European journal of orthodontics最新文献

Objective: Molar distalization is a therapeutic approach commonly used for treating Class II malocclusions. However, the extended duration of this treatment often leads to its replacement with alternative methods that offer shorter treatment times. Micro-osteoperforation (MOP) has been introduced as a technique aimed at accelerating tooth movement and reducing treatment duration. The purpose of this study is to evaluate the impact of MOP on molar distalization outcomes to provide evidence for its effective and safe use.

Search methods: A comprehensive search was conducted across multiple databases, including MEDLINE, Web of Science, EMBASE, Scopus, and Cochrane's CENTRAL, up to April 2024, without any language or date restrictions.

Selection criteria: Only randomized clinical trials (RCTs) that addressed the defined PICO question were included in the analysis. The risk of bias in the included studies was assessed using the Cochrane Risk of Bias 2.0 (RoB 2) tool.

Data collection and analysis: Relevant data were extracted using custom-designed forms, and a random-effects inverse variance meta-analysis was performed to synthesize the results. The primary outcomes analyzed were the rate and amount of molar distalization, while secondary outcomes included pain levels, root resorption, and periodontal health.

Results: Four RCTs, involving a total of 71 participants, were included in this exploratory review. Most studies were at low or some concerns risk of bias. The meta-analysis revealed no significant differences in the rate or amount of molar distalization between the MOP and control groups (mean difference [MD] = 0.1 mm/month and 0.01 mm, respectively, P > .05). However, the MOP group reported significantly higher pain levels on the day of the procedure (MD = 2, P = .01) on a 10-point visual analog scale (VAS) compared to the control group. This difference in pain perception was no longer significant seven days after the procedure (MD = 0.52, P = .52).

Conclusion: While MOP is associated with increased immediate postoperative pain, it does not significantly enhance the efficiency of molar distalization. Therefore, the use of MOP for distalization should be judiciously considered and reserved for cases that involve particularly challenging or prolonged movements, based on the specific needs and characteristics of each patient. Limitations of this review include the small number of available RCTs and variability in MOP protocols, which may limit the generalizability of the findings.

Registration: The protocol for this systematic review was registered at PROSPERO with the ID CRD42024589482.

Background: Extraction of premolars is usually prescribed for the orthodontic treatment of cases with inadequate space within the dental arch or when anterior teeth retraction is indicated; however, it has been advocated that this treatment approach could negatively influence the airways.

Objective: To identify and critically appraise studies of premolar extractions during orthodontic treatment on upper airway dimensions. Search methods: Electronic unrestricted searches in nine databases until October 2024. Selection criteria: Clinical studies on humans comparing comprehensive orthodontic treatment with versus without the extraction of premolars using cone-beam computed tomography to assess upper airway volume or minimum cross-sectional area (minCSA). Data collection and analysis: After duplicate study selection, data extraction, and risk-of-bias assessment according to Cochrane, random-effects meta-analyses of Mean Differences (MD) with their 95% confidence intervals (CI) were performed, followed by subgroup/meta-regression analyses and assessment of the quality of evidence.

Results: Twelve papers corresponding to 11 unique retrospective non-randomized studies were included, covering 891 patients (35.8% male; 20.0 years-old on average). No statistically significant differences in the effect of orthodontic treatment on the volume of the nasopharynx, palatopharynx, glossopharynx, oropharynx or oral cavity were seen between patients treated with versus without premolar extractions (P > .05). Similarly, no significant differences were seen between extraction and non-extraction patients in terms of minCSA of the nasopharynx, palatopharynx, or glossopharynx (P > .05). On the contrary, patients treated with premolar extractions showed increased minCSA of the oropharynx compared to those treated without premolar extractions (4 studies; MD = 23.00 mm2; 95% CI = 10.74-35.26 mm2; P = .009). No significant effects from patient age, sex, or equivalence of the extraction/non-extraction groups were found, while the strength of evidence was moderate in all cases due to the inclusion of non-randomized studies with high risk of bias.

Conclusions: Limited evidence of moderate strength indicates that, on average, premolar extractions during comprehensive orthodontic treatment have little to no effect on the volume and minCSA of the airways.

Registration: CRD42024621355.

Introduction: Palatal rugae are used as anatomical landmarks on the hard palate, in various clinical applications; in forensics, for insertion of mini-screws, and for superimposition. There is ambiguous evidence on whether they change during orthodontic treatment and to what extent. Therefore, we investigated changes in the shape, complexity, and area occupied by palatal rugae following orthodontic treatment with and without extractions.

Materials and methods: Pre- and post-treatment plaster models of maxillae of 28 cases involving first premolar extractions (17 females and 11 males) and 33 non-extraction cases (19 females and 14 males) were scanned and analysed. All participants were selected from a parent sample via discriminant analysis and represent borderline cases. We applied mesh cropping, ball pivoting, distance mapping, contour cropping of rugae, best-fit superimposition, fractal dimension (FD) analysis, and creation of rugae's convex hull area with Viewbox 4 software. The average distance between the closest points of the outlines of pre- and post-treatment palatal rugae (indicating shape change in the set of rugae), disparity in their pre- and post-treatment FDs (reflecting the complexity of their shapes), area occupied by rugae, arch depth, and size of palatal surface were then computed.

Results: The medians of the average distance between pre- and post-treatment outlines after best-fit superimposition were 0.39 mm (interquartile range [IQR]: 0.34-0.51) and 0.27 mm (IQR: 0.22-0.34) mm for the extraction and non-extraction groups, respectively (P < 0.001). The median pre-treatment FDs were 1.497 (IQR: 1.481-1.521) for the extraction group and 1.481 (IQR: 1.456-1.509) for the non-extraction group, whereas their median post-treatment FDs were 1.502 (IQR: 1.472-1.532) and 1.489 (IQR: 1.469-1.501), respectively. The differences between pre- and post-treatment fractal dimensions were not found to be significant, neither within each group, nor across the groups. On the other hand, the surface area occupied by rugae showed a median increase of 14.7 mm2 (IQR: 0.0-46.5) (P = 0.003) following non-extraction treatment only.

Conclusion: Palatal rugae change shape during orthodontic treatment, but their shape complexity, as measured by fractal dimensions, remains unaltered. Extraction treatment exerts a more pronounced effect in shape change compared to treatment without extractions. Nevertheless, non-extraction orthodontic treatment increases the surface on which rugae lie, as measured by means of the convex hull. Although the alterations may appear minor, it is necessary to exercise caution and prudence when employing rugae for superimposition and forensic dentistry purposes.

Objectives: To evaluate whether unilateral functional posterior crossbite in growing children creates an asymmetry in masseter muscle thickness and whether this asymmetry is normalized after crossbite correction.

Materials and methods: Two groups of growing individuals were studied prospectively: (i) a treatment group: children with unilateral functional posterior crossbite, undergoing crossbite correction with maxillary expansion; and (ii) a control group: children without transversal malocclusions and orthodontic treatment. The thickness of the masseter muscles was measured bilaterally using ultrasonographic recordings at three time points: pre-treatment (T0); 9 months after (T1); and 30 months after posterior crossbite correction (T2); and at equivalent time points in the control group. Differences within and between the groups were evaluated using paired and unpaired t-tests respectively.

Results: It was found that the thickness of the masseter muscles in patients with unilateral functional posterior crossbite was significantly thinner on the crossbite side (P = .013) by 0.5 mm. At T1, the masseter muscle of the treated crossbite side was thicker than that of the previous normal side (0.3 mm difference; P = .046) while this difference disappeared at T2 (P > .05).

Limitations: The lack of the inclusion of an untreated posterior crossbite group, and the heterogeneity in appliances used are the principal limitations of this study.

Conclusions: The masseter muscles in untreated individuals with unilateral functional posterior crossbite are thinner in the crossbite side than in the contralateral non-crossbite side. This muscular asymmetry however is eliminated some time after successful treatment of this malocclusion, possibly due to the bilateral symmetrization of the activity of the elevator masticatory muscles.

Objectives: We aimed to characterize a craniofacial skeletal phenotype (CSP) of adult obstructive sleep apnea (OSA) patients from a multidimensional perspective, exploring the impact of transverse skeletal discrepancy (TSD) on multivariable polysomnographic profiles.

Materials and methods: This retrospective, cross-sectional study included 102 adult OSA patients. Sagittal, vertical, and transverse skeletal patterns were categorized on the cone beam computed tomography images. The CSP of OSA patients, characterized by a Class II hyperdivergent pattern, was divided into CSP2D and CSP3D subgroups according to the presence of TSD, and compared with the non-CSP of OSA patients. Both nasal and pharyngeal airway variables were involved for assessment, and 12 polysomnographic variables with a sleepiness symptom variable were used for phenotype-based inter-group comparisons.

Results: The CSP patients revealed greater disease severity than the non-CSP patients (indicated by eight polysomnographic variables), despite being younger (P < .05) and less obese (P < .01). The CSP3D patients with TSD exhibited more severe OSA than the age- and BMI-matched CSP2D patients without TSD, as indicated by nine polysomnographic variables, in relation to smaller nasal airway volume, smaller pharyngeal minimum cross-sectional area, and longer pharyngeal airway length (all P < .05). The probability of multiperspective characteristics among three phenotypes was significantly contrasted in 19 variables.

Conclusions: From a multidimensional perspective, the CSP patients showed greater OSA severity with more vulnerable nasal and pharyngeal airways than non-CSP patients, despite being younger and less obese. Specifically, the CSP3D patients revealed far more severe OSA than the CSP2D patients, indicating the significance of TSD on the polysomnographic profiles.

Objectives: This study determined the prevalence and risks of definite sleep bruxism (SB) among children and adolescents presenting for orthodontic treatment.

Methods: This was a cross-sectional study of 7-16-year-old subjects pursuing orthodontic treatment for the first time. The presence or absence of SB was determined using an overnight mandibular movement monitoring inertial measurement sensor, worn by each participant for two consecutive nights. Data from the sensor were extrapolated, then processed and analyzed to automatically identify rhythmic masticatory muscle activity for SB assessment. SB risks were evaluated from previously validated questionnaires, clinical examinations, lateral cephalometric radiographs, and digital study models.

Results: A total of 87 subjects with a mean age of 12.82 years ± 2.24 and body mass index of 21.45 ± 5.49 participated in the study. The prevalence of SB was 60.7%. Multiple linear regression analysis revealed that SB had statistically significant association with microarousals (events/h) (β=0.31, 95% Confidence Interval [CI] 0.25-0.36, P < .001) and maxillary 6-6 dimension (mm) (β = 0.08, 95% CI 0.02-0.13, P = .008). A second model excluding microarousals showed that SB had a statistically significant association with sleep efficiency (SE) percentage (β = -0.15, 95% CI -0.28 to -0.01, P = .026) and obstructive respiratory disturbance index (ORDI) (events/h) (β = 0.33, 95% CI 0.15-0.51, P < .001).

Conclusions and implications: In a growing orthodontic population, definite SB is very common. SB is related to microarousals, maxillary intermolar width, SE percentage, and ORDI.

Background: The fear of pain during the various stages of orthodontic treatment with fixed appliances is a common concern of patients. Therefore, the present research aimed to thoroughly investigate the impact of bracket architecture on pain perception during active treatment, debonding, and adhesive removal.

Materials: One hundred consecutive patients who completed treatment with one of two bracket systems (2-slot brackets with an integral base or conventional twin brackets with foil mesh) were included in this prospective cohort study. Participants were asked to evaluate the level of pain encountered throughout their orthodontic treatment with the fixed appliances and during bracket and adhesive removal, utilizing a 0-10 numerical rating scale. Two different methods of bracket removal (bracket debonding pliers and Lift-Off Debonding Instrument) and adhesive removal (adhesive removal pliers and rotary instrument) were tested.

Results: Our study found moderate and comparable levels of pain during active treatment in both groups (4.4 ± 1.6 in the 2-slot group and 3.9 ± 1.9 in the Twin group). Debonding of brackets with integral base caused more discomfort compared to conventional twin brackets and using bracket removal pliers elicited more pain sensations than when Lift-Off Debonding Instrument were employed. Patients are likely to prefer adhesive removal methods involving rotary instruments despite the sound and vibrations produced by contra-angle handpiece.

Limitations: The lack of randomization in patient grouping introduces an increased risk of bias.

Conclusions: The results of the present study suggest that the bracket architecture, particularly the construction of the bracket base, affects the level of discomfort experienced during debonding.

Trial registration: ClinicalTrials.gov, NCT06324162, Registered 20 March 2024-Retrospectively registered, https://clinicaltrials.gov/study/NCT06324162.

Objectives: This study aimed to determine the genetic and environmental contributions to phenotypic variations of palatal morphology during development.

Methods: Longitudinal three-dimensional digital maxillary dental casts of 228 twin pairs (104 monozygotic and 124 dizygotic) at primary, mixed, and permanent dentition stages were included in this study. Landmarks were placed on the casts along the midpoints of the dento-gingival junction on the palatal side of each tooth and the mid-palatine raphe using MeshLab. Palatal widths, depths, length, area, and volume were measured using those landmarks. Univariate genetic structural equation modelling was performed on twin data at each stage of dental development.

Results: Except for anterior depth, all palatal dimensions increased significantly from the primary to permanent dentition stages. The phenotypic variance for most of the palatal dimensions during development was best explained by a model, including additive genetic and non-shared environment variance components. Variance in volume and area in the primary dentition stage was best explained by a model including additive genetic, shared environment, and non-shared environment variance components. For posterior palatal depth and width, narrow-sense heritability estimates were above 0.8 for all dental developmental stages. In contrast, heritability estimates for other palatal traits fluctuated during development.

Limitation: This study was limited to twins of European ancestry.

Conclusions: Additive genetic and non-shared environmental factors primarily influenced palatal morphology during development. While the genetic influence on different aspects of the palate varied throughout development, it was particularly strong in the posterior region of the palate and during the permanent dentition stage.

Background: The infrazygomatic miniscrew implants (IZC-MSI) serve as innovative temporary anchorage devices placed parallel to the roots of molars in the infrazygomatic crest region, leveraging their extra-radicular location to support the en masse distalization and intrusion of the maxillary dentition. The efficacy and stability of these screws are crucial for their application in contemporary orthodontic practices.

Objectives: This systematic review aimed to estimate the success rate and factors affecting the stability of IZC-MSI.

Search methods: An electronic search was conducted on 7 February 2024 across the following databases: PubMed, Scopus, EMBASE, and Cochrane databases without any restriction on language and time of publication.

Selection criteria: The review included clinical trials (both randomized and non-randomized) and retrospective cohort studies that utilized infrazygomatic miniscrew anchorage for orthodontic tooth movement in human participants.

Data collection and analysis: The proportion of success rate was calculated and factors affecting stability (patient and implant-related factors) such as age, sex, implant position, and loading characteristics were subjected to subgroup analysis and meta-regression. The quality assessment of studies was done using the Cochrane risk-of-bias tools for randomized (RoB 2.0) and non-randomized trials (ROBINS-I).

Results: Fourteen studies (n = 1683 IZC-MSI) were included in the meta-analysis revealing a 92% success rate of IZC-MSI (C.I. 87%-95%; prediction interval: 66%-99%; I2 = 80%). Studies with sample size > 100 presented a 94% success rate (C.I. 91%-96%; I2 = 63%) and moderate heterogeneity. Meta-regression analysis revealed no significant relation between age and success rate. Significant heterogeneity was observed in the subgroup analysis of host-, implant- and other related risk factors affecting stability and limited correlation was found. The risk-of-bias assessment revealed high risk in five, moderate in five, and low in four studies.

Conclusions: IZC-MSI have shown a good success rate for their clinical application. Although some factors appear to influence IZC-MSI stability, the majority of them necessitate additional investigation due to the low quality of evidence. Furthermore, high-quality studies are needed to confirm the results of this meta-analysis and address other important factors such as operator's experience, insertion torque, and sinus penetration that could not be analysed due to limited data.

Registration: CRD42024469048.

Objectives: The purpose of this retrospective study was to compare the dento-skeletal changes observed in growing Class III patients treated with the Face Mask Protocol (FMP) with and without Bite Block (BB).

Materials: Thirty subjects (12 f, 18 m) who underwent FM/BB therapy were compared to a matched group (FM) of 29 patients (15 f, 14 m) treated without BB. All patients were evaluated before treatment (T0), at the end of active treatment (T1), and at a post-pubertal follow-up observation (T2). A control group (CG) of 20 subjects (10 f, 10 m) with untreated Class III disharmony was used for the comparison of post-pubertal changes. Intergroup statistical comparisons were performed with the independent samples t-test (P < .05).

Results: The comparison between treated samples showed a significant improvement of SN^GoGn (FM/BB vs FM, -2.1°), Overbite (FM/BB vs FM, +1.2 mm), and vertical position of lower molars FM/BB vs FM, -3 mm). When compared with the controls, both treated groups revealed a significant improvement of SNA (FM/BB, +1.8°; FM +2.1°), ANB (FM/BB +1.6°, FM +2.4°), gonial angle (FM/BB -4.9°; FM -4°), incisor inclination (Upper, FM/BB +1.7°, FM +2.3°; Lower, FM/BB -2.5°, FM -2.7°), and Overjet (FM/BB +3.2 mm; FM +4 mm). Improvement of SN^GoGn (-2.1°), Overbite (+1.8 mm), and vertical position of lower molars (-3.8 mm) were observed when FM/BB was compared with CG.

Limitations: Limitations are related to the difficulty to recruit a larger contemporary long-term control group due to ethical reasons.

Conclusion: Both FM protocols induced favorable changes in the treatment of Class III malocclusion with a good post-pubertal stability. The BB allows a more efficient control of the vertical skeletal relationship.