Effect of bisphosphonates on orthodontic tooth movement-an update

THE EFFECT OF BISPHOSPHONATE RISEDRONATE HYDROGEL ON ALKALINE PHOSPHATASE AND OSTEOCLASTS DURING RELAPSE MOVEMENT

Objectives: To analyze the effect of risedronate hydrogel on enzyme alkaline phosphatase (ALP) and osteoclast/osteoblast ratio during tooth relapse movement Materials and methods: The research design is experimental with time series. The lower incisors of 75 guinea pigs are distally moved using open coil spring. The guinea pigs were divided into three groups: without risedronate (group A; n = 25); given 250 µmol/L of risedronate hydrogel (group B; n = 25), and given 500 µmol/L of risedronate hydrogel (group C; n = 25). Risedronate were applied intrasulcularly in the mesial part of the gingival sulcus every 3 days. After 14 days of stabilization, the open coil spring was removed (bisphosphonate administration was continued). The relapsed teeth and ALP levels on days 0, 3, 7, 14, and 21 were measured. The osteoclast/osteoblast ratio was measured by hematoxylin and eosin staining. ANOVA test was used to determine the difference in the three groups and their interactions with concentration and time. Results: There was a significant difference in osteoclast/osteoblast ratio on day 3 (p = 0.019, p

Variation in condylar morphology in different malocclusion among Indians

Temporo-mandibular joint (TMJ) joint and the condyle of mandible are observed in the radiographs of the skull and the jaw. Therefore, it is of interest to assess the predictability of four different shapes of condyle in skeletal class I, II and III malocclusion. The four commonly visualized shapes are oval, bird beak, diamond and crooked were assessed using an ortho pantomogram (OPG). Each of the malocclusion was visualized for different shapes of the condyle. 987 OPGs were radiographically evaluated and the morphology of 1974 condylar heads was visualized. The shapes of the condyles were grouped under four different types. Data shows that oval shaped condyle was most common followed by bird beak. There was variability in the diamond and crooked shape and was lesser than the other types. Thus, the shapes of the condyle are useful predictable guide in deciding the nature of the occlusion.

Lithium chloride promotes osteogenesis and suppresses apoptosis during orthodontic tooth movement in osteoporotic model via regulating autophagy

Osteoporosis is a widely distributed disease that may cause complications such as accelerated tooth movement, bone resorption, and tooth loss during orthodontic treatment. Promoting bone formation and reducing bone resorption are strategies for controlling these complications. For several decades, the autophagy inducer lithium chloride (LiCl) has been explored for bipolar . In this study, we investigated the autophagy-promoting effect of LiCl on bone remodeling under osteoporotic conditions during tooth movement. Ovariectomy was used to induce osteoporosis status in vivo. The results showed that LiCl rejuvenated autophagy, decreased apoptosis, and promoted bone formation, thus protecting tooth movement in osteoporotic mice. Furthermore, in vitro experiments showed that LiCl reversed the effects of ovariectomy on bone marrow-derived mesenchymal stem cells (BMSCs) extracted from ovariectomized mice, promoting osteogenesis and suppressing apoptosis by positively regulating autophagy. These findings suggest that LiCl can significantly decrease adverse effects of osteoporosis on bone remodeling, and that it has great potential significance in the field of bone formation during tooth movement in osteoporosis patients.

Orthodontics in patients with significant medical co-morbidities

A wide variety of patients with medical co-morbidities may present to general orthodontic practice. It is important for the treating clinician to have a general understanding of key medical conditions that may impact upon the treatment and management options. This clinical supplement provides a treatment-focused summative update for the orthodontist regarding significant medical co-morbidities, their general prevalence and an exploration of potential impacts upon orthodontic treatment. This review also discusses the significance of key medications and provides suggestions for the safe provision of orthodontic treatment.

Therapeutic Dimensions of Bisphosphonates: A Clinical Update

Bisphosphonates (BPs) are a commonly used class of drugs for the treatment of bone disorders. An extensive review of BPs with their clinical efficacy and safety profile is unavailable. This study aimed to review the available literature on BPs, summarize their role in clinical therapy, and emphasize their safety profile. Authors reviewed the existing literature using the Google Scholar, PubMed, and Micromedex databases and analyzed the collected articles. BPs are the preferred medication for osteoporosis and other similar conditions owing to their efficient antiosteoclastic activity. Few of them are available in oral dosage forms; hence, they are patient-friendly. The mechanism of action, common adverse effects and their clinical applications, precautions and warnings pertaining to the route of administration, and safety profiles have been discussed in this manuscript. The common adverse effects are majorly related to the gastrointestinal, cardiovascular, and endocrine system. Upon chronic usage, patients may experience serious problems like osteonecrosis of the jaw and atypical bone fractures. Although BPs are effective and safe, they may cause GI adverse effects and rare cases of osteonecrosis. Patient counseling could prove beneficial in early identification and prevention of the adverse effects associated with BPs.

The intrasulcular application effect of bisphosphonate hydrogel toward osteoclast activity and relapse movement

Introduction

Orthodontic relapse occurs after orthodontic treatment and shifting of teeth to unfavorable positions. Bisphosphonates’ effects on bone resorption and relapse prevention have been extensively investigated. However, topical administration, which results in local effect, is still a problem.

Objective

This study aimed to investigate the effect of risedronate with gelatin hydrogel as a carrier to prevent relapse movement by inhibiting osteoclast activity.

Methods

Lower incisors of 75 guinea pigs were moved distally using an orthodontic appliance until ±3 mm length. Gelatin hydrogel was fabricated to obtain a semisolid controlled release of 250 (Bis-CR250) and 500 mmol/L risedronate (Bis-CR500) and then applied intrasulcularly into the mesial subperiosteal area of 50 guinea pigs (25 in each group) every 3 days; the rest were the control (Bis-CR000). After 14 days of stabilization, the apparatus was removed. The distance decrease between incisors and the osteoclast number with TRAP staining at 0, 3, 7, 14, and 21 days were measured. ANOVA was used to determine the differences among the different time and experimental groups.

Results

Both treatments showed significantly less relapse movement compared to the control (p < 0.05) at 14 and 21 days. Bis-CR500 more effectively inhibited the relapse movement than Bis-CR250 on day 21, indicating a dose dependency in the inhibition. Both treatments showed less osteoclast numbers than control (p < 0.05).

Conclusion

Controlled release of bisphosphonate risedronate with a topically administered gelatin hydrogel has shown to be effective in decreasing the tooth relapse movement and osteoclast activity.

Ionic Diffusion and Drug Release Behavior of Core-Shell-Functionalized Alginate-Chitosan-Based Hydrogel

This paper reports the core-shell structure effects in calcium alginate (CaALG) microbeads due to the threshold water level for phase transition and correlates these properties with respect to pH and electrical conductivity. Further, in this study, we used a novel microfluidic device for drug release testing to study the programmed release of risedronate (RIS-anti-osteoporotic drug) encapsulated in pH-responsive CaALG-chitosan (CHT) microbeads. Our microfluidic device contains a single straight microchannel containing a steplike barrier design used to restrict the mobility of the microbeads at the sample detection zone. For optical and fluorescence microscopy, single fluorescently labeled CaALG-CHT microbead containing RIS was placed in the sample detection zone by flowing through the inlet port with ultrapure water. The RIS release behavior from the microbeads at different pH (2.1, 4, 6.8, and 7.4) conditions was determined by using a spectrophotometer connected to the outlet port of the device. Results of our first study showed that the decrease in the concentration of CaCl₂ increases the swelling rate in CaALG microbeads. Maximum swelling was achieved with the lowest molar concentration of CaCl₂ used for fabrication of CaALG microbeads. Further, electrical current-voltage characteristic shows the nature of ionic mobility with respect to varying levels of pH indicating electrokinetic forces developed in the CaALG microbeads. By using a microfluidic device for drug release testing, we demonstrated that a sustained release delivery system for RIS can be prepared by coating with pH-sensitive and biodegradable CaALG-CHT. The CaALG-CHT microbeads used for encapsulating RIS are resistant to the acidic environment of the stomach. This may improve the therapeutic effectiveness and reduce the gastric adverse effects associated with RIS by preventing its decomposition in the acidic condition of stomach. The newly developed microfluidic device for drug release testing may find applications in screening novel drugs and delivery systems.

The role of bisphosphonates in orthodontic tooth movement-A review

The present study has reviewed and put insights on the reports and recent literatures confined to the effects of bisphosphonate (BP) medication on orthodontic tooth movement (OTM). Pharmacological anchorage control plays a vital role in orthodontic treatment planning to the required patients. BPs inhibit bone resorption by involving increased activity of mineral adsorption on the bone surfaces where BPs tend to target osteoclasts. The present study reviewed on the latest report and examined cases relating to the impact of BPs in OTM. Clinical implication, chemical formulation, and mode of action of BPs have been discussed. This reviewspecifically focused on various kinds of BPs used in medication for bone adsorption in OTM therapy. Furthermore, it tries to explore the rare adverse and side effects of BPs observed based on the literatures. A systematic literature search was attempted in the Medline database (PubMed) using appropriate keywords, such as orthodontic tooth movement, bisphosphonates, and manual hand look was more overdone. On the basis of reports examined, BP treatments in OTM have posed an increased trend toward the benefit and interfere with osteoclastic resorption. In many cases, they may be advantageous for mooring strategies and encourage long-term planned randomized controlled trials to evaluate conceivable benefits and antagonistic impacts of BP treatments for OTM, before initiating remedial use.

The effect of bisphosphonate medication on orthodontics and orthognathic surgery in patients with osteogenesis imperfecta

Introduction: Osteogenesis imperfecta (OI) is a genetic disease that primarily affects bone formation and metabolism. Craniofacial malformations belong to the broad spectrum of the OI phenotype. The introduction of bisphosphonate medications was intended to counteract the significant brittleness of the bones of OI patients. In connection with the application of bisphosphonates, drug-associated osteonecrosis of the jaw has become known as an undesirable effect of the therapeutically intended reduction of osteoclast activity. Originally, the pharmacological inhibition of bone loss was mainly used in oncological therapy. For some time now, osteoporosis has also been treated with substances that inhibit bone resorption.

In OI, malposition of the jaws is relatively common, in particular retrognathia of the maxilla and progeny of the mandible. The literature discloses complications of orthognathic surgery in OI patients. Previous literature reviews suggest that bisphosphonate medication has no significant impact on the performance of and healing after oral surgery in OI patients.

Materialandmethods: An essential prerequisite of a therapy adapted to the patient’s condition is the knowledge of the patient's medical history. This case report describes the orthodontic-surgical treatment of an OI patient and the treatment experience derived in dealing with the condition. The unusual circumstance of this case is that the patient had concealed both his underlying disease and his medication during the current treatment period. In addition, the relevant literature is evaluated for combining the keywords OI, orthodontic therapy, bisphosphonates, and orthognathic surgery.

Results: Based on the literature and our own experience, it is concluded that orthodontic treatment with bisphosphonate medication can also be carried out in OI patients. However, considerably greater forces and longer time intervals should be scheduled for each treatment. Orthognathic surgery with bisphosphonate medication turned out to be uncomplicated in our own case, considering the underlying disease in the planning of surgical procedures. However, there have been very few reports of OI patients in whom orthodontic-surgical treatment of jaw malformation has been performed with bisphosphonate medication.

Conclusion: Taking into account the reported experience of severe complications of orthognathic surgery, the multiple documented adjustments to the treatment strategy of OI patients should be taken seriously. The basic condition of therapy adapted to the disease is that the patient informs the practitioner in an appropriate manner about his or her state of health.

Effect of locally administered novel biodegradable chitosan based risedronate/zinc-hydroxyapatite intra-pocket dental film on alveolar bone density in rat model of periodontitis

The aim of this study was to develop a chitosan-based risedronate/zinc-hydroxyapatite intrapocket dental film (CRZHDF) for applications in the treatment of alveolar bone loss in an animal model of periodontitis. The physical characteristics (folding endurance, pH, mucoadhesive strength, risedronate content and release) of CRZHDF, exhibited results within the limit. X-ray diffraction analysis indicates reduced or disappeared crystallinity of risedronate and zinc-hydroxyapatite in presence of chitosan. Further, FTIR studies revealed stability of CRZHDF and compatibility between risedronate, zinc-hydroxyapatite and chitosan. Periodontitis was induced by Porphyromonas gingivalis-lipopolysaccharide injections around the mandibular first molar. We divided rats into 5 groups (12 rats/group): healthy, untreated periodontitis; periodontitis plus CRZHDF-A, periodontitis plus CRZHDF-B, and periodontitis plus chitosan film. After four weeks, blood samples and mandibles were obtained for biochemical, radiographic and histological analysis. Bone specific alkaline phosphatise activity and tartrate resistant acid phosphatase 5b was statistically lower in CRZHDF-A and CRZHDF-B groups as compared to the untreated periodontitis group (p < 0.0001). The expression of osteocalcin was statistically higher in CRZHDF-A and CRZHDF-B groups as compared to the untreated periodontitis group (p < 0.0001). Alveolar bone was intact in the healthy group. Local administration of CRZHDF resulted in significant improvements in the mesial and distal periodontal bone support (MPBS and DPBS, respectively) proportions (%), bone mineral density, and also reversed alveolar bone resorption when compared to the untreated periodontitis group (p < 0.001). The study reported here reveals that novel CRZHDF treatment effectively reduced alveolar bone destruction and contributes to periodontal healing in a rat model of experimental periodontitis.

Expression and function of osteogenic genes runt-related transcription factor 2 and osterix in orthodontic tooth movement in rats

OBJECTIVE

To investigate the expression and function of osteogenic genes osterix (OSX) and runt-related transcription factor 2 (RUNX2) in the rat periodontal tissues under orthodontic force for the remodeling of the periodontal tissues.

METHODS

24 Wistar rats were randomly divided into 4 groups of orthodontic tooth movements for 1, 3, and 7 days (experimental groups) and control group (without orthodontic force). The expression of RUNX2 and OSX in the periodontal tissues was analyzed using real time PCR for mRNA and Western blot analysis for protein. The data were also analyzed for involvement of the two genes in signal pathways using bioinformatics tools.

RESULTS

The mRNA levels of RUNX2 and OSX increased in the periodontal tissues after subjected to the orthodontic force for 1 to 7 days, with the highest level occurring at day 7. The relative expression levels of RUNX2 and OSX mRNA were 1.85 ± 0.12, 304 ± 0.06 and 4.16 ± 0.068, and 1.52 ± 0.09, 1.83 ± 0.03 and 2.56 ± 0.06 at day 1, 3 and 7, respectively. The results of Western blot analysis were consistent with the mRNA results.

CONCLUSION

In orthodontic tooth movement, the expression of RUNX2 and OSX was upregulated as a result of external stimulation, suggesting that the two genes is involved in periodontal tissue remodeling and plays an important role in periodontal tissue remodeling.