Effects of Local Low-Dose Alendronate Injections Into the Distraction Gap on New Bone Formation and Distraction Rate on Distraction Osteogenesis

Application of chemical factors for acceleration of consolidation phase of the distraction osteogenesis: a scoping review

PURPOSE

This study aimed to analyze the effect of injecting chemical factors compared to conventional distraction osteogenesis (DO) treatment on the bone formation of the distracted area of the maxillofacial region in human and animal studies.

METHOD

Electronic search was done in PubMed, Scopus, Embase, and Cochrane database for studies published until September 2021. The studies' risk of bias (ROB) was assessed using the Cochrane Collaborations and NIH quality assessment tools. Meta-analyses were performed to assess the difference in the amount of bone formation and maximal load tolerance.

RESULTS

Among a total of 58 included studies, eight studies analyzed the bone formation rate of the distracted area in human models and others in animal models. Results of the human studies showed acceptable outcomes in the case of using bone morphogenic protein-2 (BMP-2), autologous bone-platelet gel, and calcium sulfate. However, using platelet reach plasma does not increase the rate of bone formation significantly. Quantitative analyses showed that both BMP-2 (SMD = 26.57; 95% CI = 18.86 to 34.28) and neuron growth factor (NGF) (SMD = 16.19; 95% CI = 9.64 to 22.75) increase the amount of bone formation. Besides, NGF increased the amount of load tolerance significantly (SMD = 30.03; 95% CI = 19.91 to 40.16). Additionally, BMP-2 has no significant impact on the post-treatment maxillary length (SMD = 9.19; 95% CI =  - 2.35 to 20.73).

CONCLUSION

Limited number of human studies with low quality used chemical factors to enhance osteogenesis and showed acceptable results. However, more studies with higher quality are required.

Overview of Physical and Pharmacological Therapy in Enhancing Bone Regeneration Formation During Distraction Osteogenesis

Distraction osteogenesis (DO) is a kind of bone regeneration technology. The principle is to incise the cortical bone and apply continuous and stable distraction force to the fractured end of the cortical bone, thereby promoting the proliferation of osteoblastic cells in the tension microenvironment and stimulating new bone formation. However, the long consolidation course of DO presumably lead to several complications such as infection, fracture, scar formation, delayed union and malunion. Therefore, it is of clinical significance to reduce the long treatment duration. The current treatment strategy to promote osteogenesis in DO includes gene, growth factor, stem-cell, physical and pharmacological therapies. Among these methods, pharmacological and physical therapies are considered as safe, economical, convenience and effective. Recently, several physical and pharmacological therapies have been demonstrated with a decent ability to enhance bone regeneration during DO. In this review, we have comprehensively summarized the latest evidence for physical (Photonic, Waves, Gas, Mechanical, Electrical and Electromagnetic stimulation) and pharmacological (Bisphosphonates, Hormone, Metal compounds, Biologics, Chinese medicine, etc) therapies in DO. These evidences will bring novel and significant information for the bone healing during DO in the future.

Effect of bisphosphonate treatment of titanium surfaces on alkaline phosphatase activity in osteoblasts: a systematic review and meta-analysis

BACKGROUND

Bisphosphonate coating of dental implants is a promising tool for surface modification aiming to improve the osseointegration process and clinical outcome. The biological effects of bisphosphonates are thought to be mainly associated with osteoclasts inhibition, whereas their effects on osteoblast function are unclear. A potential of bisphosphonate coated surfaces to stimulate osteoblast differentiation was investigated by several in vitro studies with contradictory results. The purpose of this systematic review and meta-analysis was to evaluate the effect of bisphosphonate coated implant surfaces on alkaline phosphatase activity in osteoblasts.

METHODS

In vitro studies that assessed alkaline phosphatase activity in osteoblasts following cell culture on bisphosphonate coated titanium surfaces were searched in electronic databases PubMed/MEDLINE, Scopus and ISI Web of Science. Animal studies and clinical trials were excluded. The literature search was restricted to articles written in English and published up to August 2019. Publication bias was assessed by the construction of funnel plots.

RESULTS

Eleven studies met the inclusion criteria. Meta-analysis showed that coating of titanium surfaces with bisphosphonates increases alkaline phosphatase activity in osteoblasts after 3 days (n = 1), 7 (n = 7), 14 (n = 6) and 21 (n = 3) days. (7 days beta coefficient = 1.363, p-value = 0.001; 14 days beta coefficient = 1.325, p-value < 0.001; 21 days beta coefficient = 1.152, p-value = 0.159).

CONCLUSIONS

The meta-analysis suggests that bisphosphonate coatings of titanium implant surfaces may have beneficial effects on osteogenic behaviour of osteoblasts grown on titanium surfaces in vitro. Further studies are required to assess to which extent bisphosphonates coating might improve osseointegration in clinical situations.

Effect of Systemic Oxytocin Administration on New Bone Formation and Distraction Rate in Rabbit Mandible

PURPOSE

The main disadvantage of distraction osteogenesis is the prolonged treatment protocol. Recently, oxytocin (OT) has been found to have anabolic effects on bone metabolism. In this experimental study, the effects of OT on the mandibular distraction gap in rabbits at 2 different distraction rates were evaluated.

MATERIALS AND METHODS

This experimental study was conducted on 28 male New Zealand white rabbits. The animals were divided into 3 experimental groups and 1 control group. Group A (control group, n = 7) consisted of animals with distraction at a rate of 1 mm/day, and group B (n = 7) consisted of animals with a distraction rate of 2 mm/day; groups A and B received postoperative saline solution injection. Group C (n = 7) consisted of animals with distraction at a rate of 1 mm/day, and group D (n = 7) consisted of animals with a distraction rate of 2 mm/day; postoperative OT injection was performed in groups C and D.

RESULTS

Both histomorphologic and micro-computed tomography evaluations showed increased bone healing in the OT-treated groups.

CONCLUSIONS

On the basis of the evaluation of both the histomorphometric and micro-computed tomographic data, systemic OT administration was found to increase new bone formation and bone healing with distraction osteogenesis.

Histopathological Examination of the Effects of Local and Systemic Bisphosphonate Usage in Bone Graft Applications on Bone Healing

Background

The effect of bisphosphonates on the resorption process of normal bone tissue has been clearly mentioned in the literature, while their effect on the grafting material is a new research area. Limited former study is not sufficient to determine the strength, reliability and dosage of bisphosphonates. In this study, our aim is to examine the effects of local and systemic use of bisphosphonates in bone graft applications on bone healing, histopathologically.

Methods

Therefore, 32 Sprague-Dawley rats are separated into four groups. In the first group, only an empty bone defect is made on tibia and the tissue is sutured primarily without any other application. In the second group, bone defect is filled with allograft material and closed without any other application. In the third group (LA), alendronate solution is locally added to the graft material before its application to the site of bone defect. In the fourth group, alendronate is applied systemically after the site of bone defect is grafted and primarily closed. After 6 weeks, all rats are killed and the obtained samples are examined histopathologically.

Results

Local and systemic application of alendronate increases new bone formation in a statistically significant degree. In LA group, newly formed bone was observed more mature and well developed. Alendronate application does not cause an increase in inflammation, fibrosis and necrosis. There is no increased necrosis with alendronate application.

Conclusion

Local and systemic application of alendronate in bone grafting increases bone formation without any other complication. But we believe that further research should be made on dosage, usage and possible side effects.

The assessment of new bone formation induced by unfocused extracorporeal shock wave therapy applied on pre-surgical phase of distraction osteogenesis

Purpose:

This study aims to evaluate the effects of extracorporeal shock wave therapy applied before and/or immediately after the osteotomy on the maturation during the consolidation phase.

Materials and methods:

21 female New Zealand rabbits were used in the study. Subjects were divided randomly into three groups: Control (Distraction without ESWT), A (Distraction +ESWT After Osteotomy), AB (Distraction+ESWT After and Before Osteotomy). ESWT (500 pulses, 5 Hz, 0.19 mJ/mm2 energy flux density) was applied to group A and group AB after 5, 12 and 19 days after osteotomy and group AB only on days 7,14 and 21 before osteotomy. On the 28th day of the consolidation period, all subjects were sacrificed. Dual-energy x-ray absorptiometry (DEXA) was used to determine bone mineral density (BMD) and bone mineral content (BMC), and stereological methods were used to determine the new bone, connective tissue and neovascularization volumes.

Results:

As a result of DEXA examinations made on the 1st and 4th week of consolidation, there was no significant difference between groups regarding BMD and BMC values. According to the results of stereological examination, when the connective tissue and new bone tissue were evaluated, higher values were observed in AB when compared to A, and in AB and A compared to the control group, but the differences are not statistically significant. There was no difference between the groups in terms of neovascularization.

Conclusion:

ESWT in these parameters was not positively effective in bone maturation during consolidation when applied before osteotomy or both before and after osteotomy.