Photobiomodulation therapy assisted orthodontic tooth movement: potential implications, challenges, and new perspectives

miR-223-3p Mitigates Mitochondrial Dysfunction and Cementoblast Apoptosis in Orthodontic Root Resorption via FoxO3

AIM

The aim of this study was to elucidate the roles of miR-223-3p in orthodontically induced inflammatory root resorption (OIIRR).

METHODS

We used high-throughput miRNA sequencing and transcriptome sequencing to analyze the differentially expressed miRNAs and mRNAs in OCCM-30 cells under hypoxia. Real-time quantitative PCR (RT-qPCR) and Western blotting were used to assess the expression of genes and proteins related to apoptosis, oxidative stress, and mitochondrial dysfunction. Fluorescence staining was employed to detect changes in cellular ROS (reactive oxygen species), MMP (mitochondrial membrane potential), and mtROS (mitochondrial ROS) expression.

RESULTS

We found that miR-223-3p targeted FoxO3 to regulate apoptosis in cementoblasts under hypoxic conditions. Moreover, hypoxia-induced FoxO3 increased oxidative stress and induced mitochondrial dysfunction in cementoblasts, resulting in cell apoptosis. Administration of the ROS inhibitor NAC (N-acetyl cysteine) effectively reversed FoxO3-induced oxidative stress and mitochondrial dysfunction, thereby rescuing cell apoptosis.

CONCLUSIONS

miR-223-3p targets FoxO3 and regulates the apoptosis of cementoblasts by improving oxidative stress and mitochondrial dysfunction. These findings may offer new insights into the mechanism of OIIRR.

Adjunctive therapies in orthodontics: a scoping systematic review

BACKGROUND

Orthodontic tooth movement (OTM) induces physiological and sometimes pathological inflammation in periodontal tissues. This review evaluates the effectiveness of low-level laser therapy (LLLT), vibrational therapy, and probiotics as adjunctive treatments for managing inflammation, pain, and the duration of OTM.

METHODS

Medline via OVID, Cochrane, EMBASE, and Web of Science databases were utilized to identify randomized controlled trials (RCTs) published between January 1990 and November 2023. Studies were selected based on their evaluation of LLLT, vibrational therapy, and probiotics as adjuncts in fixed orthodontic treatment.

RESULTS

LLLT shows promise in enhancing orthodontic tooth movement by accelerating tooth movement and potentially reducing pain. However, disparate study outcomes indicate a need for standardized application protocols. The efficacy of vibrational therapy as an adjunct in OTM remains inconclusive. Some studies in this regard indicate a significant acceleration in OTM but most did not. Probiotic therapy shows potential to improve oral microbiota balance and inflammation but requires more rigorous studies to determine its efficacy and optimal administration methods.

CONCLUSION

Future research should focus on establishing standardized guidelines and protocols to achieve consistent and reliable outcomes across these adjunctive therapies.

Periodontal response to nonsurgical accelerated orthodontic tooth movement

Tooth movement is a complex process involving the vascularization of the tissues, remodeling of the bone cells, and periodontal ligament fibroblasts under the hormonal and neuronal regulation mechanisms in response to mechanical force application. Therefore, it will inevitably impact periodontal tissues. Prolonged treatment can lead to adverse effects on teeth and periodontal tissues, prompting the development of various methods to reduce the length of orthodontic treatment. These methods are surgical or nonsurgical interventions applied simultaneously within the orthodontic treatment. The main target of nonsurgical approaches is modulating the response of the periodontal tissues to the orthodontic force. They stimulate osteoclasts and osteoclastic bone resorption in a controlled manner to facilitate tooth movement. Among various nonsurgical methods, the most promising clinical results have been achieved with photobiomodulation (PBM) therapy. Clinical data on electric/magnetic stimulation, pharmacologic administrations, and vibration forces indicate the need for further studies to improve their efficiency. This growing field will lead to a paradigm shift as we understand the biological response to these approaches and their adoption in clinical practice. This review will specifically focus on the impact of nonsurgical methods on periodontal tissues, providing a comprehensive understanding of this significant and understudied aspect of orthodontic care.

Efficacy of adjunctive systemic or local antibiotic therapy in peri-implantitis: a systematic review and meta-analysis of randomized controlled clinical trials

This systematic review and meta-analysis considered the results of randomized controlled clinical trials (RCTs) to evaluate the efficacy of systemic or local antibiotic therapy in peri-implantitis. Two independent authors screened publications from three electronic databases to include RCTs meeting all the inclusion and exclusion criteria. A meta-analysis was performed to evaluate the weighted mean differences in survival rate (SR) and changes in pocket probing depth (PPD), bone level (BL), and clinical attachment level (CAL). The study cohorts were defined as antibiotic and control groups with subgroups for analysis. Seven studies including 309 patients (390 implants) were considered. Within the limitations of this review, patients in the antibiotic groups exhibited significant improvements in PPD. Subgroup analysis indicated that the administration of systemic antibiotics or the use of antibiotics in non-surgical treatments did not result in a significant alteration in BL. It was established that the addition of antibiotics can ameliorate PPD and SR in the treatment of peri-implantitis, whether through surgical or non-surgical approaches, and also shows moderate performance regarding BL and CAL. Considering the lack of application of new technologies in the control group and the hardship of assessing the potential risks of antibiotics, careful clinical judgment is still necessary.

Optimization of a Photobiomodulation Protocol to Improve the Cell Viability, Proliferation and Protein Expression in Osteoblasts and Periodontal Ligament Fibroblasts for Accelerated Orthodontic Treatment

Numerous pieces of evidence have supported the therapeutic potential of photobiomodulation (PBM) to modulate bone remodeling on mechanically stimulated teeth, proving PBM's ability to be used as a coadjuvant treatment to accelerate orthodontic tooth movement (OTM). However, there are still uncertainty and discourse around the optimal PBM protocols, which hampers its optimal and consolidated clinical applicability. Given the differential expression and metabolic patterns exhibited in the tension and compression sides of orthodontically stressed teeth, it is plausible that different types of irradiation may be applied to each side of the teeth. In this sense, this study aimed to design and implement an optimization protocol to find the most appropriate PBM parameters to stimulate specific bone turnover processes. To this end, three levels of wavelength (655, 810 and 940 nm), two power densities (5 and 10 mW/cm2) and two regimens of single and multiple sessions within three consecutive days were tested. The biological response of osteoblasts and periodontal ligament (PDL) fibroblasts was addressed by monitoring the PBM's impact on the cellular metabolic activity, as well as on key bone remodeling mediators, including alkaline phosphatase (ALP), osteoprotegerin (OPG) and receptor activator of nuclear factor κ-B ligand (RANK-L), each day. The results suggest that daily irradiation of 655 nm delivered at 10 mW/cm2, as well as 810 and 940 nm light at 5 mW/cm2, lead to an increase in ALP and OPG, potentiating bone formation. In addition, irradiation of 810 nm at 5 mW/cm2 delivered for two consecutive days and suspended by the third day promotes a downregulation of OPG expression and a slight non-significant increase in RANK-L expression, being suitable to stimulate bone resorption. Future studies in animal models may clarify the impact of PBM on bone formation and resorption mediators for longer periods and address the possibility of testing different stimulation periodicities. The present in vitro study offers valuable insights into the effectiveness of specific PBM protocols to promote osteogenic and osteoclastogenesis responses and therefore its potential to stimulate bone formation on the tension side and bone resorption on the compression side of orthodontically stressed teeth.