Journal of Orofacial Orthopedics-Fortschritte Der Kieferorthopadie最新文献

For accurate interpretation of quantitative real-time PCR (qPCR) data, stable reference genes are essential for normalization of target genes. To date, there is no information on reliable housekeeping genes in CD4+ T cells in a three-dimensional (3D) matrix under pressure stimulation. This in vitro study describes for the first time a method for pressure stimulation of CD4+ T cells in a 3D matrix in the context of orthodontic tooth movement (OTM) and identifies a set of reliable reference genes. CD4+ T cells were isolated from murine spleen and activated with anti-CD3/-CD28 Dynabeads (Thermo Fisher, Langenselbold, Germany) on standard cell culture plates or in 3D scaffolds with or without compressive strain. Expression stability of nine potential reference genes was examined using four mathematical algorithms. Gene expression of Il2 was normalized to all potential reference genes to highlight the importance of correct normalization. Cell proliferation and the expression of the surface markers CD25 and CD69 were also determined. The 3D matrix did not inhibit proliferation after immunological activation of T cells and embedded the cells sufficiently to expose them to pressure load. Expression of ubiquitin C (Ubc) and hypoxanthine phosphoribosyltransferase (Hprt) was the most stable under all conditions tested. A combination of these two genes was suitable for normalization of qPCR data. Normalization of Il2 gene expression showed highly variable results depending on the reference gene used. Pressure reduced cell proliferation and the number of CD69-positive T cells. This study provides a basis for performing valid and reliable qPCR experiments with CD4+ T cells cultured in 3D scaffolds and exposed to compressive forces simulating OTM.

Objective: To assess the remodeling effects of protraction facemask therapy on the trabecular pattern of the mandible and identify quantitatively the regions of the mandible undergoing maximum changes in the trabecular pattern.

Materials and methods: The retrospective study was conducted in 30 subjects divided into two groups. The treatment group (group 1) consisted of 15 subjects with skeletal class III malocclusion treated with a facemask (mean age: 9.1 ± 2.1 years). Digital panoramic radiographs (OPG) were obtained before treatment (T0) and at the end of active facemask therapy (T1) with a mean duration of 16.1 ± 2.5 months. In all, 15 skeletal class I subjects who did not undergo any orthodontic treatment (mean age 9.1 ± 2.2 years) comprised the control group (group 2) who had two OPGs at a mean interval of 13.6 ± 2.2 months. The fractal dimensional (FD) value was calculated in three regions: angular, condylar, and corpus region.

Results: Intragroup comparisons revealed a significant increase in the FD values in the right condylar (T0 = 1.2 ± 0.2; T1 = 1.4 ± 0.1) and left condylar (T0 = 1.2 ± 0.1; T1 = 1.4 ± 0.1) region (p < 0.05) and in the corpus region (FD values: right T0 = 1.2 ± 0.1, T1 = 1.4 ± 0.1; left T0 = 1.2 ± 0.1, T1 = 1.4 ± 0.1; p < 0.05). The intergroup comparison demonstrated that the treatment group showed greater changes compared with the controls in the condylar process (mean difference: right = 0.19, left = 0.20; p < 0.05) and the corpus region (0.172; p < 0.05).

Conclusion: FD analysis demonstrated that the condylar process and the corpus region underwent the most significant change in the trabecular pattern in subjects treated with protraction facemask therapy.

Purpose: The aim of this study was to evaluate the extent of property changes caused by heating the distal portion of heat-activated nickel-titanium (NiTi) wires.

Methods: Forty preformed heat-activated NiTi archwires (3M Unitek, Monrovia, CA, USA) with a nominal cross-section of 0.018″ were used in this study. The archwires were divided into a control group, not submitted to heat treatment and, thus, maintaining the as-received properties, and an experimental group, in which the archwires were submitted to heat treatment for distal bending at one end. Wire segments of control and experimental groups were submitted to differential scanning calorimetry (DSC) and Vickers microhardness measurements.

Results: The DSC results suggest local recrystallization and precipitate dissolution at the heat-treated tip, which decreases as the distance to the wire's tip increases. Vickers microhardness tests revealed significant changes for distances between 6 and 8 mm from the wire's tip. Heating the distal portion of heat-activated NiTi archwires should be performed with care since this clinical procedure may compromise the performance of these wires to a distance of 8 mm from the archwire end.

Conclusion: Heat treatment for distal bending in heat-activated NiTi archwires may be performed, with little impact on the areas adjacent to heat treatment. In cases presenting molars requiring significant orthodontic corrections, it should be preferred to apply other techniques to avoid archwire sliding, such as crimpable stops, or to have flame control to avoid placing a heat-treated section in the tubes of these molars.

Purpose: To ascertain the relationship between malocclusion severity, treatment expectations, socioeconomic status, objective orthodontic treatment need, and oral health-related quality of life (OHRQoL) in adolescents with class II malocclusion.

Methods: Cephalometric measurement values, arch discrepancy values, and clinical examination findings were recorded to determine the severity of malocclusion in 104 adolescents with class II malocclusion who requested orthodontic treatment. Objective orthodontic treatment need was determined by the Index of Complexity, Outcome, and Need (ICON) and Dental Aesthetic Index (DAI) scores. The Psychosocial Impact of Dental Aesthetic Questionnaire (PIDAQ) and the Oral Health Impact Profile-14 (OHIP-14) were used to assess the OHRQoL. Treatment expectations and the socioeconomic status were also evaluated.

Results: Patients with proclined upper incisors exhibited higher PIDAQ scores than those with retroclined upper incisors. Contrary, no significant difference was observed between the PIDAQ and OHIP-14 scores of the patients categorized according to overjet, overbite, growth pattern, or objective orthodontic treatment need. No statistically significant correlation was identified between socioeconomic status, OHRQoL, age, and DAI scores, except for socioeconomic status and ICON scores. Patients who reported the treatment expectation to improve their social relationships and communication skills exhibited the highest OHIP-14 scores, indicating the poorest OHRQoL.

Conclusion: Significantly poorer OHRQoL was observed in adolescents with class II malocclusion who presented an increased proclination of their upper incisors and requested orthodontic treatment with the expectation of improvement in social relations and communication skills. Larger study samples would improve the generalizability of the results.

Purpose: This pilot study aimed to assess the relationship between bite force variation and dental arch and facial shape using geometric morphometrics, an advanced method of statistical analysis that provides a detailed shape analysis of a structure considering the spatial relationship of its parts.

Methods: The sample consisted of 16 German adult men and women. For each individual, maximum bite force was recorded in four positions: maximum intercuspation, protrusion, laterotrusion to the right and to the left. Facial and three-dimensional (3D) dental reconstructions were obtained from 3D facial photographs and 3D scans of dental stone models. A total of 51 landmarks were placed. General shape variation was assessed by principal component analysis. Partial least squares analyses were performed to evaluate the covariation between bite force, facial shape, and dental shape.

Results: There was no clear pattern or statistically significant covariation between our variables.

Conclusions: Our results suggest a weak relationship between bite force, dental arch, and facial shape. Considering previous work in this field, we propose that low masticatory loads, characteristic in Western urban populations, may explain this. Further studies should, therefore, address this issue, taking into account effect size, the mechanical properties of the diet, and other relevant variables.

Aims: To investigate the effect of tumor necrosis factor (TNF) on the growth of human periodontal ligament (PDL) cells, their osteogenic differentiation and modulation of their matrix secretion in vitro.

Methods: The influence of 10 ng/ml TNF on proliferation and metabolic activity of PDL cells was analyzed by cell counting (DAPI [4',6-diamidino-2-phenylindole] staining) and the MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay. In addition, cells were cultured under control conditions and osteogenic conditions (media containing 10 mM β-glycerophosphate). Quantitative expression analysis of genes encoding the osteogenic markers alkaline phosphatase (ALP), collagen type I alpha 1 chain (COL1A1), osteoprotegerin (OPG), and osteopontin (OPN) was performed after 7 and 14 days of cultivation. Calcium deposits were stained with alizarin red.

Results: Our studies showed that 10 ng/ml TNF did not affect the survival and metabolic activity of PDL cells. Quantitative expression analysis revealed that long-term cultures with TNF impaired osteogenic cell fate at early and late developmental stages. Furthermore, TNF significantly reduced matrix secretion in PDL cells.

Conclusion: The present data confirm TNF as a regulatory factor of proinflammatory remodeling that influences the differentiation behavior but not the metabolism and cell proliferation of the periodontium. Therefore, TNF represents an interesting target for the regulation of orthodontic remodeling processes in the periodontium.

Purpose: The aim of this study was to investigate the impact of malocclusion and oral habits on oral health-related quality of life and sleep disturbance in young adults.

Methods: A cross-sectional study was conducted with a sample of 213 young adults aged 18-30 years. Dental occlusion data were assessed through clinical examination. A questionnaire was used to collect data on oral habits. Outcomes were collected using the Oral Health Impact Profile (OHIP-14) and Mini Sleep Questionnaire.

Results: Anterior open bite (adjusted odds ratio [OR] = 2.41, 95% confidence interval [CI] = 1.02-5.67, p = 0.044), swallowing disorders (adjusted OR = 2.39, 95% CI = 1.13-5.05, p = 0.022), and sleeping on hands were associated with a negative impact on oral health-related quality of life. Females (adjusted OR = 2.61, 95% CI = 1.10-6.17, p = 0.029), teeth grinding (adjusted OR = 2.78, 95% CI = 1.08-7.14, p = 0.034), biting lips or cheeks (adjusted OR = 4.28, 95% CI = 1.49-12.29, p = 0.007), and self-perception of need for orthodontic treatment (adjusted OR = 7.88, 95% CI = 2.12-29.30, p = 0.002) were associated as a risk for sleep disturbances.

Conclusion: The findings suggest that oral habits and some types of malocclusions can impact oral health-related quality of life. In addition, sleep disturbances were associated with a greater need for orthodontic treatment and a habit of grinding teeth in young adults.

Purpose: This observational study aimed to evaluate the stability of unilateral posterior crossbite (UPXB) correction with the functional appliance function generating bite (FGB appliance) during follow-up and its effects on craniofacial growth.

Materials and method: A total of 102 age- and gender-matched patients were included: 51 with UPXB (male [M] = 19; female [F] = 32; mean age ± standard deviation [SD] = 7.6 ± 1.4 [years.months]) and 51 controls (C; M = 19; F = 32; mean age ± SD = 7.9 ± 1.3). UPXB was corrected with the FGB appliance. Study casts were collected before treatment (T0), after correction (T1), after a follow-up of 3.7 ± 1.6 [years.months] (T2) and different transversal measurements were performed with calipers: intermolar (IMD), intermolar gingival (IMGD), intercanine (ICD), and intercanine gingival distances (ICGD). In treated patients, in addition, lateral cephalometric tracings were analyzed at T0 and T2.

Results: At T0, all maxillary measurements were significantly smaller in the UPXB group compared to the controls (p < 0.001). Between T0 and T1, all maxillary variables increased significantly in the UPXB group (p < 0.001; IMD +4.3 ± 2.1 mm; ICD +3.1 ± 2 mm). Between T1 and T2, maxillary IMD increased further (p < 0.05; +2.2 ± 2 mm). The mean T0-T2 increases were 6.6 ± 2.6 mm (IMD) and 4.3 ± 2.6 mm (ICD). At T0, the cephalometric analysis showed significantly stronger mandibular clockwise rotation (p < 0.01) in the UPXB group compared to the control group. Between T0 and T2, the UPXB group showed a significant reduction of mandibular (p < 0.001; SpP-CoOr T0 = -3.47°± 4.38, T2 = -1.14°± 4.01) and occlusal plane (p < 0.01; SpP-Oc T0 = 11.37°± 3.91, T2 = 9.86°± 3.83) clockwise rotation, and of intermaxillary divergence (p < 0.01; SpP-GoGn T0 = 27.8°± 5.39, T2 = 26.65°± 5.49).

Conclusions: Treatment of UPXB with the FGB appliance effectively increased maxillary transversal width measurements, especially in the posterior region, even after follow-up, indicating stable results. Concurrently, mandibular clockwise rotation was reduced, indicating control of the vertical dimension.

Aim: The purpose of the present study was to compare the interproximal accuracy (IA) of two different CAD/CAM (computer-aided design/computer-aided manufacturing) manufactured and conventionally bent retainers.

Materials and methods: On 20 digitized debonding casts (10 upper, 10 lower), a canine-to-canine retainer was designed using two different CAD/CAM software: OnyxCeph^® (Image Instruments, Chemnitz, Germany) and FixR™ (YOAT Corp., Lynnwood, WA, USA). Each design was bent using the Bender II™ retainer bending machine (YOAT Corp.) and 3‑ or 6‑stranded twistflex wires (0.018-inch Dentaflex^®, Dentaurum, Ispringen, Germany), respectively. For each cast, one CAD/CAM machine cut retainer (Memotain^®, SCHEU DENTAL custom-made, Hilden, Germany) was fabricated and one retainer was bent manually by a dental technician using the 6‑stranded wire. All retainers were passively waxed on the dental casts and digitized using a laboratory scanner (Atos, Carl Zeiss IQS Deutschland, Oberkochen, Germany). For each of the five interproximal areas, IA was measured (1) as vertical distance between retainer and the reference retainer plane and (2) as horizontal distance between the interproximal reference point and the retainer in millimeters. For both directions, it was assumed that the smaller the distance, the higher the interproximal accuracy of the retainer. Statistical analysis was performed using Mann-Whitney and Kruskal-Wallis tests.

Results: Considering the vertical deviation, significant differences of interproximal accuracy were seen between the jaws (upper 0.25 mm > lower 0.18 mm, p < 0.001), planning software (FixR 0.25 mm > OnyxCeph 0.21 mm, p = 0.03) and settings (upper jaw: CAD/CAM bent [FixR] 0.34-0.32 mm > manually bent 0.27 mm > CAD/CAM bent [Onyx] 0.23-0.18 mm > CAD/CAM cut 0.17 mm, p = 0.001; lower jaw: CAD/CAM bent [FixR 3‑stranded and Onyx] 0.22-0.21 mm > manually bent 0.18 mm > CAD/CAM bent [FixR 6‑stranded] 0.13 mm > CAD/CAM cut 0.10 mm, p = 0.004). For horizontal deviation, significant differences were observed between the jaws (upper 0.97 mm > lower 0.66 mm, p < 0.001), planning software (OnyxCeph 0.90 mm > FixR 0.72 mm, p < 0.001), settings (upper jaw: CAD/CAM bent [Onyx] = CAD/CAM cut 1.16-1.10 mm > CAD/CAM bent [FixR] 0.96-0.89 mm > manually bent 0.76 mm, p < 0.001; lower jaw: CAD/CAM bent [Onyx] 0.84-0.71 mm > CAD/CAM cut 0.66 mm = CAD/CAM bent [FixR] 0.66-0.63 mm > manually bent 0.51 mm, p < 0.001) and location of the interdental area in the upper jaw (13-12 = 22-23 > 22-21 > 11-21 > 12-11, p < 0.001). The wire quality had no significant impact in either of the dimensions.

Conclusion: Interproximal accuracy in the vertical plane was achieved best by CAD/CAM cut retainers, while horizontally, manually bent retainers were the most accurate. Overall, the accuracy of lower retainers seems clinically acceptable for their u

Purpose: This in vitro study aimed to examine aging-associated adaptations in the mechanoresponse of periodontal ligament fibroblasts (PdLFs) and explore a potential regulatory role of growth differentiation factor 15 (GDF15).

Methods: Replicative senescence was induced in cultured human PdLFs (hPdLFs) by repeated enzymatic subcultivation as a valid in vitro aging model. The senescent phenotype was assessed by analyzing cellular morphology, proliferative capacity, and senescence marker expression. Furthermore, GDF15 levels were measured and subsequently modulated by small interfering RNA(siRNA)-mediated knockdown and by ponsegromab, a novel GDF15-neutralizing antibody. Tensile and compressive forces were applied using BioFlex® Culture Plates (FLEXCELL®, Dunn Labortechnik, Asbach, Germany) and sterile glass plates, respectively. The mechanoresponses of hPdLFs were characterized by analyzing pro-inflammatory cytokine levels and the activation of immune cells as well as of bone-remodeling osteoblasts and osteoclasts.

Results: Aged hPdLFs exhibited decreased proliferation, increased β‑galactosidase activity, and morphological changes indicative of cellular senescence. Elevated baseline and force-induced intra- and extracellular GDF15 levels were observed in aged hPdLFs correlating with enhanced pro-inflammatory cytokine expression and immune cell activation. While aged hPdLFs showed reduced activation of osteoblasts in response to tensile forces, compressive forces led to increased osteoclast activation. Remarkably, modulating intra- and extracellular GDF15 levels partially restored the deregulated activation of bone-remodeling cells.

Conclusion: Aging altered the mechanobiological response of PdL fibroblasts by promoting a hyperinflammatory microenvironment and shifting bone remodeling towards degenerative processes. Senescence-associated increases in GDF15 contributed to these changes by force-dependent intra- and extracellular signaling pathways. Targeting GDF15 could offer a therapeutic potential to optimize bone remodeling and improve orthodontic care for the elderly.