Bony Segments Research Articles

Treatment of Dentofacial Deformities Secondary to Osteochondroma of the Mandibular Condyle Using Virtual Surgical Planning and 3-Dimensional Printed Surgical Templates

One-stage treatment for condylar osteochondroma and secondary facial deformities by resection and reconstruction of the mandibular condyle, orthognathic surgery, and mandibular contouring has been reported recently. This study investigated the clinical feasibility of treating osteochondroma of the mandibular condyle and secondary dento-maxillofacial deformities by virtual surgical planning and 3-dimensional (3D) printed surgical templates. A composite skull model with accurate dentition was obtained with data from spiral computed tomography (CT) and surface scanning of the dental arch. Virtual surgical simulation was performed using Dolphin Imaging 11.7 Premium and Mimics software after a comprehensive 3D diagnosis and surgery planning. Surgical templates were fabricated by 3D printing using data from virtual surgical simulation for guidance of excision of the mandibular condyle with osteochondroma, reconstruction of the mandibular condyle, mandibular contouring, and reconstruction of a normal occlusion. Le Fort I osteotomy of the upper jaw and genioplasty were performed when indicated. The linear difference between virtually simulated and postoperative skull models was evaluated. All surgeries were successfully simulated using virtual surgical planning, and the guiding templates were successfully applied for all patients. Successful reconstruction of condylar function, normal occlusion, and symmetry of the facial profile was achieved. Postoperative CT scans and quantitative analysis showed that virtual surgical plans provided acceptable accuracy in the operating room. The linear difference of the incisors and first molars was no more than 1.4 mm, and the greatest difference was found for the menton landmark, which was up to 2.4 mm. Results from this study suggested that virtual surgical planning and guiding templates facilitated accurate diagnosis, treatment planning, accurate osteotomy, repositioning of bony segments, and contouring of the mandibular border in the treatment of condylar osteochondroma and secondary facial asymmetry.

Presurgical nasoalveolar molding for cleft lip and palate: the application of digitally designed molds.

The authors present a novel nasoalveolar molding protocol by prefabricating sets of nasoalveolar molding appliances using three-dimensional technology. Prospectively, 17 infants with unilateral complete cleft lip and palate underwent the authors' protocol before primary cheiloplasty. An initial nasoalveolar molding appliance was created based on the patient's first and only in-person maxillary cast, produced from a traditional intraoral dental impression. Thereafter, each patient's molding course was simulated using computer software that aimed to narrow the alveolar gap by 1 mm each week by rotating the greater alveolar segment. A maxillary cast of each predicted molding stage was created using three-dimensional printing. Subsequent appliances were constructed in advance, based on the series of computer-generated casts. Each patient had a total three clinic visits spaced 1 month apart. Anthropometric measurements and bony segment volumes were recorded before and after treatment. Alveolar cleft widths narrowed significantly (p < 0.01), soft-tissue volume of each segment expanded (p < 0.01), and the arc of the alveolus became more contiguous across the cleft (p < 0.01). One patient required a new appliance at the second visit because of bleeding and discomfort. Eleven patients had mucosal irritation and two experienced minor mucosal ulceration. Three-dimensional technology can precisely represent anatomic structures in pediatric clefts. Results from the authors' algorithm are equivalent to those of traditional nasoalveolar molding therapies; however, the number of required clinic visits and appliance adjustments decreased. As three-dimensional technology costs decrease, multidisciplinary teams may design customized nasoalveolar molding treatment with improved efficiency and less burden to medical staff, patients, and families. Therapeutic, IV.

Zygomatic Complex Change After Reduction Malarplasty and Its Geometric Model: A Retrospective Clinical Study

To achieve optimal outcomes in reduction malarplasty, the amount of removed zygomatic bone must be planned accurately. This study aimed to analyze the associations between the width of bony resection and changes in zygomatic bony parameters, to propose a geometric model to guide surgical planning, and to objectively evaluate the surgical outcomes of reduction malarplasty based on computed tomographic (CT) images. This was a retrospective observational study of patients who underwent reduction malarplasty. Digitized CT images were used to evaluate the bony parameters of the zygomatic complex. A geometric model was proposed to guide surgical planning for malar reduction. The primary predictor variable was the width of the bony segment to be resected. The primary outcome variables were changes in malar prominence and attractiveness. Other variables included gender, age, and other bony parameters of the zygoma. Bivariate correlation analysis and multiple linear regression analyses were performed between predictor and outcome variables. Presurgical and postsurgical data were analyzed with paired-samples t test to evaluate surgical outcomes. Differences were considered statistically significant at a P value less than .05. Fifty-one patients who underwent reduction malarplasty with an L-shaped osteotomy from 2012 through 2014 were included in the study. Statistical analysis showed a significant decrease in malar prominence and increased attractiveness between presurgical and postsurgical images (P < .001). The width of bony resection was statistically associated with all outcome variables after adjusting for potential confounders. Reduction malarplasty with a modified L-shaped osteotomy resulted in a notable decrease in malar prominence and a statistical decrease in the zygomatic arch width. The amount of bone that must be removed from the zygoma to achieve a desired reduction can be calculated with geometric equations. The proposed methodology could assist surgical design and improve surgical accuracy.

The Post‐surgical Stability of the Nitinol Shape Memory Staple in Orthopaedics

The Nitinol shape memory compression staple has been used in surgeries &amp; its unique mechanical properties may strongly influence a fracture's post‐operative stability. This study examines the biomechanical behavior of Nitinol compression staples (Nts) assessing its efficacy over standard orthopaedic staples in bone fixation techniques in transverse scaphoid &amp; humeral fractures. Bones were dissected, disarticulated &amp; cleaned from 8 embalmed donor bodies. Sectioning of scaphoid &amp; humeral samples (to mimic transverse fractures) was undertaken with subsequent realignment with embedded stapling. A set of four humeral mid‐shaft sectioning was performed yielding two pairs of bony segments, which were fixated with standard staple and the Nts with current applied to the staple before strength of staple tests were assessed. Results showed carpal bones too fragile fracturing before accurately measuring the staples' effectiveness under the Instron 8874 Servohydraulic machine loads of compression failure test. Nts used on the humeral sample, however, showed greater resistance to load of failure than standard staples lending support that compression staples in Orthopaedic surgeries may yield more favorable surgical outcomes. Our findings show promising potential but further studies on Nts are required to strengthen their favorability among methods of fixating small bone fractures.

The Hapln1a‐ECM Influences Sema3d Signal Transduction During Fin Regeneration

The zebrafish regenerating fin is an important model system to understand skeletal morphogenesis, the process of how the skeleton achieves its appropriate size and shape. The fin skeleton is comprised of multiple bony fin rays where each fin ray is comprised of bony segments separated by joints. Our research on the short fin (sof) mutant revealed that the gap junction protein Connexin43 (Cx43) coordinates bone growth and skeletal patterning. Downstream mediators of Cx43 function include the secreted signaling molecule Semaphorin3d (Sema3d) and the link protein Hyaluronan and Proteoglycan Link Protein 1a (Hapln1a). Hapln1a stabilizes the hyaluronan (HA) and proteoglycan network in the extracellular matrix (ECM). We suggest that components of the Hapln1a ECM, including HA and the proteoglycan Aggrecan (Acan), influence the ability of Sema3d to interact with its cell surface receptors to mediate cell proliferation and joint formation. Indeed, knockdown of Hapln1a destabilizes HA, Acan, and strikingly, Sema3d. Thus, HA and/or Acan may be required for the presentation of Sema3d to its receptors. Moreover, we find that hapln1a and sema3d interact genetically, suggesting that the Hapln1a and Sema3d gene products function in common pathways to coordinate skeletal growth and patterning. These findings provide the first evidence that the Hapln1a-ECM regulates Sema3d signal transduction in vivo. Moreover, these findings reveal tangible connections between the Hapln1a-ECM, signal transduction, and skeletal morphogenesis. This research was supported by the NSF.

Shaping the fibula without fumbling: the SynpliciTi customised guide-plate

Systems designed to reposition bone in free flap operations optimise morphological results and reduce ischaemic time. We describe SynpliciTi (OBL, Châtillon, France), a new approach to reconstruction of the jaw using fibular flaps, which is based on customised drilling guides and titanium plates obtained by direct manufacturing after reversed planning, in a fully digital process. We used Surgicase 5.0 (Materialise, Leuven, Belgium) to make a 3-dimensional operating plan of the final positions of the bony segments and osteotomy planes. Three or more non-aligned titanium screws were placed in ideal positions on each segment of the virtually reconstructed jaw according to accessibility, and quantity and quality of bone. We also planned dental implants where required and designed 1.5 mm thick plates based on these screw positions.

Clinical feasibility and efficacy of using virtual surgical planning in bimaxillary orthognathic surgery without intermediate splint.

Computer-aided jaw surgery has been extensively studied recently. The purpose of this study was to determine the clinical feasibility of performing bimaxillary orthognathic surgery without intermediate splint using virtual surgical planning and rapid prototyping technology. Twelve consecutive patients who underwent bimaxillary orthognathic surgery were included. The presented treatment plan here mainly consists of 6 procedures: (1) data acquisition from computed tomography (CT) of the skull and laser scanning of the dentition; (2) reconstruction and fusion of a virtual skull model with accurate dentition; (3) virtual surgery simulation including osteotomy and movement and repositioning of bony segments; (4) final surgical splint fabrication (no intermediate splint) using computer-aided design and rapid prototyping technology; (5) transfer of the virtual surgical plan to the operating room; and (6) comparison of the actual surgical outcome to the virtual surgical plan. All procedures of the treatment were successfully performed on all 12 patients. In quantification of differences between simulated and actual postoperative outcome, we found that the mean linear difference was less than 1.8 mm, and the mean angular difference was less than 2.5 degrees in all evaluated patients. Results from this study suggested that it was feasible to perform bimaxillary orthognathic surgery without intermediate splint. Virtual surgical planning and the guiding splints facilitated the diagnosis, treatment planning, accurate osteotomy, and bony segments repositioning in orthognathic surgery.

Bioabsorbable osteofixation for orthognathic surgery.

Orthognathic surgery requires stable fixation for uneventful healing of osteotomized bony segments and optimal remodeling. Titanium plates and screws have been accepted as the gold standard for rigid fixation in orthognathic surgery. Although titanium osteofixation is the most widely used approach, the use of bioabsorbable devices has been increasing recently. Biodegradation of bioabsorbable devices eliminates the need for a second operation to remove metal plates and screws. However, long-term stability and relapse frequency in bioabsorbable osteofixation are still insufficiently studied, especially in cases of segmental movements of great magnitude or segmental movements to a position where bony resistance exists. This paper reviews the background, techniques, and complications of bioabsorbable osteofixation and compares bioabsorbable and titanium osteofixation in orthognathic surgery in terms of skeletal stability.

Retrospective lumbar fusion outcomes measured by ODI sub-functions of 100 consecutive procedures.

Low back pain has been quite prevalent in the general population. Chronic low back pain can be defined as back pain lasting for more than 12 weeks. For chronic symptoms, fusion surgeries are the most common surgeries to alleviate the pain. Visual Analog Scale (VAS) is a measurement for subjective characteristics or attitudes that can be difficult to be directly measured. Respondents specify their level of agreement to a statement by indicating a position along a continuous line between two end points. The purpose of this study is to investigate patient-reported pain using our own modified ODI with sub-functions. This allowed the study to show how patient outcomes differ with and without co-morbidity as well as functional outcomes after spinal fusion for degenerative disk disease (DDD) with the consistency of using one device and all procedures performed by the same surgeon. One hundred patients with DDD were treated with spinal fusion using one device. All procedures were performed by the same surgeon over a 3-year period. Patients were evaluated with discography and MRI preoperatively. Diagnosis of DDD was made when imaging showed bony segment erosion with decreased disc space >50%. Fifty-six patients participated in the initial questionnaire and their data were tabulated and statistically analyzed. Twenty male patients aged 49-85 (median: 67, mean: 66), and thirty-six female patients aged 30-84 (median: 67, mean 64) responded to the questionnaire. There were no differences in pain total by gender, fusion level, single/multiple fusions, degenerative versus deformity condition, type of graft, and lumber area (all p values ≥ 0.15). Five-year pain measurements used by the VAS questionnaire as well as pain and functional outcomes measured by the ODI after lumbar fusion were superior to the results at 2 years (p = 0.025). Improvement was seen in all of the ODI sub-scores after 5 years, however, only physical function and social function reached statistical significance (p = 0.016 and 0.061, respectively). Successful outcomes were demonstrated for each of the categories assessed and no statistical differences were seen in the ODI % for any comparison after 5 years on 19% of data reported which may have limited forecast reliability. Our data suggest that post-operative outcome is independent of preoperative condition, procedure to be preformed, age, and BMI. Our data support the continual practice of spinal fusion for the treatment of degenerative disk disease.

Characterization of the Performance of Memetic Algorithms for the Automation of Bone Tracking With Fluoroscopy

Reliable knowledge of in vivo joint kinematics is fundamental in clinical medicine. Fluoroscopic motion tracking theoretically permits a millimeter/degree level of accuracy in 3-D joint motion analysis, but the reliability of the local optimization algorithm [Levenberg–Marquardt (LMA)], typically used for the pose estimation, is highly operator dependent. A new memetic algorithm (MA), hybridizing global evolution and a local search metaphor for learning, is proposed to automate the analysis and improve its reliability and robustness. The performance of MA was assessed for in silico and in vivo elbow kinematics, with and without user supervision. The best learning strategy between Lamarckian and Baldwinian evolution was identified. MA's accuracy and repeatability was quantified and compared with LMA's. The algorithm performed best using a partial Lamarckian learning strategy. The geometric symmetry of analyzed bony segments influenced the accuracy, whereas the absolute bone pose with respect to the projection geometry affected the repeatability. In contrast to LMA, MA provided robust, repeatable, and operator independent pose estimations, even for in vivo analyses. The pose can be automatically estimated with errors lower than 1 mm and 1 $^{\circ}$ for all the pose parameters except the depth position, if the investigated motion task avoids symmetric bony projection silhouettes.

Collecting shoulder kinematics with electromagnetic tracking systems and digital inclinometers: A review

The shoulder complex presents unique challenges for measuring motion as the scapula, unlike any other bony segment in the body, glides and rotates underneath layers of soft tissue and skin. The ability for clinicians and researchers to collect meaningful kinematic data is dependent on the reliability and validity of the instrumentation utilized. The aim of this study was to review the relevant literature pertaining to the reliability and validity of electromagnetic tracking systems (ETS) and digital inclinometers for assessing shoulder complex motion. Advances in technology have led to the development of biomechanical instrumentation, like ETS, that allow for the collection of three-dimensional kinematic data. The existing evidence has demonstrated that ETS are reliable and valid instruments for collecting static and dynamic kinematic data of the shoulder complex. Similarly, digital inclinometers have become increasingly popular among clinicians due to their cost effectiveness and practical use in the clinical setting. The existing evidence supports the use of digital inclinometers for the collection of shoulder complex kinematics as these instruments have been demonstrated to yield acceptable reliability and validity. While digital inclinometers pose a disadvantage to ETS regarding accuracy, precision, and are limited to two-dimensional and static measurements, this instrument provides clinically meaningful data that allow clinicians and researchers the ability to measure, monitor, and compare shoulder complex kinematics.

Comprehensive Review of Adipose Stem Cells and Their Implication in Distraction Osteogenesis and Bone Regeneration.

Bone is one of the most dynamic tissues in the human body that can heal following injury without leaving a scar. However, in instances of extensive bone loss, this intrinsic capacity of bone to heal may not be sufficient and external intervention becomes necessary. Several techniques are available to address this problem, including autogenous bone grafts and allografts. However, all these techniques have their own limitations. An alternative method is the technique of distraction osteogenesis, where gradual and controlled distraction of two bony segments after osteotomy leads to induction of new bone formation. Although distraction osteogenesis usually gives satisfactory results, its major limitation is the prolonged duration of time required before the external fixator is removed, which may lead to numerous complications. Numerous methods to accelerate bone formation in the context of distraction osteogenesis have been reported. A viable alternative to autogenous bone grafts for a source of osteogenic cells is mesenchymal stem cells from bone marrow. However, there are certain problems with bone marrow aspirate. Hence, scientists have investigated other sources for mesenchymal stem cells, specifically adipose tissue, which has been shown to be an excellent source of mesenchymal stem cells. In this paper, the potential use of adipose stem cells to stimulate bone formation is discussed.

An overview of surgery-first approach: Recent advances in orthognathic surgery.

The disadvantages of having orthodontic interventions both before and after orthognathic surgery include a long treatment time of 7–47 months and temporary worsening of facial appearance. Nowadays, the concept of surgery-first, followed by orthodontic treatment is applied to orthognathic surgery cases in different orthodontic centers in the world. This concept and technique is called “surgery-first-orthognathic-approach” or “surgery-first approach” (SFA) rigid fixation (skeletal anchorage system) of the bony segments and regional acceleratory phenomenon were keys to broad implementation of the SFA. This article is intended to provide an overview of SFA including indications, general and specific guidelines, different protocol variations, success rate and potential problems.

Soft tissue changes after a combined lefort I and anterior maxillary osteotomy: A clinical and cephalometric study

Background: Orthognathic Surgery is indicated in severe skeletal disharmony on the best means of improving functional facial esthetic. Assessment of the facial harmony in relation to soft tissue contour the thickness of the tissues, the lip length to postural tone plays an important role. This article aims determining the changes of the soft tissue profile cephalometrically after maxillary osteotomy. Material and Methods: The entire concept of orthognathic surgery involves the identification of the hard and soft tissue deformity by clinical examination, cephalometric radiographs, models and photographs. This study is to assist the pre and post-operative soft tissue changes clinically including width of the nasal bone and upper incisor exposure of rest and cephalometrically including nasolabial angle, facial convexity, lip protuberance and inter-labial gap by using Rickets E Line, Steiner's S Line, Merrifield's Z Angle and Holdaway Soft Tissue Analysis. Results: There is significant dramatic improvement in the soft tissue profile cephalometrically after maxillary osteotomy. Conclusion: The conclusion of the study is that there is a change in the soft tissue in relation to the hard tissue movement, and also the stability of the soft tissue profile was established by rigid fixation of bony segments.

Simple and atraumatic technique for the advancement of the genioglossus muscle for treatment of obstructive sleep apnoea

osteotomy have been designed for the advancement of thegenioglossus muscle and the genial tubercle complex. Wedescribe a new method that uses a specially designed ini-tial trephine drill for indentation, a final trephine drill forbicortical osteotomy, and a C-shaped plate that supports theadvanced bony segment from the inside and is stepped lin-gually

Inverted V-shape Osteotomy with Central Strip Resection: A Simultaneous Narrowing and Vertical Reduction Genioplasty.

Background:In East Asian countries, a prominent, long, and squared contour of the lower third of the face is considered unattractive, strong, and masculine. To change such a facial contour into an ovular contour, correction of the chin area is essential to accomplish the overall curve in the mandibuloplasty, and various methods for the horizontal reduction of the chin area have been suggested. The horizontal osteotomy and central strip resection technique, which is the most widely used method, has comparatively little effect and some restrictions. To improve these points, the authors introduced an effective method for simultaneously reducing the width and height of the chin without additional procedures.Methods:From March 2010 to May 2013, 432 women and 117 men underwent mandibular contouring surgery. Of these patients, 321 needed correction of the chin shape with simultaneous mandibular contouring surgery. Narrowing and vertical reduction genioplasty was performed for these patients using an inverted V-shaped osteotomy with central bony segment resection.Results:Narrowing and vertical reduction genioplasty was successfully performed in all cases. No severe complications were observed. Transient sensory changes of the skin around the chin were observed in 87 patients, but all recovered within 3 months. All of the patients were satisfied with the results.Conclusions:The method that we introduce in this article is a simple and more effective method for simultaneous reduction of the width and height of the chin without additional procedures. The square and long face was effectively and easily reshaped into a slender ovular contour, and the shape of the chin was changed from square to slender.

A New Technique for Sandwich Osteoplasty with Interpositional Bone Grafts for Fixation

To present a new technique for sandwich osteoplasty in the posterior mandible and to evaluate its feasibility as part of dental implant treatment. A retrospective study of sandwich osteoplasty in the posterior mandible was conducted. No osteosynthetic material was used to stabilize the osteotomy. Fixation was achieved with the interposition of two bone blocks harvested from the retromolar region. Eighteen patients with 26 sites of severe atrophy of the posterior mandible were treated. After a healing period of 4 months, 53 dental implants were inserted into the augmented region. The implants were loaded with single crowns or fixed dental prostheses 3 months after placement. The mean vertical bone gain after 4 months of healing was 4.2 mm (standard deviation 1.4 mm). The average bone loss between augmentation and implantation was 2.3 mm (35.4%). All implants osseointegrated and showed no clinical signs of peri-implantitis. In three subjects, the elevated bony segment perforated the lingual mucosa near the adjacent teeth after excessive elevation (> 6 mm) but healed without any sequelae. An alternative method for vertical alveolar ridge augmentation of the posterior mandible is presented. No osteosynthetic material is required for fixation, and related complications can be avoided. Further prospective clinical studies are required to demonstrate the feasibility of this technique versus the conventional sandwich osteoplasty.

Computer simulation surgery for mandibular reconstruction using a fibular osteotomy guide.

In the present study, a fibular osteotomy guide based on a computer simulation was applied to a patient who had undergone mandibular segmental ostectomy due to oncological complications. This patient was a 68-year-old woman who presented to our department with a biopsy-proven squamous cell carcinoma on her left gingival area. This lesion had destroyed the cortical bony structure, and the patient showed attenuation of her soft tissue along the inferior alveolar nerve, indicating perineural spread of the tumor. Prior to surgery, a three-dimensional computed tomography scan of the facial and fibular bones was performed. We then created a virtual computer simulation of the mandibular segmental defect through which we segmented the fibular to reconstruct the proper angulation in the original mandible. Approximately 2-cm segments were created on the basis of this simulation and applied to the virtually simulated mandibular segmental defect. Thus, we obtained a virtual model of the ideal mandibular reconstruction for this patient with a fibular free flap. We could then use this computer simulation for the subsequent surgery and minimize the bony gaps between the multiple fibular bony segments.

Soft Tissue Artifact compensation using Triangular Cosserat Point Elements (TCPEs)

Existing methods which compensate for the Soft Tissue Artifact (STA) in optoelectronic motion measurements estimate the rigid motion of a nearly rigid underlying body segment based on analysis of the motion of all fiducial markers. The objective of the proposed Triangular Cosserat Point Elements (TCPE) method is to estimate the motion of the underlying body segment even when the STA in the entire cluster of markers can be large. This is accomplished by characterizing the cluster of markers with TCPEs defined by triangles based on all combinations of three markers. Then, scalar deformation measures characterizing the magnitudes of strain and relative rotation of pairs of TCPEs are defined for each TCPE. These deformation measures are used to define a filtered group of TCPEs which best represents the motion of the underlying body segment. The method was tested using an experimental setup that consists of a rigid pendulum with a deformable 300ml silicone breast implant attached to it as a simulation of the soft tissue around a bony segment. The rotation angles extracted from markers on the deformable implant were compared with simultaneous measurements of the rigid pendulum using an optoelectronic system. Analysis of the experimental data shows that this filtering process substantially reduces the error due to the STA even though the data set includes large deformations. In particular, the analysis shows that the error reduction using the TCPE approach is larger than the reductions obtained using standard least-squares minimization methods.

Surgical Correction of Hemifacial Microsomia: Simultaneous Orthognathic and Distraction Osteogenesis Treatment. A Case Report on How This Hybrid Technique Can Correct Severe Facial Asymmetries

Hemifacial microsomia (HFM) is one of the most common congenital craniofacial soft and hard tissue deformities, manifesting as a unilateral underdevelopment of anatomical structures arising from the first and second brachial arches. The most salient feature is the underdevelopment of the mandible, particularly the ramus and condyle. Developmental disturbances at various times can lead to numerous presentations in size and function, which might require different treatment options. Conventional therapy for asymmetric patients with severe forms of HFM has been unilateral distraction osteogenesis. However, there has been noted relapse into facial asymmetry due to contraction of the bony segments and a lack of downward growth. With regard to avoiding such complications, we have elected to utilize both the distraction osteogenesis method and traditional orthognathic surgery, allowing us to better control vector movement of the maxillary and mandibular segments. It is our goal that by demonstrating this technique on such an extreme case of HFM, we can show that both methods can be used simultaneously to successfully correct this deformity, whereas each one individually might not have.