Progress in Orthodontics最新文献

Background: To establish consensus of skeletal anchorage versus conventional anchorage in treating: 1. Maxillary transverse deficiency in growing and adult patients, 2. Class II skeletal disharmony due to mandibular retrusion in growing patients, 3. Class III skeletal disharmony in growing patients.

Methods: A four-rounds modified Delphi method was conducted. A steering committee performed a literature selection and compiled a list of 33 statements. An international panel of 25 experts in orthodontics agreed to participate. In each round, panelists were asked to rate their level of agreement with each statement using a 5-point Likert scale and provide comments. Statements that reached consensus were either accepted or rephrased. Statements that did not reach consensus were either rephrased, rejected, or split into two statements or merged with another.

Results: After the four rounds, 24 statements achieved consensus while 9 were rejected. The distribution of consensus statements was as follows: Maxillary transverse deficiency: 4 statements; Class II skeletal disharmony: 10 statements; Class III skeletal disharmony: 10 statements.

Conclusions: This modified Delphi consensus study aimed to provide guidance for orthodontists in choosing between skeletal and conventional anchorage for various treatment conditions. The study generated 24 consensus statements across three key domains. While the Delphi method provides valuable expert opinions, future studies, including randomized controlled trials, are needed to confirm these findings and address remaining uncertainties. Such efforts will aid in refining orthodontic treatment protocols and enhancing patient outcomes.

Background: Orthodontically induced root resorption (OIRR) is a common side effect of orthodontic treatment. This study compares the degree of OIRR between root-filled teeth (RFT) and vital pulp teeth (VPT), and analyzes relevant study variables.

Methods: We conducted a retrospective study on 69 patients who had undergone orthodontic treatment. Using Cone-beam computed tomography (CBCT), we measured changes of root length before and after treatment through a unique method involving three-dimensional (3D) image registration and superimposition. Factors related to the OIRR such as gender, type of treatment, tooth type, age, duration of treatment and distance of root movement were considered.

Results: The sample included 55 females and 14 males aged 27.19 ± 6.08 years. On the basis that there was no significant difference in the root movement distance between RFT and VPT, RFT showed significantly less OIRR than VPT (P < 0.05). Gender did not significantly impact on OIRR for either RFT or VPT group (P > 0.05). In women specifically, RFT displayed less resorption than VPT (P < 0.05). For treatment type, extraction cases demonstrated a lower degree of OIRR in RFT than VPT (P < 0.05), and notable greater OIRR in with-extraction group compared to no-extractions group was found in RFT (P < 0.05), but not in VPT (P > 0.05). Tooth type did not yield significant differences in OIRR overall; however, upper teeth and premolars experienced lower resorption in RFT than in VPT (P < 0.05). Cases treated with fixed appliance had higher OIRR in both RFT and VPT than those with clear aligners (P < 0.05). Age did not correlate significantly with OIRR for either group (P > 0.05). And duration of treatment positively correlated with OIRR for both types (RFT: r = 0.5506, P < 0.0001; VPT: r = 0.4371, P = 0.0002), so did root movement distance (RFT: r = 0.2955, P = 0.0140; VPT: r = 0.2790, P = 0.0206).

Conclusions: RFT exhibit significantly less OIRR than VPT after orthodontic treatment. Treatment type, appliance type, duration of treatment and root movement distance are significant factors influencing OIRR. Personalized orthodontic treatment plans and vigilant monitoring are crucial to mitigate OIRR risks.

Background: Primary failure of eruption (PFE) is a rare disorder characterized by a posterior open bite. While mutations in the parathyroid hormone 1 receptor (PTH1R) gene have been demonstrated to cause PFE, the underlying mechanisms remain largely unknown.

Methods: Whole exome sequencing was conducted to identify PTH1R variants in a PFE family. MG63 cells that stably expressed the corresponding mutant PTH1R were established using lentiviruses. Next, osteogenesis was assessed by measuring cell alkaline phosphatase activity, conducting alizarin red staining, and evaluating osteoblast-specific gene expression. Then, computational analysis of binding affinity and RNA sequencing were carried out. Lastly, rescue experiments were performed to validate the mechanism underlying the pathogenesis of PFE.

Results: A novel PTH1R missense mutation (c.904G > A, p.E302K) was identified in a Chinese family affected by PFE. Moreover, the E302K mutation inhibited the expression of osteogenic-specific genes and proteins in MG63 cells. Computational analysis revealed the E302K mutation decreased the binding affinity of Gα_s to the PTH1R protein. Consistently, cAMP accumulation assays demonstrated that the E302K mutation impaired the intracellular PTH_1-34 -induced accumulation of cAMP. Further RNA sequencing analysis and validation experiments revealed that the PI3K-AKT signaling pathway was predominantly down-regulated in response to the E302K mutation. Finally, forskolin partially restored the effects of the E302K mutation on osteogenesis.

Conclusions: This study indicated that the E302K mutation in PTH1R decreased the binding affinity of PTH1R protein for Gα_s, down-regulated the cAMP-PI3K/AKT signaling pathway, and inhibited osteogenesis, eventually leading to PFE. This study not only expands the genotypic spectrum of PTH1R mutations but also elucidates the underlying pathogenic mechanism of PTH1R-associated PFE.

Objective: This study aims to evaluate the incidence of open gingival embrasures (OGES) after orthodontic treatment and analyze its correlation with various clinical and radiographic parameters.

Methods: We retrospectively analyzed 330 orthodontic patients at West China Hospital of Stomatology from 2016 to 2023, categorizing them into Non-OGES (200) and OGES (130) groups based on post-treatment OGES presence in the central incisor area. Basic information of patients, pre- and post-treatment lateral cephalometric radiographs, and cone-beam computed tomography (CBCT) data were collected. Chi-square tests, two-sample t-tests, Welch's t-tests, and Mann-Whitney U tests were used to compare differences in gender, initial age, treatment duration, and cephalometric and CBCT indicators between the two groups. Binary logistic regression analysis was further employed to explore the clinical characteristics and cephalometric indicators of the study population.

Results: Univariate analysis revealed that the occurrence of maxillary central incisor OGES was significantly correlated with gender, initial age, treatment duration, and related cephalometric and CBCT indicators (P < 0.05). Similarly, the occurrence of mandibular central incisor OGES was also significantly associated with gender, initial age, treatment duration, and specific cephalometric changes (P < 0.05). Binary logistic regression analysis indicated that the occurrence of maxillary central incisor OGES was significantly related to initial age, treatment duration, and the change in the U1-SN angle, while the occurrence of OGES in the mandibular central incisor area was mainly related to initial age and treatment duration.

Conclusion: Orthodontic treatment plans should consider a variety of influencing factors, including initial age, treatment duration, anterior tooth angle and position, root-bone relationship, and the distance from the anterior tooth contact point to the alveolar crest, to prevent or reduce the occurrence of OGES after orthodontic treatment, thereby improving patients' aesthetic outcomes and periodontal health.

Background: Mid-palatal placement of temporary skeletal anchorage devices (TSADs) has become increasingly popular among clinicians due to high success rates, low associated risk and streamlining and enhanced customization of associated supra-structures. There is however limited patient data in relation to associated experiences and impacts.

Methods: A survey of patients undergoing mid-palatal TSAD insertion was undertaken using a 27-item bespoke questionnaire. Questionnaires were sent using both electronic and surface mail with a 3-month period allowed for response. Pain experience; the use of analgesia; requirement for additional visits; impacts on hygiene, speech, eating, and hobbies; and social impacts were assessed. Reponses involved the use of a Visual Analogue Scale as well as binary information.

Results: Overall, 152 responses were obtained with 87.5% describing experience of TSAD insertion either "as expected" or "better". Procedural pain was reported as mild in 62.5%. Local post-operative pain was scored as moderate in 21.1%. Some functional impairment was reported with 63.2% attributing difficulty with speech and 67.8% difficulty with eating due to the implant. However, these functional impairments were generally considered mild (by 68.1% and 60.2%, respectively) and most were very likely to recommend this treatment to others, with 65.1% (n = 99) scoring 8 or above out of 10.

Conclusions: Appreciable levels of pain, discomfort and functional impairment were noted with the use of mid-palatal TSADs. However, any unpleasant experiences were generally regarded as mild with most highly likely to recommend mid-palatal TSADs to prospective patients.

Objective: This study aimed to evaluate the positional and morphological changes in the temporomandibular joint (TMJ) in adult patients with skeletal Class I malocclusion treated with fixed orthodontic appliances (FAs) and clear aligners (CAs), both with and without premolar extractions.

Methods: This retrospective study involved 120 adult patients divided into non-extraction and extraction groups, each further subdivided equally into those treated with FAs and CAs. Cone beam computed tomography (CBCT) was used to assess the TMJ measurements before (T0) and after treatment (T1). Statistical analyses were conducted to compare the mean changes in intra- and inter-groups. A significance level of p ≤ 0.05 was considered.

Results: In the non-extraction group, specifically in FAs, significant increases were observed in TMJ parameters; anteroposterior condylar position (APCP) and mediolateral condylar inclination (MCI). Conversely, significant decreases were noted in vertical condylar position (VCP) and vertical condylar inclination (VCI). In the extraction group, significant increases were noted in APCP and anterior joint space (AJS), while posterior joint space (PJS) and anteroposterior condylar joint position (APCJP) decreased. For inter-group comparisons, the extraction group showed significant increases in APCP in FAs compared to CAs, and a significant decrease in APCJP in FAs compared to CAs.

Conclusion: FAs significantly impact condylar positions and joint spaces, especially in extraction cases. Monitoring TMJ parameters during orthodontic treatment is crucial to ensure positive outcomes and prevent TMJ disorders (TMDs). These findings may guide the selection of orthodontic appliances based on individual malocclusion characteristics.

Background: Tooth wear is an important mechanism for reducing dental dimensions and, consequently, dental crowding. The objective of this cohort study was to examine the relation of tooth wear, adjusted for covariates (age, tooth loss, arch perimeter and intercanine width), on tertiary crowding in Amazon Indigenous populations.

Methods: A sample of 40 Indigenous people in permanent dentition at T0 (baseline) and after 13 years (T1) were evaluated. The sample included 16 males and 24 females belonging to two villages, Arara (n = 22, mean ages 16.6 and 29.9 years) and Assurini do Xingu (n = 18, mean ages 16.0 and 29.6 years). Clinical, intraoral photograph and dental cast evaluations were performed at both times. The anterior crowding was measured using Little's Irregularity Index (LI) and modeled through a multilevel linear regression with the predictor variables: village, tooth wear (T1-T0), age (T0), tooth loss (T1-T0), changes in intercanine width (T1-T0) and changes in arch perimeter (T1-T0).

Results: A slight increase was observed (< 1 mm) in anterior dental crowding and a decrease in arch perimeter < 1.5 mm, while tooth wear increased between 0.65 and 0.99 units. The contextual variable (village) had no significant association with LI. In the upper arch, tooth loss was the only variable that showed an inverse association with LI (β=-0.41, p < 0.05). In the lower arch, the increase in dental crowding was inversely associated with tooth wear (β=-1.30, p < 0.05) and changes in arch perimeter (β=-0.31, p < 0.05). The other variables did not show significant associations.

Conclusion: After 13 years, dental crowding and tooth wear increased, while the arch dimensions tended to decrease. The changes in long-term dental crowding seem to have distinct etiological components for each dental arch. In the mandible, the changes in incisor alignment were associated with increased tooth wear and decreased dental arch dimensions. Whereas in the maxilla, only tooth loss caused alterations in tooth alignment. It is suggested that the effect of increased tooth wear on the etiology of tertiary crowding is of small magnitude and restricted to the lower dental arch.

Background: Yes-associated protein (YAP) is a crucial mechanosensor involved in mechanotransduction, but its role in regulating mechanical force-induced bone remodeling during orthodontic tooth movement (OTM) is unclear. This study aims to elucidate the relationship between mechanotransduction and mechanical force-induced alveolar bone remodeling during OTM.

Results: Our study confirms an asynchronous (temporal and spatial sequence) remodeling pattern of the alveolar bone under mechanical force during OTM. Both compression and tension activate osteoclasts recruiting to the alveolar bone, whereas no significant presence of osteoblasts in the alveolar bone at the early stages of bone remodeling. Specifically, applying different force magnitudes (10, 25, 50, 100 g) to rats' 1st molars affected OTM distance. Force-induced alveolar bone remodeling was characterized by osteoclastogenesis and YAP activation at compressive/tensile sites on day 1 of OTM. Notably, 25 g force triggered peak YAP expression and osteoclastic activity early on. Time-course analysis revealed two YAP activity peaks on day1 and 14, contrasting with one peak of type I collagen expression on day14. In addition, RNA-sequencing highlighted increased nuclear factor kappa B (NF-κB) signaling, mineral absorption, and osteoclast differentiation at day-1 and 3. Moreover, gene expression analysis showed similar trends for NF-κB p65, YAP1, and TEA domain 1 (TEAD1) during this time. Furthermore, experiments on osteoclast cultures indicated YAP activation via large tumor suppressor (LATS) and TEAD under mechanical stimuli (compression/tension), promoting osteoclastogenesis by regulating NF-κB p65 and receptor activator of NF-κB (RANK). Inhibiting YAP with verteporfin delayed OTM by impairing force-induced osteoclastic activities in vivo and ex-vivo.

Conclusions: We propose that YAP mediates alveolar bone remodeling through NF-κB p65-induced osteoclastogenesis in an asynchronous remodeling pattern during OTM. Both compression and tension activate osteoclasts recruiting to the alveolar bone at early stages of bone remodeling, offering evidence for orthodontists as a reference.

Background: White spot lesions (WSLs) may develop in adolescents undergoing clear aligner (CA) therapy with poor oral hygiene. The specific effects of CAs on the microbial composition and functional characteristics of supragingival plaques remain unclear. The present study investigated the shift in the supragingival microbial community induced by CAs in adolescents through metagenomic technology.

Methods: Fifteen adolescents (12-15 years old) with Invisalign appliances were recruited. Supragingival plaque specimens were obtained twice, before treatment (T₁) and three months after treatment (T₂). All the bacterial plaque specimens were analyzed for microbial communities and functions using metagenomic analyses.

Results: A total of 2,840,242,722 reads disclosed 180 phyla, 3,975 genera, and 16,497 microbiome species. During the first three months, the microbial community was relatively stable. The genus level revealed a higher relative abundance of Capnocytophaga, Neisseria, and Arachnia in the T₂ period. Furthermore, the functional analysis suggested that the relative abundances of folate biosynthesis, biotin metabolism and biofilm formation-vibrio cholerae were increased in the T₂ period compared to the T₁ period. Finally, virulence factor analysis demonstrated that the relative abundance of genes associated with type IV pili (VF0082) and polar flagella (VF0473) was higher in the T₂ period than in the T₁ period.

Conclusion: In adolescents undergoing CA therapy with poor plaque control, caries progresses quickly within three months and noticeable WSLs develop on the tooth surface. Although the microbial community remained relatively steady and CA therapy did not cause significant changes in the overall functional gene composition in the first three months, virulence factors, including type IV pili and flagella, were more abundant and actively contributed to microorganism adhesion and biofilm formation.