Hard Tissue Reconstruction Research Articles

Comparative Histological Analysis of Dentine-Derived Tooth Grafts in Maxillary vs Mandibular Socket Preservation: A Retrospective Study of 178 Cases.

(1) Background: In recent years, there has been a growing interest in tooth-derived materials as valuable alternatives to synthetic biomaterials for preventing alveolar ridge dimensional changes. This study aimed to evaluate the histological and clinical differences between alveolar ridge preservation procedures in the maxilla and mandible using demineralized dentin treated with Tooth Transformer®. (2) Methods: A total of 178 patients in good general health were enrolled, with 187 post-extractive sockets lacking buccal and/or palatal bone walls. Alveolar socket preservation procedures and histological evaluations were performed. The sites were divided into two groups: Group A (99 mandibular samples) and Group B (108 maxillary samples). After 5 months (±1 month), single bone biopsies were performed for histologic and histomorphometric analysis. (3) Results: Clinical outcomes demonstrated a good healing of hard and soft tissues with an effective maintenance of bone architecture in both groups. Histomorphometric analysis revealed a total bone volume of 50.33% (±14.86) in Group A compared to 43.53% (±12.73) in Group B. The vital new bone volume was 40.59% (±19.90) in Group A versus 29.70% (±17.68) in Group B, with residual graft dentin material volume at 7.95% (±9.85) in Group A compared to 6.75% (±9.62) in Group B. (4) Conclusions: These results indicate that tooth-derived material supports hard tissue reconstruction by following the structure of the surrounding bone tissue. A 6.8% difference observed between the maxilla and mandible reflects the inherent disparities in natural bone structures in these regions. This suggests that the bone regeneration process after tooth extraction adheres to an anatomical functional pattern that reflects the specific bone characteristics of each area, thus contributing to the preservation of the morphology and functionality of the surrounding bone tissue.

A hierarchical Bilayered scaffold for periodontal complex structure regeneration.

The periodontal tissue comprises alveolar bone, cementum, and periodontal ligament (PDL), forming a highly hierarchical architecture. Although current therapies could regenerate the hard tissue well, the simultaneous reconstruction of hard and soft tissue remains a great clinical challenge with the major difficulty in highly orientated PDL regeneration. Using the unidirectional freeze-casting method and biomimetic mineralization technique, we construct a hierarchical bilayer scaffold with the aligned chitosan scaffold with ZIF-8 resembling PDL, and intrafibrillarly mineralized collagen resembling alveolar bone. The hierarchical bilayer scaffold exhibits different geomorphic clues and chemical microenvironments to realize a perfect simulation of the natural periodontal hierarchical architecture. The aligned scaffold with ZIF-8 could induce the fibrogenic differentiation of bone mesenchymal stromal cells (BMSCs), and the mineralized scaffold could induce osteogenic differentiation of BMSCs. The hierarchical bilayer scaffold could simulate periodontal complex tissue, exhibiting great promise for synchronized multi-tissue regeneration of periodontal tissue.

Expression of Kielin/chordin-like protein is regulated by BMP-2 in osteoblasts

Bone morphogenetic protein (BMP), an osteoinductive factor, is a cytokine that induces osteoblast differentiation and mineralization, and expected to be applicable for hard tissue reconstruction. Kielin/chordin-like protein (Kcp), a member of the family of cysteine-rich proteins, enhances BMP signaling. The present study found that expression of Kcp in osteoblasts was induced by BMP-2 in a concentration- and time-dependent manner. Up-regulation of Kcp by BMP-2 was inhibited by Dorsomorphin, a SMAD signaling inhibitor. The involvement of up-regulation of Kcp by BMP-2 in induction of osteoblast differentiation by BMP-2 was also examined, which showed that suppression of Kcp expression by si Kcp partially inhibited induction of osteoblast differentiation and mineralization by BMP-2. Together, these results suggest that Kcp induced by BMP-2 functions to provide positive feedback for promotion of osteoblastic differentiation and mineralization by BMP-2 in osteoblasts.

Bone-flap-harvest-related donor site morbidity in reconstructive jaw microsurgery: Retrospective analysis based on 220 patients over a ten-year period

Microsurgery is the gold standard for hard and soft tissue reconstruction in head and neck neoplasia and malformations. Fibular, iliac crest, and scapular free flaps are the main choices for reconstructive surgery of the jaws. Although widely described in the literature, no statistical comparison analysis of the donor site morbidity of these has been performed to our knowledge. Therefore, in this study, the medical records of patients who underwent microsurgical jaw reconstruction at the Maxillofacial Oncological Reconstructive Surgery Unit of Umberto I General Hospital in Rome between 2011 and 2021 were analysed retrospectively. Inclusion criteria were complete clinical and radiological records, microsurgical reconstruction harvesting one of the three flaps, and a minimum follow up of 12 months. Principal donor site complications were recorded and compared among the flaps. The data were analysed using IBM SPSS Statistics (28.0.1.1, IBM Corp). The study enrolled 220 patients: 103 with deep circumflex iliac artery (DCIA) flaps, 87 with fibular free flaps (FFF), and 30 with scapular bone flaps (SBF). The main DCIA donor site complications were dysaesthesia (13.6%), abdominal hernia (2.9%), dehiscence (1.9%), infection (1.9%), and anterior superior iliac spinal fracture (1.9%). Similarly, the main FFF complications were dehiscence (8%), skin graft necrosis (6.9%), infection (5.7%), and dysaesthesia (3.4%). Subcutaneous seroma occurred in 13.3% of SBF patients and dehiscence in 6.7%. Regional dysaesthesia occurred significantly (p < 0.05) more often in DCIA than FFF or SBF patients. Dehiscence was significantly (p < 0.05) more frequent in FFF than DCIA or SBF patients. All flaps were safe and associated with low donor site morbidity. The jaws should be reconstructed selecting the flap that best satisfies the reconstructive needs based on the patient’s clinical features.

Surface modification of biomedical titanium alloy for hard tissue repair and reconstruction

In biomedical applications, various materials are used, including metals and their alloys, polymers and ceramics. Among them, titanium (Ti) and titanium alloys are widely utilised in implant materials due to their excellent corrosion resistance and high mechanical strength. However, despite these advantages, titanium is biologically inert and does not integrate well with human cells. Therefore, surface modification of titanium implants plays a crucial role in determining the rate of osseointegration and the overall success of the implants. The primary objective of this review is to provide a detailed introduction to surface modification technologies for titanium alloy implants. The aim is to enhance the biological activity, wear resistance, corrosion resistance and antibacterial properties and reduce the release of ions from the implants. By modifying the surface of titanium implants, it is possible to create a more favourable environment for cell adhesion, proliferation and differentiation. Various techniques, such as physical methods (e.g. sandblasting, acid etching) and chemical methods (e.g. surface oxidation, plasma treatment) can be employed to modify the surface properties of titanium implants. These surface modification techniques can enhance the interaction between the implant and the surrounding biological environment, promoting osseointegration and improving the long-term stability of the implant. Additionally, surface modifications can help reduce the release of potentially harmful ions from the implant, minimise bacterial adhesion and improve the overall biocompatibility of the implant. In conclusion, surface modification of titanium alloy implants is a critical aspect of biomedical engineering. By improving the biocompatibility of titanium implants, these modifications contribute to the success and longevity of implants used in hard tissue repair and reconstruction.

A novel approach in orthodontics: Archwise distraction osteogenesis

Distraction osteogenesis can be described as a procedure that is based on the principles of physiologic remodeling and indirect fracture healing. In dentoalveolar level, conventional appliances may present some difficulties such as the need for multiple stages of DO to achieve a good occlusion due to distraction on a straight vector; incompetency to reduce the oronasal fistula in cleft patients; and the difficulty in achieving complete hard and soft tissue reconstruction, especially in cases with large alveolar defects.ArchWise Distraction Appliance (AWDA) have been developed to overcome these limitations and obtain a regenerated bone curvilinear in shape, similar to the original alveolar bone configuration. This article aims to introduce and explain the AWDA method in detail so that every clinician will be able to perform the treatment. The reader can observe the application of the procedure on a variety of cases including cleft lip and palate, trauma, and bone pathology. Possible complications and their solutions are also explained on actual cases.

Posterior open wound healing in immediate implant placement using reactive soft tissue versus absorbable collagen sponge: a retrospective cohort study

The soft and hard tissue healing of open wounds in immediate implant placement are yet to be explored. The aim of this study was to compare the clinical outcomes of open wound healing using reactive soft tissue (RST) and absorbable collagen sponge (ACS). Forty implants placed immediately in posterior sockets were included; autologous RST was used in 20 and ACS substitute was used in 20. Soft tissue healing was primarily assessed through a novel scoring system and the evaluation of gingival recession. The horizontal bone width (HBW) and interproximal marginal bone level (MBL) were measured on radiographs to observe the hard tissue healing. No significant difference in total soft tissue healing score was observed at 2 weeks postoperatively. Notably, the ACS group showed better tissue colour (P = 0.016) but worse fibrous repair (P = 0.043) scores than the RST group. Gingival recession levels were comparable in the two groups, both before tooth extraction and after placement of the restoration. Regarding hard tissue, HBW and MBL changes showed no intergroup differences. Within the limitations of this study, both RST and ACS seemed effective for open wound closure, achieving ideal soft and hard tissue healing in immediate implant placement.

Investigation of Porous Ceramic Structures Based on Hydroxyapatite and Wollastonite with Potential Applications in the Field of Tissue Engineering

Bioceramics are the most promising materials used for hard tissue reconstruction. In this study, wollastonite/hydroxyapatite (HAp/WS)-type composite ceramic structures were synthesized with the aim of reaching a material with improved properties for use in bone tissue regeneration. The scaffolds were synthesized using a foam replica method, starting from ceramic powders with different mass ratios. These were subsequently studied and compared to identify the ideal mass ratio in terms bioactive character, appropriate mechanical properties, but also microstructural influence. The results indicate that all of the samples showed a highly porous microstructure with interconnected pores and high mineralization after 21 days of immersion in SBF. The porous structures with 90% and 70% mass contents of hydroxyapatite presented a well-defined structure and the highest values of mechanical compressive strength. Biocompatibility evaluation showed that osteoblast-like cells are able to penetrate the inner volume of the structures, exhibiting a biocompatible behavior in terms of morphological features and viability following 7 days of incubation. All results show that the porous composite ceramics with 90% and 70% mass contents of hydroxyapatite are promising materials for bone tissue regeneration.

The Use of Three Iliac Crest Muscles for Head and Neck Soft Tissue Reconstruction: Technical Note.

This technical note describes a novel approach to reconstructing soft tissue in the head and neck region by diverting a flap originally intended for hard tissue reconstruction. We present a case of a 79-year-old woman with a large tumor on the left side of the mobile tongue, where the use of a radial free flap was challenging. Instead, we used the muscular portion of the iliac crest as a reliable alternative for reconstruction, offering a suitable oral lining. Using a muscular free flap, we achieved effective tongue reconstruction while minimizing donor site morbidity. The deep circumflex iliac artery muscular free flap demonstrates promising outcomes for large defects in the oral cavity and facial regions. However, a comprehensive case series with functional assessments and long-term follow-up is necessary to evaluate potential complications, such as hernia formation.

Chitosan as a biomaterial for the prevention and treatment of dental caries: antibacterial effect, biomimetic mineralization, and drug delivery.

Dental caries is a chronic, progressive disease caused by plaque, influenced by multiple factors and can damage the hard tissues of the teeth. In severe cases, it can also lead to the onset and development of other oral diseases, seriously affecting patients' quality of life. The creation of effective biomaterials for the prevention and treatment of dental caries has become one of the relentless goals of many researchers, with a focus on inhibiting the production of cariogenic plaque and retaining beneficial bacteria, guiding and promoting the reconstruction of dental hard tissues, and delaying the progression of existing caries. Chitosan is a natural cationic polymer extracted from the shells of crustaceans and shellfish. Since its discovery, chitosan has shown to have various biological functions such as antibacterial, biomimetic mineralization, drug delivery, etc., making it one of the most promising biopolymers for new caries prevention and materials of prostheses. Therefore, this article provides an overview of the anti-caries applications of chitosan, which mainly covers the basic research on the application of chitosan in caries prevention and treatment since 2010, with a focus on categorizing and summarizing the following characteristics of chitosan as a caries prevention material, including its antibacterial effect, biomimetic mineralization effect and delivery ability of caries prevention drugs and vaccines. It also explores the limitations of current research on chitosan as a caries prevention biomaterial and the difficulties that need to be focused on and overcome in the future to provide theoretical reference for the clinical implementation of chitosan as a caries prevention biomaterial.

A novel clinico-surgical algorithm for management of maxillofacial gunshot wound injuries

Ballistic injuries commonly called gunshot wound injuries (GSWI) can be catastrophic in the head and neck regions. The degree of destruction correlates with the range and type of the weapon and projectile speed. The intricacies of the facial anatomy makes the reconstructive phase a challenge. The dilemma lies in decision-making of immediate (single stage) or delayed (multiple stage) reconstruction of hard and soft tissues. In this article we highlight a novel clinico-surgical algorithm for managing gunshot wound injuries.

Impact exerted by scaffolds and biomaterials in periodontal bone and tissue regeneration engineering: new challenges and perspectives for disease treatment

The periodontium is an appropriate target for regeneration, as it cannot restore its function following disease. Significantly, the periodontium's limited regenerative capacity could be enhanced through the development of novel biomaterials and therapeutic approaches. Notably, the regenerative potential of the periodontium depends not only on its tissue-specific architecture and function but also on its ability to reconstruct distinct tissues and tissue interfaces, implying that the development of tissue engineering techniques can offer new perspectives for the organized reconstruction of soft and hard periodontal tissues. With their biocompatible structure and one-of-a-kind stimulus-responsive property, hydrogels have been utilized as an excellent drug delivery system for the treatment of several oral diseases. Furthermore, bioceramics and three-dimensional (3D) printed scaffolds are also appropriate scaffolding materials for the regeneration of periodontal tissue, bone, and cartilage. This work aims to examine and update material-based, biologically active cues and the deployment of breakthrough bio-fabrication technologies to regenerate the numerous tissues that comprise the periodontium for clinical and scientific applications.

Efficacy and volume stability of a customized allogeneic bone block for the reconstruction of advanced alveolar ridge deficiencies at the anterior maxillary region: a retrospective radiographic evaluation

ObjectivesThe aim of this retrospective case series was to evaluate the efficacy and volume stability of a customized allogeneic bone block (CABB) for the hard tissue reconstruction of severely atrophied anterior maxillary ridges.Materials and methodsHard tissue alterations between baseline (T1), 2-month follow-up (T2), and 6-month follow-up (T3) cone-beam computed tomography scans were evaluated with semi-automatic segmentation. Following automatic spatial alignment of the datasets, 3D subtraction analysis was performed. The volume stability of the inserted allogeneic bone block was determined on the basis of the ratio of the T3 and T2 hard tissue volumes.ResultsThe newly formed hard tissue volume at T2 averaged at of 0.75 cm3 ± 0.57 cm3, whereas at T3, an average of 0.52 cm3 ± 0.42 cm3 volumetric hard tissue gain could be detected. The T3/T2 ratio was found to be 67.83% ± 18.72% on average. The dice similarity coefficient between the T2 and T3 hard tissue models averaged at 0.73 ± 0.15.ConclusionsCancellous CABBs are a reliable option for the reconstruction of severely atrophied alveolar ridges. The resorption rates of these grafts are similar to those found in the literature; however, with precise manufacturing and proper intraoperative flap management, the resorption rates may be reduced.Clinical relevanceWith precise knowledge of the resorption patterns, the shape of blocks can be altered in the future to compensate for the volumetric loss.

Radiological and histochemical study of bone regeneration using the costal cartilage in rats.

The purpose of this study was to conduct basic research on the possibility of using cartilage tissue for hard-tissue reconstruction and to observe morphological changes in the transition of the cartilage to bone. A 4-mm diameter bone defect was created in the right mandibular angle of rats. Cartilage, autologous bone, and artificial bone were grafted into the defect. Computed tomography (CT) was performed to measure the increase in bone volume. Further histological evaluation of the grafted site was performed. At 12 weeks, CT show that bone formation in the costal cartilage group was comparable to that in the autogenous bone group. Histologically, in the artificial bone group, a clear boundary was observed between the existing bone and defect, whereas in the costal cartilage and autologous bone groups, laminar plate bone repair of the defect was observed. The findings in this study suggest that bone reconstruction achieved with cartilage grafting is almost equivalent to that with autogenous bone grafting and that bone reconstruction using cartilage is clinically feasible. In future, if regenerated cartilage is successfully applied clinically, bone reconstruction using regenerated cartilage may be feasible.

Marine sources as an unexplored bone tissue reconstruction material -A review

ABSTRACT Hard tissue reconstruction of bone has attracted the interest of clinical researchers to overcome the anomalous effect on general well-being. Bone is a supporting skeleton structure that also plays a pivotal role in the normal physiological functioning body. The introduction of bone tissue engineering has been instrumental in overcoming fragmental defined bone to diseases, accidents, or debilitating conditions. For this, various bone grafting materials are used to restore the patency. These various bone grafting options have shown promising results. But the search for ideal grating material continues. However, the available grafting resources may not ensure regeneration. And the grafts like autogenous grafts that provide the capacity, are often, acquired in limited quantity. Its incapacity to fill the defect has led to the requirement of alternative material. Marine sources have shown acceptable clinical outcomes and are rendered safe for use also have a rich calcium phosphate-containing scaffold, over which the new cells are formed owing to its porous and 3D grains. The wide range of available marine sources has been put into clinical trials. The collagen found in the Marine sources has shown comparatively better results than that of the available synthetic alternatives.

Gentamycin-loaded halloysite-based hydrogel nanocomposites for bone tissue regeneration: fabrication, evaluation of the antibacterial activity and cell response

Biocompatible hydrogels are promising approaches for bone repair and engineering. A novel therapeutic nanocomposite hydrogel was designed based on triblock copolymer poly e-caprolactone (PCL)-polyethylene glycol-PCL and natural gelatin (PCEC/GEL) and reinforced with halloysite nanotube (HNT). Gentamicin (GM) loaded HNT was immobilized in polymeric hydrogel matrix to fabricate scaffolds using the freeze-drying method. Scaffolds were characterized via Fourier transform infrared (FT-IR), x-ray powder diffraction, and scanning electron microscope (SEM) methods. The swelling ratio, density, porosity, degradation, and mechanical behavior were evaluated to investigate the effects of HNT on the physicochemical properties of the composite. Cell viability and cell attachment were investigated by microculture tetrazolium (MTT) assay and SEM. Cell proliferation was observed without any cytotoxicity effect on human dental pulp-derived mesenchymal stem cells (h-DPSCs). Alizarin red staining and real-time reverse transcription polymerase chain reaction (QRT-PCR) assay were carried out to monitor the osteoconductivity of scaffolds on h-DPSCs which were seeded drop wise onto the top of scaffolds. The quantification of the messenger RNA (mRNA) expression of osteogenic marker genes, bone morphogenetic protein 2, SPARK, bone gamma-carboxyglutamate protein and runt-related transcription factor 2 over a period of 21 d of cell seeding, demonstrated that cell-encapsulating PCEC/GEL/HNT-GM hydrogel scaffolds supported osteoblast differentiation of h-DPSCs into osteogenic cells through the up-regulation of related genes along with moderate effects on cell viability. Moreover, the antibiotics loading reduced bacterial growth while maintaining the osteogenic properties of the scaffold. Therefore, the bactericidal PCEC/GEL/HNT-GM hydrogel nanocomposite, with enhanced durability, maintenance the functionality of seeded cells in vitro that can be a remarkable dual-functional candidate for hard tissue reconstruction and customized bone implants fabrication via the direct incorporation of bactericidal drug to prevent infection.

Advanced biomaterials for periodontal tissue regeneration.

The periodontium is a suitable target for regenerative intervention, since it does not functionally restore itself after disease. Importantly, the limited regeneration capacity of the periodontium could be improved with the development of novel biomaterials and therapeutic strategies. Of note, the regenerative potential of the periodontium depends not only on its tissue-specific architecture and function, but also on its ability to reconstruct distinct tissues and tissue interfaces, suggesting that the advancement of tissue engineering approaches can ultimately offer new perspectives to promote the organized reconstruction of soft and hard periodontal tissues. Here, we discuss material-based, biologically active cues, and the application of innovative biofabrication technologies to regenerate the multiple tissues that comprise the periodontium.

Donor Site Morbidity and Quality of Life after Microvascular Head and Neck Reconstruction with a Chimeric, Thoracodorsal, Perforator-Scapular Flap Based on the Angular Artery (TDAP-Scap-aa Flap).

Extensive defects in the head and neck area often require the use of advanced free flap reconstruction techniques. In this study, the thoracodorsal perforator-scapular free flap technique based on the angular artery (TDAP-Scap-aa flap) was postoperatively evaluated regarding the quality of life and the donor site morbidity using the standardized SF-36 and DASH questionnaires (short form health 36 and disabilities of the arm, shoulder and hand scores). Over a five-year period (2016–2020), 20 selected cases (n = 20) requiring both soft and hard tissue reconstruction were assessed. On average, the harvested microvascular free flaps consisted of 7.8 ± 2.1 cm hard tissue and 86 ± 49.8 cm2 soft tissue components. At the donor site (subscapular region), only a mild morbidity was observed (DASH score: 21.74 ± 7.3 points). When comparing the patients’ postoperative quality of life to the established values of the healthy German norm population, the observed SF-36 values were within the upper third (>66%) of these established norm values in almost all quality-of-life subcategories. The mild donor site morbidity and the observed quality of life indicate only a small postoperative impairment when using the TDAP-Scap-aa free flap for the reconstruction of extensive maxillofacial defects.

Usage of Guided Bone Regeneration in the Case of Lateral Periodontal Cyst in the Maxilla with Buccal Cortical Expansion

A lateral periodontal cyst (LPC) is a rare finding. Patients diagnosed with LPC younger than 40 years of age are not that common. Mostly asymptomatic LPCs can be discovered on routine radiographs as an oval radiolucency between two mandibular premolar teeth roots and can vary in shape and size. Most cases are treated with enucleation, bone curettage, or a combination of both, greatly depending on the surgeon’s preference. Because most LPCs are quite small, lesions do not require any regenerative procedures. In the presented case, because of cortical expansion of the lesion and loss of vital bone bridge surrounding two adjacent maxillary teeth, a guided bone regenerative procedure (GBR) with xenograft bone substitute was used. Despite that small lesions can heal on their own, nowadays the approach of full-mouth therapy (FMT), including direct soft or hard tissue reconstruction in the oral cavity, seems to be a wise treatment. The presented paper presents and describes an unusual LPC case with cortical bone expansion in a very rare maxillary canine–premolar region.

OMENS+ Classification Correlations Analysis of Craniofacial Microsomia in China: The Relationship Between Macrostomia and Mandibular Hypoplasia.

Macrostomia is arare congenital craniofacial deformity that influences the appearance and function of patients. In most cases, it coexists with craniomaxillofacial deformities such as craniofacial microsomia (CFM). This study aimed to analyze the relationship between macrostomia and mandibular hypoplasia so as to facilitate the early detection and diagnosis of children with CFM. It included 236 patients diagnosed with CFM. All underwent facial expression analysis, multi-angle photography, computed tomography, and three-dimensional reconstruction of soft and hard tissues. The clinical classification was performed according to OMENS+. Spearman (rank) correlation analysis was used to analyze the relationship between the severity of macrostomia (C1 and C2) and the degree of mandibular involvement (M1, M2a, M2b, and M3), and the correlation among the components of OMENS+. Of the 80 cases of macrostomia (34%) reported, 72 cases (90%) were C1 and 8 (10%) were C2. The analysis of OMENS+ revealed significant correlations among OMENS+ components. Also, a high correlation was observed between macrostomia (C) and hypoplasia of the mandible (M) ( P = 0.002). Macrostomia was closely related to mandibular hypoplasia among children diagnosed with CFM. These results suggested that patients with macrostomia, who might also have craniofacial malformations caused by other first branchial arch anomalies, should be comprehensively physically examined for other syndromes.