Progress in Orthodontics最新文献

Background: It is generally accepted that the ideal time to benefit from functional therapy in Class II patients is during the circumpubertal growth period (CVM 3-4). However, in severe cases, early intervention during the mixed dentition phase may be indicated, particularly to reduce the risk of dental trauma and to protect the child from potential bullying. The aim of this study was to evaluate the effects of the Manni Telescopic Herbst (MTH) appliance in young patients with mixed dentition, comparing the outcomes with two control groups: one treated with Class II elastics and a Wilson arch, and the other with a removable functional appliance (Paolone-Kaitsas, PK).

Methods: Following statistical matching for age, sex and pre-treatment overjet, lateral cephalograms taken at beginning (T0) and at appliance removal (T1) from 30 patients treated with the MTH appliance were compared with those of 15 patients treated with Class II elastics and 15 treated with the PK appliance.

Results: Regarding skeletal parameters, significant differences were observed in the mandibular sagittal position (SNB (T1-T0), p = 0.01) and in the relationships between skeletal bases (ANB (T1-T0), p = 0.03; Wits (T1-T0), p < 0.01), when comparing MTH and PK groups to the Class II elastics group. The Herbst group exhibited the most substantial skeletal changes. For dental variables, better incisor control was achieved with the removable PK appliance (Ii/GoGn T1-T0 1.513 ± 5.739, and Is/PP (T1-T0) 2.507 ± 6.482). No statistically significant difference was found regarding skeletal divergence (SN/GoGn (T1-T0), p = 0.38) when focusing on younger patients in mixed dentition phase.

Conclusion: Both the fixed MTH appliance and the removable PK appliance produced greater skeletal effects compared to Class II intermaxillary elastics, even when applied during the mixed dentition phase. Although the PK group demonstrated better dentoalveolar control, when significant skeletal modifications are required in young patients with mixed dentition, the use of a fixed functional appliance - such as the Herbst - is preferable.

Background: This study aimed to screen favorable and unfavorable profile outcomes in orthodontic camouflage treatment of skeletal Class II cases, based on which to identify the reference line and the associated value for the optimal incisor position objective (IPO) in such cases.

Methods: A total of 140 Chinese adult skeletal Class II cases were included, who finished orthodontic camouflage treatment with anterior retraction following premolars extraction. Post-treatment lateral cephalograms were trimmed and converted into silhouettes, rated by a panel of orthodontists. The top 30% and bottom 30% ranked cases were included as the favorable and unfavorable profile group respectively. The distances of U1 anterior to the GALL line (U1-GALL), point A vertical (U1-Av), and ANS-Pog line (U1-ANPo) were measured as IPO indicators.

Results: U1-ANPo in the favorable profile group was 4.74 ± 1.65 mm, significantly different from that in the unfavorable profile group (6.02 ± 3.61 mm). U1-GALL was -2.68 ± 2.30 mm and -1.12 ± 2.02 mm, and U1-Av was 4.49 ± 3.97 mm and 6.22 ± 4.42 mm, in the favorable and unfavorable profile group respectively, neither showing significant difference. Among three indicators, only U1-ANPo had a significant discriminatory capacity (AUC = 0.74, P = 0.007) for differentiating between the favorable and unfavorable profile group.

Conclusions: In skeletal Class II orthodontic camouflage treatment, the relatively favorable post-treatment profiles are associated with the U1 position anterior to the ANS-Pog line. U1-ANPo of around 4.7 mm could be tentatively proposed as a practical IPO reference in treatment planning for such cases.

Primary failure of eruption (PFE) is an uncommon autosomal dominant disorder predominantly defined by an impaired tooth eruption mechanism. It is characterized by a unilateral or bilateral open bite in the posterior area and incomplete or absent tooth eruption. Nonetheless, its etiology remains unclear. Current studies indicate that PFE may be directly associated with mutations in several genes, including parathyroid hormone receptor 1 (PTH1R), lysine (K)-specific methyltransferase 2 C (KMT2C), and transmembrane protein 119 (TMEM119). Despite the growing research on PFE genetics, no cohesive conceptual framework exists to integrate the known genetic information. This review seeks to address this gap and introduce a novel pathogenic model. The model posits that the normal eruption of teeth relies on the precise equilibrium between "The Pro-Eruptive Axis" and "The Anti-Resistance Axis," with the Dental Follicle (DF) serving as the central regulatory hub of this mechanism. This research will systematically categorize PFE-related genes and classify their pathogenic mechanisms as "insufficient motivation" or "excessive resistance" in eruption. On this basis, this review will analyze in depth the crosstalk of key signaling pathways (such as PTH, Wnt, TGF-β, and RANKL/OPG), investigate the complexity of genetic influences and temporal factors in elucidating phenotypic variability, enhance the existing classification framework into a dynamic, multi-dimensional comprehensive network, and ultimately suggest precise diagnostic approaches and prospective therapeutic targets based on pathogenic mechanisms from a translational medicine perspective. By constructing this integrated pathophysiological model, we aim to establish a robust theoretical framework for investigating molecular mechanisms and clinical diagnosis and formulating novel individualized treatment options for PFE.

Background: Clear aligners face biomechanical limitations in complex tooth movements, particularly first molar mesialization, despite attachment use. Finite element analysis (FEA) can elucidate optimal attachment designs for force delivery.

Objectives: To compare displacement patterns and stress distribution during maxillary first molar mesialization using four attachment designs via 3D FEA.

Methods: A maxillary model (MRI-derived) was created with periodontal ligament (PDL), alveolar bone, and clear aligner (0.75 mm thickness). Five scenarios were simulated: no attachment (Model-I), vertical rectangular (Model-II), horizontal rectangular (Model-III), optimized double semi-ellipsoidal (Model-IV), and Yin-Yang attachments (Model-V). Mesial displacement (0.5 mm) was applied, and deformation/stress were analyzed using ANSYS Workbench.

Results: Model-IV (optimized attachment) demonstrated the least first molar tipping, evidenced by its lowest total mesial crown displacement (0.319 mm), and provided the best mesiodistal control. Conversely, Model-I (no attachment) exhibited the highest tipping, with a total mesial crown displacement of 0.376 mm. Yin-Yang attachments (Model-V) significantly reduced buccal displacement by 92% compared to Model-I. Horizontal rectangular attachments minimized rotational movement.

Conclusions: Optimized double semi-ellipsoidal attachments provide superior first molar mesialization control, while Yin-Yang designs enhance buccal-lingual stability. Attachment geometry critically influences aligner efficacy.

The "periodontal ligament-periosteum (PDL-PS) sandwich hypothesis" has been proposed to explain the mechanism of bone recovery around roots moved outside their bony housing. This hypothesis suggests that the presence of the periosteum and periodontal ligament facilitates bone recovery in such cases. This retrospective case series examines three adult patients who developed iatrogenic dehiscences and fenestrations of the anterior teeth due to the placement of fixed lingual retainers after orthodontic treatment. Each patient then underwent orthodontic retreatment aimed at repositioning the roots back into the alveolar housing. Cone-beam computed tomography (CBCT) scans and intraoral photographs taken before (T2) and after (T3) retreatment were used to evaluate bone recovery. To test the PDL-PS sandwich hypothesis, predictions of bone recovery were made based on T2 parameters and the root movements achieved during retreatment. The observed bony recovery at T3 was then compared with these predictions. Roots that were partially or fully repositioned into the original alveolar housing exhibited partial to complete bony recovery. In contrast, teeth with minimal root movement back into bone showed limited or no recovery. In cases with pre-existing gingival recession, bone recovery occurred only apical to the areas of recession, even with favorable root movements. Additionally, the dimensions of the alveolar housing remained stable as roots moved through the alveolar bone, supporting the theory that roots move through alveolar bone, rather than with bone, in adults. These findings highlight the need for evidence-based clinical strategies to guide the management of inadvertent tooth movement caused by orthodontic appliances or retainers, with particular attention to the potential for bone recovery when repositioning teeth into their original alveolar housing.

Background: Maxillary expansion has been a treatment of choice for correcting transverse skeletal discrepancies, especially in growing patients. For older patients, Mini-implant Assisted Rapid Palatal Expansion (MARPE) offers a promising treatment option. This study evaluates the treatment outcomes of Custom 3D-printed MARPE compared to Conventional MARPE (MSE-II).

Methods: This retrospective study analyzed CBCT images from 42 patients aged 16 to 35 years, comparing measurements before (T1) and after (T2) expansion. The conventional (n = 21) and custom (n = 21) MARPE groups were matched with age and sex. Skeletal and dental changes were evaluated measuring twelve distances and four angles using Dolphin Imaging Software (Chatsworth, Calif). The measurements included frontozygomatic and maxillary widths, nasal cavity width, and dentoalveolar inclination. The effectiveness of each appliance was evaluated based on magnitude of expansion and successful correction of transverse discrepancy.

Results: The custom MARPE group demonstrated comparable or greater increase in width across various anatomical landmarks to the conventional group. Logistic regression suggested a trend toward higher odds of successful transverse discrepancy correction with custom MARPE.

Conclusions: Custom 3D-printed MARPE appliances may offer advantages in achieving skeletal expansion in older patients. Individualized appliance design and strategic mini-implant placement could contribute to effective treatment. However, further research is needed to evaluate long-term outcomes, cost-effectiveness, and potential complications to better guide appliance selection for each patient.

Background: The aims of this study were to gather expert agreement about essential aspects of clear aligner therapy (CAT) and to determine what research areas need further investigation.

Materials and methods: A steering committee performed literature selection and compiled a list of 25 statements. This study used a modified Delphi method involving a panel of 23 international orthodontic experts. Six essential areas of CAT were investigated: treatment efficacy, quality of life, side effects, management of growing patients, treatment with extraction, and treatment of periodontal patients. A panel of experts assessed 25 statements using a 5-point Likert scale throughout 3 rounds of the study. A steering committee adjusted statements that failed to achieve consensus through either revision, splitting, merging, or complete removal.

Results: After the third round, 22 statements achieved consensus while 3 statements were rejected. The panel agreed that aligners could be used effectively in some types of malocclusions, such as those with mild or moderate crowding or open bite cases. The experts reached a consensus on the biomechanical limits of clear aligners. However, they agreed on the benefits in terms of improved quality of life during treatment and easier maintenance of oral hygiene maneuvers. Regarding specific patient categories, the panelists supported the use of aligners in periodontal patients with tooth migration requiring tipping movements. They also agreed on the advantages of using a rapid palatal expander over aligners in growing patients.

Conclusions: The panel members reached agreement on most topics. However, they acknowledged limitations in the current literature regarding root resorption and orthodontic relapse with CAT compared to fixed appliances. The absence of agreement on treatment duration, effects on skeletal growth, and the management of periodontally compromised patients highlights significant evidence gaps that warrant further research.

Objective: There is a lack of studies on patient-reported outcomes in orthodontics. The aim of this study was to evaluate the changes in patient-reported chief complaints during orthognathic surgery treatment.

Materials and methods: Patients undergoing orthognathic surgery at the University Hospital Münster between 2019 and 2023 were eligible for inclusion in this prospective cohort study. Patient-reported chief complaints were recorded on visual analogue scale (VAS) forms before treatment ([Formula: see text]), and reevaluated after presurgical orthodontic treatment ([Formula: see text]), and 6-9 months after surgery ([Formula: see text]). Chief complaints were grouped into three main categories (pain, function, aesthetics) and ten subcategories, and their intensity was quantified over time.

Results: A total of 217 out of 386 recruited patients (56%) completed all study assessments and were included in the final analysis (female/male = 126/91, median age 24.1 years). Dental function, facial aesthetics, and dental aesthetics were the most frequently reported complaints at [Formula: see text]. At [Formula: see text], there was a statistically significant improvement in dental aesthetics. There was a statistically significant reduction in the intensity of each of the 10 subcategories from [Formula: see text] to [Formula: see text].

Conclusion: Orthognathic surgery patients most frequently report dental function, facial aesthetics, and dental aesthetics as their chief complaints, and these complaints were improved significantly after treatment.

Clinical relevance: The improvement in patient-reported chief complaints can be used to inform patients prior to treatment.