The Experts below are selected from a list of 204 Experts worldwide ranked by ideXlab platform
Mark M Urata - One of the best experts on this subject based on the ideXlab platform.
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current status of surgical planning for orthognathic surgery traditional methods versus 3d surgical planning
Plastic and reconstructive surgery. Global open, 2015Co-Authors: Jeffrey A Hammoudeh, Lori K Howell, Shadi Boutros, Michelle A Scott, Mark M UrataAbstract:Orthognathic surgery requires precise evaluation of complex dentofacial deformities of the craniofacial skeleton. The success of the surgical plan is not only dependent on the accuracy of the skeletal and dental diagnosis of the deformity but also is unequivocally dependent on presurgical prediction of the proposed jaw movements. It is the task of the surgeon to first define the original position of the dentofacial skeleton and then to estimate the desired final position and finally to develop a 3-dimensional representation of the movements necessary to accomplish the intended goal.1 Traditionally, this has involved detailed preoperative clinical examination, standard facial photography, cephalometric radiographs with tracings, dental impressions, and articulator-mounted models. The end goal of all of these steps is to develop a representative blueprint of the current relationship of the maxilla/mandible and the associated dentofacial skeletal dysplasia. That relationship then is used to facilitate model surgery to determine the feasibility of the proposed jaw movements and to subsequently directly fabricate surgical guide splints which are critical for the accurate intraoperative positioning of the maxilla and/or mandible. This traditional analytical model surgery integrates the quantitative data and allows transfer of the anticipated 3D movements directly to the patient to facilitate the intraoperative position of the maxilla and/or the mandible.2 This technique has stood the test of time and has allowed for accurate and reproducible surgical correction of the dentofacial skeleton. This technique, however, requires an extensive process of analytical and radiographic analysis, dental model fabrication and splint preparation which require an extensive time commitment, and a firm grasp of dental materials and has the potential to have inaccuracies amplified during the algorithmic process. The advent of virtual surgical planning (VSP) has recently called into question the efficacy and accuracy of traditional analytical model surgery. Maxillofacial surgery as a discipline was not an organized specialty until the latter half of the 20th century requiring particularly trained surgeons with masterful knowledge of both anatomy and surgical techniques to accomplish successful bony reconstruction.3 Orthognathic surgery in patients with dentofacial abnormalities is an original field within maxillofacial surgery. Modern practices within this particular field have undergone evolutionary development and refinement since its derivation by the first teachers in the early 1900s. The historic development traces its roots back to 1906 when the first surgery to correct at prognathic mandible was performed on a Washington University medical student by plastic surgery pioneer Vilray Blair.4 This ushered in decades of jaw surgery eclipsed by Obwegeser’s introduction of the sagittal split osteotomy in the 1950s and Bell’s research on the vascularization of the upper jaw leading to the safe downfracture of the maxilla in a LeFort I osteotomy.5 In present-day orthognathic surgery, the spectrum of surgical intervention ranges from simple single-jaw and double-jaw surgery to complex cleft craniomaxillofacial orthognathic surgery. Albeit more than 20 years ago and likely an underestimation, a survey performed in 1990 estimated that the current number of people in the United States benefiting from orthognathic surgery was more than 1.5 million.6 With the likelihood of craniomaxillofacial surgeons facing a growing number of patients requiring orthognathic surgery, it is imperative for the clinician to have a sound understanding of dental facial proportions, development of the craniofacial skeleton, orthodontic preparation for surgical intervention requiring a collaborative team approach with the patient’s orthodontist, and the ability to plan and execute single- and double-jaw surgery. Throughout the last 100 years, the field has undergone significant refinement and development as it relates to technique modification, innovation as it relates to rigid fixation, and recent technological advancements in presurgical planning and splint fabrication. Any discussion surrounding orthognathic surgery in present-day medicine now includes the argument of traditional model surgery versus VSP. In review of recent literature, one can identify a number of articles defining and celebrating the use of computer-aided design/computer-aided manufacturing (CAD/CAM) in development of surgical planning for the treatment of complex craniomaxillofacial deformities.3,7–12 In addition to the gaining popularity of VSP within orthognathic surgery, a series of recent investigations performed at multiple institutions have confirmed the accuracy of this technique.10 As VSP is proving both highly accurate and efficient, the future of traditional model surgery comes into question. It is our objective in this article to (1) define both traditional model surgery and VSP and (2) determine the accuracy and relevance of the 2 methods.
Ye Lin - One of the best experts on this subject based on the ideXlab platform.
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internal midface distraction in correction of severe maxillary hypoplasia secondary to cleft lip and palate
Plastic and Reconstructive Surgery, 2005Co-Authors: Xiaoxia Wang, Xing Wang, Cheng Liang, Ye LinAbstract:Background: Maxillary hypoplasia is a familiar deformity in patients with cleft lip and palate. A large amount of maxilla advancement is often needed to correct the severe deformity, but local soft-tissue scars around the maxilla restrict maxilla advancement and increase the relapse rate. By gradually lengthening both the bones and the soft tissues, midface distraction can greatly increase postoperative stability and lower the relapse rate. Methods: Ten patients with severe maxillary hypoplasia secondary to cleft lip and palate were treated with midface distraction using three kinds of internal distraction devices. Among them, six patients received an alveolar bone graft from the iliac crest during their Le Fort I osteotomy, and a bilateral sagittal split ramus osteotomy was performed simultaneously to push back the mandible in five patients with Prognathia, to obtain a normal soft-tissue profile and occlusal relationship. Results: Successful maxillary advancements ranging from 5 to 15 mm were measured from preoperative and postoperative cephalograms. Patients' sella-nasion-point A angles increased from an average of 71.25 degrees preoperatively to 79.05 degrees postoperatively. Orthodontic therapies were adopted before and/or after midface distraction. After the consolidation period, dense new bone was found to have formed in the distraction gap. During the follow-up period, the position of the maxilla and the final occlusal relationship were stable and acceptable, and no obvious relapses were seen. Conclusion: Midface distraction is an ideal choice for the correction of severe maxillary hypoplasia secondary to cleft lip and/or palate.
J Barrera - One of the best experts on this subject based on the ideXlab platform.
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maxillary distraction aesthetic and functional benefits in cleft lip palate and prognathic patients during mixed dentition
Plastic and Reconstructive Surgery, 1998Co-Authors: Fernando Molina, Ortiz F Monasterio, M De La Paz Aguilar, J BarreraAbstract:In the last few years, distraction techniques have been used successfully to correct the hypoplastic human mandible. In patients with cleft lip and palate, normal growth of the maxilla may be impaired by early cleft repair, and many of them do not respond to orthodontic procedures alone. Maxillary distraction is an alternative technique to correct maxillary hypoplasia during mixed dentition. In the last 3 years, the procedure was performed in 38 patients aged between 6 and 12 years; 18 patients had unilateral cleft lip and palate, 9 patients had bilateral cleft lip and palate, 7 patients had unilateral cleft palate, 2 patients had prognathism, and 2 patients had nasomaxillary dysplasia. Photographs, posteroanterior and lateral cephalograms, and dental models are obtained preoperatively (as well as an orthopantomogram) to locate the tooth buds. A subperiosteal dissection is performed exposing the anterior and lateral aspects of the maxilla, and an incomplete horizontal osteotomy is done above the tooth buds. Using a facial mask and an intraoral fixed appliance system as an anchorage, we initiate on the fifth postoperative day the application of distraction forces. Maxillary advancement between 4 and 12 mm is achieved during 3 to 4 weeks, and a satisfactory class I or II molar relationship is also obtained. A combination of forward and downward distraction forces can be used to achieve simultaneous advancement and elongation of the hypoplasic maxilla. The aesthetic results are excellent, and the nasolabial angle is increased, including a more anterior projection of the upper lip. Nasal breathing is improved as well as the air flow and patency of the nasal airway. Velopharyngeal function remains unchanged after the procedure. The follow-up in this series varied from 6 months to 3 years. No relapses have been observed.
Etsuhide Yamamoto - One of the best experts on this subject based on the ideXlab platform.
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change in condylar long axis and skeletal stability following sagittal split ramus osteotomy and intraoral vertical ramus osteotomy for mandibular Prognathia
Journal of Oral and Maxillofacial Surgery, 2005Co-Authors: Koichiro Ueki, Kohei Marukawa, Mayumi Shimada, Kiyomasa Nakagawa, Etsuhide YamamotoAbstract:Purpose The purpose of this study was to compare postsurgical time course changes in condylar long axis and skeletal stability between sagittal split ramus osteotomy (SSRO) and intraoral vertical ramus osteotomy (IVRO). Patients and Methods Of 40 Japanese patients with a diagnosed jaw deformity, 20 underwent IVRO without internal fixation and 20 underwent SSRO with rigid internal fixation. The time course change in condylar long axis and skeletal stability were assessed with axial, frontal, and lateral cephalograms. Results A significant difference in the rotation direction of condylar long axis was seen in horizontal axial cephalogram images (P Conclusion The present results suggest a significant difference between SSRO and IVRO in time course changes in proximal segment including condyle and distal segment.
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the assessment of blood loss in orthognathic surgery for Prognathia
Journal of Oral and Maxillofacial Surgery, 2005Co-Authors: Koichiro Ueki, Kohei Marukawa, Mayumi Shimada, Kiyomasa Nakagawa, Etsuhide YamamotoAbstract:Purpose It is difficult to predict the need for blood transfusion during orthognathic surgery. The purpose of this study was to evaluate differences between patients who underwent different orthognathic procedures, and to assess the need for transfusion in orthognathic surgery. Subjects and methods We examined 62 prognathic patients who underwent orthognathic surgery in our hospital. The subjects were divided into 4 groups according to procedure. Pre- and postoperative values of blood parameters were evaluated statistically. Results A greater amount of blood was lost in the double-jaw surgeries than in the single-jaw surgeries. There was a significant difference between sagittal split ramus osteotomy (SSRO) combined with Le Fort I osteotomy and intraoral vertical ramus osteotomy (IVRO) ( P P P Conclusion The present results indicate that there is little risk of marked bleeding in routine procedures, and that IVRO causes minimal bleeding. Transfusion was not necessary in IVRO or SSRO with or without Le Fort I osteotomy.
Jeffrey A Hammoudeh - One of the best experts on this subject based on the ideXlab platform.
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current status of surgical planning for orthognathic surgery traditional methods versus 3d surgical planning
Plastic and reconstructive surgery. Global open, 2015Co-Authors: Jeffrey A Hammoudeh, Lori K Howell, Shadi Boutros, Michelle A Scott, Mark M UrataAbstract:Orthognathic surgery requires precise evaluation of complex dentofacial deformities of the craniofacial skeleton. The success of the surgical plan is not only dependent on the accuracy of the skeletal and dental diagnosis of the deformity but also is unequivocally dependent on presurgical prediction of the proposed jaw movements. It is the task of the surgeon to first define the original position of the dentofacial skeleton and then to estimate the desired final position and finally to develop a 3-dimensional representation of the movements necessary to accomplish the intended goal.1 Traditionally, this has involved detailed preoperative clinical examination, standard facial photography, cephalometric radiographs with tracings, dental impressions, and articulator-mounted models. The end goal of all of these steps is to develop a representative blueprint of the current relationship of the maxilla/mandible and the associated dentofacial skeletal dysplasia. That relationship then is used to facilitate model surgery to determine the feasibility of the proposed jaw movements and to subsequently directly fabricate surgical guide splints which are critical for the accurate intraoperative positioning of the maxilla and/or mandible. This traditional analytical model surgery integrates the quantitative data and allows transfer of the anticipated 3D movements directly to the patient to facilitate the intraoperative position of the maxilla and/or the mandible.2 This technique has stood the test of time and has allowed for accurate and reproducible surgical correction of the dentofacial skeleton. This technique, however, requires an extensive process of analytical and radiographic analysis, dental model fabrication and splint preparation which require an extensive time commitment, and a firm grasp of dental materials and has the potential to have inaccuracies amplified during the algorithmic process. The advent of virtual surgical planning (VSP) has recently called into question the efficacy and accuracy of traditional analytical model surgery. Maxillofacial surgery as a discipline was not an organized specialty until the latter half of the 20th century requiring particularly trained surgeons with masterful knowledge of both anatomy and surgical techniques to accomplish successful bony reconstruction.3 Orthognathic surgery in patients with dentofacial abnormalities is an original field within maxillofacial surgery. Modern practices within this particular field have undergone evolutionary development and refinement since its derivation by the first teachers in the early 1900s. The historic development traces its roots back to 1906 when the first surgery to correct at prognathic mandible was performed on a Washington University medical student by plastic surgery pioneer Vilray Blair.4 This ushered in decades of jaw surgery eclipsed by Obwegeser’s introduction of the sagittal split osteotomy in the 1950s and Bell’s research on the vascularization of the upper jaw leading to the safe downfracture of the maxilla in a LeFort I osteotomy.5 In present-day orthognathic surgery, the spectrum of surgical intervention ranges from simple single-jaw and double-jaw surgery to complex cleft craniomaxillofacial orthognathic surgery. Albeit more than 20 years ago and likely an underestimation, a survey performed in 1990 estimated that the current number of people in the United States benefiting from orthognathic surgery was more than 1.5 million.6 With the likelihood of craniomaxillofacial surgeons facing a growing number of patients requiring orthognathic surgery, it is imperative for the clinician to have a sound understanding of dental facial proportions, development of the craniofacial skeleton, orthodontic preparation for surgical intervention requiring a collaborative team approach with the patient’s orthodontist, and the ability to plan and execute single- and double-jaw surgery. Throughout the last 100 years, the field has undergone significant refinement and development as it relates to technique modification, innovation as it relates to rigid fixation, and recent technological advancements in presurgical planning and splint fabrication. Any discussion surrounding orthognathic surgery in present-day medicine now includes the argument of traditional model surgery versus VSP. In review of recent literature, one can identify a number of articles defining and celebrating the use of computer-aided design/computer-aided manufacturing (CAD/CAM) in development of surgical planning for the treatment of complex craniomaxillofacial deformities.3,7–12 In addition to the gaining popularity of VSP within orthognathic surgery, a series of recent investigations performed at multiple institutions have confirmed the accuracy of this technique.10 As VSP is proving both highly accurate and efficient, the future of traditional model surgery comes into question. It is our objective in this article to (1) define both traditional model surgery and VSP and (2) determine the accuracy and relevance of the 2 methods.