203 research outputs found
The clinical application of recombinant human bone morphogenetic protein 7 for reconstruction of alveolar cleft; 10 years follow up
Purpose:
The purpose of this study was to report on a 10-year assessment after the application of recombinant human bone morphogenetic protein 7 (rhBMP-7) for the reconstruction of alveolar clefts.
Patients and Methods:
This study was conducted as a prospective phase II clinical trial on 9 unilateral and 2 bilateral alveolar clefts that received rhBMP-7 (Osigraft; Stryker Biotech, UK). The mean age of the patients at surgery was 10.4 years. At 6 months postoperatively, occlusal radiographs were taken to evaluate bone formation at the cleft site. Patients were followed within the routine cleft care pathway for 10 years to monitor the impact of bone morphogenetic protein 7 on orthodontic treatments and maxillary growth. Radiographs were taken according to the standard cleft care protocol.
Results:
The radiographic assessment of the unilateral cleft lip and palate cases suggested good bone formation with a Kindelan score of grade 1 or 2. The bilateral alveolar cleft cases had a score of grade 3 or 4, indicating failure or partial failure. The children with successful grafts underwent a routine orthodontic follow-up without incident. The maxillary growth appeared to be similar to that in cases grafted with autogenous bone. No long-term complications and no abnormal pattern of bone formation were detected.
Conclusions:
The study provides unique evidence on the long-term safety of rhBMP-7 when applied at the area of skeletal immaturity for the reconstruction of alveolar clefts in children
Bone Tissue Engineering in the Maxillofacial Region: The State-of-the-Art Practice and Future Prospects
Bone reconstruction in the maxillofacial region is a challenging task due to the exclusive anatomical complexity of the tissue, aesthetic requirements and functional demands. The gold standard method for maxillofacial reconstruction is based on autogenous bone grafting, which is associated with certain drawbacks. In this review, we describe recent bone tissue engineering approaches in reconstructive surgery of the maxillofacial region. Proper cell sources, scaffolds, signaling molecules as well as recent bioreactor technology are discussed.
The application of virtual reality and augmented reality in oral & maxillofacial surgery
Background:
Virtual reality is the science of creating a virtual environment for the assessment of various anatomical regions of the body for the diagnosis, planning and surgical training. Augmented reality is the superimposition of a 3D real environment specific to individual patient onto the surgical filed using semi-transparent glasses to augment the virtual scene.. The aim of this study is to provide an over view of the literature on the application of virtual and augmented reality in oral & maxillofacial surgery.
Methods:
We reviewed the literature and the existing database using Ovid MEDLINE search, Cochran Library and PubMed. All the studies in the English literature in the last 10 years, from 2009 to 2019 were included.
Results:
We identified 101 articles related the broad application of virtual reality in oral & maxillofacial surgery. These included the following: Eight systematic reviews, 4 expert reviews, 9 case reports, 5 retrospective surveys, 2 historical perspectives, 13 manuscripts on virtual education and training, 5 on haptic technology, 4 on augmented reality, 10 on image fusion, 41 articles on the prediction planning for orthognathic surgery and maxillofacial reconstruction. Dental implantology and orthognathic surgery are the most frequent applications of virtual reality and augmented reality. Virtual planning improved the accuracy of inserting dental implants using either a statistic guidance or dynamic navigation. In orthognathic surgery, prediction planning and intraoperative navigation are the main applications of virtual reality. Virtual reality has been utilised to improve the delivery of education and the quality of training in oral & maxillofacial surgery by creating a virtual environment of the surgical procedure. Haptic feedback provided an additional immersive reality to improve manual dexterity and improve clinical training.
Conclusion:
Virtual and augmented reality have contributed to the planning of maxillofacial procedures and surgery training. Few articles highlighted the importance of this technology in improving the quality of patients’ care. There are limited prospective randomized studies comparing the impact of virtual reality with the standard methods in delivering oral surgery education
Reproducibility of the dynamics of facial expressions in unilateral facial palsy
The aim of this study was to assess the reproducibility of non-verbal facial
expressions in unilateral facial paralysis using dynamic four-dimensional (4D)
imaging. The Di4D system was used to record five facial expressions of 20 adult
patients. The system captured 60 three-dimensional (3D) images per second; each
facial expression took 3–4 seconds which was recorded in real time. Thus a set of
180 3D facial images was generated for each expression. The procedure was
repeated after 30 min to assess the reproducibility of the expressions. A
mathematical facial mesh consisting of thousands of quasi-point ‘vertices’ was
conformed to the face in order to determine the morphological characteristics in a
comprehensive manner. The vertices were tracked throughout the sequence of the
180 images. Five key 3D facial frames from each sequence of images were
analyzed. Comparisons were made between the first and second capture of each
facial expression to assess the reproducibility of facial movements. Corresponding
images were aligned using partial Procrustes analysis, and the root mean square
distance between them was calculated and analyzed statistically (paired Student ttest,
P < 0.05). Facial expressions of lip purse, cheek puff, and raising of eyebrows
were reproducible. Facial expressions of maximum smile and forceful eye closure
were not reproducible. The limited coordination of various groups of facial muscles
contributed to the lack of reproducibility of these facial expressions. 4D imaging is a
useful clinical tool for the assessment of facial expressions
Comparison of the accuracy of voxel based registration and surface based registration for 3D assessment of surgical change following orthognathic surgery
Purpose:
Superimposition of two dimensional preoperative and postoperative facial images, including radiographs and photographs, are used to evaluate the surgical changes after orthognathic surgery. Recently, three dimensional (3D) imaging has been introduced allowing more accurate analysis of surgical changes. Surface based registration and voxel based registration are commonly used methods for 3D superimposition. The aim of this study was to evaluate and compare the accuracy of the two methods.<p></p>
Materials and methods:
Pre-operative and 6 months post-operative cone beam CT scan (CBCT) images of 31 patients were randomly selected from the orthognathic patient database at the Dental Hospital and School, University of Glasgow, UK. Voxel based registration was performed on the DICOM images (Digital Imaging Communication in Medicine) using Maxilim software (Medicim-Medical Image Computing, Belgium). Surface based registration was performed on the soft and hard tissue 3D models using VRMesh (VirtualGrid, Bellevue City, WA). The accuracy of the superimposition was evaluated by measuring the mean value of the absolute distance between the two 3D image surfaces. The results were statistically analysed using a paired Student t-test, ANOVA with post-hoc Duncan test, a one sample t-test and Pearson correlation coefficient test.<p></p>
Results:
The results showed no significant statistical difference between the two superimposition methods (p<0.05). However surface based registration showed a high variability in the mean distances between the corresponding surfaces compared to voxel based registration, especially for soft tissue. Within each method there was a significant difference between superimposition of the soft and hard tissue models.<p></p>
Conclusions:
There were no significant statistical differences between the two registration methods and it was unlikely to have any clinical significance. Voxel based registration was associated with less variability. Registering on the soft tissue in isolation from the hard tissue may not be a true reflection of the surgical change
Design and Development of Sur-Face: An interactive mobile app for educating patients regarding corrective surgery of facial deformities
Corrective surgery of face, also known as orthognathic surgery, is a complex procedure performed to correct the underlying facial deformities. In case of elective surgeries like these, patients need to make voluntary decisions whether or not undergoing the surgery. Hence, it is very important for them to under-stand the intricacy of the techniques and potential side effects of the surgery before they sign the consent form. Conventional methods of patient education us-ing leaflet-based instructions were found to be ineffective in providing them the required information.
Sur-Face, named after surgery of face is a healthcare app exploring a new dimension in patient education with the help of interactive 3D visualizations and serious gaming elements on a mobile platform. It demonstrates the surgical process and it’s after effects using high quality 3D animations. The aim of this study is to evaluate the efficacy of Sur-Face by comparing two methods of delivery of instructions: a mobile app with interactive 3D animations and an audio file containing only verbal instructions. To evaluate these methods, participant’s ability to understand and retain the instructions was analyzed using a questionnaire. The null hypothesis was that there would be no difference between the two methods of instructions. On analysis, participants of the ‘app’ group per-formed significantly better (p<0.0034) than the ‘voice’ group suggesting the role of interactive visualizations in improved understanding, intuitive knowledge transfer and communication. This paper describes the principles of design, development and potential advances of Sur-Face. Further it also explores the application of serious games in patient education and informed consent process
Innovation in prediction planning for anterior open bite correction
This study applies recent advances in 3D virtual imaging for application in the prediction planning of dentofacial
deformities. Stereo-photogrammetry has been used to create virtual and physical models, which are creatively combined in
planning the surgical correction of anterior open bite. The application of these novel methods is demonstrated through the surgical
correction of a case
Skeletal Changes and Stability Following Various Orthognathic Surgical Procedures for Correction of Mandibular Retrognathia
The improvement of diagnostic methods, treatment planning, orthodontic preparation of the patients and techniques of orthognathic surgery within the last decade have evolved to allow optimal correction of the facial disproportion resulting from structural abnormalities of the jaws. Nevertheless, relapse has been a major problem. Multiple factors are associated with or contribute to postsurgical instability and the resulting relapse. The results of recent investigations have shown that there is considerable relapse following surgical correction of mandibular retrognathia more than any other orthognathic surgical procedure. Therefore, the aim of this thesis was to evaluate skeletal stability following various orthognathic surgical procedures for correction of mandibular retrognathia. The following surgical procedures were assessed in this thesis; pedicled advancement genioplasty, sagittal split advancement osteotomy, bimaxillary osteotomy with internal rigid fixation and bimaxillary osteotomy with non-rigid fixation. Bimaxillary osteotomy cases had simultaneous maxillary impaction and sagittal split advancement osteotomy. The cases studied in this thesis were treated at either Canniesburn Hospital, West of Scotland Regional Plastic & Maxillofacial Unit, U.K. or at Michigan University Hospital, Ann Arbor, U.S.A. Lateral cephalometric radiographs were used to evaluate surgical and post-surgical changes. It has been shown in the literature that conventional cephalometry is inappropriate tool for morphometric analysis. The limitations of conventional cephalometric technique had induced stasis in the understanding of facial form and its changes. The recently introduced methods of morphometric analysis, Finite Element and Euclidean Distance Matrix analyses have seemed to overcome most of the problems associated with cephalometric analysis. The methods allow assessment of surgical changes independently to any plane of orientation or registration e.g. Sella-Nasion or Frankfort plane and do not require any cephalometric superimposition. These methods in addition to conventional cephalometric analysis were used to evaluate surgical stability in the different group of cases considered in the thesis. Advancement genioplasties were performed by horizontal osteotomy to provide chin prominence. Three inter-osseous wires were used for the stabilisation of the symphysis segments. This study has shown that the standard advancement genioplasty produced excellent results. Bone stability was generally very good irrespective of any other concomitant type of orthognathic surgery which was carried out. In the group of cases who had bimaxillary osteotomy with rigid internal fixation at Canniesburn Hospital, the maxillray osteotomy was more stable when compared to mandibular advancement. The mandibular postsurgical changes at 6 month follow up demonstrated clockwise rotation with posterior settling. This was mainly secondary to the posterior condylar displacement during surgery. No further changes were detected at one year follow up. The cases who had bimaxillary osteotomy at Michigan, with rigid internal fixation were more stable. At 6 months follow up, the mandible showed less posterior settling than Canniesburn cases. The condyles were in their presurgical anatomical position which may have enhanced mandibular stability. However, in comparison with a similar group of cases treated at Canniesburn, the magnitude of mandibular advancement was smaller, with less presurgical facial deformity. In cases who had bimaxillary osteotomy with non-rigid fixation, at Canniesbum Hospital, the maxilla was generally stable similar to other groups. However, mandibular stability was different in comparison with the rigid fixation group treated at the same centre
Impact of Internet Blockade Post Abrogation of Article 370 of Indian Constitution on Doctoral Students Pursuing Research in Kashmir
This paper aims to gauge the impact of internet blockade on the research students pursuing research in Kashmir post abrogation of article 370 of Indian constitution that granted political autonomy to erstwhile state of Jammu & Kashmir. In order to collect the data survey method was employed. A close-ended questionnaire was distributed among the select group. The data for the study was gathered from these questionnaires as per the objectives was analysed and interpreted to reach logical conclusions. The study revealed that the majority (76.92%) of researchers are of the view that the internet is a backbone for education and research. In the absence of the internet facility, the majority of research students (74.04%) were not able to pursue their research, while the research work of 61.54% was extremely hampered by 76-100%. It was also observed that the majority of researchers (78.85%) failed to complete their research in a set timeline, thereby hampering their academic growth. Majority of the research students (77.88%) failed to access the internet in e-kiosks setup by the administration due to the huge rush outside these centres while 42.31% migrated to mainland India avail internet facility. The study also explored the information seeking pattern of respondents before the internet blockade and it was observed that the majority of scholars (80.77%) consulted both print and online sources of information before the blockade. The researchers also claimed that resources of the library are not current and comprehensive.
The study can be a good starting point for the researchers to understand how people cope with limited information sources, in the absence of the internet. It will also be beneficial for the information scientists in making plans and strategies for tackling such e-crises in the future.
The study does not claim to be the final word in this matter as respondents were limited to only one university though university under study is the oldest and major source of imparting higher education in Kashmir valley
Experimental and numerical analyses of a thin cylindrical shell model
The analysis of thin shell structures is generally based on theoretical principles. The experimental tests on this type of structure are important for understanding the effect of loading and the geometrical shapes on its mechanical behavior. In this paper, an experimental test of a cylindrical shell under the effect of concentrated static loads is presented. A comparative numerical study is carried out by using two finite elements: the first element called ACM_RSBE5, recently formulated, and the second one, S4R, of ABAQUS code are used for the study of thin shells. The experimental results are compared with those obtained numerically. The results of both elements, ACM-RSBE5 and S4R, are in agreement with those obtained experimentally. The efficiency and the importance of the approach of the flat shell element for thin shell structures are confirmed
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