Progress in Orthodontics最新文献

Background: The angulation of third molars is a critical factor influencing the likelihood of impaction. Orthodontic premolar extractions have been hypothesized to affect the eruption path of developing third molars by modifying available space and mesial drift patterns.

Objective: This systematic review and meta-analysis aimed to assess whether premolar extraction during orthodontic treatment alters the angulation of developing third molars compared to non-extraction protocols.

Eligibility criteria: Observational studies comparing angular measurements of third molars between extraction and non-extraction orthodontic treatments were included. Studies without a control group or adequate cephalometric data were excluded.

Information sources: A comprehensive literature search was conducted across two electronic databases (MEDLINE, Scopus) up to November 2024, following PRISMA 2020 guidelines.

Risk of bias and synthesis of results: Risk of bias was evaluated independently by two reviewers using the ROBINS-I tool. A random-effects meta-analysis was conducted, and the certainty of the evidence was assessed using the GRADE approach.

Results: Nine studies (865 participants) were included. For mandibular third molars, extraction was significantly associated with improved angulation (SMD = - 0.37; 95% CI: - 0.59 to - 0.15; p = 0.004). Significant differences were found in M3L/M2L (MD = - 1.31; 95% CI: - 1.76 to - 0.85; p = 0.003) and M3L/PP (MD = - 4.85; 95% CI: - 8.50 to - 1.21; p = 0.02). No statistically significant difference was observed in the M3L/MP angle. In the maxilla, only the M3U-PP angle showed a significant change (MD = - 5.79; 95% CI: - 11.53 to - 0.04; p = 0.049). Meta-regression revealed no association with age, sex, or premolar type. Certainty of evidence ranged from low to moderate.

Background: Skeletal Class II malocclusion is commonly treated using mandibular advancement appliances during growth. Evaluating the comparative effectiveness of different appliances can help optimize treatment outcomes.

Objectives: This study aimed to compare dental and skeletal outcomes of Class II malocclusion treatment using Herbst and PowerScope appliances in conjunction with fixed orthodontic therapy.

Methods: This retrospective comparative study included 46 consecutively treated patients in two university clinics: 26 with PowerScope and 20 with Herbst MiniScope. CBCT scans were obtained before and after treatment. Skeletal and dental changes were analyzed using maxillary and mandibular voxel-based regional superimpositions and cranial base registrations, aided by AI-based landmark detection. Measurement bias was minimized through the use of a calibrated, blinded examiner. No patients were excluded from the analysis. Due to the study's retrospective nature, no prospective registration was performed; the institutional review board granted ethical approval.

Results: The Herbst group showed greater anterior displacement at B-point and Pogonion than PowerScope (2.4 mm and 2.6 mm, respectively). Both groups exhibited improved maxillomandibular relationships, with PowerScope's SNA angle reduced and Herbst's SNB increased. Vertical skeletal changes were observed at points A, B, and Pog in both groups. Herbst also resulted in less lower incisor proclination and more pronounced distal movement of upper incisors.

Conclusion: Both appliances effectively corrected Class II malocclusion. Herbst promoted more pronounced skeletal advancement, while PowerScope induced greater dental compensation. These findings may be generalizable to similarly aged Class II patients in CVM stages 3-4.

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.