosted osteogenic differentiation. However, increased ROS from H₂O₂ hindered this process. Notably, NAD⁺ levels rose with cyclic stretch, and experiments showed it supported osteogenesis by controlling ROS level in BMSCs. Furthermore, NAD⁺ regulated BMSC ROS via Nrf2 nuclear translocation. Rat models indicated that NMN supplementation enhanced osteogenic and osteoclastic markers and accelerated tooth movement, while FK866 inhibited this effect.

Conclusions: We identified that NAD⁺/Nrf2 signaling regulated oxidative level and thus promoted osteogenic commitment of BMSCs under cyclic stretch stress. Targeting NAD⁺ metabolism or administrating exogenous supplementation to promote bone rebuilding could be a prospective therapy to accelerate OTM.

Background: Skeletal Class II malocclusion, often associated with mandibular deficiency, is commonly treated with functional appliances. Precision Wings are a functional appliance that provides an alternative approach by combining mandibular advancement with dental alignment.

Objective: This systematic review aimed to evaluate the effectiveness of Precision Wings in treating skeletal Class II malocclusion in growing patients.

Eligibility criteria: Studies assessing the correction of skeletal Class II malocclusion in growing patients treated with Precision Wings were selected according to the PICOS strategy. The PRISMA guidelines were followed.

Information sources: Unrestricted electronic searches were conducted across seven databases up to February 2025.

Risk of bias and synthesis of results: The ROBINS-I tool was used to assess the risk of bias (RoB) in non-randomized studies. A random-effects meta-analysis was performed, and the certainty of the evidence was evaluated using the GRADE approach.

Results: Seven studies were included, and data were extracted. Mean differences (MDs) with 95% confidence intervals (CIs) were calculated using random-effects meta-analysis. The findings suggest that Precision Wings may be effective in treating skeletal Class II malocclusion in growing patients through both dental and skeletal changes. Regarding skeletal effects, sagittal changes were limited to the mandible and were of small magnitude, with a reduction in ANB° (MD = -0.81; 95% CI: -1.04 to -0.58; p < 0.001) occurring exclusively due to an increase in SNB° (MD = 0.55; 95% CI: 0.11 to 0.98; p = 0.01), while no significant changes were observed in SNA° (MD = -0.02; 95% CI: -0.42 to 0.38; p = 0.91). The included studies did not report significant vertical effects. Meta-analyses comparing Precision Wings with other functional appliances were not feasible due to the small number of studies evaluating each comparison and the substantial clinical and methodological heterogeneity across the included studies.

Conclusion: Although the available scientific evidence on this topic is limited, treatment with Precision Wings appears to offer minimal clinical improvement in mandibular growth for the correction of skeletal Class II malocclusion. To obtain more conclusive findings, future research should prioritize well-structured randomized clinical trials with standardized treatment protocols, extended follow-ups, and consistent cephalometric assessment methods.

Objective: This study aimed to elucidate metabolic alterations in gingival crevicular fluid (GCF) during orthodontic tooth movement (OTM) and investigate the role of the succinate-SUCNR1 axis in bone resorption and tooth movement.

Results: OTM was accompanied by the change of TCA cycle and increase of succinate in the human GCF. Succinate accumulation was observed in periodontal ligament cells (PDLCs) under compressive force, accompanied by increase of glycolysis and decrease of succinic dehydrogenase activity. Suppression of the succinate-SUCNR1 axis reduced osteoclastogenesis in BMDMs. OTM slowed down in the SUCNR1^-/^- mice when compared with wild mice.

Conclusion: OTM is accompanied by the increase of succinate in periodontal tissues. Compressive force induces metabolic reprogramming in PDLCs, leading to enhanced succinate production. Succinate promotes macrophage migration and osteoclast differentiation via the SUCNR1 axis, ultimately facilitating orthodontic tooth movement. These findings provide a new potential therapeutic target for regulating periodontal tissue remodeling during orthodontic treatment.

Background: Observational studies indicate that obesity correlates with jaw development and remodeling; however, causality remains unclear. This study aimed to examine the potential causal relationship between life-course adiposity and jaw anomalies.

Methods: Utilizing summary statistics from genome-wide association studies predominantly of European ancestry, we conducted univariable and multivariable Mendelian randomization (MR) to estimate overall and independent effects of six obesity traits (birth weight, childhood body size, childhood body mass index [BMI], adult BMI, adult body fat percentage, and adult waist circumference) on seven jaw anomalies, including bimaxillary hypoplasia, prognathism, retrognathism, and jaw asymmetry. Comprehensive sensitivity analyses verified robustness, assessed heterogeneity, and examined pleiotropy.

Results: In univariate analyses, genetically predicted thinner childhood body size (inverse variance weighted [IVW] OR: 0.41, 95% CI: 0.27-0.62, p < 0.001), adult BMI (IVW OR: 0.65, 95% CI: 0.53-0.80, p < 0.001), and waist circumference (IVW OR: 0.60, 95% CI: 0.45-0.82, p = 0.001) were significantly associated with the risk of mandibular retrognathia following Bonferroni correction. Multivariable MR analysis revealed a direct causal effect of childhood body size on mandibular retrognathia, independent of birth weight, adult adiposity, growth hormones, and lifestyle factors. No evidence was found for causal associations between life-course adiposity and other jaw anomalies. Sensitivity analyses produced broadly consistent findings.

Conclusions: This MR study provides new evidence on the direct causal effects of thin childhood body size on the risk of mandibular retrognathia, emphasizing the critical role of early childhood nutrition and weight management in craniofacial development.

Objective: Molar sequential distalization with clear aligners was advantageous. However, the effect of periodontal status on it has yet to be investigated. This study aimed to analyze the influence of the different periodontal states on molar distalization to reduce the adverse mechanical stimulation caused by periodontal states by the different stagings of movement and further explore therapeutic recommendations for clinical practice.

Methods: To ascertain the initial displacement of dentition and periodontal ligament (PDL) hydrostatic stress, finite element models (FEMs) were developed. These models included the distalization of the second molars (Step A) and the first molar (Step B) in three distinct periodontal conditions (simulating the periodontal state of mild, moderate, and severe periodontitis) and three distinct distances (0.10 mm, 0.18 mm, 0.25 mm).

Results: Periodontal status affected the tooth movement during molar distalization. During the molar distalization with 0.25 mm step distance, the initial displacement of the molar was greater in the model with worse periodontal condition. However, it did not increase the efficiency of tooth movement because the initial displacement is accompanied by tipping. Moreover, the second molar relapse to mesialization for a reaction from the first molar distalization affected efficiency. Fortunately, reducing the step distance could control those undesired tooth movements positively associated with alveolar bone resorption.

Limitations: The finite element method cannot simulate complex periodontal conditions in clinical practice.

Conclusion: To reduce the undesired tipping and relapse, the personalized staging of movement should be designed according to the periodontal condition. Designing 0.18 mm step distance for patients with 1/3 alveolar bone resorption is recommended, whereas patients with 1/2 alveolar bone resorption need 0.1 mm. These recommendations can guide orthodontists in designing effective treatment plans for patients with varying degrees of periodontal disease.

Background: Early intervention in Class III malocclusion aims to prevent the need for surgery in adulthood by enhancing upper jaw growth while limiting lower jaw development. Although traditional facemask treatment remain common, bone-anchored devices are increasingly used, claiming better skeletal control and patient compliance. However, strong evidence supporting these advantages is limited.

Methods: Single-center, parallel-group, randomized controlled trial with 1:1 allocation ratio.

Participants:  28 growing Class III patients (mean age 9.7 ± 1.3 years) in mixed dentition with skeletal class III malocclusion.

Interventions:  Patients were randomly assigned to either hybrid hyrax with facemask (HH + FM, n = 14) or hybrid hyrax with mentoplate (HH + MP, n = 14). All received Alt-RAMEC protocol expansion. FM group used 360-400 g/side elastic traction 12-14 h daily; MP group used 185 g/side continuous traction.

Objective:  To compare 5-year three-dimensional (3D) skeletal effects between HH + FM and HH + MP protocols.

Outcome:  Primary outcome was 3D volumetric changes of upper and lower jaw at 1 year (T1) and 5 years (T2) post-treatment, measured using low-dose CT scans.

Randomization: 28 patients were allocated to either treatment-protocols using sequentially numbered opaque, sealed envelopes. The randomization sequence was generated with a 1:1 allocation ratio.

Blinding: Due to the nature of the trial, the operator and children could not be blinded to the treatment allocation. However, blinding was used when assessing the outcomes.

Results: Follow-up: one patient was lost at the one-year follow-up and an additional three patients were lost at the 5-year-follow-up.

Outcomes: At T2 (5 years), maxillary advancement was identical between both groups (0.85 mm ± 0.5). Mandibular growth control showed minimal difference (FM: - 0.01 mm ± 0.24; MP: 0.10 mm ± 0.33). No significant differences were found between groups for any skeletal measurements (p > 0.05). Male patients showed lager mandibular changes both signed (p < 0.03) and unsigned (p < 0.01).

Harms: minor harms were encountered with the anchor hooks (fracture or mucosal irritation), however none led to treatment cessation.

Conclusions: Both protocols demonstrated comparable long-term skeletal effects in Class III correction. Treatment choice should be based on individual patient factors rather than assumed mechanical advantages.