Journal of Orofacial Orthopedics-Fortschritte Der Kieferorthopadie最新文献

Aim: This systematic review aimed to assess and quantify the dentoalveolar compensation in skeletal class III malocclusion subjects.

Materials and methods: Untreated class III subjects whose dentoalveolar compensations were radiologically evaluated were included. Predetermined inclusion and exclusion criteria were applied across PubMed, Scopus, LILACS, Ovid, and Web of Science electronic databases up to 27 January 2025, with no restriction on the year of publication. A total of 1007 articles were obtained, of which 10 studies met the eligibility criteria and were included in the systematic review, while 7 were included for the meta-analysis.

Results: Risk of bias assessment was performed using the Newcastle Ottawa scale. Four studies scored 8 points, four studies scored 7 points, and two studies scored 6 points. The qualitative evaluation indicated that the dentoalveolar compensation in class III malocclusion was a result of proclined maxillary and retroclined mandibular incisors. Quantitative evaluation showed that when compared to class I subjects, maxillary incisors in class III subjects were proclined by 4.75° (95% confidence interval [CI] 0.72-8.77). Mandibular incisors were retroclined with a mean change in inclination of -8.40° (95% CI -11.21 to -5.60), thus, indicating a greater contribution of mandibular incisors to the compensatory mechanism.

Conclusion: The present systematic review and meta-analysis conclusively proved that maxillary incisor proclination and mandibular incisor retroclination contributed to dentoalveolar compensation in class III subjects. Quantitative analysis provided evidence that mandibular incisor retroclination contributed more to dentoalveolar compensation. The findings of this systematic review and meta-analysis would be of importance to the clinician while planning treatment, since respecting the anatomical limits of the underlying structures is essential.

Purpose: The goal is to assess long-term oral health-related quality of life in adults who had previously undergone compensatory orthodontic treatment for class III malocclusion and to identify associated factors.

Methods: A total of 26 patients who underwent treatment by dental compensation more than 5 years ago were followed for an average of 14 years and were evaluated using cephalograms, photographs, the Oral Health Impact Profile (OHIP)-14 questionnaire, and self-perception questions on treatment stability. Poisson regression was used to analyze the association between quality of life and the stability of class III treatment, considering posttreatment cephalometric measurements, sex, posttreatment age (T2), treatment and posttreatment duration, use of retainers, tooth extractions, gingival recession, and clinical changes in incisor alignment.

Results: The median OHIP-14 score was 3 (range 0-8.5), indicating a good level of quality of life over the long-term. In all, 30.76% of patients reported minor worsening in treatment results after its completion. When asked to identify the observed changes that occurred after treatment, whether in the teeth, face, or both regions, 80% associated the worsening with the dental region. Of these, 90% reported willingness to undergo orthodontic retreatment. Only 12% of the variation in OHIP-14 scores was attributed to the chosen predictor variables, and none of the analyzed variables showed a significant association with quality of life (p = 0.20-0.99).

Conclusion: Adults with class III malocclusion subjected to treatment with dental compensation reported a good OHRQoL in the long-term, even in the presence of minor posttreatment changes. Cephalometric changes, clinical and assessed demographic factors did not significantly impact quality of life.

Purpose: Mandibular retrognathism (MR) is a common skeletal malocclusion in humans with a strong genetic component. Single nucleotide polymorphisms (SNPs) in genes encoding epidermal growth factor (EGF) and EGF receptor (EGFR) could be involved in the etiology of mandibular retrognathism. Therefore, in this study, we investigated whether SNPs in the genes encoding for EGF and EGFR are associated with MR in German teenagers.

Methods: This nested case-control study evaluated German orthodontic patients, aged 10-18 years. DNA, which was isolated from buccal epithelial cells using two cytobrushes, was used for genotyping analysis and digital pretreatment lateral cephalograms were examined to calculate SNB and ANB. Patients with a retrognathic mandible (SNB < 78°) were included as cases, while patients with an orthognathic mandible (SNB = 78-82°) were included as controls. Four SNPs in the genes encoding for EGF and EGFR were chosen and genotyped using real-time PCR. Allele, genotype, and haplotype frequency were compared across groups (α = 5%).

Results: Finally, 119 patients were included in this study (45 orthognathic mandible, 74 retrognathic mandible). The minor allele G in rs4444903 (EGF) was statistically more frequent in individuals with an orthognathic mandible (p = 0.008). The haplotype formed by the mutant alleles for rs4444903|rs2237051 (EGF; G|A) was statistically more frequent in the orthognathic mandible group (p = 0.007). The SNPs rs4444903 and rs2237051 in EGF, and rs2227983 in EGFR were statistically associated with a decreasing risk of developing a retrognathic mandible according to univariate and multivariate statistical analysis (p < 0.05).

Conclusion: SNPs in EGF (rs4444903 and rs2237051) and EGFR (rs2227983) were associated with MR in our German sample and could be genetic biomarkers for early and individualized diagnostic identification of retrognathic mandibular development by means of genetic screening tests.

Background: The present study aimed to assess the frequency and variation of 13 nonmetric dental crown traits (NDCT) in permanent and primary molars in German orthodontic patients.

Methods: Dental records from orthodontic patients were screened and evaluated. First and second permanent and primary upper and lower molars (from left and right sides) were assessed. Teeth with cavitated dental caries, occlusal wear, restorations and obvious dental deformities were not evaluated. The NDCT for permanent molars were identified and scored according to the odontoscopic system developed by Arizona State University Dental Anthropology System (ASUDAS). The NDCT for primary molars were identified and scored according to ASUDAS, Hanihara's method and Sciulli's method. The χ² test was used to investigate side preference and sexual dimorphism at a significance level of p ≤ 0.050.

Results: A total of 163 orthodontic patients (82 males and 81 females) aged 8-14 years were included. A sexual dimorphism was observed for the hypocone in first upper permanent molar (p = 0.041). The protostylid was observed in lower permanent molars (range 2.1-10%). Males presented more hypoconulid than females (p = 0.019). Only females presented the distal trigonid crest in lower first permanent molars (p = 0.002). The most common groove pattern in primary molars was Y; male presented more Y grade than females in the lower second primary molar (p = 0.039). Asymmetry was observed in some traits, ranging from 0 to 100%.

Conclusion: The present study showed the frequency of NDCT of molars in German orthodontic patients and demonstrated that some traits present sexual dimorphism.

Background: Acceleration of tooth movement has gained remarkable attention during the last decade. The aim of this study was to evaluate the effect of low-level laser therapy (LLLT) on en masse retraction of upper anterior teeth in adult women with bimaxillary dentoalveolar protrusion.

Materials and methods: In this two-arm parallel trial, 36 women with bimaxillary dentoalveolar protrusion were randomly divided into two equal groups. Eligibility criteria included class I Angle molar relationship, good general and oral health as well as no systemic disease or syndrome. Four temporary anchorage devices (TADs) were used in the upper and lower arches for anchorage purposes. A 0.019×0.025-inch stainless steel wire with crimped hooks just distal to the maxillary canines was inserted. Nickle titanium (NiTi) closed coil springs (200 g/side) were employed for en masse retraction following extraction of the first premolars. In the laser group (LG), retraction of the upper anterior teeth was done along with the application of LLLT on days 0, 3, 7, and 14 after extraction and then repeated biweekly until the end of retraction. Retraction was completed without LLLT application in the nonlaser group (NLG). Data concerning the rate of retraction as well as first molars and anterior positional changes were gained from digitized models and cone beam computed tomography (CBCT) scans taken just before extraction and at the end of retraction. Treatment-associated pain and root resorption were evaluated using visual analogue scale (VAS) and CBCT scans, respectively.

Results: Four patients dropped out prior to follow-up. The duration of retraction was 10.125 ± 2.876 and 13.643 ± 3.455 months in the LG and NLG, respectively. The LG showed a statistically significant faster rate of en masse retraction (0.833 ± 0.371 mm/month) compared to the NLG (0.526 ± 0.268 mm/month; P ≤ 0.035). The observed root resorption was significantly less in the LG (P ≤ 0.05) with comparable pain scores in both groups.

Conclusions: Within the constraints of the parameters of the LLLT used in the current study and despite the statistically significant results on the rate of en masse retraction and the associated root resorption, LLLT did not demonstrate a clinically relevant effect that justifies its use to enhance en masse retraction.

Name of the registry: Clinicaltrials.gov TRIAL REGISTRATION NUMBER: NCT05183451 DATE OF REGISTRATION: January 10, 2022, "Retrospectively registered" URL OF TRIAL REGISTRY RECORD: https://www.

Clinicaltrials: gov/study/NCT05183451.

Purpose: The purpose of this study was to analyze the biomechanical effects of four different designs of frog appliances for molar distalization using finite element analysis.

Methods: A three-dimensional finite element model including complete dentition, periodontal ligament, palatine, and alveolar bone was established. Four types of frog appliances were designed to simulate maxillary molar distalization: tooth-button-borne (Type A), bone-borne (Type B), bone-button-borne (Type C), and tooth-bone-borne (Type D) frog appliances. A force of 10 N was applied simulating a screw in the anteroposterior direction. To assess the von Mises stress distribution and the resultant displacements in the teeth and periodontal tissues, geometric nonlinear theory was utilized.

Results: Compared to the conventional tooth-borne frog appliance (Type A), the bone-borne frog appliances showed increased first molar distalization with enhanced mesiolingual rotation and distal tipping, but the labial inclination and intrusion of the incisors were insignificant. When replacing the palatal acrylic button with miniscrews (Types B and D), more anchorage forces were transmitted from the first premolar to palatine bone, which was further dispersed by the assistance of a palatal acrylic button (Type C).

Conclusions: Compared to tooth-borne frog appliances, the bone-borne variants demonstrated a clear advantage for en masse molar distalization. The combined anchorage system utilizing palatal acrylic buttons and miniscrews (Type C) offers the most efficient stress distribution, minimizing force concentration on the palatine bone.

Purpose: This in vitro study aimed to compare the shear bond strength (SBS) and Adhesive Remnant Index (ARI) scores of two-step orthodontic bonding systems: self-etching primer (SEP) and a self-adhesive composite. Both systems were compared to a control group with a conventional three-step adhesive.

Methods: A total of 72 extracted maxillary and mandibular premolars were randomly divided into four groups (n = 18): group 1(XT), the control group, used Transbond™ XT (conventional adhesive; 3M Unitek, Monrovia, CA, USA); group 2 (GC) used GC Ortho Connect™ (self-adhesive composite; GC Orthodontics Inc., Tokyo, Japan); group 3 (GCP) used GC primer with GC Ortho Connect™; and group 4 (SEP) used Transbond™ Plus Self-Etching Primer with Transbond™ XT. Teeth were stored in water at 37 °C for 24 h prior to SBS testing using an Instron 5543 device (Instron, Norwood, MA, USA), and ARI scores were assessed under a stereomicroscope. Data were analyzed using analysis of variance (ANOVA) and nonparametric tests.

Results: In total, 60 samples were analyzed. The GCP group exhibited the highest SBS (8.35 MPa ± 1.99), significantly higher than the XT (4.99 MPa ± 1.32, p < 0.001) and SEP (5.69 MPa ± 2.10, p = 0.001) groups. The GC group (7.50 MPa ± 1.92) also showed higher SBS than XT (p = 0.003) and the SEP group (p = 0.048). ARI scores showed no significant difference between groups overall (p = 0.303), but the GCP group had significantly higher ARI scores than the SEP group (p = 0.023).

Conclusion: GC Ortho Connect™ with or without primer demonstrated superior bond strength compared to conventional and self-etching systems, making it a viable alternative for clinical use. Further in vivo studies are needed to confirm these findings.

Purpose: This study aimed to evaluate the accuracy of different mixed dentition analysis methods in predicting the mesiodistal diameters (MDD) of unerupted permanent canines and premolars (PCP) in a Turkish population and to determine the most reliable method for clinical application.

Methods: This research represents a retrospective, population-based cross-sectional study. Seven commonly used maxilla (Mx) and mandible (Md) unerupted PCP mesiodistal diameter prediction methods (Tanaka-Johnston, Moyers, Tränkmann, Legovic, Gross-Hasund, Bachmann, and Melgaço methods) were compared. The study included 120 Turkish children (60 males, 60 females) aged 13-16 years. MDD was measured using digital dental models. The predicted values were analyzed for accuracy by comparing them with the actual tooth diameters. Statistical analyses assessed the differences between the methods and their reliability in male and female subjects.

Results: For the investigated Turkish population, the Gross-Hasund (Mx female: 0.32 ± 1.07 mm; Mx male: 0.22 ± 0.79 mm; Md female: 0.29 ± 0.79 mm; Md male: 0.55 ± 0.80 mm) and Bachmann methods (Mx female: 0.26 ± 1.04; Mx male: 0.24 ± 0.82 mm; Md female: 0.17 ± 0.72 mm; Md male: 0.52 ± 0.83 mm) provided the most accurate predictions, with minimal deviation from actual tooth sizes. The Tanaka-Johnston and Moyers methods tended to overestimate tooth sizes in males and underestimate them in females. The Tränkmann method showed the highest prediction error, particularly in males (Mx: 2.98 ± 1.40 mm; Md: 3.05 ± 0.78 mm). Sex differences were statistically significant in most methods, highlighting the necessity for population- and sex-specific adjustments in mixed dentition analyses.

Conclusion: The findings suggest that currently available prediction methods may not fully apply to the Turkish population without modifications. The Gross-Hasund and Bachmann methods were the most dependable, whereas the Tränkmann method showed significant discrepancies. Developing population-specific regression equations may improve the accuracy of mixed dentition analysis and enhance orthodontic treatment planning in Turkish individuals.