A novel modular retention system for midfacial distraction osteogenesis

A Technical Innovation in Midface Advancement With the External Frame Distraction Device

BACKGROUND

Maxillary advancement with a rigid external distractor (RED) II is a commonly performed procedure for correcting midface hypoplasia. While there are various methods of anchoring the osteotomized maxillary segment to the halo device, the looped transpyriform wire is the simplest and most cost-effective. However, a common complication with this is the cutting through of the stainless steel traction wire across the pyriform buttress during distraction. The patient with cleft undergoing midface distraction is particularly vulnerable since the force needed for distraction is higher due to scarring from previous operations.

INNOVATION AND DESIGN

A single-hole titanium plate is introduced as an interface between the bone of the pyriform buttress and the looped stainless steel traction wire attached to the external frame device.

EVALUATION

Twenty-four patients with cleft who underwent midface advancement using the external frame distractor before the introduction of the innovation were compared with 26 patients who underwent the same procedure after its introduction. The former group had 12.5% complication in the form of cut through of the traction wire, while the latter group had only 3.8% complication rate.

CONCLUSION

Introduction of the titanium eyelet as an interface between the traction wire and the bone is a simple technical addition for a more reliable distraction using the RED II device in patients with cleft even in the presence of extensive scarring.

Rigid External Distraction Using Skeletal Anchorage to Cleft Maxilla United with Alveolar Bone Grafting

Objective

Documentation of the application of maxillary distraction osteogenesis using rigid external distraction (RED) with skeletal anchorage combined with predistraction alveolar bone grafting (ABG) in cleft maxilla.

Design

Case report.

Patient

A patient with numerous congenital missing teeth and severe maxillary deficiency related to complete bilateral cleft lip and palate with large alveolar bone defect.

Intervention

The patient received preoperative orthodontic treatment, predistraction ABG, and maxillary distraction osteogenesis using RED with skeletal anchorage.

Results

Predistraction ABG completely united the cleft maxilla. The united maxilla was successfully advanced by the RED system with skeletal anchorage, despite unsound dentition with numerous congenital missing teeth.

Conclusion

The present study demonstrates that the combination of predistraction ABG and RED system with skeletal anchorage is effective for the treatment of severe maxillary deficiency related to complete bilateral cleft lip and palate with large bone defect and numerous congenital missing teeth.

Le Fort II midfacial distraction combined with orthognathic surgery in the treatment of nasomaxillary hypoplasia

Patients with nasomaxillary hypoplasia have severe facial concavity and compromised skeletal class III malocclusion. Its treatment is still a challenge to surgeons. Our aim was to evaluate the combination of midfacial distraction and orthognathic surgery in the treatment of nasomaxillary hypoplasia. Four patients with nasomaxillary hypoplasia were enrolled in this study. After Le Fort II osteotomy, the rotational distraction of nasomaxillary complex was performed to rehabilitate facial convexity. Then bilateral sagittal split ramus osteotomy with or without Le Fort I osteotomy was used to correct malocclusion. All patients healed uneventfully, and the maxillae moved forward conspicuously. No obvious pain and severe discomfort were complained during distraction. A significant advancement and downward movement of the maxilla were shown by cephalometric analysis. The combination of midfacial distraction and orthognathic surgery provides us an ideal alternative in the treatment of nasomaxillary hypoplasia.

Long-term results of surgically assisted maxillary protraction vs regular facemask

OBJECTIVE

To evaluate the short- and long-term treatment results of rapid maxillary expansion (RME) and surgical assistance during maxillary protraction with a facemask (FM).

MATERIALS AND METHODS

This study was carried out in 28 patients (12 male, 16 female) with maxillary retrognathism, anterior crossbite, and Class III skeletal and dental malocclusion characteristics. Seventeen patients (9 male, 8 female) with mild maxillary retrognathism were treated by RME and FM. The other 11 patients (8 female, 3 male), who had moderate to severe maxillary retrognathism, were treated with surgically assisted FM treatment. Patients treated with RME and FM were recalled after 5.64 years, and the surgically assisted FM group was recalled after 6.08 years. Cephalometric films taken before treatment (T0), right after maxillary protraction (T1), and at recall (T2) were used to evaluate and compare the results.

RESULTS

In the short term, good maxillary advancement and a shorter treatment period were achieved with surgically assisted FM therapy. However, in the long term, maxillary advancement and some soft tissue improvements were lost. On the other hand, in the RME and FM protraction group, maxillary advancement and soft tissue improvement were well maintained.

CONCLUSION

In the short term, statistically significant maxillary advancement was achieved with surgically assisted maxillary protraction. However, in the long term, these sagittal changes were not stable, whereas RME and FM provided stability.

MIA - A free and open source software for gray scale medical image analysis

BACKGROUND

Gray scale images make the bulk of data in bio-medical image analysis, and hence, the main focus of many image processing tasks lies in the processing of these monochrome images. With ever improving acquisition devices, spatial and temporal image resolution increases, and data sets become very large.Various image processing frameworks exists that make the development of new algorithms easy by using high level programming languages or visual programming. These frameworks are also accessable to researchers that have no background or little in software development because they take care of otherwise complex tasks. Specifically, the management of working memory is taken care of automatically, usually at the price of requiring more it. As a result, processing large data sets with these tools becomes increasingly difficult on work station class computers.One alternative to using these high level processing tools is the development of new algorithms in a languages like C++, that gives the developer full control over how memory is handled, but the resulting workflow for the prototyping of new algorithms is rather time intensive, and also not appropriate for a researcher with little or no knowledge in software development.Another alternative is in using command line tools that run image processing tasks, use the hard disk to store intermediate results, and provide automation by using shell scripts. Although not as convenient as, e.g. visual programming, this approach is still accessable to researchers without a background in computer science. However, only few tools exist that provide this kind of processing interface, they are usually quite task specific, and don't provide an clear approach when one wants to shape a new command line tool from a prototype shell script.

RESULTS

The proposed framework, MIA, provides a combination of command line tools, plug-ins, and libraries that make it possible to run image processing tasks interactively in a command shell and to prototype by using the according shell scripting language. Since the hard disk becomes the temporal storage memory management is usually a non-issue in the prototyping phase. By using string-based descriptions for filters, optimizers, and the likes, the transition from shell scripts to full fledged programs implemented in C++ is also made easy. In addition, its design based on atomic plug-ins and single tasks command line tools makes it easy to extend MIA, usually without the requirement to touch or recompile existing code.

CONCLUSION

In this article, we describe the general design of MIA, a general purpouse framework for gray scale image processing. We demonstrated the applicability of the software with example applications from three different research scenarios, namely motion compensation in myocardial perfusion imaging, the processing of high resolution image data that arises in virtual anthropology, and retrospective analysis of treatment outcome in orthognathic surgery. With MIA prototyping algorithms by using shell scripts that combine small, single-task command line tools is a viable alternative to the use of high level languages, an approach that is especially useful when large data sets need to be processed.

A novel anchorage technique for transnasal traction in rigid external maxillary distraction

We describe an effective technique for anchorage of transnasal traction in the management of maxillary rotation during external distraction.

Success rate of miniplate anchorage for bone anchored maxillary protraction

OBJECTIVE

To evaluate the success rate of Bollard miniplate anchorage for bone anchored maxillary protraction (BAMP).

MATERIALS AND METHODS

Twenty-five consecutive patients (mean age, 12.0 ± 1.2 years; range, 8.7-14.8 years) with maxillary hypoplasia without congenital or acquired deformation were included in this study. A total of 100 Bollard modified miniplates were placed by the same surgeon. Ninety-nine miniplates were inserted under general anesthesia, and one was placed under local anesthesia because of initially soft bone conditions. Loading of the miniplates with 150 g elastics was initiated at 17.5 ± 6.9 days (range, 11-38 days) after surgery. Mean follow-up was provided at 20.8 ± 11.1 months (range, 6.5-46.2 months).

RESULTS

The overall success rate of miniplate anchorage in terms of stability was 97%. During orthodontic loading, five miniplates showed signs of mobility. After interruption of loading over 2 months, two miniplates became stable again. However, a total of three miniplates needed to be removed and were successfully replaced under local anesthesia after a mean healing period of 3 months.

CONCLUSION

Skeletal anchorage by means of Bollard modified miniplates is effective for BAMP. Success depends on proper presurgical patient counseling, minimal invasive surgery, good postsurgical instructions, and orthodontic follow-up.

Correction of midface deficiency using intra-oral distraction device

A wide variety of disease processes produce alteration of midfacial skeletal growth, resulting in moderate-to-severe midface deficiency presenting as retrusion associated with Angle's class III malocclusion. Most cases of midface deficiency are seen in patients of cleft lip/palate. The surgical procedure to correct the clefts, undertaken over a long period of time from infancy to the teens tends to take its toll on the soft tissues over the midface. The scarring that is a feature in these conditions results in hampering of normal growth of the midface causing the deformity. Conventional procedures to correct the deformity by surgical advancement have been less than satisfactory in terms of success. This is where the concept of multidimensional growth using distraction proved useful. Today distraction has proved to be a versatile tool in the correction of midface deficiencies due to its various advantages. Six patients of cleft lip/palate were taken up for advancement of the hypoplastic midface using intra-oral distractors with successful and stable results.

External frame distraction osteogenesis of the midface in the cleft patient

Distraction osteogenesis has established itself as an accepted form of treatment in the management of midface deficiency in cleft patients. However, it is well known that some amount of relapse is inevitable in patients who undergo this procedure. Like most surgical techniques, it has its specific indications, limitations, and complications. The problems are amplified in some patients because of severe fibrosis resulting from previous palate and lip operations. This article reviews treatment planning, pre- and postoperative orthodontic management, operative technique, and mechanics of distraction. It also discusses long-term changes following distraction and protocols to optimize the results and minimize complications.

The Use of Internal Maxillary Distraction for Maxillary Hypoplasia: A Preliminary Report

PURPOSE

Distraction osteogenesis is a useful alternative to advance the maxilla in complicated cases of maxillary hypoplasia. The purpose of this article is to review the workup, experience, and preliminary results with the use of internal distraction osteogenesis for maxillary hypoplasia at one teaching institution.

PATIENTS AND MATERIALS

Over a 5-year period, more than 300 patients with craniofacial and dentofacial defects have undergone oral and maxillofacial surgery at our center to correct their skeletal discrepancies. Of these, 10 have had maxillary distraction osteogenesis done with internal distractors. Follow-up of 6 months or more was available for 8 patients. Stereolithographic models were used to bend distractors prior to surgery in 6 patients.

RESULTS

Latency prior to the start of distraction was 3 to 7 days and varied with the age of the patient. Distraction occurred at approximately 1 mm per day with an average distraction length of 8.5 mm (range, 6-10 mm). Excellent occlusal results were obtained in 5 patients. Major complications including nonunion and failure to achieve acceptable occlusal results were observed in 3 patients. Minor complications including pain and loosening of the distracter devices were observed in 2 patients, but did not appear to affect the esthetic and functional results.

CONCLUSIONS

Distraction osteogenesis is a useful alternative to traditional orthognathic surgery to treat maxillary hypoplasia. Internal distractions are attractive to patients, but are more difficult to place and can cause discomfort to patients when trying to achieve an ideal primary vector of distraction. Stereolithographic models can help with placement of the device. Changes in design of distractors may help with patient discomfort.

Maxillary distraction osteogenesis using Le Fort I osteotomy without intraoperative down-fracture

The aim of this study is to present a technique for maxillary distraction osteogenesis using Le Fort I osteotomy without down-fracture. Six cleft-related patients suffering from severe midfacial deficiency were treated with maxillary distraction osteogenesis. The RED II system was chosen as the extraoral device and the Leipzig retention plate system to anchor the maxillary segment. Maxillary distraction osteogenesis was successful in all cases. Cephalometric and clinical evaluation after an average follow-up period of 1 year showed stable results with respect to skeletal and dental relationships. The SNA angle increased from 72.3 degrees to 81.4 degrees and the ANB angle increased by 11.0 degrees immediately after removing the distraction device. After 1 year, the sagittal bone gain remained and the SNA angle had decreased by 0.8 degrees . This technique seems to minimize the risk of the surgical procedure and shorten the operation time. It may become an alternative method for the treatment of patients with severe midfacial hypoplasia.

A device for determining the position of intraoral distractors for protracting the maxilla

Distraction osteogenesis of the maxilla is indicated for jaw deformities in patients with extreme dysgnathia. First, extraoral appliances were introduced, and currently intraoral appliances are in vogue. These have significantly reduced the amount of physical and psychological stress placed on the patients. The direction of force vector may be varied according to the individual patient's requirements. This paper presents positioning devices for bilateral intraoral maxillary distraction plates, which have been developed to place maxillary distraction plates parallel to the direction of lengthening.

Immediate versus delayed midface distraction in a primate model using a new intraoral internal device

The theoretic advantage of distraction osteogenesis of the craniofacial skeleton, especially in cases of severe midface retrusion and in the presence of maxillary scarring, is prevention of relapse following significant advancements. The purpose of this study is to demonstrate the utility of a new low-profile, intraoral, internal device for midface distraction at the conventional or high Le Fort I level. In addition, the present study compares the efficacy of immediate versus delayed distraction on subsequent maxillary relapse. Four adult rhesus Macaca mulatta monkeys were divided into two groups. Group 1 underwent immediate midface distraction; group 2 underwent delayed distraction. All four monkeys underwent a modified Le Fort I osteotomy through an upper buccal sulcus incision and bilateral application of the intraoral midface distraction devices. No other osteotomies or incisions were necessary. Immediate distraction, performed in group 1, entailed intraoperative activation of the devices and distraction of 10 mm followed by a 5-day lag period before postoperative activation and distraction of an additional 10 mm at the rate of 1 mm/day. Delayed distraction, performed in group 2, entailed a 5-day postoperative lag period before device activation and distraction of 20 mm at the rate of 1 mm/day. Both groups thus underwent 20 mm of midface distraction. All devices were removed 6 weeks after completion of distraction. All monkeys tolerated the devices and daily distraction uneventfully. On the basis of serial cephalograms and dental models obtained throughout the experimental period, there was no evidence of relapse in either the immediate or delayed groups 6 months after distraction. In addition, on the basis of histologic, ultrastructural, and dry skull analysis, no significant differences were observed in the quality of regenerate bone obtained when comparing the immediate and delayed distraction groups. Significant midface advancement is thus feasible using this new internal, intraoral distraction device, which presents several advantages over other internal devices that require coronal incisions and additional osteotomies to achieve midface advancement. In addition, immediate distraction may abbreviate the distraction period without adverse sequelae.