Advancement of the midface using distraction techniques

LeFort III Versus Monobloc Frontofacial Advancement: A Comparative Analysis of Soft Tissue Changes

INTRODUCTION

The LeFort III and monobloc are commonly used midface advancement procedures for patients with syndromic craniosynostosis with well characterized postoperative skeletal changes. However, the differential effects of these procedures on facial soft tissues are less understood. The purpose of this study was to critically analyze and compare the effects of these 2 procedures on the overlying soft tissues of the face.

METHODS

Frontal and lateral preoperative and postoperative photographs of patients undergoing monobloc or LeFort III were retrospectively analyzed using ImageJ to measure soft tissue landmarks. Measurements included height of facial thirds, nasal length and width, intercanthal distance, and palpebral fissure height and width. Facial convexity was quantified by calculating the angle between sellion (radix), subnasale, and pogonion on lateral photographs.

RESULTS

Twenty-five patients with an average age of 6.7 years (range 4.8-14.5) undergoing monobloc (n=12) and LeFort III (n=13) were identified retrospectively and analyzed preoperatively and 6.4±3.6 months postoperatively. Patients undergoing LeFort III had a greater average postoperative increase in facial convexity angle acuity (28.2°) than patients undergoing monobloc (17.8°, P =0.021). Patients in both groups experience postoperative increases in nasal width ( P <0.001) and decreases in palpebral fissure height ( P <0.001).

CONCLUSIONS

Both subcranial LeFort III advancements and monobloc frontofacial advancements resulted in significant changes in the soft tissues. Patients undergoing LeFort III procedures achieved greater acuity of the facial convexity angle, likely because the nasion is not advanced with the LeFort III segment.

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

Background

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.

Methods

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.

Results

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.

Conclusion

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.

Long-term follow-up of a patient diagnosed with Crouzon syndrome who underwent Le Fort I and III distraction osteogenesis using a rigid external distractor system

OBJECTIVE

This case report describes the successful treatment of a patient with Crouzon syndrome with severe midfacial deficiency and malocclusion, including reverse overjet.

MATERIALS AND METHODS

In Phase I treatment, maxillary lateral expansion and protraction were performed. In Phase II treatment, after lateral expansion of the maxilla and leveling of the maxillary and mandibular dentition, an orthognathic approach including simultaneous Le Fort I and III osteotomies with distraction osteogenesis (DO) was used to improve the midfacial deficiency.

RESULTS

After DO, 12.0 mm of the medial maxillary buttress and 9.0 mm of maxillary (point A) advancement were achieved, which resulted in a favorable facial profile and stable occlusion.

CONCLUSION

Even after 8 years of retention, the patient's profile and occlusion were preserved without any significant relapse.

Magnitude of Horizontal Advancement is Associated With Apnea Hypopnea Index Improvement and Counter-Clockwise Maxillary Rotation After Subcranial Distraction for Syndromic Synostosis

PURPOSE

Subcranial midface distraction is used to treat central midface deficiency in syndromic synostosis. Our aim was to determine which maxillary movements were associated with improvement in measures of obstructive sleep apnea.

METHODS

This was a retrospective cohort study that reviewed patients with syndromic midface retrusion and documented sleep apnea who underwent subcranial midface distraction via either Le Fort 3 osteotomy or Le Fort 2 osteotomy with zygomatic repositioning. The predictor variables measured on cephalograms were the magnitude and direction of midface and mandibular movements. The primary outcome was the change in the apnea hypopnea index (AHI) from polysomnography before and after surgery. The secondary outcomes were volumes of upper airway containing bone spaces calculated from computed tomography scans. Data analysis included linear regression to estimate the effect of distraction vectors on bone space volumes and AHI changes.

RESULTS

We included 18 patients primarily with Crouzon or Apert syndrome. The magnitude of distraction in a horizontal direction was the most significant factor for AHI improvement and primarily expanded the nasopharyngeal space, but with a smaller impact on the oral cavity space. Clockwise palate rotation was most influenced by a downward direction of distraction, with 24° below horizontal creating a neutral advancement. The greater the magnitude of advancement, the more likely a counterclockwise rotation was observed.

CONCLUSIONS

Horizontal magnitude of advancement had the greatest impact on AHI improvement. Vertical lengthening and closure of anterior open bite deformities can be done without compromising airway results as long as total advancement is not compromised. Palate rotation is best controlled by a downward distraction vector, but counterclockwise rotation increases with greater advancement.

Long Term Speech Outcomes Following Midface Advancement in Syndromic Craniosynostosis

Midface advancement by distraction osteogenesis (DO) is commonly performed in patients with craniosynostosis for indications including midface hypoplasia, exorbitism, obstructive sleep apnea, class III malocclusion, and overall aesthetic facial deficiency. There is evidence to suggest that maxillary LeFort I advancement increases the risk of velopharyngeal dysfunction in the cleft palate population, yet few studies have investigated changes in speech following LeFort III or monobloc midface advancement in patients with syndromic craniosynostosis. The purpose of this study was to examine the effect of midface DO on speech as indicated by the Pittsburgh Weighted Speech Score in patients with Apert, Crouzon, and Pfeiffer Syndrome. Among 73 midface advancement cases performed during the study period, 19 cases met inclusion criteria. Overall, the highest post-advancement Pittsburgh Weighted Speech Score (PWSS) was significantly higher than the pre-advancement PWSS (0.52 versus 2.42, P = 0.01), indicating an acute worsening of VPI post-advancement. Specifically, the PWSS components nasal emission and nasality were significantly higher post-advancement than pre-advancement (nasal emission: 1.16 versus 0.21, P = 0.02) (nasality: 0.68 versus 0.05, P = 0.04). However, there was no significant difference between pre-advancement PWSS and the latest post-advancement PWSS (P = 0.31). Midface distraction is associated with an acute worsening of VPI post-operatively that is followed by improvement, and often resolution over time. Future work with additional patient accrual is needed to determine the effect of different advancement procedures and syndromes on VPI rates and profundity.

Le Fort III Distraction Osteogenesis Without Bicoronal Incision

PURPOSE

Recently, midfacial hypoplasia for syndromic craniosynostosi has been corrected by Le Fort III distraction osteogenesis. During conventional Le Fort III osteotomy, osteotomy is performed via bicoronal incision. In contrast, the authors have developed a technique for performing Le Fort III osteotomy using internal devices but without bicoronal incision.

PATIENTS AND METHODS

The authors performed the Le Fort III distraction technique in 22 patients. Of these, 17 patients underwent an approach using conventional coronal incision; the others underwent an approach without coronal incision. This new approach was performed using a McCord incision, a brow incision, and gingivo-buccal sulcus incisions. We then performed osteotomy and attached the internal device.

RESULTS

The age of patients ranged from 6 to 21 years (mean: 14.1 ± 5.0 years) and 6 to 38 years (mean: 19.6 ± 11.5 years) in the groups with or without coronal incision, respectively. Mean operative time was 410 ± 196 minutes in the group with coronal incision and 357 ± 121 minutes in the group without coronal incision. Mean blood loss (per unit of body weight) was 51.3 ± 38.5 and 33.9 ± 9.9 ml/kg) in the groups with or without coronal incision, respectively. There were no complications, except in the case of a 38-year-old patient, the oldest patient, who lost vision in the left eye after surgery.

CONCLUSION

A direct facial approach for Le Fort III distraction was useful because of its reduced operative time and blood loss. However, down fracture following incomplete osteotomy or inadequate dissection of the orbit may cause blindness. Consequently, this technique requires careful attention.

Orthodontic-Orthopedic-Surgical Treatment of Syndromic Third Class: Proposal of a New Craniofacial Cephalometric Method

The management of patients suffering from class III due to syndromic craniosynostosis requires a multidisciplinary team to prevent and correct the complex clinical features related to the syndrome. Among the main clinical features, the midface hypoplasia requires surgical advancement with a rigid external distraction device. The comparison of pre- and postdistraction lateral cephalometries is often difficult in these patients, because the craniofacial advancement mobilizes the landmarks routinely used in cephalometry. Aim of this study is to evaluate occlusal, maxillary, and facial changes obtained after the midface osteodistraction using as reference the PM plane, that does not undergo postsurgical spatial modifications.The before and after surgery lateral X-rays of 12 patients were compared to test the cephalometric protocol: 10 angles and 11 linear distances were evaluated.The cephalometric comparison before and after osteodistractions of syndromic class III, using as reference the Enlow's PM plane, has confirmed the data present in current literature, consisting in forward and downward movements of facial middle 3rd, with clockwise rotation of the splanchnocranium and increase of the facial heights. The use of the PM plane as reference could be the solution to problems that have been an obstacle for the study of occlusal and facial changes in patients affected by craniofacial dysostosis.

Comparison of Midface Advancement by External and Internal Craniofacial Distraction Osteogenesis

BACKGROUND

Distraction osteogenesis (DO) is employed to address the midface abnormalities using either an external DO (EDO) or an internal DO (IDO) device. There are few studies that have reported EDO and IDO outcomes through cephalometric evaluation. The aim of this retrospective, record-based study is to compare the change in position of the midface resulting from distraction of noncomplicated cases of Le Fort III osteotomies with EDO as well as IDO and compare the groups using standard right facing lateral cephalometry. We hypothesized that there would be no difference between EDO and IDO in terms of displacement (of point of reference) as well as complications.

MATERIALS AND METHODS

Retrospective analyses of cases fulfilling inclusion and exclusion criteria were retrieved from archives. Using two sets of right-side cephalometry, preoperative and after consolidation (at the end of the treatment), the changes in Point A and Orbitale (O) as described by Lima et al. were used for the study. Movement in X-axis and Y-axis was noted down and subjected to statistical analysis. Descriptive statistics, the coefficient of variability (expressed as percentage), and the interquartile range (maximum and minimum values) were presented. P ≤ 0.05 was taken as statistically significant.

RESULTS

Significant midface advancement was achieved with the procedure. There were five cases of EDO and eight cases of IDO. The age at which patients were operated ranged from 9 to 18 years (mean: 13 years). The mean follow-up time was for 14 ± 8 months. There were eight females (3 - EDO and 5 - IDO) and five males in total. There was no complication in the entire study group. The difference in total bone length gain along the horizontal axis was as follows: 12.19 and 12.84 along the Point A for EDO and IDO and 3.89 and 4.65 along the Point O for EDO and IDO, respectively. The difference was not statistically significant (P = 0.833 and 0.622, respectively). The total movement along the vector at Point A in EDO and IDO was 13.08 and 12.56, respectively, the difference of which was not statistically significant (P = 1); while along the vector at Point O in EDO and IDO, the total movement was 10.98 and 11.48, respectively, the difference of which was not again statistically significant (P = 0.833).

DISCUSSION

The significance of the difference in EDO and IDO is discussed using the biomechanical principles and the results deliberated based on the existing literature.

CONCLUSION

The positioning of the devices plays a significant role in deciding the outcome. Both the distractors have their distinct advantages and their applications have to be customized.

Unusual Craniofacial Distraction

A retrospective Institutional Review Board-approved review was performed at the Institute of Reconstructive Plastic Surgery, NYU Langone Medical Center, of patients undergoing craniofacial distraction osteogenesis procedures using the rigid external distractor device between 2000 and 2010. Three particularly challenging cases were identified and are presented here.

The Effect of Cranio-Maxillofacial Osteotomies and Distraction Osteogenesis on Speech and Velopharyngeal Status: A Critical Review

Objectives

To review the impact of maxillary advancement by orthognathic surgery and distraction osteogenesis on speech and velopharyngeal status based on the literature of the past 30+ years, to review the methods employed in previous studies to explain discrepancies in results, and to make recommendations for future studies.

Method

Thirty-nine published articles on the effect of cranio-maxillofacial osteotomies and distraction osteogenesis on speech and velopharyngeal status were identified and were systematically analyzed. A total of 747 cases of cleft and noncleft patients were selected, including craniofacial deformities and syndromes mainly involving maxillary hypoplasia.

Results

Findings varied. Many studies found that surgery had no impact on speech and velopharyngeal status. Some reported worsening only in patients with preexisting velopharyngeal impairment or those with borderline velopharyngeal function before surgery. There was no clear difference in outcome between distraction and conventional osteotomy, although there have been few systematic comparisons. There was great variation among reviewed studies in the number of subjects, speech sample, number and type of listeners, speech outcome measures, and timing of postoperative assessment. Few studies employed reliability measures.

Conclusion

None of the 39 reviewed studies compared conventional osteotomy and distraction by including both groups in a single study. Randomized controlled trials with adequate number of subjects and follow-up duration are needed.

Distraction Osteogenesis for Bony Repair of Cleft Palate by Using Persistent Elastic Force: Experimental Study in Dogs

Objective

The purpose of this study was to investigate the possibility of closing a cleft and lengthening the hard palate by the technique of distraction osteogenesis with elastic forces and to evaluate the influence of the management on the facial structure.

Design

Thirty 6-month-old mongrel dogs were assigned randomly to two groups with five subgroups for different purpose.

Interventions

An 8- × 25-mm cleft was surgically created in the posterior hard palate in experimental and sham control dogs. Bone markers were implanted in the hard palate. Osteotomies were carried out followed by the installation of a distractor made of NiTi-shape memory alloy.

Outcome measures

The results were evaluated clinically, radiographically, and histologically. Anthropometric data that represented the length, width, and height of the maxilla were taken on the dry skull of the control and experimental dogs and were analyzed statistically.

Results

The cleft was closed and the hard palate was lengthened after 2 to 3 weeks of distraction in all the experimental dogs. New bone formation was found at the site of osteotomy. The variables of facial length, height, and width showed no significant difference between the two groups (p > .05). The length of the hard palate in the experimental group was longer than that in the control group (p < .01).

Conclusion

Distraction osteogenesis with the elastic device of NiTi-shape memory alloy is effective for closing the cleft and lengthening the hard palate in a canine cleft model. There is no interference on the growth of the maxillofacial structures with the technique.

Speech Outcome and Velopharyngeal Function in Cleft Palate: Comparison of Le Fort I Maxillary Osteotomy and Distraction Osteogenesis—Early Results

Objective:

To compare speech outcome and velopharyngeal (VP) status of subjects with repaired cleft palate who underwent either conventional Le Fort I osteotomy or maxillary distraction osteogenesis to correct maxillary hypoplasia.

Design:

Prospective randomized study with blind assessment of speech outcome and VP status.

Subjects:

Twenty-two subjects were randomized into conventional Le Fort I osteotomy and Le Fort I distraction groups. All were native Chinese (Cantonese) speakers.

Method:

Perceptual judgment of resonance and nasal emission, study of VP structures by nasoendoscopy, and instrumental measurement by nasometry. Assessments were performed preoperatively and at 3 months postoperatively.

Main Outcome Measures:

Assessment of VP closure, perceptual rating of hypernasality and nasal emission, nasalance, and amount of maxillary advancement.

Results:

There was no statistical difference in any of the outcome measures between the 10 subjects with conventional Le Fort I osteotomy and the 12 subjects with maxillary distraction: hypernasality (chi-square = 3.850, p = 0.221), nasal emission (chi-square = 0.687, p = 0.774), VP gap size (chi-square = 1.527, p = 0.635, and nasalance (t = −0.145, p = 0.886). There was no correlation between amount of maxillary advancement and any of the outcome measures (p = .05 for all). Changes in VP gap size and resonance are described.

Conclusion:

Results need to be interpreted with caution because of the small sample size and early follow-up. However, this study utilized an assessment protocol involving a variety of outcome measures and careful consideration of reliability factors, which can be a model for further and follow-up studies.

Distraction osteogenesis as a treatment of obstructive sleep apnea syndrome: A systematic review

BACKGROUND

To conduct a systematic review to answer the clinical question "What are the effectiveness of mandibular distraction osteogenesis (MDO) and its complications to treat patients with obstructive sleep apnea syndrome (OSAS)?".

METHODS

A systematic search including a computer search with specific keywords, reference list search, and manual search were done. Relevant articles on MDO were assessed and selected in 3 rounds for final review based on 5 predefined inclusion criteria and followed by a round of critical appraisal. Different types of distraction and their treatment outcomes of OSAS were recorded with standardized form and analyzed.

RESULTS

Twelve articles were included in the final review. A total of 256 patients aged 7 days to 60 years were treated with either external or internal MDO, with a mean follow-up period of 6 to 37 months. The average distraction distance of 12 to 29 mm was achieved with various distraction protocols. The success rate for adult patients was 100%, and cure rates were ranged from 82% to 100%. The definition of success or cure for OSAS in children or infants was not defined. Therefore, there were no clearly reported success or cure rates for children/infants in the included studies. However, all studies reported that these patients showed significant improvement in OSAS, with many of them who avoided tracheostomy or had the tracheostomy decannulated. The complication rates were ranged from 0% to 21.4%, with most being from local wound infections or neurosensory disturbances.

CONCLUSION

This systematic review showed that MDO was effective in resolving OSAS in adults with retrognathic mandible. MDO also showed promising results in infants or children with OSAS. From the results of this systematic review, we recommend to define the criteria of success or cure for OSAS surgery in children and infants. We also recommend setting up randomized controlled trials to compare MDO with traditional maxillomandibular advancement surgery for OSAS patients and to provide a better evidence on the success and complication rates of the techniques.

An Update on Midface Advancement Using Le Fort II and III Distraction Osteogenesis

Le Fort II and III distraction osteogenesis (DO) is a powerful tool in the craniofacial armamentarium that is most often employed to treat patients with craniofacial syndromes such as Crouzon, Apert, or Pfeiffer syndrome who present with midfacial retrusion, shallow orbits, exorbitism, malocclusion, obstructive sleep apnea and facial imbalance. In this article, the authors will provide the reader with an update on techniques for the treatment of various forms of midfacial retrusion.

Bilateral squamosal suture synostosis: A rare form of isolated craniosynostosis in Crouzon syndrome

Craniosynostosis is a pathologic condition which is characterized by the premature fusion of cranial sutures. It may occur alone or in association with other anomalies making up various syndromes. Crouzon syndrome is the most common craniosynostosis syndrome. Bicoronal sutures fusion is most commonly involved in Crouzon syndrome. There have only been a handful of cases of squamosal suture synostosis described in the surgery literature with the few ones described in Crouzon syndrome associated with other types of craniosynostosis. To the best of our knowledge, we are presenting the first case of isolated bilateral squamosal suture synostosis in a patient with Crouzon syndrome in a radiology journal with emphasis on its radiological appearance.

The role of distraction osteogenesis in the management of craniofacial syndromes

Distraction osteogenesis (DO) has been established as a useful technique in the correction of skeletal anomalies of the long bones for several decades. However, the use of DO in the management of craniofacial deformities has been evolving over the past 20 years, with initial experience in the mandible, followed by the mid-face and subsequently, the cranium. This review aims to provide an overview of the current role of DO in the treatment of patients with craniofacial anomalies.

Pediatric Craniofacial Surgery: A Review for the Multidisciplinary Team

Pediatric craniofacial surgery is a specialty that grew dramatically in the 20th century and continues to evolve today. Out of the efforts to correct facial deformities encountered during World War II, the techniques of modern craniofacial surgery developed. An analysis of the relevant literature allowed the authors to explore this historical progression.

Current advances in technology, tissue engineering, and molecular biology have further refined pediatric craniofacial surgery. The development of distraction osteogenesis and the progressive study of craniosynostosis provide remarkable examples of this momentum. The growing study of genetics, biotechnology, the influence of growth factors, and stem cell research provide additional avenues of innovation for the future. The following article is intended to reveal a greater understanding of pediatric craniofacial surgery by examining the past, present, and possible future direction. It is intended both for the surgeon, as well as for the nonsurgical individual specialists vital to the multidisciplinary craniofacial team.

Orbital change following Le Fort III advancement in syndromic craniosynostosis: quantitative evaluation of orbital volume, infra-orbital rim and globe position

Patients with syndromic craniosynostosis suffering from shallow orbits due to midface hypoplasia can be treated with a Le Fort III advancement osteotomy. This study evaluates the influence of Le Fort III advancement on orbital volume, position of the infra-orbital rim and globe. In pre- and post-operative CT-scans of 18 syndromic craniosynostosis patients, segmentation of the left and right orbit was performed and the infra-orbital rim and globe were marked. By superimposing the pre- and post-operative scans and by creating a reference coordinate system, movements of the infra-orbital rim and globe were assessed. Orbital volume increased significantly, by 27.2% for the left and 28.4% for the right orbit. Significant anterior movements of the left infra-orbital rim of 12.0mm (SD 4.2) and right infra-orbital rim of 12.8mm (SD 4.9) were demonstrated. Significant medial movements of 1.7mm (SD 2.2) of the left globe and 1.5mm (SD 1.9) of the right globe were demonstrated. There was a significant correlation between anterior infra-orbital rim movement and the increase in orbital volume. Significant orbital volume increase has been demonstrated following Le Fort III advancement. The position of the infra-orbital rim was moved forward significantly, whereas the globe position remained relatively unaffected.

Meningoencephalocele and other dural disruptions: complications of Le Fort III midfacial osteotomies and distraction

OBJECTIVE

Complications of Le Fort III midfacial advancement include cerebrospinal fluid (CSF) rhinorrhea, meningitis, and ocular and cerebral injury. This report reviews our experience with Le Fort III distraction, highlighting complications of dural disruption, and correlates occurrences with the anatomy of the cranial base and prior cranial procedures.

METHODS

This was a retrospective chart review of all patients who had Le Fort III subcranial osteotomies and midfacial advancement with distraction. Complications related to dural disruption were documented. The anatomy of the anterior cranial fossa was assessed with preoperative computed tomographic (CT) scans and compared with age- and sex-matched normal control scans, with particular attention paid to the anterior cranial fossa and fovea ethmoidalis (FE). On reconstructed midline sagittal images, the anterior cranial fossa was characterized as normal, sagging, or slanting. On reconstructed coronal images, immediately posterior to the plane of the lacrimal sac, each FE was characterized as normal, flattened, or depressed, relative to the adjacent cribriform plates.

RESULTS

Thirty-one patients have had Le Fort III midfacial advancement with distraction at Children's Hospital Boston since 1995. Two patients underwent a second Le Fort III distraction. Two patients (6.5%) had postoperative CSF rhinorrhea, 2 had CSF leak at a pin site, and 1 patient had a late complication of meningoencephalocele. Twenty-six patients had 27 available preoperative three-dimensional reformatted CT scans. Seven of these had a normal sagittal anterior cranial fossa and normal coronal FE morphology. One of these 7 patients had a second CT at an older age showing development of bilateral FE flattening. Eleven patients had a sagging midline anterior cranial fossa including both patients who developed CSF rhinorrhea. Of these 11 patients, all had unilateral or bilateral flattening or depression of the FE, and 5 had abnormal slanting of the anterior cranial fossa. Eight patients had normal sagittal morphology, but bilateral or unilateral depression of the FE, including the patient who developed a meningoencephalocele. All patients with CSF leak had previously had a fronto-orbital advancement (FOA). Three of 4 patients with CSF leak did not have prior ventriculoperitoneal shunt placement. The patient with postoperative meningoencephalocele had prior FOA and shunt.

CONCLUSIONS

We studied the abnormal position of the sagging or slanted anterior cranial base and depressed FE in patients with syndromic coronal synostosis. These findings may explain the risk for dural tear during osteotomies at the nasofrontal suture and superior-medial orbital wall. Attention to the morphology of the anterior cranial base, as seen on sagittal and coronal CT images, aids in preventing these complications. Patients who have a shunt are at lower risk for CSF leak; however, patients who have had an FOA are at higher risk.

Meningoencephalocele: a late complication of Le Fort III midfacial advancement in a patient with Crouzon syndrome

Complications of Le Fort III midfacial advancement include CSF rhinorrhea, meningitis, and ocular and cerebral injury. This report reviews the anatomy of the Le Fort III osteotomies and their relevance to the unusual complication of meningoencephalocele. In this report, a young male patient with Crouzon syndrome underwent subcranial midfacial advancement at the age of 10 years for obstructive sleep apnea and ocular exposure. He presented 4 years later complaining of nasal obstruction. On physical examination, a mucous-covered mass was noted in the left upper nasal vault medial to the turbinates. Computed tomography scanning and MR imaging confirmed the diagnosis of frontoethmoidal meningoencephalocele. Repair of the meningoencephalocele was accomplished using a combined neurosurgery and plastic surgery approach. Meningoencephalocele is a rare complication of subcranial midfacial advancement. The abnormal anatomy of the anterior cranial base in patients with syndromic craniosynostosis places them at greater risk for fracture of the cribriform plate and dural tears during this procedure. Unrecognized dural injury is the etiology of this complication in this young patient; however, elevated intracranial pressure may have been a confounding factor. Attention to the anatomy of the anterior cranial base, as seen on sagittal CT images, will aid in preventing this complication.

Craniofacial surgery, from past pioneers to future promise

OBJECTIVES

As a surgical subspecialty devoted to restoration of normal facial and calvarial anatomy, craniofacial surgeons must navigate the balance between pathologic states of bone excess and bone deficit. While current techniques employed take root in lessons learned from the success and failure of early pioneers, craniofacial surgery continues to evolve, and novel modalities will undoubtedly arise integrating past and present experiences with future promise to effectively treat craniofacial disorders.

METHODS

This review provides an overview of current approaches in craniofacial surgery for treating states of bone excess and deficit, recent advances in our understanding of the molecular and cellular processes underlying craniosynostosis, a pathological state of bone excess, and current research efforts in cellular-based therapies for bone regeneration.

RESULTS

The surgical treatment of bone excess and deficit has evolved to improve both the functional and morphological outcomes of affected patients. Recent progress in elucidating the molecular and cellular mechanisms governing bone formation will be instrumental for developing improved therapies for the treatment of pathological states of bone excess and deficit.

CONCLUSIONS

While significant advances have been achieved in craniofacial surgery, improved strategies for addressing states of bone excess and bone deficit in the craniofacial region are needed. Investigations on the biomolecular events involved in craniosynostosis and cellular-based bone tissue engineering may soon be added to the armamentarium of surgeons treating craniofacial dysmorphologies.

Calvarial reshaping using bifocal bidirectional transport distraction osteogenesis

PURPOSE

The aim of this study is to assess 3-dimensional reconstruction of cranial defects by use of bifocal bidirectional transport distraction osteogenesis (BBTDO).

MATERIALS AND METHODS

This study was performed on 8 sheep, divided into a control group (n = 3) and treatment group (n = 5). Full-thickness cranial defects (50 x 40 mm) were created on calvaria. In the control group only the skin was closed. In the treatment group BBTDO was performed. Distraction was performed with a custom-made distraction device with a transport segment of 40 x 20 mm. After a 5-day period of latency, distraction was applied to the transport segment. During the first 20 days of distraction, the transport segment was distracted 1 mm in the forward direction and 0.5 mm in the upward direction. After the next 20 days of distraction, the transport segment was distracted 1 mm forward and 0.5 downward. After a total of 40 days' distraction, a 30-day consolidation period was applied. Macroscopic, radiologic (computed tomography with volume measurements), and histologic evaluations were done.

RESULTS

No major complications were seen during the whole study period. In the control group the bone defects remained unhealed at the end of the study period. The same-sized defects in the treatment group healed with a convexity like the calvaria. Preoperative and postoperative cranial volume measurements of the treatment group animals showed an increase in cranial volume (P < .05). Histologic evaluation showed inductive bone regeneration and mature bone structure development within the distraction zone.

CONCLUSION

The BBTDO is an effective and safe technique for 3-dimensional closure of cranial defects.

Evaluation of cephalometric points in midface bone lengthening with the use of a rigid external device in syndromic craniosynostosis patients

Distraction osteogenesis has been extensively used to correct severe midface hypoplasia in syndromic craniosynostosis patients. However few studies have reported midface distraction outcomes through cephalometric evaluation.

Aim

The purpose of the present study was to evaluate outcomes with midface distraction rigid external device (RED) in patients with syndromic craniosynostosis, in terms of quantity of bone lengthening, skeletal stability and facial growth.

Materials and methods

Eleven patients were retrospectively evaluated in this study. Cephalometrics was carried out through three teleradiographies from each patient (T1 -before surgery; T2- immediate postop, rigth after distractor removal; T3 - late postop, obtained with a minimal interval of 12 months after surgery).

Results

Significant midface advancement was achieved with the procedure. The rate of horizontal relapse was minimal. We noticed a clear vertical facial growth, contrary to what was seen in the horizontal aspect, when there was a mild posterior relapse and no growth evidence.

Conclusion

Cephalometric evaluation showed adequate results in midface bone lengthening with rigid external distractor.

Stability of orthognathic surgery and distraction osteogenesis: options and alternatives

Relapse in orthognathic surgery is multifactorial and can be attributed to posttreatment growth, condylar changes, lack of rigid fixation, and muscle pull and function. Consideration of these factors can aide the surgeon in the decision-making process with regards to treatment options and alternatives. This article reviews the stability of various orthognathic movements using traditional osteotomies and fixation, and compares them to what is currently in the literature regarding distraction osteogenesis.

Long-term stability after craniofacial distraction osteogenesis

PURPOSE

This study was conducted to systematically review long-term skeletal stability after craniofacial distraction osteogenesis.

MATERIALS AND METHODS

Several electronic databases (Old Medline, Medline, Medline In-Process and Other Non-Indexed Citations, Pubmed, Embase, Web of Science, and all EBM reviews [Cochrane Database of Systematic Reviews, ACP Journal Club, DARE, and CCTR]) were searched. Key words used in the search were "distraction," "osteogenesis," "craniofacial," "maxillofacial," "stability," "relapse," and "recurrence." MeSH terms and truncations of these terms were selected with the help of a health science librarian. Abstracts that appeared to contain at least 3 years of postsurgical data were selected. The original articles were then retrieved and evaluated to ensure that they actually had 3 years of data after craniofacial distraction osteogenesis. The references were also hand-searched for possible missing articles that were not indexed in the searched databases.

RESULTS

A total of 118 abstracts were found in the electronic searches. After the first set of selection criteria was applied on these abstracts, 22 articles were retrieved. After the final selection criteria were applied on these 22 articles, only 6 articles were finally selected. These 6 articles reported long-term stability after craniofacial distraction osteogenesis. Sample sizes were small, and the methodological quality of the studies was poor.

CONCLUSIONS

Although, based on the selected studies, craniofacial bone distraction osteogenesis appeared to show long-term stability; limitations of the studies merit caution in interpreting these findings. Some early relapse occurred in the first 3 years postdistraction, but stability was maintained thereafter. Some methodologically sounder studies are needed to confirm the present findings.

Advancement of the midface, from conventional Le Fort III osteotomy to Le Fort III distraction: review of the literature

Since its introduction in about 1950, the Le Fort III (LF III) procedure has become a widely accepted treatment for correction of midface hypoplasia and related functional and esthetic problems. As long-term surgical experience grows and improvements are made in technique, equipment and peri-operative care, the number of LF III procedures performed worldwide is increasing. A number of fundamental questions concerning the technique remain unclear, and large, conclusive studies are lacking owing to the relative rarity of severe midface hypoplasia. This literature review aims to address problems, such as the indication field, timing of surgery, rate of relapse and the use of distraction osteogenesis. An overview of the history and technique of LF III osteotomy and distraction is provided, together with a comprehensive review of the available clinical data.

Midface osteotomy versus distraction: the effect on speech, nasality, and velopharyngeal function in craniofacial dysostosis

OBJECTIVE

To assess speech outcomes following midface advancement and to explore whether the type of advancement surgery affects speech differently in patients with craniofacial dysostosis.

DESIGN

Prospective, before-after group design.

SUBJECTS

Fifteen consecutive patients were included in the study. Eight underwent advancement by osteotomy and seven by distraction. All patients were seen preoperatively and at least once postoperatively.

MAIN OUTCOME MEASURES

Percentage of consonants correct, nature and type of articulation errors, nasalance score, severity ratings of resonance and of velopharyngeal function using nasendoscopy and lateral videofluoroscopy, and amount of forward advancement.

RESULTS

No statistically significant differences were found between groups for pre- and postoperative changes of percentage of consonants correct (p = .755, median difference 3.0, 95% confidence interval for median difference [-14.22, 20.22]) and nasalance (p = .171, median difference = -12.00, 95% confidence interval for median differences [-30.46, 6.46]). There was no statistically significant correlation between amount of forward advancement and nasalance (r = .87, p = .799) and percentage of consonants correct (r = -.550, p = .064). Findings from lateral videofluoroscopy and nasendoscopy are described. Individual changes of speech outcomes are reported.

CONCLUSIONS

In view of the small sample size, results need to be interpreted with caution. However, the study adds to current limited knowledge with this clinical group. Further research with bigger sample sizes and randomization of patients into the different surgical groups is warranted.