Histological Analysis of Bone Repair in Mandibular Body Osteotomy Using Internal Fixation System in Three Different Gaps without Bone Graft in an Animal Model

In-house virtual surgical planning and guided mandibular reconstruction is less precise, but more economical and time-efficient than commercial procedures

BACKGROUND

To compare an in-house and a commercially available surgical planning solution for mandibular reconstruction in terms of postoperative reconstruction accuracy and economic benefit.

METHODS

Twenty-nine consecutive patients with advanced oral squamous cell carcinoma (OSCC) requiring segmental mandibular reconstruction were enrolled. Fifteen patients underwent in-house surgical planning and 14 patients underwent a commercially available planning solution. A morphometric comparison of preoperative and postoperative computed tomography (CT) data sets and a cost-benefit comparison were performed.

RESULTS

Volumes of planned and reconstructed bone segments differed significantly for both in-house planning (p = 0.0431) and commercial planning (p < 0.0001). Significant differences in osteotomy angles were demonstrated for in-house planning (p = 0.0391). Commercial planning was superior to in-house planning for total mandibular deviation (p = 0.0217), intersegmental space volumes (p = 0.0035), and lengths (p = 0.0007). No significant difference was found between the two planning solutions in terms of intersegmental ossification and the incidence of wound healing disorders. In-house planning took less time than commercial planning (p < 0.0001). Component manufacturing costs (p < 0.0001) and total cumulative costs (p < 0.0001) were significantly lower for in-house planning.

CONCLUSIONS

In-house surgical planning is less accurate but has a cost advantage and could be performed in less time.

Impact of Different Osteotomy Techniques on Bone Reserve in the Osteotomy Line in Sagittal Split Osteotomy: Experimental In Vitro Study in Caprine Mandible Model

OBJECTIVE

The objective of this study was to investigate of the effect of piezzo and conventional osteotomy techniques on bone reserve in the osteotomy line and comminuted fracture ratios that is able to compromise bone to bone contact negatively.

METHODS

Bilateral sagittal split ramus osteotomy was performed on 12 fresh male Thracian curly caprine mandible. In the first group (n: 12) osteotomies were performed with piezzo device. In the second group (n: 12) osteotomies were performed with micromotor and manual osteotomes. Operative time was measured. The number of comminuted fractures, length and width of the osteotomy, and the space between the osteotomy lines was evaluated from 3-dimensional computed tomography scans.

RESULTS

The mean value of procedure duration was 320.4±10.76 seconds for piezo osteotomy and 238.8±8.29 seconds for conventional micromotor ( P <0.0001). Number of comminuted fractures was 1.41±1.3 in piezoelectric group, 1.5±1.3 in conventional group and the difference was not statistically significant (p: 0,88). Osteotomy lengths and widths were 35.58±5.2, 2.196±1.9 and 36.23±5.05, 2.27±1.85 in the piezzo and conventional groups, respectively. (p lengths :0,75; p widths :0,92) The volume of the bony interface between the distal and proximal segments of the mandible after osteotomy was 166.3±184.2 mm 3 in the piezzo group and 163.5±129.3 mm 3 in the conventional group (p: 0,96).

CONCLUSION

The piezo surgery and the conventional osteotomy were found to be similar in terms of the gap between the distal and proximal mandible and the number of comminuted fractures. The duration to perform the conventional osteotomy was found to be shorter than the piezo surgery.

Temporal Pattern of micro-CT Angiography Vascular Parameters and VEGF mRNA Expression in Fracture Healing: a Radiograph and Molecular Comparison

Angiogenesis plays an important role in fracture healing with vascular endothelial growth factor (VEGF) as the main protein involved. Micro-computed tomography (CT) angiography may be used to analyze this revascularization with several parameters such as number of branches, total volume, and diameter. This systematic review is aimed to assess available studies on the temporal pattern of vascular imaging on micro-CT angiographs, especially in terms of the number of branches, total volume, and diameter as well as the temporal pattern of VEGF mRNA expression as the molecular comparison during bone fracture healing. This review was conducted according to the PRISMA guidelines. Electronic database searches were performed using PubMed, ProQuest, ScienceDirect, EBSCOhost, Taylor & Francis Online, and hand searching. The search strategy and keywords were adjusted to each database using the Boolean operators and other available limit functions to identify most relevant articles based on our inclusion and exclusion criteria. Screening and filtration were done in several stages by removing the duplicates and analyzing each title, abstract, and full-text in all included entries. Data extraction was done for syntheses to summarize the temporal pattern of each parameter. A total of 28 articles were eligible and met all criteria, 11 articles were synthesized in its angiograph's analysis, 16 articles were synthesized in its VEGF mRNA expression analysis, and 1 article had both parameters analyzed. The overall temporal pattern of both three micro-CT angiographic parameters and VEGF mRNA expression was in line qualitatively. The number of branches, total volume, and diameter of the blood vessels in micro-CT angiography showed an exponential rise at week 2 and decline at week 3 of fracture healing, with the VEGF mRNA expression concurrently showing a consistent pattern in the phase.

Hydrogel: A Potential Material for Bone Tissue Engineering Repairing the Segmental Mandibular Defect

Free flap surgery is currently the only successful method used by surgeons to reconstruct critical-sized defects of the jaw, and is commonly used in patients who have had bony lesions excised due to oral cancer, trauma, infection or necrosis. However, donor site morbidity remains a significant flaw of this strategy. Various biomaterials have been under investigation in search of a suitable alternative for segmental mandibular defect reconstruction. Hydrogels are group of biomaterials that have shown their potential in various tissue engineering applications, including bone regeneration, both through in vitro and in vivo pre-clinical animal trials. This review discusses different types of hydrogels, their fabrication techniques, 3D printing, their potential for bone regeneration, outcomes, and the limitations of various hydrogels in preclinical models for bone tissue engineering. This review also proposes a modified technique utilizing the potential of hydrogels combined with scaffolds and cells for efficient reconstruction of mandibular segmental defects.

Complicated Mandible Fracture Treatment with Xenogenic Bone Graft

The problem of filling bone cavities remains relevant in maxillofacial and oral surgery. There is a large selection of osteotropic materials, of various natures, for filling bone defects of different etiologies. The aim of our research was to improve the outcome of surgical treatment in a patient with a complicated mandibular fracture, with the use of a collagenic xenograft during osteosynthesis. In this article, we share our experience of the treatment of a patient with a complicated mandibular angle fracture, in combination with a follicular cyst. The obligate steps of treatment included stabilization of the bone fragments, decreasing the risk of fracture line malposition, using titan mini-plates, and shortening the time of bone regeneration, by filling the bone defect with osteotropic material. This approach allowed us to reduce the rehabilitation period and further prosthetic treatment after 4–5 months, without additional bone grafting manipulations. Thus, the use of collagen osteotropic materials, possessing osteoconductive properties, can improve the treatment of patients with mandibular fractures.

Biomineralization inspired engineering of nanobiomaterials promoting bone repair

A biomineralization processes is disclosed for engineering nanomaterials that support bone repair. The material was fabricated through a hot press process using electrospun poly(lactic acid) (PLA) matrix covered with hybrid composites of carbon nanotubes/graphene nanoribbons (GNR) and nanohydroxyapatite (nHA). Various scaffolds were devised [nHA/PLA, PLA/GNR, and PLA/nHA/GNR (1 and 3%)] and their structure and morphology characterized through Scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDS), and Atomic force microscope (AFM). Moreover, thorough biocompatibility and toxicity studies were performed. Here, in vivo studies on toxicity and cytotoxicity were conducted in aqueous dispersions of the biomaterials at concentrations of 30, 60, and 120 μg/mL using the Allium cepa test. Further toxicity studies were performed through hemolysis toxicity tests and genotoxicity tests evaluating the damage index and damage frequencies of DNAs through comet assays with samples of the animals' peripheral blood, marrow, and liver. Additionally, the regenerative activity of the scaffolds was analyzed by measuring the cortical tibiae of rats oophorectomized implanted with the biomaterials. Biochemical analyzes [glutamic pyruvic transaminase (GPT), glutamic oxaloacetic transaminase (GOT), urea, calcium, phosphorus, and alkaline phosphatase (ALP)] were also performed on blood samples. The results suggested a toxicity and cytotoxicity level for the GNR biomaterials at a concentration of 60 and 120 μg/mL, but non-toxicity and cytotoxicity for the 30 μg/mL concentration. The scaffolds obtained at a concentration of 0.3 mg/cm² were not toxic in the hemolysis test and demonstrated no cytotoxicity, genotoxicity, and mutagenicity in the blood, marrow, and liver analyzes of the animals, corroborating data from the biochemical markers of GPT, GOT, and urea. Tissue regeneration was performed in all groups and was more pronounced in the group containing the combination of nHA/GNR (3%), which is consistent with the data obtained for the calcium, serum phosphorus, and ALP concentrations. Consequently, the study indicates that the engineered nanobiomaterial is a promising candidate for bone tissue repair and regenerative applications. STATEMENT OF SIGNIFICANCE: The scientific contribution of this study is the engineering of a synthetic hybrid biomaterial, in nanoscale by a pressing and heating process. A biodegradable polymeric matrix was covered on both sides with a carbonated hybrid bioceramic/graphene nanoribbons (GNR), which has hydrophilic characteristics, with chemical elements stoichiometrically similar to bone mineral composition. The nanomaterial displayed promising bone regeneration ability, which is the first example to be used in an osteoporotic animal model. Moreover, detailed biocompatibility and toxicity studies were performed on the nanomaterials and their compositions, which is of great interest for the scientific community.

Distraction Osteogenesis Versus Orthognathic Surgery: Demystifying Differences in Concepts, Techniques and Outcomes

Introduction

The popularity and interest evoked by orthognathic surgery and distraction osteogenesis are undisputed in the field of oral and maxillofacial surgery. However, questions regarding the individual identities of either of them with clarity in their concepts, techniques and outcomes have remained unanswered. The aim of this review is to shed light on these questions.

Methods

This review is structured as a narrative review of thirty years of literature available in the specialities of orthognathic surgery and distraction osteogenesis.

Conclusion

The authors present a review of existing literature combined with contrasting experience gained over the years in providing an overview of the merits and demerits of the two surgical techniques which will aid the clinician in justifying the use of one technique over the other.