Analysis of New Bone Formation Induced by Periosteal Distraction in a Rat Calvarium Model

Pumping the Periosteum: A Feasibility Study: Periosteal Distraction Osteogenesis in a Rat Model

PURPOSE

Gradual elevation of periosteum from the bone surface is known to promote the adaptation of soft tissues and the formation of hard tissues. The aim of our study was to estimate the benefit of periosteal distraction osteogenesis (PDO) on de novo bone formation in a rat model.

MATERIALS AND METHODS

After device placement, animals were allowed for a latency period of 7 days. Animals in the PDO group were subjected to distraction at a rate of 0.1 mm/d for 10 days. In the periosteal pumping (PP) group, the animals were subjected to distraction at a rate of 0.1 mm/d. The direction of distraction was alternated every 2 days. The animals were euthanized at 17, 31, and 45 days after surgery, and the samples were analyzed histologically and by microcomputed tomography.

RESULTS

In both groups, the new bone was characterized as primary woven bone that was located at the leading edge of bone apposition. Bone volumes significantly increased throughout the observation period both in the PP group (P = 0.018) and in the PDO group (P < 0.001). The new bone was denser and more mature in the PP group than in the PDO group, and the difference was significant at the 31-day time point (P = 0.024). However, the volume of the new bone was higher in the PDO at the 45-day time point (P < 0.001).

CONCLUSIONS

We propose that the PP may be applied to enhance the osteogenic capacity of periosteum without plate elevation. Because this is only a proof-of-principle study, the alternated protocol of periosteal distraction warrants evaluation in the future studies.

Regeneration of Craniofacial Bone Induced by Periosteal Pumping

A variety of surgical techniques and tissue engineering strategies utilizing osteogenic potential of the periosteum have been developed for the repair of extended bone deficiencies. The aim of the present study was to assess the impact of an alternating protocol of periosteal distraction osteogenesis (PDO) on bone regeneration in an intraoral model. Eight adult, male Beagle dogs were used for the study. Two distraction devices were placed on each side of the mandible. After a 7-day latency period, distraction devices in all animals were manipulated at the rate of 0.5 mm for a total of 8 days. The pumping protocol in two test groups proceeded twice daily by alternating activation with relaxation. In the periosteal pumping/distraction (PPDO) group, the distraction screws were activated two times (at 12 and 24 h) and then turned back (at 36 h), and in the periosteal pumping (PP) group repeatedly activated and turned back (at 12 h). In the PDO group, only activation was performed once daily (positive control). Devices were left inactivated in the negative control (NC) group. The samples were harvested after 8 weeks of consolidation period and investigated by micro-CT and histological analysis. New mature, lamellar bone was formed over the pristine bone in all groups. PPDO and PDO groups showed more new bone area (NBA) compared to the PP (p < 0.001 and p < 0.001, respectively) and to the NC group (p = 0.032 and p = 0.031, respectively). Furthermore, greater NBA was found in the PP group than the NC group (p = 0.006). PDO demonstrated higher relative connective tissue area than the PPDO group (p = 0.005) and lower relative new bone volume than the NC group (p = 0.025). Pumping protocol of periosteal distraction may successfully induce the endogenous regeneration of the mandibular bone in dogs. Impact Statement Repair of extended bone defects impose a significant challenge to oral and maxillofacial surgeons. In this article, a principle of distraction osteogenesis was applied to stimulate bone regeneration in the mandible. A periosteum-based regeneration approach may represent a valuable step toward creating a significant volume of hard and soft tissues, without need for autogenous bone harvesting or application of biomaterials.

The effect of the platelet-rich plasma on osteogenic potential of the periosteum in an animal bone defect model

Objectives

This study aims to investigate whether plasma-rich plasma (PRP) enhances the osteogenic potential of periosteal grafts used to repair bone defects and maintains both histologically and biomechanically more durable bone tissue.

Materials and methods

A standard bone defect was formed to the left femurs of 54 Sprague-Dawley rats and three groups were formed. In the first group (n=18), no periosteal repair was done for bone defect. In the second group (n=18), periosteal graft tissue was sutured to cover the defect entirely. In the third group (n=18), before periosteal repair, a 1 mL of PRP fibrin was applied into the bone defect. All femoral specimens were compared histologically at four and six weeks and biomechanically by three-point bending test at six weeks after treatment.

Results

In the PRP applied group, healing of the bone defect at four weeks was significantly better than the other groups in terms of histological new bone formation (p<0.05). At six weeks, new bone formation in both of the periosteum preserved groups was superior to the first group (p<0.05, for both). There was no statistically significant difference between the second and third groups at the end of the sixth week in the biomechanical analysis, although both groups were significantly stronger than the first group (p<0.05).

Conclusion

Stimulation of the periosteum with PRP application causes early osteogenic differentiation of precursor cells. Although, at biomechanical basis, PRP application does not create any significant difference, in the recovery of the bone defects at very early period, application of PRP may play a role to accelerate fracture healing and to decrease nonunions.

Induced osteogenesis using biodegradable and titanium periosteal distractors

Background

New bone formation can result from periosteal distraction. This is achieved through progressive uplifting of the periosteum by increasing the interface between it and the bone surface.

Objective

This study investigated the impact of gradual periosteal distraction using biodegradable materials and titanium distraction devices.

Materials and methods

20 rabbits were separated into 2 groups. Distraction devices were placed in all groups after reflecting the calvarial periosteum. The device was actuated following 7 days. Group 1 got titanium device and Hydroxyapatite HA with poly-l-lactide (PLLA) device was utilized in group 2. Five animals were sacrificed from each group following 4 and 6 weeks. Newly formed bone was histologically and radiographically assessed.

Results

The histological observations showed that both distraction devices successfully induced osteogenesis and effectively distracted the soft tissue following 4 and six weeks. The study showed scattered bone trabeculae, with adipose tissue and multiple dome-shaped bones. Micro-computed tomography showed newly formed bone that was far less radiopaque than the initial basal bone. The connective tissue appeared as a radiolucent area that decreased gradually toward the fixation point of the device. At 6 weeks, the percentage of new bone was significantly higher than at 4 weeks for both devices. The PLLA device showed more bone than did the titanium device at both 4 and 6 weeks, but no significant difference was observed.

Conclusions

Both distraction devices were effective in distracting the periosteum and inducing new vascularized bone. The PLLA device induced more bone than the titanium device. Thus, the distractor composition may influence the new bone.

In situ soft tissue regeneration using periosteal distraction: A preliminary study in the rat calvarial model

Aim

In this study, we aimed to evaluate soft tissue generated by periosteal distraction.

Background

Management of soft tissue defects represents a challenge in dentistry. Previous periosteal distraction studies documented partial fill of the distraction space with newly-generated bone and fibrous connective tissue.

Material and methods

Titanium meshes were inserted in subperiosteal tunnels in the calvaria of 20 rats through coronal incision. The devices were immediately activated after insertion by elevation of one side at 1 mm/day for 3 days. Rats were then divided into two groups (n = 10). Animals were sacrificed after 2 weeks (Group 1) and after 4 weeks (Group 2). Distraction sites specimens were embedded in paraffin and analyzed histologically and histomorphometrically.

Results

In both groups, new periosteum was regenerated and covered the original bone surface in the distraction site. Distraction spaces showed a predomination of hyper-vascularized connective tissue and little new bone formation near to the stable end of the device. The 4-week findings showed more organized collagen fibers with less vascularity compared to the 2-week findings.

Conclusion

The periosteal distraction technique can effectively regenerate connective tissue. It may open a new modality in the guided tissue regeneration for soft tissue augmentation.

Systematic Review and Quality Evaluation Using ARRIVE 2.0 Guidelines on Animal Models Used for Periosteal Distraction Osteogenesis

The objective of this systematic review was to synthesize all the preclinical studies carried out in periosteal distraction osteogenesis (PDO) in order to evaluate the quality using the ARRIVE guidelines. The animal models used, and the influence of the complications, were analysed in order to establish the most appropriate models for this technique. The PRISMA statements have been followed. Bibliographic sources have been consulted manually by two reviewers. Risk of bias was evaluated using the SYRCLE tool for animal studies, and the quality of the studies with the ARRIVE 2.0 guidelines. The selection criteria established by expert researchers were applied to decide which studies should be included in the review, that resulted in twenty-four studies. Only one achieved the maximum score according to the ARRIVE 2.0 guidelines. The rabbit as an animal model has presented good results in PDO, both for calvaria and jaw. Rats have shown good results for PDO in calvaria. The minipig should not be recommended as an animal model in PDO. Despite the increase in the quality of the studies since the implementation of the ARRIVE 2.0 guidelines, it would be necessary to improve the quality of the studies to facilitate the transparency, comparison, and reproducibility of future works.

Comparison of the Efficiency of Two Novel Guided Bone Regeneration Devices in the Rabbit Calvarial Model

Background

Creating a secluded large space using guided bone regeneration (GBR) is a novel osteogenesis technique used in the prevention of premature membrane exposure complications. However, this technique is not considered clinically feasible.

Objectives

This study aimed to compare the outcome of the insertion of two novel GBR devices in a rabbit calvarial model in terms of mode of action, simplicity, and amount of new space and bone gained.

Materials and Methods

The expansible GBR (EGBR) device, composed mainly of a titanium plate, silicone membrane, and activation screw, was inserted beneath the periosteum in the calvarial area of eight rabbits. The smart GBR (SGBR) device, composed of silicone sheets and Nitinol strips, were inserted beneath the periosteum in the calvarial area of another 10 rabbits. Half of each group was sacrificed 2 months after surgery, and the other half was sacrificed after 4 months.

Results

Histological and microradiographical analysis showed that, at 2 months, the EGBR device achieved a mean space gain of 207.2 mm³, a mean bone volume of 68.2 mm³, and a mean maximum bone height of 1.9 mm. Values for the same parameters at 4 months were 202.1 mm³, 70.3 mm³, and 1.6 mm, respectively. The SGBR device had significantly higher (P < 0.05) mean space gain (238.2 mm³; 239.5 mm³), bone volume (112.9 mm³, 107.7 mm³), and bone height (2.7 mm; 2.6 mm) than the EGBR device at 2 and 4 months, respectively.

Conclusion

Both devices proved to be effective in augmenting bone vertically through the application of GBR and soft tissue expansion processes. However, the SGBR device was more efficient in terms of mode of action, simplicity, and amount of bone created in the new space.

Three-Dimensional-Printed Poly-L-Lactic Acid Scaffolds with Different Pore Sizes Influence Periosteal Distraction Osteogenesis of a Rabbit Skull

The repair of bone defects is a big challenge in reconstructive surgery. Periosteal distraction osteogenesis (PDO), as a promising technique used for bone regeneration, forms a space between the periosteum and bone cortex to regenerate the new bone merely by distracting the periosteum. In order to investigate the influence of distractor framework on the PDO, we utilized three-dimensional (3D) printing technology to fabricate three kinds of poly-L-lactic acid (PLLA) scaffolds with different pore sizes in this study. The in vitro experiments showed that the customized PLLA scaffolds had different-sized microchannels with low toxicity, good biocompatibility, and enough mechanical strength. Then, we built up an in vivo bioreactor under the skull periosteum of New Zealand white rabbits. The distractors with different pore sizes all could satisfy the demand of periosteal distraction in the animal experiments. After 8 weeks of consolidation period, the quality and quantity of the newly formed bone were improved with the increasing pore sizes of the distractors. Moreover, the newly formed bone also displayed an increasing degree of vascularization. In conclusion, 3D printing technology could promote the innovation of PDO devices and fabricate optimized scaffolds with appropriate pore sizes, shapes, and structures. It would help us regenerate more functional tissue-engineered bone and provide new ideas for further clinical application of the PDO technique.

Periosteal distraction osteogenesis versus immediate periosteal elevation in a rat model: Histological and micro-CT analysis

PURPOSE

The aim of the present study was to compare periosteal distraction osteogenesis (PDO) to immediate periosteal elevation (IPE) in terms of de novo bone formation.

MATERIAL AND METHODS

Animals of PDO Group were subjected to a 7-day latency period and a 10-day distraction period. Distraction device in IPE Group were activated for 1 mm at placement. Both groups of animals were euthanized at 17, 31 and 45-day following surgery and the samples analyzed histologically and by micro-CT. Total gap region (TG) was divided in two subregions, less than 0.5 mm (LG) and over 0.5 mm of the gap height (HG).

RESULTS

Bone formation in PDO Group was observed in the distal region of the distraction gap, whereas in IPE Group proximally and distally from the distraction gap. Bone volume increased in both groups in LG, HG and TG (p < 0.001), while bone mineral density only in HG (p = 0.001). More new bone was observed in PDO than in IPE Group in HG (p = 0.017) and in TG (p < 0.001), without differences found in bone mineral density.

CONCLUSIONS

The function of immediately elevated periosteum is limited to the distance to the underlying bone. PDO may be successfully applied to maintain the osteogenic capacity of elevated periosteum.

Periosteal Distraction Osteogenesis: An Effective Method for Bone Regeneration

The treatment of bone defects is challenging and controversial. As a new technology, periosteal distraction osteogenesis (PDO) uses the osteogenicity of periosteum, which creates an artificial space between the bone surface and periosteum to generate new bone by gradually expanding the periosteum with no need for corticotomy. Using the newly formed bone of PDO to treat bone defects is effective, which can not only avoid the occurrence of immune-related complications, but also solve the problem of insufficient donor. This review elucidates the availability of PDO in the aspects of mechanisms, devices, strategies, and measures. Moreover, we also focus on the future prospects of PDO and hope that PDO will be applied to the clinical treatment of bone defects in the future.

Effects of collagen membrane application and cortical bone perforation on de novo bone formation in periosteal distraction: an experimental study in a rabbit calvaria

OBJECTIVES

The aim of the present study was to assess the impact of collagen membrane application and cortical bone perforations in periosteal distraction osteogenesis.

STUDY DESIGN

A total of 32 New Zealand rabbits were randomized into four experimental groups, considering two treatment modalities. Calvarial bone was perforated or left intact (P+/-). In half the animals, the distraction mesh was covered with a collagen membrane (M+/-). All animals were subjected to a 7-day latency period and a 10-day distraction period. The samples were harvested after 4-week and 8-week consolidation periods and analyzed histologically and by means of micro-computed tomography.

RESULTS

Primary, woven bone observed at the 4-week consolidation period was gradually replaced by lamellar bone at the 8-week consolidation period. Significant increase in bone volume was found in all groups (P < .001) and in bone mineral density in groups I (P-/M-; P < .001), III (P+/M-; P < .001), and IV (P+/M+; P = .013). Group III (P+/M-) showed significantly more new bone at the 8-week consolidation period compared with the other three groups (P = .001), with no differences observed in bone mineral density between groups at a given time-point.

CONCLUSIONS

In the present model, cortical bone perforations have more impact on the osteogenic process compared with the application of a collagen membrane.

The Molecular and Cellular Events That Take Place during Craniofacial Distraction Osteogenesis

Summary:

Gradual bone lengthening using distraction osteogenesis principles is the gold standard for the treatment of hypoplastic facial bones. However, the long treatment time is a major disadvantage of the lengthening procedures. The aim of this study is to review the current literature and summarize the cellular and molecular events occurring during membranous craniofacial distraction osteogenesis. Mechanical stimulation by distraction induces biological responses of skeletal regeneration that is accomplished by a cascade of biological processes that may include differentiation of pluripotential tissue, angiogenesis, osteogenesis, mineralization, and remodeling. There are complex interactions between bone-forming osteoblasts and other cells present within the bone microenvironment, particularly vascular endothelial cells that may be pivotal members of a complex interactive communication network in bone. Studies have implicated number of cytokines that are intimately involved in the regulation of bone synthesis and turnover. The gene regulation of numerous cytokines (transforming growth factor-β, bone morphogenetic proteins, insulin-like growth factor-1, and fibroblast growth factor-2) and extracellular matrix proteins (osteonectin, osteopontin) during distraction osteogenesis has been best characterized and discussed. Understanding the biomolecular mechanisms that mediate membranous distraction osteogenesis may guide the development of targeted strategies designed to improve distraction osteogenesis and accelerate bone regeneration that may lead to shorten the treatment duration.

Relative contributions of osteogenic tissues to new bone formation in periosteal distraction osteogenesis: histological and histomorphometrical evaluation in a rat calvaria

BACKGROUND

The relative contributions of different, potential factors to new bone formation in periosteal distraction osteogenesis are unknown.

PURPOSE

The aim of the present study was to assess the influence of original bone and periosteum on bone formation during periosteal distraction osteogenesis in a rat calvarial model by means of histology and histomorphometry.

METHODS

A total of 48 rats were used for the experiment. The contribution of the periosteum was assessed by either intact or incised periosteum or an occlusive versus a perforated distraction plate. The cortical bone was either left intact or perforated. Animals were divided in eight experimental groups considering the three possible treatment modalities. All animals were subjected to a 7-day latency period, a 10-day distraction period and a 7-day consolidation period. The newly formed bone was analyzed histologically and histomorphometrically.

RESULTS

New, mainly woven bone was found in all groups. Differences in the maximum height of new bone were observed and depended on location. Under the distraction plate, statistically significant differences in maximum bone height were found between the group with perforations in both cortical bone and distraction plate and the group without such perforations.

CONCLUSIONS

If the marrow cavities were not opened, the contribution to new bone formation was dominant from the periosteum. If the bone perforations opened the marrow cavities, a significant contribution to new bone formation originated from the native bone.