Application of cranial bone grafts for reconstruction of maxillofacial deformities

Use of Injectable Platelet-Rich Fibrin Accompanied by Bone Graft in Socket Endurance: A Radiographic and Histological Study

Background Ridge preservation became a crucial dental health issue and strategy to keep away from ridge defacement after post-tooth loss. The recent scientific evolution of platelet-rich fibrin (PRF) comprises a parenteral formulation of PRF. The combined allograft for socket preservation gives benefits. In this study, bone allografts, demineralized freeze-dried bone allografts (DFDBA) and freeze-dried bone allografts (FDBA) are used in a 30:70 ratio alone or in combination with injectable PRF (I-PRF) for socket preservation. Methods This study is a radiographic and histological examination conducted on 60 participants aged between 19-65 years. Participating patients agreed voluntarily that they would not bear any fixed prosthesis for the next nine months and plan for implanted teeth placement, including multi-rooted mandibular molars denticles. Both groups received atraumatic extraction; then, the socket was preserved with bone allograft alone in the control group and bone allograft mixed with I-PRF, forming sticky bone, in the experimental group. Clinical, radiological, and histological assessments were taken at the inception stage, three months, six months, and nine months. A multivariate regression model and a generalized estimating equation (GEE) model were used to analyse the effects of these changes on outcomes. Results In all the parameters, the test group indicated a good amount of bone growth with increasing intervals of time for bone height radiographically with statistically significant difference present (p<0.05) and histologically after nine months when socket site grafted with bone graft in combination with I-PRF. Conclusion This study's results demonstrated that I-PRF possesses the potential to regenerate and heal in the tooth-extracted socket. This study further recommends the implementation of I-PRF in safeguarding and conserving the raised rim of the tooth. Future research should take place on the osteogenic capability of I-PRF in more comprehensive ridge accession surgical procedures and additional expanding and improving capacities in periodontal reconstruction.

[Relationship between prognosis and different surgical treatments of zygomatic defects: A retrospective study]

OBJECTIVE

To evaluate the effect and summarize the characteristics of different treatment methods in repairing zygomatic defect.

METHODS

A total of 37 patients with zygomatic defect were reviewed in the Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology from August 2012 to August 2019. According to the anatomical scope of defect, the zygomatic defects were divided into four categories: Class 0, the defect did not involve changes in zygomatic structure or continuity, only deficiency in thickness or projection; Class Ⅰ, defect was located in the zygomatic body or involved only one process; Class Ⅱ, a single defect involved two processes; Class Ⅲa, referred to a single defect involving three processes and above; Class Ⅲb, referred to zygomatic defects associated with large maxillary defects. The etiology, defect time, defect size and characteristics of zygomatic defects, the repair and reconstruction methods, and postoperative complications were collected and analyzed. Postoperative computed tomography (CT) data were collected to evaluate the outcome of zygomatic protrusion. Chromatographic analysis was used to assess the postoperative stability.

RESULTS

Among the causes of defects, 25 cases (67.57%) were caused by trauma, and 11 cases (29.73%) were of surgical defects following tumor resection. We performed autologous bone grafts in 19 cases, 6 cases underwent vascularized tissue flap, 5 cases underwent external implants alone, and 7 cases underwent vascularized tissue flap combined with external implants. After the recovery of the affected side, the average difference of the zygomatic projection between the navigation group and the non-navigation group was 0.45 mm (0.20-2.50 mm) and 1.60 mm (0.10-2.90 mm), with a significant difference (P=0.045). Two patients repaired with titanium mesh combined with anterolateral thigh flap had obvious deformation or fracture of titanium mesh; 2 patients with customized casting prosthesis had infection after surgery and fetched out the prosthesis finally.

CONCLUSION

Autologous free grafts or alloplastic materials may be used in cases without significant structural changes. Pedicle skull flap or vascularized bone tissue flap is recommended for zygomatic bone defects with bone pillar destruction, chronic inflammation, oral and nasal communication or significant soft tissue insufficiency. Titanium mesh can be used to repair a large defect of zygomatic bone, and it is suggested to combine with vascularized bone flap transplantation.

Standard and Customized Alloplastic Facial Implants Refining Orthognathic Surgery: Outcome Evaluation

PURPOSE

Conventional orthognathic osteotomies provide appropriate functional outcomes but might be unable to correct midface deficiency, achieve a satisfactory outcome in asymmetrical cases, or allow sufficient chin advancement. We evaluated the outcome of both standard and customized facial high-density porous polyethylene implants used to refine the cosmetic outcome of orthognathic surgery.

PATIENTS AND METHODS

We implemented a retrospective study. The sample was composed of all patients who underwent facial alloplastic augmentation between June 2011 and October 2018 in our department. The complication rate was recorded after a mean follow-up period of 41 months postoperatively, and patient satisfaction was assessed through a qualitative evaluation based on an 11-item questionnaire.

RESULTS

The sample was composed of 24 implants placed in 14 patients: 13 mandibular angle implants, among which 4 were customized; 8 malar implants; and 3 chin implants. No physical complications such as hematoma, infection, migration, or hypoesthesia were observed. Two implants had to be removed because of early unsatisfactory esthetic outcomes. Of 14 patients, 11 answered our questionnaire. Eighty-two percent strongly agreed that the overall outcome was satisfactory.

CONCLUSIONS

The results of this study confirm the low physical complication rate described in the literature, and the esthetic complication rate remains lower than the rates observed in previous reports. A high satisfaction rate was found among patients. The lowest mean satisfaction score was noted for appropriate implant symmetry (3.5), whereas the highest mean satisfaction score (3.8) was achieved when using customized implants. If standard high-density porous polyethylene implants appear to be relevant adjuncts to orthognathic surgery, customized implants seem to achieve higher satisfaction, although their prohibitive cost should be considered.

Efficacy of orthodontic and orthognathic treatment for oral and maxillofacial deformities

BACKGROUND

This study aims to assess the efficacy and safety of orthodontic and orthognathic treatment (OOT) for patients with oral and maxillofacial deformities (OMDF) systematically.

METHODS

This study will comprehensively search Cochrane Library, PubMed, EMBASE, Scopus, Web of Science, PsycINFO, Index to Nursing and Allied Health Literature, Allied and Complementary Medicine Database, Chinese Biomedical Literature Database, and China National Knowledge Infrastructure from their inceptions to the July 1, 2019. Grey literature will be explored via searching dissertations, Google scholar and conference abstracts. Two team members will independently perform all citations, data extraction, and methodological quality. We will also utilize RevMan 5.3 Software for statistical analysis.

RESULTS

This study will provide high quality evidence of OOT for OMDF. The primary outcomes consist of number of patients cured; proportion of patients healed; and time to complete healing within trial period. Secondary outcomes include quality of life (often assessed as any relevant scales, such as 36-Item Short Form Survey), costs, and complications.

CONCLUSION

This study will provide evidence for judging whether OOT is effective treatment for OMDF.

SYSTEMATIC REVIEW REGISTRATION

CRD42019144610.

Ameloblastic Fibroma of the Mandible Reconstructed with Autogenous Parietal Bone: Report of a Case and Literature Review

Ameloblastic fibroma (AF) is a rare, slow-growing benign neoplasm, comprised of tissues of odontogenic origin. It constitutes 2% of odontogenic tumours, occurring at any age, but has a predilection to present in the first two decades of life. AF principally affects the posterior mandible. It is characterized by epithelial islands and cords immersed in ectomesenchyme that mimics the dental papilla and enamel organ but without actual hard tissue formation. Herein, we describe the case of a 6-year-old Caucasian male who presented to the Oral and Maxillofacial Department at Alder Hey Children's Hospital, Liverpool, UK, with a painless expansile mass in the left mandible which was diagnosed as a benign ameloblastic fibroma and subsequently enucleated and reconstructed with a parietal calvarial bone graft. A brief literature review and the issues surrounding diagnosis are discussed.

Reconstruction of Liposarcoma Resection Defect With a Made-to-Measure Polyethylene Prosthesis Using Three-Dimensional Digital Technology

BACKGROUND

Liposarcoma is considered one of the most frequently occurring tumors of the soft tissues, representing 17% to 30% of all mesenchymal cell tumors. It is less common in the head and neck representing <10% of tumors in this region. The reconstruction of defects derived from resection of these tumors presents a surgical challenge. New three-dimensional digital technologies allow more exact surgery, cause less morbidity, and achieve adequate aesthetic outcomes.

OBJECTIVE

The aim of this article was to describe the complex reconstruction of a defect caused by the resection of a liposarcoma in the temporal region.

METHODS

Three-dimensional technology allowed patient planning and a reconstruction that was as exact as possible. A made-to-measure polymethyl methacrylate prosthesis was used to correct the defect in the zygomatic arch. The temporal fossa was covered with a standard porous polyethylene prosthesis.

CONCLUSIONS

Satisfactory esthetic and functional results were achieved using three-dimensional digital technology for treatment planning and to fabricate a made-to-measure polyethylene prosthesis and surgical guide.

Interferon-γ enhances the efficacy of autogenous bone grafts by inhibiting postoperative bone resorption in rat calvarial defects

PURPOSE

Interferon (IFN)-γ is a major cytokine produced by immune cells that plays diverse roles in modulating both the immune system and bone metabolism, but its role in autogenous bone grafting remains unknown. Here, we present that local IFN-γ administration improved the efficacy of autogenous bone graft treatment in an experimental rat model.

METHODS

An autogenous bone graft model was prepared with critically sized rat calvariae defects. Four weeks (w) after bone graft implantation, rats were treated locally with IFN-γ or were not treated. The effect of IFN-γ on bone formation was evaluated for up to 8w with micro-computed tomography, quantitative histomorphometry, and Von Kossa staining. Osteoclastogenesis was assessed by tartrate-resistant acid phosphatase staining. Immunohistochemistry staining or quantitative polymerase chain reactions were used to estimate the expression of osteoclast differentiation factor and inflammatory cytokines including tumor necrosis factor (TNF)-α, a well-known stimulant of osteoclastogenesis and an inhibitor of osteoblast activity, in defects.

RESULTS

Newly formed bone gradually replaced the autogenous bone grafts within 4w, although severe bone resorption with osteoclastogenesis and TNF-α expression occurred after 6w in the absence of IFN-γ administration. IFN-γ administration markedly attenuated bone loss, osteoclastogenesis, and TNF-α expression, while it enhanced bone formation at 8w.

CONCLUSION

Local IFN-γ administration promoted bone formation in autogenous bone grafts possibly via regulating osteoclastogenesis and TNF-α expression. The data provide insights into the potential roles of IFN-γ in autogenous bone grafting.

Computed Tomography and Optical Imaging of Osteogenesis-angiogenesis Coupling to Assess Integration of Cranial Bone Autografts and Allografts

A major parameter determining the success of a bone-grafting procedure is vascularization of the area surrounding the graft. We hypothesized that implantation of a bone autograft would induce greater bone regeneration by abundant blood vessel formation. To investigate the effect of the graft on neovascularization at the defect site, we developed a micro-computed tomography (µCT) approach to characterize newly forming blood vessels, which involves systemic perfusion of the animal with a polymerizing contrast agent. This method enables detailed vascular analysis of an organ in its entirety. Additionally, blood perfusion was assessed using fluorescence imaging (FLI) of a blood-borne fluorescent agent. Bone formation was quantified by FLI using a hydroxyapatite-targeted probe and µCT analysis. Stem cell recruitment was monitored by bioluminescence imaging (BLI) of transgenic mice that express luciferase under the control of the osteocalcin promoter. Here we describe and demonstrate preparation of the allograft, calvarial defect surgery, µCT scanning protocols for the neovascularization study and bone formation analysis (including the in vivo perfusion of contrast agent), and the protocol for data analysis. The 3D high-resolution analysis of vasculature demonstrated significantly greater angiogenesis in animals with implanted autografts, especially with respect to arteriole formation. Accordingly, blood perfusion was significantly higher in the autograft group by the 7(th) day after surgery. We observed superior bone mineralization and measured greater bone formation in animals that received autografts. Autograft implantation induced resident stem cell recruitment to the graft-host bone suture, where the cells differentiated into bone-forming cells between the 7(th) and 10(th) postoperative day. This finding means that enhanced bone formation may be attributed to the augmented vascular feeding that characterizes autograft implantation. The methods depicted may serve as an optimal tool to study bone regeneration in terms of tightly bounded bone formation and neovascularization.