Evaluation of two 3D virtual computer reconstructions for comparison of cleft lip and palate to normal fetal microanatomy

Three Dimensional Reconstruction Models for Medical Modalities: A Comprehensive Investigation and Analysis

BACKGROUND

Image reconstruction is the mathematical process which converts the signals obtained from the scanning machine into an image. The reconstructed image plays a fundamental role in the planning of surgery and research in the medical field.

DISCUSSION

This paper introduces the first comprehensive survey of the literature about medical image reconstruction related to diseases, presenting a categorical study about the techniques and analyzing advantages and disadvantages of each technique. The images obtained by various imaging modalities like MRI, CT, CTA, Stereo radiography and Light field microscopy are included. A comparison on the basis of the reconstruction technique, Imaging Modality and Visualization, Disease, Metrics for 3D reconstruction accuracy, Dataset and Execution time, Evaluation of the technique is also performed.

CONCLUSION

The survey makes an assessment of the suitable reconstruction technique for an organ, draws general conclusions and discusses the future directions.

The New Frontier: A Review of Augmented Reality and Virtual Reality in Plastic Surgery

Mixed reality, a blending of the physical and digital worlds, can enhance the surgical experience, leading to greater precision, efficiency, and improved outcomes. Various studies across different disciplines have reported encouraging results using mixed reality technologies, such as augmented and virtual reality. To provide a better understanding of the applications and limitations of this technology in plastic surgery, we performed a systematic review of the literature in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The initial query of the National Center for Biotechnology Information database yielded 2544 results, and only 46 articles met our inclusion criteria. The majority of studies were in the field of craniofacial surgery, and uses of mixed reality included preoperative planning, intraoperative guides, and education of surgical trainees. A deeper understanding of mixed reality technologies may promote its integration and also help inspire new and creative applications in healthcare.

Comparison of 3D reconstructive technologies used for morphometric research and the translation of knowledge using a decision matrix

The use of three-dimensional (3D) models for education, pre-operative assessment, presurgical planning, and measurement have become more prevalent. With the increase in prevalence of 3D models there has also been an increase in 3D reconstructive software programs that are used to create these models. These software programs differ in reconstruction concepts, operating system requirements, user features, cost, and no one program has emerged as the standard. The purpose of this study was to conduct a systematic comparison of three widely available 3D reconstructive software programs, Amira(®), OsiriX, and Mimics(®) , with respect to the software's ability to be used in two broad themes: morphometric research and education to translate morphological knowledge. Cost, system requirements, and inherent features of each program were compared. A novel concept selection tool, a decision matrix, was used to objectify comparisons of usability of the interface, quality of the output, and efficiency of the tools. Findings indicate that Mimics was the best-suited program for construction of 3D anatomical models and morphometric analysis, but for creating a learning tool the results were less clear. OsiriX was very user-friendly; however, it had limited capabilities. Conversely, although Amira had endless potential and could create complex dynamic videos, it had a challenging interface. These results provide a resource for morphometric researchers and educators to assist the selection of appropriate reconstruction programs when starting a new 3D modeling project.

Severely Scarred Oronasal Cleft Defects in Edentulous Adults: Initial Data on the Long-Term Outcome of Telescoped Obturator Prostheses Supported by Zygomatic Implants

Objective

Prosthetic rehabilitation of edentulous patients presenting with severely scarred oronasal cleft defects. To document the outcome of telescopic obturator prostheses attached to zygomatic implants in edentulous cleft lip and palate patients.

Patients and Methods

Four edentulous patients suffering from the consequences of cleft lip and palate were selected from a cohort of 52 patients who had received zygomatic implants between 1998 and 2010. Oronasal communication had persisted and severe scars and chronic infection were noted in the cleft region. Bone grafting procedures were contraindicated due to high risk for dehiscence. For the functional support of telescopic prostheses, nine zygomatic implants and two standard dental implants had been placed.

Results

The zygomatic implants and the telescopic prostheses survived an average of 62 months (37 to 99 months) and were successful. Patients' satisfaction and oral function improved (on visual analog scale and oral health impact profile).

Conclusions

Telescopic obturator dentures supported by zygomatic implants represent a feasible option for the prosthetic rehabilitation of cleft lip and palate patients with severe impairments of the edentulous ridges including atrophy, scar tissue, ridge defects, oronasal communication, and chronic infection in the cleft region.

New Details on the Clefted Uvular Muscle: Analyzing Its Role at Histological Scale by Model-Based Deformation Analyses

Objective

As an initial step to a complex reconstruction model for virtual surgery, the present study was carried out to provide data on the prenatal cleft lip and palate uvular muscle in eight specimens.

Method

Serial sections of viscerocrania of 18 aborted embryos and fetuses were studied microscopically and segmented manually. Registration, three-dimensional reconstruction, and finite element analyses were conducted.

Results

Incompletely clefted uvulae showed anterior fusion and dorsal fission of the bilateral uvular muscle bodies. A complete cleft lip and palate specimen evidenced single bilateral uvular muscle bodies lying medially and orally below the cleft shelf, its central longitudinal fibers running beneath the oral-median mucosa. In incompletely clefted uvulae, 10% to 50% of circular peripheral fibers crossed the midline within the central third of the anterioposterior muscle, behind the levator loop. Of the fibers, 30% to 60% crossed to the ipsilateral palatopharyngeus muscle. Fibers inserted into the uvular basal membrane in a 60% nasal and 40% oral distribution at the middle third of the macroscopically clefted uvula. The macroscopic uvula itself consisted of loose connective tissue and salivary glands. Deformation analysis did disclose local stress, suggesting the uvular muscle contributes to velopharyngeal closure in normal anatomy and extends the cleft edges in cleft palate.

Conclusion

Cleft lip and palate reconstruction should reasonably use the uvular muscle to augment the velar midline bulk. Uvular muscle deformation calculation was successful, permitting functional insight on the basis of microanatomical specimens, so far a bigger complete velar model can be ventured.

Histology and function: analyzing the uvular muscle

OBJECTIVE

Virtual surgery and virtual patients necessitate quantitative data on the area of interest. The study was conducted to exactly describe the embryonic and fetal uvular muscle (MU), relevant for clinical as well as virtual surgery and virtual patient generation.

METHOD

Serially sectioned viscerocrania of 10 aborted embryos and fetuses underwent three-dimensional reconstruction to obtain detailed anatomic data and perform finite element analyses.

RESULTS

The MU was paired in 80% of cases, while 20% allowed no clear-cut distinction. The MU merged with the levator muscle beneath the palatal aponeurosis without a hard palate insertion. Superior longitudinal central fibers ran below the nasal mucosa, and few circular peripheral fibers crossed in the central third to the contralateral side. This was seen in 30% of the paired muscles and in all cases when no differentiation was possible; about 40% to 80% MU fibers crossed to the ipsilateral and contralateral palatopharyngeus muscle behind the levator loop. MU fibers inserted 60% nasal and 40% oral to the basal membrane at the middle third of the macroscopic uvula, made of loose connective tissue and salivary glands. The results of the finite element simulation of the uvula showed no distinct patterns or distributions of local stress.

CONCLUSIONS

Detailed anatomical study supported the concept of mediocranial MU repositioning during corrective surgery, although the impact is minor to the levator muscle's action. Future mathematical models describing effects of such a maneuver should integrate surrounding structures.

Stochastic modelling of biased cell migration and collagen matrix modification

Matrix dynamics plays a crucial role in several physiological and pathological processes. In this paper we develop a model framework, which describes the temporal fibre network evolution depending on the influence of migrating fibroblasts. The cells are regarded as discrete objects in the plane, whose velocities are determined by a generalised Langevin equation. For its solution we verify existence and uniqueness. The courses of the trajectories are affected by two external impulses, chemotaxis and contact guidance, respectively. The extracellular matrix is described by a continuous vector field which contains both information on density and orientation of the fibrous material. Modelling dynamic interaction between the discrete and the continuum variables is an essential point of this paper. In particular, the smoothing of the fluctuating paths plays a key role. Besides a detailed description of the formulated equations, we also supply the condensed pseudo code of the algorithm. We investigate several examples and present results both from artificial and real data.

Computer applications in facial plastic and reconstructive surgery

PURPOSE OF REVIEW

Computer applications in facial plastic and reconstructive surgery continue to evolve as image-guided surgical technology and software applications improve. Surgeons use these technological advances in order to simplify complex and historically challenging reconstructive issues. This paper reviews the recent literature pertaining to advances in computer-aided presurgical planning and intraoperative navigation.

RECENT FINDINGS

Although many different computer-aided surgical applications have previously been described, the recent literature focuses on orbital, midface and mandibular reconstruction. These studies highlight primary and secondary repair of complex maxillofacial trauma using computer software platforms for analysis of computed tomography data, presurgical planning, and intraoperative navigation.

SUMMARY

Computer-assisted facial reconstructive surgery is an area which continues to evolve. The current technology is best served in the repair of complex primary or secondary posttraumatic deformities. Congenital and oncologic reconstructive applications, however, are growing rapidly. While computer-aided surgery has historically been limited to tertiary care centers, easy access to intraoperative navigation systems and more user friendly software applications make these techniques more accessible to a greater number of surgeons.

Tissue-plastinated vs. celloidin-embedded large serial sections in video, analog and digital photographic on-screen reproduction: a preliminary step to exact virtual 3D modelling, exemplified in the normal midface and cleft-lip and palate

This study analyses tissue-plastinated vs. celloidin-embedded large serial sections, their inherent artefacts and aptitude with common video, analog or digital photographic on-screen reproduction. Subsequent virtual 3D microanatomical reconstruction will increase our knowledge of normal and pathological microanatomy for cleft-lip-palate (clp) reconstructive surgery. Of 18 fetal (six clp, 12 control) specimens, six randomized specimens (two clp) were BiodurE12-plastinated, sawn, burnished 90 microm thick transversely (five) or frontally (one), stained with azureII/methylene blue, and counterstained with basic-fuchsin (TP-AMF). Twelve remaining specimens (four clp) were celloidin-embedded, microtome-sectioned 75 microm thick transversely (ten) or frontally (two), and stained with haematoxylin-eosin (CE-HE). Computed-planimetry gauged artefacts, structure differentiation was compared with light microscopy on video, analog and digital photography. Total artefact was 0.9% (TP-AMF) and 2.1% (CE-HE); TP-AMF showed higher colour contrast, gamut and luminance, and CE-HE more red contrast, saturation and hue (P < 0.4). All (100%) structures of interest were light microscopically discerned, 83% on video, 76% on analog photography and 98% in digital photography. Computed image analysis assessed the greatest colour contrast, gamut, luminance and saturation on video; the most detailed, colour-balanced and sharpest images were obtained with digital photography (P < 0.02). TP-AMF retained spatial oversight, covered the entire area of interest and should be combined in different specimens with CE-HE which enables more refined muscle fibre reproduction. Digital photography is preferred for on-screen analysis.