Le Fort III Distraction Osteogenesis Versus Conventional Le Fort III Osteotomy in Correction of Syndromic Midfacial Hypoplasia: A Systematic Review

Reducing the risk of unfavourable fractures in Le Fort III osteotomy via a navigation-guided technique

The aim of this study was to investigate the clinical feasibility of reducing the risk of unfavourable fractures during Le Fort III osteotomy by using a navigation-guided technique. A study was carried out involving 20 patients with Crouzon syndrome treated with Le Fort III osteotomy and distraction osteogenesis from 2018 to 2023 at the International Hospital of Peking University. The Le Fort III osteotomy procedure in experimental group (9 patients) was carried out under the guidance of navigation technique, while in historical control group (11 patients) was carried out by free hand. Immediate postoperative CT scans were acquired within 24h after surgery to observe the osteotomy lines and detect unfavourable fracture lines. There were 4 patients with unfavourable fractures in the navigation group (4/9 = 44%) while 10 patients in the freehand group (10/11 = 91%), with a statistically significant difference in the probability of unfavourable fracture and the number of fracture lines between the two groups (P < 0.05). The difference in unfavourable fracture incidence in the two groups was significant in zygomatic area (P < 0.05) while not significant in mid-palatal area (P > 0.05). And the surgical duration of the navigation group was significantly shorter than that of the freehand group (216 min vs 280 min) (P < 0.05). The above findings suggest that the navigation-guided technique is effective in reducing the risk of unfavourable fractures in Le Fort III osteotomy procedure and decreasing the surgical duration.

Perioperative Care for Children With Syndromic Craniofacial Synostosis Undergoing Le Fort III Surgery: A Retrospective Cohort Study

OBJECTIVE

To present characteristics, surgical variables, complications, and postoperative care in pediatric patients with craniofacial synostosis undergoing Le Fort III osteotomy.

BACKGROUND

Craniofacial synostoses are a group of genetic syndromes that result in premature fusion of cranial and facial sutures, leading to craniofacial deformities and associated complications. Midface advancement through Le Fort III osteotomy is the most frequent surgical option for these conditions.

METHODS

Retrospective monocentric cohort study including patients with syndromic craniofacial synostosis who underwent Le Fort III osteotomy between 2009 and 2022 in a specialized referral center. Data collection encompassed surgical time, blood loss, intraoperative transfusions, fluid balance, and postoperative parameters such as duration of invasive mechanical ventilation and intensive care unit (ICU) length of stay.

RESULTS

Twenty-six children were included in the analysis. The median surgical time was 345 minutes (300-360), with an estimated blood loss of 15 (9.9-24) mL/kg. Patients required a median transfusion of 12.63 (7.1-24.5) mL/kg of packed red blood cells and 19.82 (11.1-33) mL/kg of fresh frozen plasma. Intraoperative fluid balance was + 12.5 (0.8-22.8) mL/kg, with a median infusion of 30.4 (23.9-38.7) mL/kg of crystalloids. All patients were transferred to the ICU after surgery to ensure a safe environment for extubation. The median duration of mechanical ventilation in the ICU was 30 (20.25-45) hours, and postoperative ICU length of stay was 2 (2-4) days, and complications were infrequent, with only one extubation failure recorded.

CONCLUSION

Le Fort III osteotomy in craniofacial synostosis patients may be characterized by a complex perioperative course. A multidisciplinary approach in the care of these patients allows for minimizing complications in the perioperative phase. Further research is needed to enhance perioperative management in this unique patient population.

An Adult Case of Crouzon Syndrome: Diagnostic Features and Treatment Modalities

Craniosynostosis syndromes are birth defects characterized by the premature fusion of one or more cranial sutures before the completion of brain growth and development. Crouzon syndrome (CS) is the most common craniosynostosis condition. The CS manifestations result from the early fusion of superior and posterior sutures of the maxilla along the orbital wall and affect the cranial vault, base, orbital, and maxillary regions. This report presents a rare case of a 25-year-old male CS patient referred for orthodontic treatment with the chief complaint of severe irregularities in the arrangement of teeth and abnormal facial appearance. In this report, the clinical, cephalometric features, and initial orthodontic management of this patient are discussed as part of multidisciplinary management.

Craniofacial Distraction Osteogenesis

Distraction osteogenesis (DO) of the craniofacial skeleton has become an effective technique for the treatment of both nonsyndromic and syndromic conditions. The advent of craniofacial DO has allowed for earlier intervention in pediatric patients with less complication risk and morbidity compared to traditional techniques. In this review, we will discuss current application and technique for craniofacial DO by anatomical region and explore future applications in craniofacial surgery.

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.

Cranial Base Reconstruction and Secondary Frontal Advancement for Meningoencephalocele Following LeFort III Osteotomy in a Patient with Crouzon Syndrome: Case Report

Patients with Crouzon syndrome have increased risks of cerebrospinal fluid rhinorrhea and meningoencephalocele after LeFort III osteotomy. We report a rare case of meningoencephalocele following LeFort III midface advancement in a patient with Crouzon syndrome. Over 10 years since it was incidentally found during transnasal endoscopic orbital decompression, the untreated meningoencephalocele eventually led to intermittent clear nasal discharge, frontal headache, and seizure. Computed tomography and magnetic resonance imaging demonstrated meningoencephalocele in the left frontal-ethmoid-maxillary sinus through a focal defect of the anterior cranial base. Through bifrontal craniotomy, the meningoencephalocele was removed and the anterior cranial base was reconstructed with a pericranial flap and split calvarial bone graft. Secondary frontal advancement was concurrently performed to relieve suspicious increased intracranial pressure, limit visual deterioration, and improve the forehead shape. Surgeons should be aware that patients with Crouzon syndrome have the potential for an unrecognized dural injury during LeFort III osteotomy due to anatomical differences such as inferior displacement and thinning of the anterior cranial base.

Subcranial Midface Advancement in Patients with Syndromic Craniosynostosis

Patients with syndromic craniosynostosis can present with midface hypoplasia, abnormal facial ratios, and obstructive sleep apnea. These symptoms can all be improved with midface advancement, but it is essential to evaluate the specific morphologic characteristics of each patient's bony deficiencies before offering subcranial advancement. Midface hypoplasia in Crouzon syndrome is evenly distributed between the central and lateral midface and reliably corrected with Le Fort III distraction. In contrast, the midface hypoplasia in Apert/Pfeiffer syndromes occurs in both an axial and a sagittal plane, with significantly more nasomaxillary hypoplasia compared with the orbitozygomatic deficiency.

Characterization of Treatment Modalities for Patients With Syndromic Craniosynostosis in Relation to Degree of Midface Hypoplasia and Patient's Age Using Longitudinal Follow-Up Data

ABSTRACT

The purpose of this study was to investigate the type and frequency of use of treatment modalities (Tx-Mods) in patients with syndromic craniosynostosis (SC) using longitudinal follow-up data. A total of 28 patients with SC (24 Crouzon, 2 Apert, and 2 Antley-Bixler syndromes), who were treated at the Department of Orthodontics, Seoul National University Dental Hospital, Seoul, South Korea between 1998 and 2020, was included. According to the degree of midface hypoplasia (MH) at the initial visit (T1), the patients were divided into the mild-MH (78°≤SNA < 80°, n = 8), moderate-MH (76≤SNA < 78°, n = 7), and severe-MH (SNA < 76°, n = 13) groups. T1-age and Tx-Mods, including cal-varial surgery (CALS), orthopedic treatment (OPT), fixed orthodontic treatment, and midface advancement surgery in childhood (MAS-child) and adulthood (MAS-adult), were investigated. Complexity of MAS-adult was graded as follows: 0, no surgery; 1, orthognathic surgery; 2, distraction osteogenesis (DOG); 3, combination of distraction osteogenesis and orthognathic surgery. Then, statistical analysis was performed. Percentage distribution of Tx-Mods was 71.4% in CALS, 21.4% in MAS-child, 42.9% in OPT, 100% in fixed orthodontic treatment, and 89.3% in MAS-adult. 92.9% of patients underwent MAS more than once. The number of MAS increased according to the severity of MH ( P < 0.05). The complexity of MAS-adult increased as T1-age and severity of MH increased (all P < 0.05); whereas it decreased when CALS and OPT were performed (all P < 0.05). However, MAS in childhood did not guarantee the avoidance of additional MAS in adulthood ( P > 0.05). These findings may be used as basic guidelines for successful treatment planning and prognosis prediction in patients with SC.

Update in Management of Craniosynostosis

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Understand the craniofacial dysmorphology of craniosynostosis, and the variation of each type. 2. Identify the functional concerns and learn the rationale behind timing of operative intervention. 3. Approach each dysmorphology critically and identify the operative intervention needed to improve form and function 4. Understand and address the specific issues related to syndromic craniosynostosis and be able to delineate management plan.

SUMMARY

Craniosynostosis is a condition in which premature fusion of one or more cranial sutures lead to abnormal head shape and growth restriction of the brain. Nonsyndromic craniosynostosis occurs in isolation, and usually involves a single suture, whereas syndromic craniosynostosis may involve multiple sutures and is associated with extracraniofacial findings. Although surgical management can be similar, the treatment plan must take into consideration issues specific to the syndromes. This article aims to provide a concise overview of the authors' current understanding regarding the presentation, treatment principle, surgical option, and debates in craniosynostosis.

Síndrome de Apert: alternativas de tratamiento ortodóntico - quirúrgico y tiempos de ejecución. Una revisión de la literatura

Objetivo: realizar una revisión de la literatura acerca de los tratamientos ortodónticos y quirúrgicos del síndrome de Apert durante las diferentes etapas de crecimiento y desarrollo. Métodos: se llevó a cabo una búsqueda en las bases de datos MedLine (PubMed), Science Direct, Scopus y Wiley Online Library con la combinación de los siguientes términos: Syndromic craniosynostosis, Dental treatment, orthodontic treatment, Apert Syndrome, surgical treatment, dental care. Se incluyeron revisiones sistemáticas y de literatura, estudios retrospectivos, longitudinales y de cohorte, series y revisiones de caso publicados entre 1990 y 2020 en español o inglés; se excluyeron artículos relacionados con otros síndromes, así como estudios en animales. Los artículos fueron seleccionados según su pertinencia y disponibilidad de texto completo; hallazgos repetidos fueron eliminados; adicionalmente, se utilizó el sistema bola de nieve en los artículos seleccionados; la calidad de la evidencia fue evaluada mediante el sistema GRADE. Resultados: 34 artículos fueron incluidos (calidad alta: 2, moderada: 1, baja: 19 y muy baja: 12). Entre estos, se identificaron discusiones relacionadas con la etapa de crecimiento a la que se recomienda realizar los procedimientos quirúrgicos requeridos para minimizar sus impactos negativos. La mayoría de los artículos apoyan el manejo terapéutico ejecutado por equipos multidisciplinarios. Conclusiones: un plan de tratamiento combinado de ortodoncia y cirugía ortognática se presentó como la mejor opción para obtener los mejores resultados funcionales y estéticos para la población en cuestión. El momento adecuado durante el crecimiento y desarrollo de los individuos para implementar cada fase de tratamiento fue decidido por cada equipo multidisciplinario.

Algorithm to the treatment of Crouzon syndrome

Clinical reports regarding the entire surgical sequence in Crouzon syndrome from the neonatal period to the adult age are rare. The purpose of this study is to trace an operative algorithm with a long term follow up in a homogenous group of patients affected by Crouzon syndrome. A retrospective review was conducted for all patients affected by Crouzon syndrome who completed the entire surgical sequence. 7 Crouzon patients (4 females, 3 males) completed the entire surgical sequence at different ages: fronto-orbital advancement (0.9 years), LF III distraction osteogenesis (11.5 years) and orthognathic surgery (18 years). The mean age at the last follow up was 19.3 years; normalization of the face was obtained in all cases with improvement of the respiratory problems. After orthognathic surgery, all patients had stable occlusion. A one-year postoperative CBCT scan revealed almost complete ossification of all osteotomy sites. Frontoorbital advancement and modified Le Fort III distraction osteogenesis are reliable surgical procedures. SARME and conventional orthognathic surgery with reductive genioplasty and fat grafting are performed at the end of the surgical sequence to enhance facial aesthetics.

Comprehensive management of Crouzon syndrome: A case report with three-year follow-up

Crouzon syndrome is one of the most common craniosynostosis facial syndromes caused by a mutation in the fibroblast growth factor receptor 2 (FGFR2) gene. Less commonly, there is a mutation of the FGFR3 gene which results in Crouzon syndrome syndrome with acanthosis nigricans. It involves the premature fusion of sutures of the cranial vault, base, orbital and maxillary region. The clinical presentation of this congenital deformity depends on the pattern and timing of sutural fusion. The present report describes the features and management of this syndrome in an 18-year-old woman. The patient presented with a hypoplastic maxilla, deficient midface, exorbitism due to shallow orbits, severe crowding and bilateral crossbite. A multidisciplinary approach involving orthodontics and surgical intervention with distraction osteogenesis brought about marked improvement in the facial profile, occlusion and upper airway. The aesthetics and function were greatly enhanced, and the results were found to be stable at the end of three years.

Craniosynostosis: Le Fort III Distraction Osteogenesis

The Le Fort III advancement was first described in 1950 and has since become a key technique in the armamentarium of craniofacial surgeons. The application of distraction osteogenesis to the craniofacial skeleton has allowed for large movements to be performed safely in young patients. This technique is valuable for correcting exorbitism, airway obstruction owing to midface retrusion, and class III malocclusion. It can be performed with either an external distractor or internal distractors. Although serious complications have been reported, these occur rarely when performed by experienced providers.

Lefort II distraction with zygomatic repositioning versus Lefort III distraction: A comparison of surgical outcomes and complications

The aim of the study was to determine if the additional surgical complexity of Lefort II distraction with zygomatic repositioning (LF2ZR) results in increased complications compared to Lefort III distraction (LF3). A retrospective review was performed of all LF3 and LF2ZR advancements performed by the senior author over 15 years. Demographic, operative, postoperative, and cephalometric data were collected from initial procedure through greater than 1 year postoperatively. Univariate and multivariate analyses were performed to compare procedures. 19 LF2ZR and 39 LF3 in 53 patients met inclusion criteria. Diagnoses differed between procedures, with more Crouzon Syndrome in LF3 and more Apert Syndrome in LF2ZR. Complication rate was 7/19 for LF2ZR and 12/39 for LF3 with no severe morbidity or mortality, and no difference between procedures (p = 0.56). The types of complications encountered differed between procedures. LF2ZR had a significantly longer operative time (506 ± 18 vs. 358 ± 24 min, p<0.001). However, a greater number of LF2ZR patients underwent concomitant procedures (15/19 vs. 13/39, p<0.001). Multivariate analysis revealed that Apert Syndrome and reoperative midface advancement were the most significant predictors of increased blood loss. LF2ZR has an equivalent complication rate to LF3. Therefore, it is our treatment of choice for cases requiring differential sagittal and vertical distraction of the central midface.

Characteristics of the Sphenoid Bone in Crouzon Syndrome

BACKGROUND

The goal of this study is to analyze the safety of reconstructive surgeries for Crouzon syndrome, and to understand the deformities and complications related to the surgical procedure.

METHODS

Thirty-nine subjects underwent preoperative computed tomographic scans were included (Crouzon, n = 19; controls, n = 20) in this study. Craniofacial cephalometric measurements were analyzed by Materialise software.

RESULTS

The overall average distance from the pterygoid junction to the coronal plane in the patients with Crouzon syndrome was 21.34 mm (standard deviation [SD] 5.13), which was deeper than that in the controls by 35% (P = 0.000).The overall average distances between the left and right foramen ovale and pterion on the sphenoid bone in the subjects were 64.93 mm (SD 7.56) and 67.83 mm (SD 8.57), which were increased by 13% (P = 0.001) and 14% (P = 0.001) compared with those in the controls.The overall distances between the most inferior point of the left and right lateral pterygoid plate and the medial pterygoid plate in the subjects were 51.09 mm (SD 6.68) and 51.51 mm (SD 10.98), which was not statically different from the controls (P = 0.887, P = 0.991, respectively).

CONCLUSIONS

This study characterized the surgically relevant anatomy of the sphenoidal bone. The pterygomaxillary junction is located in the posterior of the skull. Though there are some anatomical differences due to age, it is well known that the cranial cavity of the sphenoid side is likely to be enlarged in Crouzon syndrome, which may contribute to the other complications of the disease.

Distraction Osteogenesis Versus Orthognathic Surgery: Demystifying Differences in Concepts, Techniques and Outcomes

Introduction

The popularity and interest evoked by orthognathic surgery and distraction osteogenesis are undisputed in the field of oral and maxillofacial surgery. However, questions regarding the individual identities of either of them with clarity in their concepts, techniques and outcomes have remained unanswered. The aim of this review is to shed light on these questions.

Methods

This review is structured as a narrative review of thirty years of literature available in the specialities of orthognathic surgery and distraction osteogenesis.

Conclusion

The authors present a review of existing literature combined with contrasting experience gained over the years in providing an overview of the merits and demerits of the two surgical techniques which will aid the clinician in justifying the use of one technique over the other.

Non-invasive Ventilation and CPAP Failure in Children and Indications for Invasive Ventilation

Non-invasive ventilation (NIV) and continuous positive airway pressure (CPAP) are effective treatments for children with severe sleep disordered breathing (SBD). However, some patients may present too severe SDB that do not respond to NIV/CPAP or insufficient compliance to treatment. A careful revaluation of the interface and of ventilator settings should be performed before considering alternative treatments. In patients with obstructive sleep apnea (OSA), alternatives to CPAP/NIV rely on the underlying disease. Ear-nose-throat (ENT) surgery such as adeno-tonsillectomy (AT), turbinectomy or supraglottoplasty represent an effective treatment in selected patients before starting CPAP/NIV and should be reconsidered in case of CPAP failure. Rapid maxillary expansion (RME) is restricted to children with OSA and a narrow palate who have little adenotonsillar tissue, or for those with residual OSA after AT. Weight loss is the first line therapy for obese children with OSA before starting CPAP and should remain a priority in the long-term. Selected patients may benefit from maxillo-facial surgery such as mandibular distraction osteogenesis (MDO) or from neurosurgery procedures like fronto-facial monobloc advancement. Nasopharyngeal airway (NPA) or high flow nasal cannula (HFNC) may constitute efficient alternatives to CPAP in selected patients. Hypoglossal nerve stimulation has been proposed in children with Down syndrome not tolerant to CPAP. Ultimately, tracheostomy represents the unique alternative in case of failure of all the above-mentioned treatments. All these treatments require a multidisciplinary approach with a personalized treatment tailored on the different diseases and sites of obstruction. In patients with neuromuscular, neurological or lung disorders, non-invasive management in case of NIV failure is more challenging. Diaphragmatic pacing has been proposed for some patients with central congenital hypoventilation syndrome (CCHS) or neurological disorders, however its experience in children is limited. Finally, invasive ventilation via tracheotomy represents again the ultimate alternative for children with severe disease and little or no ventilatory autonomy. However, ethical considerations weighting the efficacy against the burden of this treatment should be discussed before choosing this last option.

Surgical Management of Lateral Orbital Contour Following Le Fort III Distraction

Le Fort III distraction is indicated for the management of skeletal malocclusions, midface hypoplasia, and exorbitism and has been found to be a safe procedure with predictable results. Although variation in the placement of the lateral orbital osteotomy has been described, the classic osteotomy divides the zygomatic arch, crosses the lateral orbital rim, transverses the orbital floor, and ends in the midline. Distraction of this segment may lead to a palpable, and sometimes visible, step deformity between the lower and upper segments of the lateral orbital wall. The authors present a novel approach to the management of the lateral orbital wall step deformity following Le Fort III distraction.

Classification of Subtypes of Apert Syndrome, Based on the Type of Vault Suture Synostosis

Supplemental Digital Content is available in the text.

Background:

Apert syndrome patients are different in clinical pathology, including obstructive sleep apnea, cleft palate, and mental deficiency. These functional deficiencies may be due to anatomic deformities, which may be caused by different forms of associated suture fusion. Therefore, a classification system of Apert syndrome based on the type of craniosynostosis pattern might be helpful in determining treatment choices.

Methods:

CT scans of 31 unoperated Apert syndrome and 51 controls were included and subgrouped as: class I. Bilateral coronal synostosis; class II. Pansynostosis; and class III. Perpendicular combination synostosis: a. unilateral coronal and metopic synostosis; b. sagittal with bilateral/unilateral lambdoid synostosis; and c. others.

Results:

Class I is the most common (55%) subtype. The cranial base angulation of class I was normal; however, the cranial base angulation on the cranium side of the skull in class II increased 12.16 degrees (P = 0.006), whereas the facial side cranial base angle of class IIIa decreased 4.31 degrees (P = 0.035) over time. The external cranial base linear measurements of class I showed more evident reduction in anterior craniofacial structures than posterior, whereas other subtypes developed more severe shortening in the posterior aspects.

Conclusions:

Bicoronal synostosis is the most common subtype of Apert syndrome with the normalized cranial base angulation. Combined pansynostosis patients have flatter cranial base, whereas the combined unilateral coronal synostosis have a kyphotic cranial base. Class I has more significant nasopharyngeal airway compromise in a vertical direction, whereas classes II and III have more limited oropharyngeal space.

Le Fort III in Syndromic Craniosynostosis: Cost Comparison of Distraction Osteogenesis Versus Single-Stage Internal Fixation Techniques

Purpose

In syndromic craniosynostosis, the Le Fort III osteotomy is used to correct dental/skeletal imbalance, improve exorbitism, and increase the airway. The purpose of this study is to perform a cost comparison between the standard technique of single-stage rigid internal fixation and distraction osteogenesis (DO) in the Le Fort III osteotomy in this patient population.

Method

Hospital cost accounting databases were queried for patients undergoing single-stage advancement (SS) or DO from 2007 to 2016. Nominal cost data were adjusted using the Bank of Canada Consumer Price Index. Reported costs represented the full length of stay for all utilization per patient. Demographic information and cost data for single-stage osteotomy and DO were compared.

Results

Total costs for single-stage (n = 8) were higher than distraction (n = 6; mean $CAD57 825 vs $38 268, P < .05). Intensive care unit (ICU) costs for single-stage were significantly higher than distraction (mean, $17 746 vs $5585, P < .005). Distraction cases had higher operating room (OR) costs than single stage, but the difference was not significant (mean, $12 540 vs $9696). Length of stay was significantly longer for SS patients (mean, 11 days vs 7 days, P < .05).

Conclusions

This single-institution retrospective cost analysis indicates standard SS rigid internal fixation Le Fort III is more costly than DO. Despite higher OR costs, prolonged ICU and hospital stay was the primary reason behind this difference. This information may be of benefit when advocating for new technology perceived as high cost.

Rigid External Distraction with Intranasal Bone-borne Traction Hooks for Midfacial Hypoplasia

Rigid external distraction is currently performed to correct cases of severe maxillary hypoplasia. As an improvement of this technique, we propose the use of an intranasal bone-borne traction hook. This study is a retrospective chart review of the intranasal bone-borne traction hooks used in the treatment of severe maxillary hypoplasia. There were 110 patients treated with the hooks from 2005 to 2017. The maximum traction force was 7.75 kg, and there were few complications encountered during distraction. There were 76 patients who had the hooks removed under local anaesthesia. A cephalometric analysis was conducted in 56 patients. The average advancement of A-point was 9.9 ± 4.2 mm, 8.4 ± 2.5 mm, 11.0 ± 3.7 mm, 17.9 ± 4.4 mm for the trans-sutural distraction osteogenesis (DO), maxillary anterior segment DO, Le Fort I osteotomy DO and Le Fort III/II osteotomy DO, respectively. The average changes of sella-nasion-point A (SNA) were 8.89 ± 4.30 degrees, 8.21 ± 3.17 degrees, 10.49 ± 3.26 degrees, and 15.10 ± 4.00 degrees, respectively. The A point-nasion-B point (ANB) also showed increases in all procedures with P < 0.001. In conclusion, this technique sufficiently advances the midface and ensures the scars are concealed in the nasal base. The traction hook can bear a large traction force, causes minimal complications and is easily removed.

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.

Modified Lefort Distraction Osteogenesis for the Treatment of Nager Syndrome-Associated Midface Hypoplasia: Technique and Review

The surgical management of midface hypoplasia in the setting of Nager syndrome remains a significant challenge for craniofacial surgeons. This study describes a novel technique using distraction osteogenesis and modified osteotomies for the treatment of midface bony defects in an 11-year-old child with Nager syndrome.

Presurgical 3-dimensional planning was performed to design the osteotomies and placement of distractors. The surgical approach required upper buccal sulcus and extended transconjunctival incisions only. Osteotomies were performed from the pyriform aperture through the orbit to include the lateral orbital wall, with bilateral osteotomy of the zygomas through the anterior arch via the transconjunctival incision. Distraction of the en bloc midface segment was successfully performed using external distractors. Bone grafting was not required. There were no complications.

External distraction was well tolerated and there were no intraoperative or postoperative complications. The distractors were removed uneventfully after consolidation. The midface was successfully advanced without the need for bone grafting or bicoronal incision. The occlusal plane was leveled and the aesthetic appearance of the child was improved.

Symmetrical midface hypoplasia in the context of Nager syndrome can be successfully corrected with en bloc distraction osteogenesis of the maxilla and bilateral zygomas through modified osteotomies that exclude the upper nasal pyramid. The approach is simplified and the need for bicoronal incision and bone grafting is mitigated in this technique, which the authors have named Lefort 2.5.

Le Fort III Distraction With Internal vs External Distractors

Objective:

This study compares the change in midface position following Le Fort III advancement using either rigid external distraction (group 1) or internal distraction (group 2). We hypothesized that, with reference to right-facing cephalometry, internal distraction would result in increased clockwise rotation and inferior displacement of the midface.

Design:

Le Fort III osteotomies and standardized distraction protocols were performed on 10 cadaveric specimens per group. Right-facing lateral cephalograms were traced and compared across time points to determine change in position at points orbitale, anterior nasal spine (ANS), A-point, and angle ANB.

Setting:

Institutional.

Patients, Participants:

Twenty cadaveric head specimens.

Interventions:

Standard subcranial Le Fort III osteotomies were performed from a coronal approach and adequately mobilized. The specified distraction mechanism was applied and advanced by 15 mm.

Main Outcome Measure(s):

Changes of position were calculated at various skeletal landmarks: orbitale, ANS, A-point, and ANB.

Results:

Group 1 demonstrated relatively uniform x-axis advancement with minimal inferior repositioning at the A-point, ANS, and orbitale. Group 2 demonstrated marked variation in x-axis advancement among the 3 points, along with a significant inferior repositioning and clockwise rotation of the midface ( P < .0001).

Conclusion:

External distraction resulted in more uniform advancement of the midface, whereas internal distraction resulted in greater clockwise rotation and inferior displacement. External distraction appears to provide increased vector control of the midface, which is important in creating a customized distraction plan based on the patient’s individual occlusal and skeletal needs.

Midface Distraction Osteogenesis Using a Modified External Device With Elastic Distraction for Crouzon Syndrome

PURPOSE

Midface distraction osteogenesis has been popularized for the correction of midface hypoplasia associated with exophthalmos and obstructive sleep apnea in patients with Crouzon syndrome. The purpose of this study was to present the method of utilizing the modified external device with elastic distraction for the midface advancement in Crouzon syndrome, and the clinical outcomes and skeletal changes were analyzed.

METHODS

Five consecutive patients with Crouzon syndrome underwent Le Fort III osteotomy with midface advancement using a modified external device with elastic distraction. The distraction system consists of a rigid external distractor, nickel-titanium shape memory alloy spring, and bone-borne traction hooks. The midface advancement was initiated with the bony anchorage around the nasomaxillary buttress at the level between occlusal plane and infraorbital margin. The device was activated at a rate of 1 to 1.5 mm per day by the length of spring. The skeletal changes were analyzed by cephalometric and computed tomographic measurement.

RESULTS

All the patients achieved improvements in midface appearance, obstructive sleep apnea, exophthalmos, and occlusion. No complications occurred during this procedure. After the distraction, 1 patient developed an open bite that was corrected by a definitive orthognathic surgery. Cephalometric and computed tomographic measurement analysis showed a differential advancement of midface with more at the occlusal level than the orbital level. In addition, midface suture and bone remodeling was also observed in growing patient.

CONCLUSIONS

Our modified external device with elastic distraction offers an alternative method to achieve midface advancement in patients with Crouzon syndrome.

Retrospective study on midfacial advancement in syndromic craniosynostosis: case series

AIMS

The aim of this study was to evaluate elastic distraction surgical procedures performed on patients with syndromic craniosynostosis using cephalometric analyses.

METHODS

Eleven patients who underwent surgical midfacial advancement were divided into three groups: G1 - monobloc frontofacial; G2 - Le Fort III; and G3 - high-level Le Fort I. The cephalometric analyses were manually created through cephalometric radiographs of each patient: T1 - preoperative; T2 - 6 months postoperatively; and T3 - 12 months postoperatively. The cephalometric landmark points were A and O. The distances between preoperative and postoperative tracings were measured.

RESULTS

Point A advanced with no significant relapse 12 months after surgery. Point O advanced with a significant relapse rate of 28.5% postoperatively (p = 0.019). The vertical movement of points A and O increased by 40.6% (p = 0.033) and 38.8% (p = 0.032), respectively. There were no significant statistical differences between the assessed surgical techniques and syndromes with regard to midfacial advancement.

CONCLUSION

Point O has presented statistically significant relapse only in horizontal movement after 12 months. The cephalometric analysis performed in the present study only suggested no differences between the studied surgical techniques and syndromes with regard to midfacial advancement in syndromic craniosynostosis.

Subcranial Le Fort III Advancement with Equine-Derived Bone Grafts to Correct Syndromic Midfacial Hypoplasia: A Case Report

Patients with hypoplasia of the midface normally present a flattening of their facial profile due to insufficient development of the nose and maxilla. Treatment aimed to restore function and an aesthetic appearance calls for a Le Fort III osteotomy and the advancement of the midfacial segment either through distraction or interposition of autogenous bone blocks. However, drawbacks in using autogenous bone suggest that use of alternative graft material may be advisable. The present report describes a Le Fort III advancement using two enzyme-treated equine cancellous bone blocks to correct syndromic midfacial hypoplasia in a 22-year-old patient. A 12-mm surgical advancement was achieved, improving the patient's facial profile. At the 28-month follow-up, the midface advanced position was stable. Equine bone blocks could be a valid alternative to autogenous bone in Le Fort III midface advancement.

Is Distraction Osteogenesis of the Irradiated Craniofacial Skeleton Contraindicated?

BACKGROUND

Craniofacial distraction osteogenesis (DO) is a common treatment modality today. Despite its numerous advantages, however, concerns have been expressed regarding the use of DO in the irradiated setting.

METHODS

A systematic review was performed to identify all published reports of patients who underwent DO of the irradiated craniofacial skeleton. The following parameters were of particular interest: postoperative complications, specifically, insufficient bone formation, fracture, and hardware exposure (intraoral and cutaneous), as well as the need for additional bone grafting.

RESULTS

The initial search retrieved a total of 183 articles of which 20 articles (38 patients) met predetermined inclusion criteria. The most common site of distraction was the mandible (76.3%). The median radiation dose was 50.7 Gy (range, 30-70 Gy). Bone defects ranged from 30 to 80 mm (median, 42.5 mm). Complications were encountered in 19 patients (50%), with insufficient bone formation being most common (9 patients; 23%). The overall incidence of complications was not significantly associated with radiation dosage (P = 0.79). The remaining procedural and demographic variables also failed to meet statistical significance when compared against the overall complication rate (P = 0.27-0.97).

CONCLUSION

The complication rate associated with craniofacial DO of the irradiated skeleton does not appear to be substantially higher than what is reported for DO in the nonirradiated setting. As such, patients should be offered this treatment modality, particularly in light of the fact, that it offers the option to decrease patient morbidity as well as treatment complexity.

[Rational use of distraction osteogenesis in craniofacial surgery]

Distraction osteogenesis, initially developed by Ilizarov for limb, is the tissular extension caused by the progressive space of the osseous pieces following an osteotomy. Distraction is osteogenesic and histogenic. Twenty-five years ago, at the instigation of McCarthy, this technique was used to handle the craniofacial malformations in the various floors of the face : mandibular, mediofacial and cranial. The most wide-spread protocols respect a latency period from 0 to 7 days, a rhythm of distraction from 1 to 2mm a day in 2 at 4 times and a period of consolidation from 4 to 8 weeks. Distraction is the result of the inventiveness of the pioneers then the work to always adapt to the multiple complex clinical situations. The surgeon has to choose between internal or external materials allowing a mono- or multi-vectorial extension, in osseous and/or dental anchoring. The mandibular distraction is very effective for the treatment of the secondary obstructive syndromes in the unilateral or bilateral severe hypomandibular malformations. She also allows desobstruction of the superior airways within the framework of the mediofacial hypoplasies as well as the secondary treatment of the growth defects in cleft lips and palates. Finally, the distraction osteogenesis enhanced reliability of the fronto-facial advancement in early and secondary treatment of craniofaciosynostosis. This is a real support of the facial growth, which has to be included in a plan of global treatment.

Apert syndrome: Surgical outcomes and perspectives

PURPOSE

Apert syndrome is a rare congenital malformation with severe craniofacial anomalies. The aim of this study was to review the outcomes of craniofacial and neurosurgical interventions in Apert syndrome patients treated at a single institution.

MATERIALS AND METHODS

A retrospective review of all patient records with a diagnosis of Apert syndrome assessed and managed in the Australian Craniofacial Unit (ACFU) from 1985 to 2013 was conducted.

RESULTS

A total of 94 patients were identified, and 130 transcranial procedures were performed. Of the patients, 83 underwent a fronto-orbital advancement (FOA) as their primary procedure, and 18 patients also underwent a posterior vault procedure. Twenty patients underwent a fronto-facial monobloc advancement. Overall, 70% of patients underwent at least 2 transcranial procedures. Shunts were inserted in 2 patients preoperatively and in 5 patients postoperatively for cerebrospinal fluid (CSF) leaks or acute hydrocephalus. Re-do FOAs were performed in 8 patients. Patients who underwent an FOA at the age of more than 18 months had no recurrence of raised intracranial pressure (ICP). Of 18 patients who also underwent a posterior vault procedure, 1 patient had recurrence of raised ICP. Midfacial surgery was performed early if there was evidence of obstructive sleep apnoea (OSA), but delayed midfacial surgery was preferred. Complications were reported in 18% of procedures. The most common complications were CSF leaks and acute hydrocephalus.

CONCLUSION

Shunting is rarely required in Apert syndrome patients, confirming a predominantly nonprogressive ventriculomegaly. FOA appears to be a more stable procedure when performed at an age of more than 18 months. Undergoing a posterior vault procedure may reduce the risk of recurrent raised ICP and lead to fewer transcranial procedures needed in childhood. Midfacial surgery should be delayed until adolescence where there is no evidence of OSA, psychological disturbance, or complications of exorbitism. Complications are rare when these patients are treated by an experienced craniofacial team.

Clinical Use of Deferoxamine in Distraction Osteogenesis of Irradiated Bone

The deleterious effects of radiotherapy, including hypovascularity and hypocellularity, have made distraction of irradiated bones challenging. Animal studies, however, have demonstrated adjunctive measures such as the administration of deferoxamine to significantly improve bone regeneration across irradiated distraction gaps. In this report, the authors demonstrate, for the first time, enhanced bone formation following deferoxamine application in a patient following distraction of a previously irradiated maxilla. Computed tomography imaging of the pterygomaxillary buttress on the side of administration revealed significantly increased bone area and density relative to the contralateral buttress. This is the first presentation of clinical deferoxamine use to promote bone formation following irradiated bone distraction and highlights the promise for this adjunctive measure to make outcomes after distraction of irradiated bone more reliable.

Postnatal Ontogeny of the Cranial Base and Craniofacial Skeleton in Male C57BL/6J Mice: A Reference Standard for Quantitative Analysis

Growth of the craniofacial skeleton is a complex process controlled by both genetic and epigenetic factors, perturbations of which can lead to varying degrees of dysmorphology. Mouse models that recapitulate clinical craniofacial phenotypes are instrumental in studying the morphogenetic progression of diseases as well as uncovering their genetic and molecular bases. Commonly encountered phenotypes in these models include defects in the cranial base synchondroses, calvarial sutures, mandible or the midface, or any combination thereof, with the concurrent presence of altered overall craniofacial growth. However, the literature lacks an adequate normative timeline of developmental events and growth trends that shape the mouse craniofacial skeleton. In this report, we analyzed the postnatal craniofacial ontogeny (from postnatal day 7 [P7] through to P112) of male mice from the most widely used inbred mouse strain, C57BL/6J, using high-resolution microcomputed tomography (μCT) in combination with classic morphometric approaches. We also evaluated cranial base synchondroses at the histological level, and compared it to μCT-generated data to assess the timing and pattern of closure of these structures. Our data underscore the complex and unique growth patterns of individual bones and cranial regions and highlight the need to include younger animals in studies aimed at analyzing craniofacial growth processes. Furthermore, these data serve as a reference standard for future quantitative work.

Rigid External Distractor Aided Conventional Le Fort III Osteotomy Advancement in Adult With Severe Midfacial Hypoplasia

BACKGROUND

Management of severe midfacial hypoplasia is still a challenge for craniofacial team, adult patients with syndromic midfacial hypoplasia made the situation even worse. The authors present the clinical result in an adult patient with Crouzon syndrome treated by rigid external distractor aided conventional Le Fort III procedure.

METHODS

A 26-year-old patient with Crouzon syndrome presented with severe midfacial hypoplasia, a negative overjet of -17 mm, exorbitism, airway obstruction, and masticatory problem, while chief complaint of the patient was abnormal appearance. After Le Fort III osteotomy, rigid external distractor and distraction hooks were fixed. With the aid of rigid external distractor, the midfacial mass was immediately advanced to a desired position, allograft bone grafted in the gaps, and microplate fixed. The device was removed 3 weeks later when the advanced midface was stable.

RESULTS

Point A was advanced by 18.6 mm in horizontal and displaced superiorly 0.5 mm in vertical at the time of device removal. Point A moved backward 1.5 mm and upward 0.3 mm at 2-year follow-up. A good and balanced facial profile was obtained in a short treatment period. Airway obstruction symptoms and exorbitism were relieved.

CONCLUSIONS

The midfacial advancement achieved by rigid external distractor aided conventional Le Fort III osteotomy is a stable, controllable, and timesaving procedure. This technique may become an important choice for adult patients with severe midfacial hypoplasia.

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.