External Distraction Device Research Articles

Application of Near Infrared Spectroscopy to Enhance Safety and Individualize Distraction of Severely Contracted Joints in Far-Advanced Dupuytren's Disease.

Background: Slow distraction of contracted joints is a well-established treatment in far-advanced stages of Dupuytren's disease (DD). To assess finger perfusion and avoid malperfusion, we studied near infrared spectroscopy (NIRS) to evaluate the maximum extent of distraction that would not harm microcirculation to the finger. This technique also allows an optimized treatment in accordance with sufficient blood perfusion during distraction. Methods: Eligible patients with stage IV finger contractures who needed treatment for Dupuytren's contracture were included and prospectively investigated. The operation was performed with local anaesthesia. First, the Dupuytren strand of the treated finger was dissected in the palm to allow distraction. Under X-ray control, the distraction device was applied. Then, slow distraction of the treated joint was performed to evaluate the finger perfusion. To assess perfusion of the treated finger, NIRS was used to measure tissue oxygen saturation. If impaired finger perfusion was detected, traction was reduced until sufficient oxygen levels and perfusion patterns were reestablished. Results: NIRS was performed after application of the distraction device in seven cases. We treated six male and one female patient (mean age 70 years, range 51-80 years). Rapid distraction resulted in malperfusion of the treated fingers. Using NIRS proved to render reliable and reproducible information on finger perfusion and oxygenation in all seven patients. Conclusions: Application of NIRS enhances safety in the treatment of far-advanced DD finger contractures with an external skeletal distraction device. It is non-invasive, reproducible, easy to use and allows for an individualized adapted distraction velocity.

Mandibular distraction osteogenesis in children with Pierre Robin sequence: long-term analysis of teeth and jaw growth

Treatment of children with Pierre Robin sequence (PRS) having a hypoplastic mandible and upper airway distress after birth may consist of external distraction devices. Shape anomalies of the permanent molars and positional changes due to surgery have been documented. The aim of this study is to compare the long-term effects (>5 years) on the growth pattern of PRS-patients treated with an external mandibular distraction device with no-surgery cases and to investigate the dental development or damage. A retrospective cohort study was performed. PRS-patients with and without surgery were included. A digital cephalometric analysis was made to evaluate the growth pattern of the mandible between groups as well as with normal values. Nine of 19 patients underwent an external mandibular distraction. All children were extubated after 4-5 days with no signs of respiratory distress. Screw and device loosening presented in one patient. The articular and sellar angles were significantly larger and smaller, respectively, in the Surgery group. Mandibular distraction surgery might result in a ‘growth boost’ compared to the No-surgery group. No significant difference in dental development was found. Mandibular distraction osteogenesis is an effective way of relieving severe upper airway obstruction.

Cleft Maxillary Hypoplasia: Comparison of Techniques and Proposal of a Novel Treatment Protocol for Management.

This study was designed to compare different techniques of managing cleft maxillary hypoplasia and to propose a treatment protocol taking patient's age of presentation, amount of maxillary hypoplasia, and presence/absence of velopharyngeal insufficiency (VPI) into consideration. Five treatment modalities, viz. facemask therapy (Group I), anterior maxillary distraction (Group II), total maxillary distraction osteogenesis using rigid external distraction devices (Group III) and internal distraction devices (Group IV), and conventional orthognathic surgery (Group V), were assessed retrospectively using lateral cephalograms (taken at 3 intervals) and speech records (studied pre- and post-operatively). The results were subjected to statistical analysis. A P value of less than 0.05 was considered statistically significant. The mean advancement achieved in groups I, II, III, IV, and V was 4.2±1.54, 9.03±2.62, 11.82±1.18, 10.41±1.42, and 7.24±2.44mm, respectively. The mean horizontal relapse noted in Groups I, II, III, IV, and V was 2.3mm (n=8), 2.1mm (n=14), 3.4mm (n=10), 1.4mm (n=5), and 2.4mm (n=24), respectively. Compared to other groups, group II had fewer patients exhibiting relapse, a statistically significant observation. Similarly, statistically significant improvement in speech outcomes was found only in group II compared to other groups. Based on the results, a treatment protocol was proposed. The authors conclude that the proposed protocol would enable surgeons to decide the most appropriate treatment modality paying attention to not only the age of presentation and amount of advancement but also presence/absence of VPI which is instrumental in deciding upon the most appropriate treatment.

Crouzon Syndrome Spanning Three Generations: Advances in the Treatment of Syndromic Midface Deficiency.

Crouzon syndrome is an autosomal dominant genetic disorder characterized by craniosynostosis, midface retrusion, and exophthalmos. Over the past century, the treatment of craniofacial disorders like Crouzon syndrome has evolved significantly. An institutional review board-approved retrospective study was conducted to ascertain the treatment of three individuals with Crouzon syndrome from one family, complemented with a series of literature searches to examine the evolution of craniofacial surgical history. Dr. David Williams Cheever developed the Le Fort I level to correct malocclusion, maxillomandibular malformations, and midface hypoplasia. Later, Dr. Paul Tessier introduced the Le Fort II and III osteotomies to treat syndromic midface hypoplasia. In 1978, Dr. Fernando Ortiz-Monasterio and Dr. Antonio Fuente del Campo published the first series of monobloc osteotomies, allowing for simultaneous correction of supraorbital and midface malformations, although complicated by blood loss and high infection rates. In 1992, McCarthy et al introduced the concept of gradual distraction to the craniofacial skeleton. In 1995, Polley et al performed the first monobloc advancement using external distraction. Subsequently, in 1997, Polley and Figueroa introduced a rigid external distraction device with multiple vector control to manage severe cleft maxillary hypoplasia. The technique was further refined and applied to treat syndromic midface hypoplasia, reducing complication rates. Currently, either external or internal distraction approaches are used to safely treat this challenging group of patients. The treatment of syndromic midface deficiency has significantly evolved over the past 50 years, as evidenced by this report of three generations of Crouzon syndrome.

TMJ Ankylosis Following Mandibular Distraction Osteogenesis: Management With Simultaneous Midface External Distraction and Bilateral Temporomandibular Joint Replacement.

Early mandibular distraction osteogenesis (MDO) can decrease upper airway and feeding complications in pediatric patients with micrognathia; however, temporomandibular joint (TMJ) complications like TMJ ankylosis (TMJA) may occur. TMJA can disturb pediatric patients' function and craniofacial growth, resulting in significant physical and psychosocial consequences. Additional surgical procedures may also be required, increasing the burden of care on patients and their families. CMF surgeons must discuss the potential complications of early MDO surgery with families as well as potential solutions should these problems occur. This report presents the case of a 17-year-old male with a severe craniofacial anomaly with features of Treacher-Collins syndrome (TCS) and a surgical history of tracheostomy, cleft palate repair, mandibular reconstruction with harvested costochondral grafts, and MDO with resultant bilateral TMJA and limited mouth opening. The patient Was treated with bilateral custom alloplastic TMJ replacements and simultaneous maxillary DO using a Rigid External Distraction (RED) device.

Does the Rigid External Distraction Device Alter Maxillary Pitch in Cleft Maxillary Distraction?

The rigid external distraction (RED) device is reported to have the ability to three-dimensionally reposition the maxilla. The purpose of this study is to assess the ability of RED to intentionally alter the maxillary pitch. Retrospective cohort study. Institutional practice. A retrospective chart review was completed over the past 12 years and a total of 50 patients met the inclusion criteria. Cephalometric changes and alteration in palatal plane angle. Cephalometric analysis of standardized landmarks was completed on calibrated, standardized lateral cephalograms. Pre-distraction and post-consolidation variables were compared via a two-tailed paired t-test. The mean age at surgery of 12.2 ± 3.2 years. Through distraction osteogenesis (DO), the maxilla was moved anteriorly with a mean distraction distance of 8.4 ± 4.8 mm. The mean change in the angles sella-nasion-A-point angle (SNA), sella-nasion-B-point angle (SNB), and A-point-nasion-B-point angle (ANB) were 10.2 ± 4.8, 0.9 ± 2.7, and 9.3 ± 4.1, respectively. The mean change in the palatal plane angle was −4.4 ± 3.7. The mean change in the vertical position of the anterior nasal spine (ANS) and posterior nasal spine (PNS) in relation to the Frankfort horizontal (FH) were −2.0 ± 4.1 mm and 1.7 ± 3.8 mm, respectively. This study documents short-term findings of RED in a large cleft lip and palate (CLP) population. Despite positioning of distraction eyelets superior to the theoretical center of resistance, a counterclockwise (CCW) rotation of the palatal plane occurred. This suggests that adjunctive methods of vector control should be considered if clockwise (CW) rotation of the palatal plane is intended with the RED device.

Long-term Management of a Patient with Apert Syndrome

To present an Apert syndrome patient with midfacial growth deficiency treated with Le Fort III distraction osteogenesis and subsequent two-jaw surgery. Apert syndrome is expressed as a severe and irregular craniosynostosis, midfacial hypoplasia, and symmetric syndactyly in the fingers and toes. For craniosynostosis syndromes, treatment planning is complex due to the disharmony between facial profile and occlusion. A 4-year-and-5-month-old boy, diagnosed with Apert syndrome, showed a concave profile accompanied with midfacial hypoplasia, moderate exorbitism, a reversed occlusion of -10.0 mm, an anterior open bite of -5.0 mm, and skeletal class III jaw-base relationship. The patient, aged 15 years and 4 months, underwent a Le Fort III osteotomy, and subsequent osteodistraction was performed via a rigid external distraction (RED) device. His midfacial bone was advanced by approximately 7.0 mm. One year after the distraction, preoperative treatment with 0.018-in preadjusted edgewise appliances was initiated. Two-jaw surgery with a Le Fort I osteotomy and bilateral sagittal split ramus osteotomy was performed after 42 months of preoperative orthodontic treatment. At the age of 20 years and 9 months, his facial profile dramatically changed to a straight profile, and an acceptable occlusion with an adequate interincisal relationship was obtained. A functional occlusion with an excellent facial profile was maintained throughout the 2-year retention period, although the upper dental arch width was slightly decreased, resulting in the recurrence of the left posterior crossbite. Our report indicates the necessity of long-term follow-up in patients with craniosynostosis because of syndrome-specific growth and methodologically induced relapse. The two-stage operation combining early distraction osteogenesis and postgrowth orthognathic surgery proves to be an effective therapy for correcting midfacial hypoplasia and skeletal mandibular protrusion caused by Apert syndrome.

An Auxiliary Cranioparietal Anchorage System to Improve the Stability of the Rigid External Distraction Device in Children With Crouzon Syndrome.

Rigid external distraction (RED) device instability because of thin skulls in syndromic craniosynostosis patients remains challenging. The authors propose the use of an auxiliary cranioparietal anchorage system to improve RED device stability in patients with Crouzon syndrome. Five consecutive patients with Crouzon syndrome underwent Le Fort III osteotomy with midface advancement using a modified external device. Cephalometric analysis and three-dimensional computed tomography images were evaluated preoperatively and after device removal. Mechanical analyses of the RED device with and without the auxiliary cranioparietal anchorage system were performed. Both postoperative photographs and follow-up computed tomographs showed obvious midfacial advancement with no intracranial pin perforation or external frame migration. Mechanical analysis showed that the new system reduced the possibility of postoperative external frame migration. The auxiliary cranioparietal anchorage system might be considered an adjunct to the RED device in patients with Crouzon syndrome to avoid postoperative complications.

Novel Use of an Internal Distractor for Metacarpal Lengthening.

In patients who have had proximal digit amputation, metacarpal distraction osteogenesis is an option to improve digital length and function. One drawback is that traditional external distraction devices are large and cumbersome; the option of a low-profile internal device is therefore appealing. Internal distractors are commonly used in craniofacial reconstruction, but use in the hand has not been reported. We describe a case series of the novel use of an internal distractor in metacarpal lengthening. In this single-center case series, patients who underwent metacarpal distraction by the senior author using a uniplanar internal distractor were reviewed, and indications, outcomes, and complications were analyzed. There were 5 cases in 4 patients (age range: 7-33 years). Indications were traumatic amputation in 4 cases and congenital hypoplasia in 1. All were successfully distracted, with a mean final length gain of 1.3 cm (range: 1.0-1.7 mm). Mean time from device placement to consolidation was 3.5 months. Complications included activation arm site infection in 2 cases, both occurring after the distraction period, necessitating device removal before full consolidation. In these cases, the device was removed after the distraction period and replaced with a Kirschner wire for stabilization through the consolidation period. Metacarpal distraction was successfully achieved with an internal distraction device. Although infection was common, it occurred after the distraction period and did not preclude length gain. We feel that this low-profile device offers advantages over cumbersome external devices typically used for metacarpal lengthening.

An Unoperated Crouzon Family Treated with Monobloc Distraction: Challenges and Lessons.

Background:Crouzon syndrome (CS) is a rare form of craniosynostosis characterized by bicoronal craniosynostosis and facial features including severe midface hypoplasia, exophthalmos, and hypertelorism. Most patients are diagnosed and treated in early childhood; however, there are a few reports of Crouzon patients treated as adults with monobloc facial advancement. To our knowledge, this is the first report of a family affected by CS treated sequentially with monobloc facial advancement using combined internal and external distraction osteogenesis (rigid external distraction).Methods:We present a family from Jamaica (mother 47 years old, older daughter 17, and younger daughter 9) who were brought to our craniofacial clinic with stigmata of CS and no previous surgical intervention. Patients had bicoronal craniosynostosis and exorbitism, with varying severity, sequelae, and comorbidities. Here, we delineate our technique of monobloc distraction osteogenesis with advancement osteotomies using dual “push–pull” method, elevation of a split anteriorly based tunneled pericranial flap to seal off nasal cavity, and internal and external distraction.Results:Our patients had favorable outcomes after reconstruction to reduce ocular symptoms and improve midface hypoplasia and aesthetic appearance. No intracranial injury, hardware/soft-tissue infection, hardware failure, or (new) loss of vision were encountered in 10 months follow-up.Conclusions:Dual “push–pull” monobloc distraction is safe and effective for a range of ages in CS; it allows good vector control, accommodates patient compliance, and allows early rigid external distraction device removal with sufficient time for consolidation. This surgery can be performed with highly satisfactory results.

Minimizing Duration of Headframe Wear for Le Fort I Maxillary Advancement with Distraction Osteogenesis Using Rigid External Distraction Devices

Minimizing Duration of Headframe Wear for Le Fort I Maxillary Advancement with Distraction Osteogenesis Using Rigid External Distraction Devices

Does the Rigid External Distraction Device Alter Maxillary Pitch in Cleft Maxillary Distraction?

Statement of problemCorrection of cleft maxillary hypoplasia remains a controversial topic. Surgical correction can be accomplished through Le Fort I orthognathic correction, internal distraction osteogenesis, or external distraction osteogenesis.1 Proponents of rigid external distraction (RED) osteogenesis describe the ability of multi-vector directional distraction control as opposed to univector internal distraction. There are currently limited data on the ability of the RED system to alter the maxillary occlusal pitch.The purpose of this study is to address the following clinical question: “Among cleft patients presenting with severe maxillary hypoplasia and treated with rigid external distraction, does the rigid external distraction system result in alteration of the maxillary pitch?”The study hypothesis is: among cleft patients presenting with maxillary hypoplasia treated with RED, the investigators hypothesize that there is no change in maxillary pitch with distraction.The study's specific aims are to design a retrospective cohort study and enroll a sample composed of cleft patients with maxillary hypoplasia treated with RED: 1) identify a cohort of patients with cleft maxillary hypoplasia, 2) quantify the degree of pre-operative maxillary hyperplasia, 3) measure changes in maxillary position achieved through RED. Materials and methodsTo address the research objectives, the investigators designed a retrospective cohort study. The study sample was derived from the population of patients with cleft maxillary hypoplasia who underwent RED by the Department of Oral and Maxillofacial Surgery at the University of Alabama - Birmingham from June 2007 to August 2019. Subjects eligible for study inclusion had cleft maxillary hypoplasia and underwent RED. Subjects were excluded if there were incomplete data collection or their records were not available for review.Demographic and radiographic variables were recorded. Demographics included gender, age at date of surgery, and history of ULCP vs. BLCP. Radiographic variables included standard cephalometric data recorded prior to distraction (T1) and after completion of distraction (T2). Methods of data analysisDescriptive statistics were computed for all study variables. Due to the potential for both positive and negative occlusal pitch change, a paired 2-tailed T-test was used to compare T1 and T2. The level of statistical significance was set at P < .05. ResultsThe study sample was composed of 45 subjects with a mean age at surgery of 12.2+3.4 years. Twenty-two (49%) were BCLP and 27 (60.0%) were male. At T1, mean SNA was 76.35+/-6.4 degrees, and the maxillary occlusal plane to Frankfort horizontal plane was 8.18+/-6.9 degrees. The mean anterior-posterior distraction distance was 11.4+/-5.7 mm. At T2, the mean SNA was 86.0+/-7.5 degrees, and the occlusal plane to FH was 3.78+/-7.3 degrees. The average maxillary occlusal pitch change was -4.4+/-5.8 degrees (P = .005). ConclusionFor cleft lip and palate patients with maxillary hypoplasia, surgical advancement with RED results in counterclockwise rotation of the maxillary occlusal plane.

Local Soft Tissue and Bone Displacements Following Midfacial Bipartition Distraction in Apert Syndrome - Quantification Using a Semi-Automated Method.

Patients with Apert syndrome experience midfacial hypoplasia, hypertelorism, and downslanting palpebral fissures which can be corrected by midfacial bipartition distraction with rigid external distraction device. Quantitative studies typically focus on quantifying rigid advancement and rotation postdistraction, but intrinsic shape changes of bone and soft tissue remain unknown. This study presents a method to quantify these changes. Pre- and post-operative computed tomography scans from patients with Apert syndrome undergoing midfacial bipartition distraction with rigid external distraction device were collected. Digital Imaging and Communications in Medicine files were converted to three-dimensional bone and soft tissue reconstructions. Postoperative reconstructions were aligned on the preoperative maxilla, followed by nonrigid iterative closest point transformation to determine local shape changes. Anatomical point-to-point displacements were calculated and visualized using a heatmap and arrow map. Nine patients were included.Zygomatic arches and frontal bone demonstrated the largest changes. Mid-lateral to supra-orbital rim showed an upward, inward motion. Mean bone displacements ranged from 3.3 to 12.8 mm. Soft tissue displacements were relatively smaller, with greatest changes at the lateral canthi. Midfacial bipartition distraction with rigid external distraction device results in upward, inward rotation of the orbits, upward rotation of the zygomatic arch, and relative posterior motion of the frontal bone. Local movements were successfully quantified using a novel method, which can be applied to other surgical techniques/syndromes.

Multidisciplinary prosthetic rehabilitation of an adult patient with cleidocranial dysplasia by using a rapid external distraction device: A clinical report

The multidisciplinary treatment of a 41-year-old man with cleidocranial dysplasia is described. A rapid external distraction device was used to reposition the maxilla before the prosthodontic rehabilitation.

Morphological improvement after multi-directional cranial distraction osteogenesis procedure for syndromic craniosynostosis.

The multidirectional cranial distraction osteogenesis (MCDO) procedure, which uses an external distraction device, enables tailor-made distraction in an arbitrary direction, eliminating the disadvantage of unidirectional distraction with an internal distraction device. Multiple-suture synostosis cases for syndromic craniosynostosis patients are better indicated for this procedure. Here the authors describe seven cases in which the MCDO procedure was used to treat syndromic craniosynostosis. In each case, the MCDO procedure and postoperative distraction, with reference to midsagittal vector analysis of normal morphology in Japanese children, resulted in morphological improvement.The video can be found here: https://vimeo.com/519006555

External Screw-Threaded Traction Device Helps Optimize Finger Joint Mobility in Severe Stage III and IV Dupuytren Disease.

BackgroundTreating advanced finger joint contractures from Dupuytren disease remains a challenge. We evaluated the effectiveness of a skeletal distraction device versus alternative treatment options.Material/MethodsWe analyzed the surgical treatment of contracted finger joints in stage III and stage IV Dupuytren’s disease over a 10-year period. Data were obtained from inpatient and outpatient medical records, including postoperative clinical examinations and extended Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire scores. Complications of infection, postoperative pain, and wound healing disorders were recorded.ResultsA total of 79 patients (83 hands) were assigned to 2 treatment groups. Patients in group 1 underwent an initial open transection of the main fibrous cord, Z-plasty, distraction with the Erlangen external distraction device, and fasciectomy. The distraction period was 13 to 81 days (mean 31 days). Group 2 underwent a conventional single-stage fasciectomy and arthrolysis. DASH scores and subjective patient satisfaction were lower in group 1 (20.7/33%) than in group 2 (10.3/50%). However, the staged approach of group 1 to treat proximal interphalangeal joint contractures in the long term (improvement >40%) was more effective than the approach of group 2 (>33%). Distraction device pin infections occurred in 20% of hands. Postoperative pain and complex regional pain syndrome type I occurred in 25% of hands in group 1 and 3% in group 2.ConclusionsA screw thread driven external fixation device is useful in end-stage Dupuytren’s finger joint contractures. It is indicated when joint contractures are advanced and simple arthrolysis is insufficient.

Relevance of a novel external dynamic distraction device for treating back pain.

Low back pain is a common, expensive, and disabling condition in industrialized countries. There is still no consensus for its ideal management. Believing in the beneficial effect of traction, we developed a novel external dynamic distraction device. The purpose of this work was to demonstrate that external distraction allows limiting the pressure exerted in standing-up position on the lower intervertebral discs. Numerical and cadaveric studies were used as complementary approaches. Firstly, we implemented the device into a numerical model of a validated musculoskeletal software (Anybody Modeling System) and we calculated the lower disc pressure while traction forces were applied. Secondly, we performed an anatomical study using a non-formalin preserved cadaver placed in a sitting position. A pressure sensor was placed in the lower discs under fluoroscopic control through a Jamshidi needle. The intradiscal pressure was then measured continuously at rest while applying a traction force of 200 N. Both numerical and cadaveric studies demonstrated a decrease in intradiscal pressures after applying a traction force with the external device. Using the numerical model, we showed that tensile forces below 500 N in total were sufficient. The application of higher forces seems useless and potentially deleterious. External dynamic distraction device is able to significantly decrease the intradiscal pressure in a sitting or standing position. However, the therapeutic effects need to be proven using clinical studies.

Return to Sport and Work after Randomization for Knee Distraction versus High Tibial Osteotomy: Is There a Difference?

Knee joint distraction (KJD) is a novel technique for relatively young knee osteoarthritis (OA) patients. With KJD, an external distraction device creates temporary total absence of contact between cartilage surfaces, which results in pain relief and possibly limits the progression of knee OA. Recently, KJD showed similar clinical outcomes compared with high tibial osteotomy (HTO). Yet, no comparative data exist regarding return to sport (RTS) and return to work (RTW) after KJD. Therefore, our aim was to compare RTS and RTW between KJD and HTO. We performed a cross-sectional follow-up study in patients <65 years who previously participated in a randomized controlled trial comparing KJD and HTO. Out of 62 eligible patients, 55 patients responded and 51 completed the questionnaire (16 KJDs and 35 HTOs) at 5-year follow-up. The primary outcome measures were the percentages of RTS and RTW. Secondary outcome measures included time to RTS/RTW, and pre- and postoperative Tegner's (higher is more active), and Work Osteoarthritis or Joint-Replacement Questionnaire (WORQ) scores (higher is better work ability). Patients' baseline characteristics did not differ. Total 1 year after KJD, 79% returned to sport versus 80% after HTO (not significant [n.s.]). RTS <6 months was 73 and 75%, respectively (n.s.). RTW 1 year after KJD was 94 versus 97% after HTO (n.s.), and 91 versus 87% <6 months (n.s.). The median Tegner's score decreased from 5.0 to 3.5 after KJD, and from 5.0 to 3.0 after HTO (n.s.). The mean WORQ score improvement was higher after HTO (16 ± 16) than after KJD (6 ± 13; p = 0.04). Thus, no differences were found for sport and work participation between KJD and HTO in our small, though first ever, cohort. Overall, these findings may support further investigation into KJD as a possible joint-preserving option for challenging "young" knee OA patients. The level of evidence is III.

Spring-Assisted Distraction Osteogenesis for the Treatment of Shunt-Induced Craniosynostosis.

Shunt-induced craniosynostosis is a rare complication of ventricular shunting for hydrocephalus in pediatric patients. Although the exact pathophysiology of this form of secondary craniosynostosis is not well understood, the current understanding is that persistent drainage of the ventricular shunt causes decreased dural tension, resulting in decreased expansile force on the cranium and premature sutural fusion. Due to the low incidence of this complication, there is no consensus on the ideal treatment for shunt-induced craniosynostosis. In recent years, distraction osteogenesis has been employed with greater frequency, as it is felt to counter the fundamental problem of decreased expansile force on the cranium. However, in a patient with a ventricular shunt, placement of external hardware in close proximity to the shunt could cause significant morbidity due to the increased risk of shunt infection. We present the management of a patient with shunt-induced craniosynostosis who continued to be shunt-dependent. We chose to use fully buried springs to create an expansile force on the cranium as an alternative to external distractors so as to mitigate the risk of infection. We demonstrate that spring-assisted distraction osteogenesis can be an effective treatment modality for patients with shunt-induced craniosynostosis. This method should be considered in patients with contraindications to external distraction devices, such as ongoing shunt dependency.

Midface distraction osteogenesis using a modified external device and 3D virtual simulation: technical note.

Distraction osteogenesis (DO) with an external distraction device such as the rigid external distraction frame has become an established method for treating midface hypoplasia in faciocraniosynostosis. It allows for greater advancement of the midface in comparison with traditional Le Fort III osteotomies, associated or not with fronto-orbital osteotomies (Le Fort IV). However, the forward movement of the bone segments may not always be performed obeying an ideal distraction vector, resulting in asymmetries, anterior open bite, and loosening of screws. In addition, the cost of the distraction devices is significant and may preclude their routine use in developing countries. We present an alternative device and method for craniofacial advancement in a clinical case of Crouzon's syndrome. A 3D virtual simulation of the distraction vector and a modified external device were used in the current case. The alternative external device in this case proved to be safe, effective, and reliable.