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3D mandible

Leonardo Koerich, André Weissheimer, Luciane Macedo de Menezes, Steven J Lindauer
OBJECTIVE: To evaluate the precision and reproducibility of a protocol to perform rapid voxel-based superimposition of the mandible in growing patients using CBCT. MATERIALS AND METHODS: The sample comprised two cone-beam computed tomography scans taken at least 1 year apart from each of 24 growing patients. Voxel-based superimposition was performed by two examiners independently. The internal part of the symphysis extending to the first molar was used as the reference...
October 21, 2016: Angle Orthodontist
Rujuta Katkar, Douglas D Steffy, Marcel Noujeim, S Thomas Deahl, Hassem Geha
OBJECTIVES: The aim of this study was to evaluate the effect of milliamperage, number of basis images, and export slice thickness on contrast-to-noise ratio (CNR) and confidence in detecting mandibular canal. STUDY DESIGN: Two phantoms were used. Each phantom consisted of a dry mandible with an epoxy resin bone tissue substitute block and a water-equivalent block, submerged in water. Each mandible was scanned with a Morita 3D Accuitomo cone beam computed tomography (CBCT) machine (Morita, Kyoto, Japan)...
November 2016: Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology
Michael Wolf, U Schulte, K Küpper, C Bourauel, L Keilig, S N Papageorgiou, C Dirk, C Kirschneck, N Daratsianos, A Jäger
OBJECTIVES: While permanent retention is today the method of choice to stabilize orthodontic treatment outcomes, recent studies have increasingly reported posttreatment changes in tooth position during permanent retention. We conducted this study to analyze changes in the anterior mandible, whether the changes follow an underlying movement pattern, and, aiming for a preventive strategy, whether any risk factors could be identified comparing findings with the pretreatment situations. METHODS: We included 30 patients who had worn fixed Twistflex retainers (UK 3-3) extending from canine to canine in the mandible...
October 19, 2016: Journal of Orofacial Orthopedics, Fortschritte der Kieferorthopädie
Naotaka Ishiguro, Yasuo Inoshima, Motoki Sasaki
A Canis skull, right half of the mandible and part of the left half of the mandible were subjected to three-dimensional (3D) computed tomography (CT) observation and mitochondrial DNA (mtDNA) analysis in order to determine whether the specimens belonged to the extinct Japanese wolf, Canis lupus hodophilax (Temminck, 1839). Osteometric analysis of the skull and right half of the mandible revealed that the material (JW275) was indeed typical of the Japanese wolf. Sequence analysis of a 600-bp mtDNA region revealed that the JW275 belonged to haplotype Group B, which is characterized by an 8-bp deletion in the mtDNA control region...
October 15, 2016: Journal of Veterinary Medical Science
Willem L J Weijs, Casper Coppen, Ruud Schreurs, Rinaldo D Vreeken, Arico C Verhulst, Matthias A W Merkx, Stefaan J Bergé, Thomas J J Maal
OBJECTIVE: Since reconstruction of composite defects in the head and neck region is a challenging and demanding problem for head and neck surgeons, surgical aids have been sought for decades. The purpose of this study was to evaluate the accuracy of prefabricated surgical resection templates used in mandibular segmental resections in comparison to the virtual surgical plan. MATERIALS AND METHODS: A prospective study was performed in 11 consecutive patients, with a primary T4 oral squamous cell carcinoma or osteoradionecrosis of the mandible...
September 9, 2016: Journal of Cranio-maxillo-facial Surgery
Satoshi Horita, Tsutomu Sugiura, Kazuhiko Yamamoto, Kazuhiro Murakami, Yuichiro Imai, Tadaaki Kirita
PURPOSE: The purpose of this study was to investigate the biomechanical behavior of immediately loaded implants in an edentulous mandible according to the "All-on-Four" concept. METHODS: A 3D-finite element model of an edentulous mandible was constructed. Four implants were placed between the bilateral mental foramen according to "All-on-Four" concept. A framework made of titanium or acrylic resin between the bilateral first molars was modeled. Immediate loading and a delayed loading protocol were simulated...
September 5, 2016: Journal of Prosthodontic Research
Han Lin, Ping Zhu, Qiuping Lin, Xiaoqiong Huang, Yue Xu, Xiaoping Yang
PURPOSE: Facial asymmetry often persists even after mandibular deviation corrected by the bilateral sagittal split ramus osteotomy (BSSRO) operation, since the reference facial sagittal plane for the asymmetry analysis is usually set up before the mandibular menton (Me) point correction. Our aim is to develop a predictive and quantitative method to assess the true asymmetry of the mandible after a midline correction performed by a virtual BSSRO, and to verify its availability by evaluation of the post-surgical improvement...
2016: PloS One
Wei Liu, Suhui Qu, Mujun Wang, Wanju Xu, Guangying Zhang, Chengqi Zhang
OBJECTIVE: The aim of this study was to observe whether there existed significant differences in the maxilla-nasion-mandible angle (MNM) between the first- and second-trimester of pregnancy, and to observe its predictive values for trisomy 18. METHODS: Two experienced ultrasonologists used 2D and 3D ultrasound imaging techniques to obtain the facial sagittal sections of fetuses in the first-trimester of pregnancy (crown-rump length 45-84 mm), respectively, so as to measure MNM...
2016: SpringerPlus
Héctor E Ramírez-Chaves, Vera Weisbecker, Stephen Wroe, Matthew J Phillips
BACKGROUND: The minute, finely-tuned ear ossicles of mammals arose through a spectacular evolutionary transformation from their origins as a load-bearing jaw joint. This involved detachment from the postdentary trough of the mandible, and final separation from the dentary through resorption of Meckel's cartilage. Recent parsimony analyses of modern and fossil mammals imply up to seven independent postdentary trough losses or even reversals, which is unexpected given the complexity of these transformations...
2016: Frontiers in Zoology
Muhanad M Hatamleh, Gurprit Bhamrah, Francine Ryba, Gavin Mack, Chrisopher Huppa
This patient report describes simultaneous bimaxillary orthognathic surgery and mandibular reconstruction by means of three-dimensional (3D) planning, 3D printed biocompatible surgical wafers, and 3D selective-laser sintered titanium implant. A 26-year-old male patient presented with a left mandibular defect secondary to trauma. The whole body of the mandible on the left hand side was deficient with a narrow connection with the remaining left condyle. He had undergone orthodontic treatment for 18 months and was ready to undergo bimaxillary orthognathic surgery...
October 2016: Journal of Craniofacial Surgery
E Sterpin
In typical treatment planning of 3D IMRT, the incident energy fluence is optimized to achieve a homogeneous dose distribution to the PTV. The PTV includes the tumour but also healthy tissues that may have a different dose response for the same incident energy fluence, like bony structures included in the PTV (mandibles in head and neck tumours or femoral bones in sarcomas). Dose to medium optimization compensates for this heterogeneous response, leading to a non-homogeneous energy fluence in the PTV and a non-homogeneous dose in the CTV in the presence of geometric errors...
September 2016: Physica Medica: PM
Adrienn Dobai, Tamás Vizkelety, Zsolt Markella, Adrienne Rosta, Ágnes Kucserá, József Barabás
OBJECT: 3D cephalometry is often the only way to set up accurate diagnosis and treatment plan in the field of reconstructive surgery. In these cases complement exposures are needed beyond common cephalograms with higher accuracy than conventional Cone-Beam CT. Consequently the aim of our study was to perform a complex 3D cephalometry. As the first step of this approach, was the 3D adaptation of DiPaolo's Quadrilateral technique, and to determine norms of references in lower face by means of CBCT...
June 2016: Fogorvosi Szemle
Toshiaki Numajiri, Hiroko Nakamura, Yoshihiro Sowa, Kenichi Nishino
BACKGROUND: Surgical cutting guides are used in mandibular reconstruction involving osteotomy of the mandible and fibula. Cutting guides produced using computer-aided design (CAD) and computer-aided manufacturing (CAM) technologies have been reported recently. These guides aim to increase the benefits to patients by improving the accuracy, shortening the operating time, and correcting occlusion. However, the availability of these advanced technologies is limited in some regions of the world...
July 2016: Plastic and Reconstructive Surgery. Global Open
Manon Galland, Denis P Van Gerven, Noreen Von Cramon-Taubadel, Ron Pinhasi
The transition to agriculture was a key event in human history. The extent to which this transition is associated with biological changes in different world regions remains debated. Cultural and osteological records in Lower Nubia throughout the Holocene have been interpreted as a result of in situ differentiation or alternatively as migratory events and possible admixture with surrounding populations. Here we investigated the patterns of craniofacial and mandibular variation from Mesolithic hunting-gathering to late farming, a period spanning 11,000 years...
2016: Scientific Reports
Elisângela Perez de Freitas, Sheila Canevese Rahal, Antonio Carlos Shimano, Jorge Vicente Lopes da Silva, Pedro Yoshito Noritomi, Alexander Oliveira El-Warrak, Alessandra Melchert
With regard to the canine mandible, a mistaken concept of application is to assume that systemic plate-bone resistance is provided by the implant so that biomechanical position could be ignored. Because the alveolar border of the mandible is a tensile zone, the plate would ideally be positioned near this area while avoiding important structures. The aim of this study was to develop 2 bridging plates for the treatment of a segmental bone defect of the canine mandible using monocortical screws to avoid damage to the tooth roots and remaining neurovascular structures...
March 2016: Journal of Veterinary Dentistry
Nelson Fernandes, Jacobus van den Heever, Kobus Hoek, Gerrie Booysen
Myoepithelial carcinomas are rare malignant tumors arising from salivary glands. They most commonly involve the parotid and minor salivary glands but may also occur in the submandibular glands. These tumors can become extensive, causing bony expansion and destruction. A 31-year-old man with a large swelling on the left side of the face is presented. Histologic examination of an incisional biopsy confirmed a diagnosis of a myoepithelial carcinoma arising from the left submandibular salivary gland. After tumor resection, the patient's mandible was reconstructed with a customized mandibular framework produced by means of 3-dimensional (3D) laser sintering...
July 13, 2016: Journal of Prosthetic Dentistry
Stefan Raith, Sebastian Wolff, Timm Steiner, Ali Modabber, Michael Weber, Frank Hölzle, Horst Fischer
PURPOSE: The reconstruction of large continuity defects of the mandible is a challenging task, especially when the shape of the missing part is not known prior to operation. Today, the surgical planning is based mainly on visual judgment and the individual skills and experience of the surgeons. The objective of the current study was to develop a computer-based method that is capable of proposing a reconstruction shape from a known residual mandible part. METHODS: The volumetric data derived from 60 CT scans of mandibles were used as the basis for the novel numerical procedure...
July 8, 2016: International Journal of Computer Assisted Radiology and Surgery
Rachna Rath, Sheetal Kaur, Shadab Ali Baig, Punyashlok Pati, Sonalisa Sahoo
Neurofibromatosis type 1 (NF1) is a clinically and genetically distinct disease involving both neuroectodermal and mesenchymal derivatives. Orofacial manifestations in NF1 have been documented before but occurrence of multifocal intraosseous (IO) and extraosseous (EO) neurofibromas is rare. The present case highlights the importance of imaging findings in the diagnosis and management of multifocal jaw, infratemporal, and parotid neurofibromas with muscular hypoplasia in an eight-year-old girl with NF1. Apart from orthopantomograms (OPG), three-dimensional computed tomography (3D CT) and cross-sectional reformations were valuable in delineating the extent of the lytic lesion and identifying additional bony deformities of the mandible...
2016: Case Reports in Radiology
Hasan Ayberk Altug, Abdullah Tugrul Coskun, Kvanc Kamburoglu, Tamer Zerener, Orhan Gulen, Metin Sencimen, Aydn Ozkan
OBJECTIVES: The aim of the present study was to retrospectively make a volumetric evaluation of symphysis sites of patients by the use of cone beam computed tomography (CBCT). METHODS: This retrospective study evaluated dentate symphysis region of the mandibles in CBCT scans taken for different reasons in 90 patients (45 women and 45 men). Three-dimensional (3D) data were obtained using a CBCT device Kodak 9000 3D CMOS sensor with optical fiber. CBCT images were then transferred as digital imaging and communications in medicine files and imported into a volumetric-rendering software 3D DOCTOR (Able Software Corp...
June 28, 2016: Implant Dentistry
H Liu, W Li, Y S Liu, Y S Zhou
OBJECTIVES: This study aims to evaluate if micro-CT can work as a method for the 3D assessment and analysis of cancellous bone by comparing micro-CT with undecalcified histological sections in OVX rats. METHODS: The mandible and tibia of sham, ovariectomised (OVX) and zoledronate-injected ovariectomised (OVX-ZOL) rats were assessed morphometrically. Specimens were scanned by micro-CT. Undecalcified histological sections were manufactured from the specimen scanned by micro-CT and stained with haematoxylin and eosin...
June 2016: Bone & Joint Research
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