Evaluation of photobiomodulation effects on pain, edema, paresthesia, and bone regeneration after surgically assisted rapid maxillary expansion: Study protocol for a randomized, controlled, and double blind clinical trial

Effect of nutritional stress and photobiomodulation protocol on in vitro viability and proliferation of murine preosteoblast cells

This study aimed to assess the impact of nutritional conditions and irradiation parameters on the viability and proliferation of murine preosteoblasts. MC3T3-E1 cells were maintained under standard culture conditions (αMEM supplemented with 10% fetal bovine serum) or nutritional deficit conditions (αMEM without serum) and irradiated or not (control) with an InGaAlP diode laser at wavelengths of 660 nm (red) or 790 nm (infrared), with doses of 1, 4, or 6 J/cm², in a single dose in continuous mode. Cell viability and proliferation were assessed 24, 48, and 72 h after irradiation using the Alamar blue reduction assay. The cell cycle and events related to cell death were evaluated via propidium iodide (PI) staining and Annexin V/PI assays, respectively, through flow cytometry. The data revealed that in cells cultured with normal nutrition (10% FBS), there was no significant difference (p > 0.05) in cell viability or proliferation among the different irradiation protocols. In contrast, in the experiments conducted under nutritional deficiency, the infrared laser at a dose of 6 J/cm² significantly increased (p < 0.05) cell viability and proliferation compared with those of the control group at 72 h. The data were confirmed by cell cycle and cell death events (Annexin V/PI) assays. These results suggest that in vitro PBM yields more consistent biostimulatory effects on pre-osteoblasts subjected to nutritional deficiency, highlighting the need for attention to simulate these conditions in studies with laser therapy in in vitro bone disease models and in in vitro experiments using PBM for bone tissue engineering.

Benefits and Effects of Laser-Based Techniques in Complementary Maxillary Expansion: A Narrative Review

Transversal maxillary deficiency is a prevalent skeletal issue that can be addressed using various devices and methods, including rapid maxillary expansion (RME) and surgically assisted rapid maxillary expansion (SARME). These techniques involve the separation and regeneration of the midpalatal suture (MPS). Laser therapies, such as low-level laser therapy (LLLT) and photobiomodulation (PBM), have been proposed to improve biological wound or bone healing. The research sought to systematically evaluate the evidence regarding the advantages and effects of laser-based techniques in conjunction with RME or SARME. An electronic search was conducted through September 2024 in the PubMed database utilizing relevant Medical Subject Headings, without any time constraints. A total of 78 publications were identified with the keywords ''Orthodontics'', ''Laser Therapy'', ''Palatal Expansion Technique'', ''Maxillary Expansion'' and ''Photobiomodulation''. Only 17 were included in this research (11 were clinical trials, and six were systematic reviews). In addition, a secondary manual literature search was performed from the references of included articles and existing systematic reviews, adding one extra article. Despite the varying intervention protocols used in each study, they consistently demonstrated that laser techniques can improve bone regeneration after RME or SARME procedures. Although the available evidence is somewhat sparse, these methods seem to offer a promising solution for alleviating pain during MPS expansion. To establish definitive outcomes and develop a reliable clinical protocol, longer randomized clinical trials are essential to ensure the practicality of this technique.

Evaluation of pterygomaxillary disjunction on skeletal and dental changes after surgically assisted rapid maxillary expansion: A systematic review and meta-analysis

Background

Surgically assisted rapid maxillary expansion (SARME) with disjunction of the pterygomaxillary suture is a procedure widely used in maxillofacial surgery. However, the pterygomaxillary disjunction (PD) procedure has often been deemed risky. The actual necessity and effectiveness of PD in SARME remain subjects of debate, with some studies suggesting that sufficient expansion can be achieved without it. This systematic review with meta-analysis aimed to evaluate the scientific literature regarding the effects of PD on skeletal and dental changes after SARME.

Methods

The systematic review followed the Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to identify relevant articles published in different databases. The study conducted a comprehensive literature search across seven databases: PubMed/Medline, Web of Science, Science Direct, Scopus, Embase, Cochrane Collaboration Library, and Google Scholar. The selected studies evaluated the effect of the extent of expansion and the stability of SARME with PD, as well as the skeletal and dental changes associated with the treatment. The intervention cohorts within the sampled population chosen for incorporation into our analysis consisted of individuals who underwent SARME accompanied by PD, whereas the control group underwent SARME devoid of PD. Data were combined in a meta-analysis using the Review Manager 5.3.5. (RevMan) program. A systematic search was performed in seven databases (PubMed/Medline, Web of Science, Science Direct, Scopus, Embase, Cochrane Collaboration Library, and Google Scholar).

Results

After applying the selection criteria, seven articles were included in the systematic review, totaling 291 patients. Five articles were selected for meta-analysis. A meta-analysis was conducted to assess the effects of anterior and posterior dental expansions. After applying the selection criteria, seven articles were included in the systematic review, totaling 291 patients. Five articles were selected for meta-analysis. A meta-analysis was conducted to assess the effects of anterior and posterior dental expansions. Expansion in the previous region was slightly higher in the SARME with PD group compared to the PD-free group (95 % CI: 1.07 to 1.1 mm; p = 0.98). In the posterior region, expansion exceeding 0.11 mm was observed in the SARME with PD group compared to the PD-free group, but without statistical significance (95 % CI: 1.64 to 1.86 mm; p = 0.903).

Conclusion

SARME combined with PD proves to be an effective surgical procedure for correcting transverse maxillary deficiencies. However, no statistically significant differences were observed when SARME with and without PD was compared, indicating that SARME with PD can be used especially in cases that require expansion in the posterior region of the maxilla.

Tailoring photobiomodulation to enhance tissue regeneration

Photobiomodulation (PBM), the use of biocompatible tissue-penetrating light to interact with intracellular chromophores to modulate the fates of cells and tissues, has emerged as a promising non-invasive approach to enhancing tissue regeneration. Unlike photodynamic or photothermal therapies that require the use of photothermal agents or photosensitizers, PBM treatment does not need external agents. With its non-harmful nature, PBM has demonstrated efficacy in enhancing molecular secretions and cellular functions relevant to tissue regeneration. The utilization of low-level light from various sources in PBM targets cytochrome c oxidase, leading to increased synthesis of adenosine triphosphate, induction of growth factor secretion, activation of signaling pathways, and promotion of direct or indirect gene expression. When integrated with stem cell populations, bioactive molecules or nanoparticles, or biomaterial scaffolds, PBM proves effective in significantly improving tissue regeneration. This review consolidates findings from in vitro, in vivo, and human clinical outcomes of both PBM alone and PBM-combined therapies in tissue regeneration applications. It encompasses the background of PBM invention, optimization of PBM parameters (such as wavelength, irradiation, and exposure time), and understanding of the mechanisms for PBM to enhance tissue regeneration. The comprehensive exploration concludes with insights into future directions and perspectives for the tissue regeneration applications of PBM.

Comparative Investigation of Photobiomodulation in Diabetes-Impaired Alveolar Bone Healing: A Histomorphometrical and Molecular Study

Objective: Diabetes mellitus is increasing worldwide. Photobiomodulation (PBM) is proposed as a therapeutic method in various medical concerns. This study aimed to compare the effects of PBM at the wavelengths of 660, 808, or 660 + 808 nm on alveolar bone healing in diabetic rats. Methods: Bilateral maxillary first molars were extracted from diabetic Wistar rats (n = 36). Right-sided sockets were treated by an In-Ga-Al-P laser at 660 nm (7.2 J/cm2, 24 s; DM660), Ga-Al-As laser at 808 nm (7 J/cm2, 14 s; DM808), or a combination of these two sets (DM-dual) (n = 12). Left sides served as controls. On days 7 or 14, specimens were assigned for histomorphometric or real-time PCR analysis of runt-related transcription factor 2, osteocalcin, collagen I, and vascular endothelial growth factor expression. Results: Irradiated sockets of groups DM-808 and DM-dual showed a significant increase in bone tissue and blood vessel establishment as compared to DM-660. Further, group DM-dual exhibited the least amount of fibrotic tissue as compared to the other groups. Conclusions: Within our study limits, the present experiment suggested PBM at 808 nm, alone or combined with 660 nm irradiation, could promote alveolar bone healing, along with minimal fibrosis induction, in diabetic rats.

Comparison of different dual-wavelength photobiomodulation protocols application in third molar extractions. A split-mouth randomized controlled trial

OBJECTIVE

To compare the use of PBMT in the soft tissue and bone healing after third molar extraction using the dual-wavelength laser directly into the post-extraction alveoli (PBMT-I), or PBMT with a red laser directly into the alveoli and with an infrared laser externally on the patient's face (PBMT-IE).

METHODS

Twenty patients underwent extraction of four third molars were involved in this split-mouth double-blind randomized controlled trial. The Post-extraction alveoli were treated with the following protocols: PBMT-IE: Application of a red laser directly into the alveolus, and infrared laser irradiation transcutaneously and PBMT-I: Application of dual-wavelength laser intraorally. Patients were clinically evaluated 3, 7, 14, 30, and 90 days after the surgical procedure. The analyses in this study were divided into qualitative (centered on the patient's report and on the evaluators' analysis), and quantitative analyses (measurement of the vertical and horizontal dimensions of the face with the objective of measuring post-surgical edema and radiographic analyses for evaluation of the density and structure of the newly formed bone).

RESULTS

A progressive improvement was observed in all parameters evaluated in this study, however, this improvement was time dependent, with no distinct effect observed between the PBMT treatments applied.

CONCLUSION

The different dual-wavelength PBMT protocols induced a similar postoperative clinical course in third molar extraction surgeries, with a reduced occurrence of complications and a good healing pattern of hard and soft tissues.

Nerve Injury and Photobiomodulation, a Promising Opportunity: A Scoping Review on Laser Assisted Protocols for Lesions in the Oral Region

The currently available therapeutic options for restoring function and sensitivity in long-term nervous injuries pose challenges. Microsurgery interventions for direct nerve repair often lead to serious complications and limited success. Non-surgical methods, although somewhat effective, have limited benefits. These methods involve drug administration, such as with analgesics or corticosteroids. Photobiomodulation therapy (PBMT) has emerged as a promising approach based on clinical and laboratory studies. PBMT stimulates the migration and proliferation of neuronal fiber cellular aggregates, as reported in the literature. Experimental studies on animal models with peripheral nerve compression injuries have shown that PBMT can enhance the functionality of damaged nerves, preserving their activity and preventing scar tissue formation. The mechanism of action depends on the wavelength, which can positively or negatively affect photo acceptor resonances, influencing their conformation and activities. These findings suggest that photobiomodulation may accelerate and improve nerve regeneration. This review explores various methodologies used in photobiomodulation for regenerating nerve sensitivity after surgical trauma involving nerve structures, in the oral and peri-oral region. Research was conducted to evaluate which laser-assisted therapeutic protocols are used to improve the recovery of nervous sensitivity, using the JBI methodology for scoping reviews and following the PRISMA methodology.

The Role of Low-Level Laser Therapy in Bone Healing: Systematic Review

Low-level laser therapy (LLLT) is a treatment that is increasingly used in orthopedics practices. In vivo and in vitro studies have shown that low-level laser therapy (LLLT) promotes angiogenesis, fracture healing and osteogenic differentiation of stem cells. However, the underlying mechanisms during bone formation remain largely unknown. Factors such as wavelength, energy density, irradiation and frequency of LLLT can influence the cellular mechanisms. Moreover, the effects of LLLT are different according to cell types treated. This review aims to summarize the current knowledge of the molecular pathways activated by LLLT and its effects on the bone healing process. A better understanding of the cellular mechanisms activated by LLLT can improve its clinical application.