Impact of extracorporeal shock wave therapy (ESWT) on orthodontic tooth movement—a randomized clinical trial

Translational Applications of Extracorporeal Shock Waves in Dental Medicine: A Literature Review

Extracorporeal shock wave therapy (ESWT) has been studied and applied extensively in medical practice for various applications including musculoskeletal, dermal, vascular, and cardiac indications. These indications have emerged from primary ESWT use in treating urolithiasis and cholelithiasis. Likewise, dental medicine has had its share of utilizing ESWT in various investigations. This review aimed to provide an up-to-date summary of ESWT use in preclinical and clinical dental medicine. There is growing interest in ESWT use stemming from its non-invasiveness, low cost, and safe qualities in addition to its proven regenerative biostimulating aspects. Targeted tissue and parameters of ESWT delivery continue to be an integral part of successful ESWT treatment to attain the clinical value of the anticipated dose’s effect.

Orthodontic force and extracorporeal shock wave therapy: Assessment of orthodontic tooth movement and bone morphometry in a rat model

OBJECTIVE

The objective was to investigate the effect of extracorporeal shock wave therapy (ESWT) on the magnitude of orthodontic tooth movement, in a rat model, based on a previously established treatment protocol.

DESIGN

In conjunction with orthodontic force commencement, rats underwent ESWT. The amount of tooth movement along with different microarchitectural parameters were measured after three weeks by means of microcomputed tomography. In addition, the percentage of cells expressing vascular endothelial growth factor, the number of tartrate-resistant acid phosphatase (TRAP) positive cells/area and blood vessel density were evaluated both for the pressure and tension sides.

RESULTS

The addition of ESWT to the orthodontic force after three weeks more than doubled the average tooth movement. The addition of ESWT on the pressure side induced a significant decrease in volumetric bone mineral density. Blood vessel density and the number of TRAP positive cells were higher after the application of ESWT.

CONCLUSION

The induction of ESWT during orthodontic tooth movement in a rat model increases the rate of tooth movement by accelerating bone resorption on the pressure side and possibly enhances bone formation on the tension side.

Cross-modality imaging of bisphosphonate-treated murine jawbones

In this proof-of-principle study, we established and implemented a cross-modality imaging (CMI) pipeline to characterize and compare bisphosphonate (BIS)-treated jawbones of Sprague-Dawley rats after tooth extraction after physical therapies (photobiomodulation and extracorporeal shockwave therapy (PBMT and ESWT)). We showcase the feasibility of such a CMI approach and its compatibility across imaging modalities to probe the same region of interest (ROI) of the same jawbone. Jawbones were imaged in toto in 3D using micro-Computed Tomography to identify ROIs for subsequent sequential 2D analysis using well-established technologies such as Atomic Force Microscopy and Scanning Electron Microscopy, and recent imaging approaches in biomedical settings, such as micro-X-Ray Fluorescence Spectroscopy. By combining these four modalities, multiscale information on the morphology, topography, mechanical stiffness (Young's modulus), and calcium, zinc and phosphorus concentrations of the bone was collected. Based on the CMI pipeline, we characterized and compared the jawbones of a previously published clinically relevant rat model of BIS-related osteonecrosis of the jawbone (BRONJ) before and after treatment with BISs, PBMT and ESWT. While we did not find that physical therapies altered the mechanical and elemental jawbone parameters with significance (probably due to the small sample size of only up to 5 samples per group), both ESWT and PBMT reduced pore thicknesses and bone-to-enamel distances significantly compared to the controls. Although focused on BIS-treated jawbones, the established CMI platform can be beneficial in the study of bone-related diseases in general (such as osteoarthritis or -porosis) to acquire complementary hallmarks and better characterize disease status and alleviation potentials.

Dose-related effects of extracorporeal shock waves on orthodontic tooth movement in rabbits

The purpose of this animal study is to investigate the quantitative effects of extracorporeal shock waves applied at two different impulses and with two different applicators on orthodontic tooth movement. Thirty-five New Zealand rabbits were randomly divided into five groups (n = 7): the four experimental extracorporeal shock wave groups-focused/500 impulses, focused/1000 impulses, unfocused/500 impulses, and unfocused/1000 impulses-and the control group. Orthodontic tooth movement was achieved by application of reciprocal force between two maxillary incisors. In the experimental groups, animals received 500 or 1000 impulses of extracorporeal shock waves at 0.19 mJ/mm² with focused or unfocused applicators depending on the group to which they belonged. These experiments were conducted on days 0, 7, and 14. Orthodontic tooth movement was measured with 0.01 mm accuracy at one-week intervals. On days 7 and 21, the bone-specific alkaline phosphatase levels were measured from blood samples. After 21 days, the animals were sacrificed and the area between the two maxillary incisors was stereologically examined. Orthodontic tooth movement in the focused/500 impulses and focused/1000 impulses groups was significantly increased compared to the control group. A significant difference in bone-specific alkaline phosphatase levels between the unfocused/500 impulses and control groups was found at 21st day. Stereological analysis showed that there were significant increases of the formation of new bone, connective tissue, and vessels in the experimental groups. The application of extracorporeal shock waves, especially with a focused applicator, could accelerate orthodontic tooth movement.

Pulsed short waves in the remineralization of alveolar bone structures of the jaw in patients with diabetes mellitus – a series of cases

This clinical study included three patients aged between 50 and 78 years who had chronic marginal periodontitis and type 2 diabetes mellitus, diseases that are frequently associated due to changes occurring in polymorphonuclear cells, as well as to alterations of microcirculation. No bone augmentation therapies were performed. Bone regeneration was strictly influenced by conventional periodontal therapy, supplemented with ten pulsed short wave sessions applied to the lower face shortly after closed periodontal curettage. The allocated time was ten minutes for the first two sessions, and 15 minutes for the following 8 sessions. Clinical and radiological evaluations were performed at the time of presentation, as well as after initiation of pulsed short wave therapy: in the first case, three weeks after initiation of therapy and three years after the end of complex oral rehabilitation; in the second case, eight weeks after the onset of pulsed short wave therapy and in the third case, five weeks after the onset of pulsed short wave therapy. The results were significant in all three cases, demonstrated radiologically by the same type of radiological examination at identical scales. Bone remineralization was obvious in the alveolar processes of the jaw. Although further studies in this direction are necessary, the results are both clinically and radiologically significant. Key words: pulsed short waves, alveolar bone resorption, periodontal disease, diabetes,

Miniscrews failure rate in orthodontics: systematic review and meta-analysis

Background

Miniscrews in orthodontics have been mainly used for anchorage without patient compliance in orthodontic treatment. The literature has reported changing failure rates.

Objective

The aim of this review was to provide a precise estimation of miniscrew failure rate and the possible risk factors of the mechanically-retained miniscrews.

Search method

Electronic search in database was undertaken up to July 2017 through the Cochrane Database of Systematic Reviews, MEDLINE, Scopus, and Ovid. Additional searching for on-going and unpublished data, hand search of relevant journals and grey lietraure were also undertaken, authors were contacted, and reference lists screened.

Eligibility criteria

Randomised controlled trials (RCTs) and prospective cohort studies (PCSs), published in English were obtained, which reported the failure rate of miniscrews, as orthodontic anchorage, with less than 2 mm diameter.

Data collection and analysis

Blind and induplicate study selection, data extraction, and risk of bias assessment were undertaken in this research. Failure rates and relevant risk factors of miniscrews with the corresponding 95 per cent confidence intervals (CIs) were calculated by using the random-effects model. The heterogeneity across the studies was assessed using the I2 and Chi2 test. The risk of bias was assessed using Cochrane risk of bias and Newcastle-Ottawa Scale. Subgroup and sensitivity analyses were performed in order to test the robustness of the results in meta-analysis.

Results

The 16 RCTs and 30 PCSs were included in this research. Five studies were not included in the meta-analysis due to a lack of the statistical information needed to compute the effect sizes. About 3250 miniscrews from 41 studies were pooled in a random-effect model. The overall failure rate of miniscrews was 13.5 per cent (95% CI 11.5-15.9). Subgroup analysis showed that miniscrews 'diameter, length and design, patient age, and jaw of insertion had minimal effect on rate of miniscrews failure while the type of the gingivae and smoking had statistically significant effect.

Conclusion

Miniscrews have an acceptably low failure rate. The findings should be interpreted with caution due to high-level of heterogeneity and unbalanced groups in the included studies. High quality randomized clinical trial with large sample sizes are required to support the findings of this review.

Extracorporeal shockwave treatment impedes tooth movement in rats

Background

Accelerated tooth movement has been a topic of interest for orthodontic research recently. Surgically facilitated orthodontic treatment has been shown to be an effective approach to accelerate tooth movement; however, it remains invasive, requires additional surgery, and may increase post-operative complications. In this study, we evaluate the effects of extracorporeal shockwave treatment (ESWT), a non-invasive approach to regenerate alveolar bone, on orthodontic tooth movement in rats.

Materials and methods

Seventy-two male rats, aged 10 weeks old, were subjected to 10-cN closed-coil nickel-titanium springs for unilateral maxillary first molar tooth movement. One group of rats received a single treatment of extracorporeal shockwave treatment at 500 impulses at energy flux density 0.1 mJ/mm², with a pulse rate of 5 pulses per second immediately after spring installation while the non-ESWT-treated group served as a control group. The rats were sacrificed at day 3, 7, 14, 21 and 28 for tooth movement evaluation and sample analyses. Faxitron radiography, histological, double bone labeling and gene expression analyses were performed. Serum biochemistry was evaluated at day 3, 7 and 28 of the study. Kruskal-Wallis analysis of variance was used to determine the mean difference among groups, and multiple comparisons were analyzed by Mann-Whitney-U tests with a significance level = 0.05.

Results

The results demonstrated that tooth movement in the ESWT-treated rats (0.11 ± 0.07 mm) was impeded compared to the tooth movement in the non-ESWT-treated rats (0.44 ± 0.09 mm). ESWT up-regulated several osteoblastic and osteoclastic gene markers and cytokines; however, the effects on osteoclasts were only transient. Double-fluorescence bone labeling demonstrated that osteoblastic activity increased after ESWT treatment. There was no difference in systemic RANKL/OPG ratio between groups.

Conclusions

ESWT at 500 impulse at energy flux density 0.1 mJ/mm² increased osteoblast and osteoclast activities and imbalanced bone remodeling resulting in impeded tooth movement in rats.

Growth Factors in Bone Marrow Blood of the Mandible With Application of Extracorporeal Shock Wave Therapy

INTRODUCTION

Enhancement of bone regeneration is crucial to dental implantology. Growth factors play a significant role during osteogenesis and angiogenesis. Extracorporeal shock wave therapy (ESWT) enhances bone healing; however, no studies have yet been performed in oral implantology.

MATERIALS AND METHODS

Twenty patients who underwent bilateral mandibular wisdom tooth removal were included. ESWT was applied to 1 side of the jaw. Blood samples were collected from the peripheral vein (PB), mandibular bone marrow without and with ESWT (BM-/+SW). Quantity and quality of the growth factors bone morphogenetic protein (BMP)-2, BMP-4, insulin-like growth factor 1 (IGF-1), vascular endothelial growth factor (VEGF), and transforming growth factor-beta (TGF-β) were investigated via ELISA and cell proliferation assay.

RESULTS

ELISA revealed superior amounts of IGF-1 and VEGF in BM-/+SW compared to PB (P < 0.05). TGF-β demonstrated no variance. Levels of BMP-2 and BMP-4 were too low for adequate detection in the ELISA. No difference was noticed upon ESWT. The cell proliferation assay did not identify any changes comparing PB versus BM-SW versus BM + SW.

CONCLUSION

IGF-1 and VEGF are present at higher levels in mandibular bone marrow than in peripheral blood (PB). This study did not identify any benefits of extracorporeal shock wave therapy to increase the investigated growth factors.