Frontofacial Monobloc Advancement Research Articles

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

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. 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. 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). 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.

Discussion: Comparison of Internal and External Distraction in Frontofacial Monobloc Advancement: A Three-Dimensional Quantification.

Discussion: Comparison of Internal and External Distraction in Frontofacial Monobloc Advancement: A Three-Dimensional Quantification.

Twenty Year review for Craniofacial Distraction in syndromic craniosynostosis

Introduction: Craniosynostosis are cranial deformities resulting from the early closure of one or more sutures. Concomitant facial changes usually result from the involvement of multiple sutures, which may lead to restriction of cranial growth and brain expansion, ocular compression, and breathing difficulties. The distraction osteogenesis (DO)for frontofacial or posterior advancement have increased the safety of the procedure. The aim of this study was a critical evaluation of the use of DO in the surgical treatment of syndromic craniosynostoses, based on the experience of a single craniofacial team.&#x0D; Methods: Retrospective review of third six patients operated from 2003 to 2022 by the same craniofacial team.&#x0D; Results: 19 boys and 17 girls were operated, all with rigid distractors. Twenty-nine of them underwent monobloc frontofacial advancement. In seven patient a Le-Fort III/subcranial advancement was performed. A posterior craniofacial advancement was performed in 5. In 11 a fronto-orbital advancement was done in the first year of life. The mean age was 6.0 years (range, 6 months to 13 years). All patients presented with some degree of exorbitism, upper airway obstruction and signs of intracranial hypertension. Cerebrospinal fluid leakage was the most frequent complication (9 cases), pterygomaxillary disjunction was revised in 8, lateral rim orbital fracture in 3 cases, and 3 complication related to the device.&#x0D; Conclusions: The evolution of surgical techniques allowed DO with rigid distractors to be an important tool for treating the craniofacial issues related to syndromic craniosynostoses. The multidisciplinary team's learning curve is critical to reducing complications associated with osteogenic distraction.

Comparison of Internal and External Distraction in Frontofacial Monobloc Advancement: A Three-Dimensional Quantification.

Crouzon syndrome is characterized by complex craniosynostosis and midfacial hypoplasia. Where frontofacial monobloc advancement (FFMBA) is indicated, the method of distraction used to achieve advancement holds an element of equipoise. This two-center retrospective cohort study quantifies the movements produced by internal or external distraction methods used for FFMBA. Using shape analysis, this study evaluates whether the different distraction forces cause plastic deformity of the frontofacial segment, producing distinct morphologic outcomes. Patients with Crouzon syndrome who underwent FFMBA with internal distraction [Hôpital Necker-Enfants Malades (Paris, France)] or external distraction [Great Ormond Street Hospital for Children (London, United Kingdom)] were compared. Digital Imaging and Communications in Medicine files of preoperative and postoperative computed tomographic scans were converted to three-dimensional bone meshes and skeletal movements were assessed using nonrigid iterative closest point registration. Displacements were visualized using color maps and statistical analysis of the vectors was undertaken. Fifty-one patients met the strict inclusion criteria. Twenty-five underwent FFMBA with external distraction and 26 with internal distraction. External distraction provides a preferential midfacial advancement, whereas internal distractors produce a more positive movement at the lateral orbital rim. This confers good orbital protection but does not advance the central midface to the same extent. Vector analysis confirmed this to be statistically significant ( P < 0.01). Morphologic changes resulting from monobloc surgery differ depending on the distraction technique used. Although the relative merits of internal and external distraction still stand, it may be that external distraction is more suited to addressing the midfacial biconcavity seen in syndromic craniosynostosis. Therapeutic, III.

Twenty Year review of a Single Surgeon's Experience for craniosynostosis surgery

Introduction: Nonsyndromic craniosynostosis (NC) is more commonly encountered than syndromic cases in pediatric craniofacial surgery. Affected children display characteristic phenotypes according to the suture or sutures involved. This study aims to report a single surgeon experience with surgery for primary craniosynostosis correction. Methods: A retrospective review was carried out including all cases performed by the same surgeon between 2001 and 2021. The clinical data of 356 patients (371 surgeries) with primary craniosynostosis that have undergone surgery were retrospectively analyzed. Results: There were 232 (65.1%) males and 124 (34.9%) females, with most of the male preponderance occurring due to the trigonocephaly (86%) and scaphocephaly (84.5%) groups. A female predominance was observed only in brachycephaly group (64.8%). There was a statistically significant male predominance between non-syndromic versus syndromic cases (p=0.0001). The most frequent forms in non-syndromic forms were scaphocephaly in 136 (51.5%), trigonocephaly in 48 (18.1%), anterior plagiocephaly in 47 (17.8%), and brachycephaly in 35 (13.2%). A named syndrome was present in 57 (16%). Genetic syndromes presented more commonly than expected with bilateral synostosis, the Kleeblattschadel deformity, and multiple suture synostosis (p=0.001). Complications were observed in 15 (4.2%). Intraoperative hemorrhage and CSF leakage were the most common ones. Morbidity was significantly associated with monobloc fronto-facial advancement. The mean follow-up was 3.7 years (9 months to 22 years). Morphological results in NC were classified in category I in 210 (70.2%), II in 82 (27.9%), and III in 7 (1.9%) cases for NC. Conclusions: Non-syndromic craniosynostosis can be corrected with good outcomes and relatively low morbidity and mortality. For syndromic cases a multidisciplinary team is fundamental to archieve satisfactory results.

10. Comparison of Internal and External Distraction in Frontofacial Monobloc Advancement: A Three-Dimensional Quantification

Crouzon syndrome is characterised by complex craniosynostosis and midfacial hypoplasia. Where frontofacial monobloc advancement (FFMBA) is indicated, the method of distraction used to achieve advancement holds an element of equipoise. This two-centre retrospective cohort study quantifies the movements produced by internal or external distraction methods used for FFMBA. Using shape analysis, this study evaluates if the different distraction forces cause plastic deformity of the frontofacial segment, producing distinct morphological outcomes.

Frontofacial Monobloc Advancement With Internal Distraction: Surgical Technique and Osteotomy Guide.

Craniosynostosis are cranial deformities resulting from the early closure of 1 or more sutures. Concomitant facial changes are complex and usually result from the involvement of multiple sutures, which may lead to restriction of cranial growth and brain expansion, ocular compression, and breathing difficulties. Surgical techniques to correct syndromic craniosynostosis have improved over time, considerably reducing the rate of complications of this procedure. To describe in detail (step-by-step) and with pertinent anatomic considerations the technique of monobloc frontofacial advancement using internal distractors. We describe the monobloc frontofacial advancement technique with the use of internal distractors, which we use in patients with primary syndromic craniosynostosis (Apert, Crouzon, and Pfeiffer) who have major facial hypoplasia and secondary respiratory repercussions. To illustrate this technique, the procedure was performed in 2 cranial models: an adult artificial acrylic skull of normal morphology for better evidence of anatomic repairs and a 3-dimensional printed infant skull from a tomography file obtained from a child diagnosed with Apert syndrome. The benefits of osteogenic distraction and better surgical timing for each procedure are presented. We presented the changes and details of osteotomies performed during the procedure, as well as anatomic details and care regarding the pterygomaxillary dysjunction. Monobloc frontofacial distraction is a procedure with widely demonstrated aesthetic and functional results, and this detailed step-by-step description may improve familiarity with the anatomic landmarks of the procedure and provide a better dynamic understanding of the distraction process.

Secondary Le Fort III after Early Fronto-Facial Monobloc Normalizes Sleep Apnea in Faciocraniosynostosis: A Cohort Study

This study aims to assess the improvement of sleep apnea after secondary Le Fort III facial advancement with distraction (LF3) in faciocraniosynostosis (FCS) patients with sleep apnea who have previously undergone fronto-facial monobloc advancement (FFMBA) with distraction. Patients having undergone secondary LF3 were selected from a cohort of FCS patients with documented sleep apnea who had previously undergone fronto-facial monobloc advancement. Patient charts and polysomnographic records were reviewed. Apnea-hypopnea index (AHI) was recorded before and at least 6 months after secondary LF3. The primary outcome was normalization of AHI (less than 5/h was considered normal). Hierarchical multilevel analysis was performed to predict postoperative AHI evolution. Seventeen patients underwent a secondary LF3, 7.0 ± 3.9 years after the primary FFMBA. The mean age was 9.6 ± 3.9 years. A total of 15 patients (88%) normalized their AHI. Two of four patients were decannulated (50%). There was a statistically significant decrease in AHI (preoperative AHI 21.5/h vs. 3.9/h postoperatively, p=0.003). Hierarchic multilevel modeling showed progressive AHI decrease postoperatively. Secondary LF3 improves residual or relapsing sleep apnea in FCS patients who have previously had FFMBA.

Computer-Assisted Frontofacial Monobloc Advancement and Facial Bipartition for Pfeiffer Syndrome: Surgical Technique

In patients with Pfeiffer syndrome, several corrections are required to correct facial retrusion, maxillary deficiency, or even hypertelorism. The frontofacial monobloc advancement (FFMA) and the facial bipartition (FB) are the gold standard surgeries. We present the correction of this deformity using a simultaneous computer-assisted FFMA and FB. The 3-dimensional surgical planning defined the virtual correction and bone-cutting guide in view of the FFMA and FB. Coronal and intraoral approaches were combined to perform the osteotomies. Four internal distractors were also placed for the postoperative distraction osteogenesis. We reported 2 cases of computer-assisted surgery with satisfying outcomes. The sagittal deficiency (fronto-facial retrusion) was corrected by FFMA and the transversal abnormality (i.e., hypertelorism and maxillary deficiency) by the FB, then followed by an internal distraction osteogenesis. Computer-assisted surgery is helpful and a reliable option for the management of complex faciocraniosynostosis such as hypertelorism and frontofacial retrusion.

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 FGFR2 Mutation-Related Syndromic Craniosynostosis: Retrospective Review of a 45-Year Experience By a Single Surgeon

PURPOSE: Mutations in the fibroblast growth receptor 2 (FGFR2) gene have been identified in syndromic craniosynostosis syndromes such as Apert, Crouzon, and Pfeiffer syndrome. Patients have severe malformations of the skull and face requiring multiple complex reconstructive procedures. As described by Paul Tessier, surgical correction of such patients is performed for 3 main reasons: functional, morphologic, and psychological. The surgical treatment algorithm has evolved over time. Despite numerous articles describing treatment of syndromic craniosynostosis, there are few reports of long-term results. Long-term follow up of patients after midface surgeries is important for evaluating which techniques result in consistent favorable outcomes, and which should be improved. We present a retrospective review reporting surgical procedures performed by a single surgeon in patients with Apert, Crouzon, and Pfeiffer Syndrome over a period of 45 years, with the intent to delineate procedures that have been effective over time. We also present our surgical treatment algorithm for pediatric patients with FGFR2 mutation–related syndromic craniosynostosis based on the senior author’s experience. METHODS: A retrospective review was performed of all patients with FGFR2 mutation–related syndromic craniosynostosis that underwent reconstruction for craniofacial defects, as performed by the senior author between 1975 and 2020. Patients without syndromic craniosynostosis were excluded. Inclusion criteria was limited to Apert, Crouzon, and Pfeiffer syndromes. Surgical procedures and complications were recorded for patients at all stages of the reconstructive process. RESULTS: A total of 68 patients were identified who had complete records for evaluation, including 30 patients with Apert syndrome, 27 patients with Crouzon syndrome and 11 patients with Pfeiffer syndrome. The average patient age was 30±15.8 years, with a range of 3–77 years of age. Mean long-term follow-up after initial surgery was 10.5 ± 10.1 years. Primary procedures performed for correction of craniofacial deformities included posterior distraction or expansion (10.3%), frontal expansion (14.7%), fronto-orbital advancement (39.7%), facial bipartition (11.8%), Le Fort III (19.1%), and Le Fort I (23.5%). Mean ages at which procedures were performed were 1.5 ± 1.6 years for posterior distraction or expansion, 1.1 ± 1.2 years for fronto-orbital advancement, 6.2 ± 3.8 years for monobloc frontoacial advancement, 4.6 ± 1.8 years for monobloc frontofacial advancement with facial bipartition, 13.2 ± 8.2 years for Le Fort III, and 17.0 ± 3.8 years for Le Fort I. Additional procedures commonly used included nasal bone grafts (25.0%) and lateral canthopexies (19.1%). CONCLUSIONS: This study, with an extensive long-term follow-up period, presents a pediatric surgical treatment algorithm for patients with FGFR2 mutation–related syndromic craniosynostosis. Our treatment algorithm entails a posterior distraction or expansion and fronto-orbital advancement at 6 months, monobloc frontofacial advancement ± facial bipartition at age 6 or 7, or a Le Fort III if morphologically indicated, and in most cases, a Le Fort I at age 17 or 18. Although multiple reconstructive procedures are necessary, complications are rare. This treatment algorithm results in good results in adolescence, allowing patients to integrate into mainstream life. However, patients tend to prematurely age, a problem that is not addressed by the current pediatric surgical treatment algorithm. Future directions include defining aesthetic surgical management of adults.

The influence of fronto-facial monobloc advancement on obstructive sleep apnea: An assessment of 109 syndromic craniosynostoses cases

Obstructive sleep apnea syndrome is prevalent in children with syndromic craniosynostoses. Here we assessed the effects of fronto-facial monobloc advancement with internal distraction on obstructive sleep apnea in syndromic craniosynostoses.All patients managed for syndromic craniosynostosis over a period of 14 years were assessed based on apnea-hyponea index (AHI) before and after fronto-facial surgery. AHI values were analyzed using multivariate models with focuses on (1) absolute decrease in AHI values after fronto-facial surgery and (2) AHI normalization (AHI < 5) after fronto-facial surgery.One hundred and nine patients were included with 407 polysomnographic studies. Higher pre-operative AHI (p < 0.001) and pre-operative vault expansion (p = 0.008) were associated with more AHI decrease. Early airways surgery (p = 0.002) and fronto-facial surgery at older ages (p < 0.001) were associated with more AHI normalization.Our results indicate that fronto-facial surgery is specifically efficient in reducing severe (AHI > 20) obstructive sleep apnea in syndromic craniosynostoses. Early airways surgery, early vault expansion and fronto-facial surgery at older ages are recommended for better respiratory results. We provide support for a protocol involving (1) early posterior vault expansion and airways surgery and (2) fronto-facial advancement performed as late as possible (>2.5 years).

Long-Term Follow-Up on Bone Stability and Complication Rate after Monobloc Advancement in Syndromic Craniosynostosis.

Monobloc advancement is a complex procedure used to treat patients with syndromic craniosynostosis. Studies directly addressing the long-term stability of monobloc advancement with distraction osteogenesis are underreported in the literature. The objectives of this study were to assess 5-year midface bone stability following monobloc advancement performed on patients with syndromic craniosynostosis, identify risk factors for relapse, and present strategies for prevention and management of complications. An observational retrospective study was performed on consecutive patients with Apert, Crouzon, or Pfeiffer syndrome (n = 23) who underwent monobloc advancement using distraction osteogenesis between 1994 and 2013. A total of 130 lateral cephalograms were used to assess both long-term stability after monobloc advancement with distraction osteogenesis and risk factors for relapse. All serious complications were identified and recorded. The analysis of variance test was used to assess horizontal relapse of the midface and mandibular plane. Cephalometric analysis revealed long-term stability of frontofacial advancement using distraction osteogenesis, regardless of the presence of tested variables. Serious complications arising from monobloc advancement using distraction osteogenesis included cerebrospinal fluid leakage in six patients (26 percent), accompanying meningitis in two patients (8.7 percent), seizures in seven patients (30.4 percent), and impaired visual acuity in one eye of one patient (4.3 percent). Frontofacial monobloc advancement with distraction osteogenesis provides long-term midface bone stability. Therapeutic, IV.

Excessive ossification of the bandeau in Crouzon and Apert syndromes

BackgroundThe study aimed at assessing the variations in thickness of the supra-orbital bar in Crouzon (CS) and Apert syndromes (AS) before and after fronto-facial monobloc advancement (FFMBA) using CT-scan data. MethodsAll CS or AS patients who underwent FFMBA between 2008 and 2018 with available clinical and CT-scan data were included. Frontal bone thickness was assessed at five locations of the supra-orbital bar using the Half-Maximum-Height protocol and plotted over the bone surface. ResultsWe included 210 CT-scans from 25 CS to 10 AS patients and 25 controls. Before FFMBA, CS children only had a significantly thicker frontal bone (+0.772 mm ± 0.312, p = 0.017). After FFMBA, a significant increase in frontal bone thickness was reported for CS at 3 months (+0.637 mm ± 0.141, p < 0.001), 6 months (+0.910 mm ± 0.120, p < 0.001) and 12 months (+1.099 mm ± 0.124, p < 0.001) post-operatively as well as in AS at 1 month (+2.069 mm ± 0.441, p < 0.001), 6 months (+1.247 mm ± 0.406, p = 0.003) and 12 months (+2.360 mm ± 0.284, p < 0.001) post-operatively. For both syndromes, age at FFMBA and specific FGFR2 mutations significantly influenced post-operative frontal bone thickness. ConclusionsCraniofacial surgeons should be aware of the potential need for secondary surgery of the supra-orbital after FFMBA in CS and AS. Furthermore, a thicker supra-orbital bar is part of the CS phenotype, illustrating the role of FGFR2 in craniofacial growth.

Chirurgie secondaire des craniosténoses et faciocraniosténoses

Secondary surgeries for single craniosynostosis surgeries are mainly esthetic refinements rather than functional indications. However, cranioplasties for bone defects correction or insufficient corrections may be undertaken. Management of syndromic craniosynostoses usually requires multiple surgical interventions, the sequence of which might vary per the genetic mutation. It is commonplace to start with posterior vault expansion before age 6 months, then treat cerebellar tonsillar herniation by the age of twelve months, and delay fronto-facial monobloc advancement until at least 18-24 months of age. Ventricular shunting is preferably avoided or delayed. Failure to respect these guidelines can significantly complicate the subsequent management. Primary fronto-orbital advancement or early facial osteotomy type Le Fort3, may compromise the subsequent fronto-facial monobloc advancement. However, this salvage secondary monobloc may be undertaken in some instances despite previous anterior osteotomies with a higher morbidity.

S3-17 SESSION 3: FACIOCRANIOSYNOSTOSIS – PART I FRONTO-FACIAL MONOBLOC ADVANCEMENT WITH DISTRACTION REDUCES SEVERE OBSTRUCTIVE SLEEP APNEA IN FACIOCRANIOSYNOSTOSES: PROSPECTIVE ASSESSMENT OF 109 CASES

Introduction: Obstructive sleep apnea syndrome (OSAS) is prevalent in children with faciocraniosynostoses and is associated with poor cognitive outcome and risk for increased intracranial pressure. Fronto-facial monobloc advancement (FFMBA) with distraction advances the midface and is performed for OSAS management. Here we aimed to provide a quantitative and prospective assessment of the effects of FFMBA on OSAS in faciocraniosynostoses. Methods: We prospectively included all patients managed for faciocraniosynostoses over a period of 18 years and followed-up their apnea-hyponea index (AHI) based on polysomnographic (PSG) studies, before and after FFMBA with internal distraction. AHI was assessed using several linear and logistic multivariate models, in order to quantify (1) pre-operative AHI values, (2) absolute decrease in AHI values after FFBMA, (3) AHI normalization (AHI<5) after FFMBA, (4) need for a secondary facial advancement and (5) genotype-phenotype correlations. In the second half of the experience, systematical removal of adenoids and tonsils were performed prior to monobloc surgery Results: A total of 109 patients were included and 407 PSG at different time points were collected. We showed a global and significant decrease in AHI after FFMBA: mean pre-operative AHI was 19.11+/-17.25 (19.31+/-18.31 in Crouzon, 17.00+/-11.87 in Apert and 21.82+/-19.38 in Pfeiffer syndrome). The mean post-operative AHI value for all patients was 12.47+/-13.58, which corresponded to a significant decrease from the mean pre-operative value of 19.11+/-17.25 (p<0.05); the decrease from pre-operative values was significant for all three syndromes (p<0.05). Pre-operative lateral and/or posterior decompression was associated with more AHI decrease in absolute value. FFMBA at older ages, Pfeiffer syndrome and pre-operative tonsillectomy and/or adenoidectomy were associated with more AHI normalization. In this subgroup with premonobloc ENT surgery, the intermediate OSAS (AHI between 10–20) the mean pre-op was 16/h and mean post-op was 11/h. In the severe OSAS patients (pre op AHI >20), the mean pre op was 43/h and mean post op was 15/h. Conclusion: FFMBA is efficient in reducing OSAS in faciocraniosynostoses. Pre-operative adenoido-tonsillectomy and lateral and/or posterior skull decompression are recommended before FFMBA in order to improve the respiratory results of the fronto-facial advancement. Delaying surgery when allowed by the neurosurgical and respiratory medicine teams is also a parameter favoring better respiratory outcomes.

S12-05 SESSION 12: FACIOCRANIOSYNOSTOSIS – PART II FRONTO-FACIAL MONOBLOC ADVANCEMENT WITH INTERNAL DISTRACTION IN CROUZON SYNDROME: LONG-TERM EFFECTS OF MOLAR DEVELOPMENT AND GROWTH

Introduction: Crouzon syndrome is a syndromic faciocraniosynostosis that can be associated with severe fronto-facial retrusion leading to major functional impairments such as ocular proptosis and obstructive sleep apnea. The procedure of choice for the primary correction of this retrusion is fronto-facial monobloc advancement (FFMBA) with internal or external distraction. FFMBA involves pterygomaxillary dysjunction (PMD), using either a superior or an intra-oral approach. This step is at risk of damaging the germs of the decidual and permanent molars. Methods: Here we considered a series of 15 patients with Crouzon syndrome who benefited from FFMBA performed by the same surgeon, using a superior approach through the infra-temporal fossa for PMD. Based on pre-operative, early post-operative and late post-operative CT-scans, we recorded missing teeth, morphological dental anomalies and the Nolla stage for the first and second permanent maxillary molars. Results: We showed that early FFMBA has significant dental consequences, and that the extent of these dental effects is correlated with an early age at surgery. The use of transfacial pins was also correlated with the extent of dental damage. Conclusion: The indications of early FFMBA in Crouzon syndrome with severe functional repercussions are not questionable, but dental outcome should be taken into account when discussing early indications without severe functional impairment. Furthermore, our results still need be compared to dental outcomes of FFMBA performed with an intra-oral PMD.

SYM9.9E Necker Experience of Frontofacial Monobloc Advancement with Distraction (FFMBA): 145 cases in faciocraniosynostotic children

Introduction: in faciocraniosynostotic children, simultaneous correction of raised intracranial pressure, frontal retrusion, exorbitism, and facial retrusion causing sleep apnea syndrome can be achieved by frontofacial monobloc advancement. Methods: Since year 2000, 145 children aged between 9 months and 17 years were operated on by the same surgeon (EA) of a frontofacial Monobloc osteotomy. Frontal bone elevation was performed in all cases. Main group of 138 patients underwent insertion of 4 internal distractors (KLS Martin, Arnaud and Marchac distractors). A subgroup of 7 patients aged under 15 months underwent postoperative external traction (3kg) applied to a zygomatic transfacial pin (K-wire 2mm in diameter). In the subgroup of young patients, a prolongated sedation was necessary during one week. In all primary patients (never operated of a frontoorbital advancement before), transposition periosteal flaps were used to seal the anterior fossa.A systematic simple protocol of lumbar puncture during 3 days was used in case of suspicion of postoperative CSF leak. In a subgroup of 109 patients who were prospectively evaluated for respiratory outcome, 44% had a systematical removal of adenoids and tonsils prior to Monobloc. Results: in 95% of patients exorbitism was corrected. Class I occlusion was obtained only in 75% of the cases at the end of distraction. The mean OSAS measured on AHI was reduced from 19.1 (+/-17.2) to a mean 12.5 (+/-13.6). But, only the patients in whom adenoids and tonsils were removed preoperatively benefited frankly from the Monobloc.The rate of major infections was 2% (3 out of 145) mostly in secondary patients. The rate of mortality was 1,3 % (2 patients out of 145): one was due to an untreated preoperative Chiari, the other to very severe venous malformations (both these complications occurred at the beginning of our experience). Minor complications included frequently contaminations of internal distractors (30%), and CSF leaks requiring temporary treatment in 8%. The use of transfacial pin was detrimental to tooth buds but helped correction of airways obstruction in severe patients around one year of age. Postoperative OSAS was significantly lower when premonobloc ENT surgery was performed (tonsils and adenoids) Conclusions: Recommendations for surgical management of FFMBA include the following: - Preoperative screening including CT scan, MRI with venous analysis, polysomnography and ophthalmologic examination. - Preliminary systematic ENT removal of tonsils and adenoids (if significally present). - Preliminary management of Chiari by posterior vault distraction associated to foramen magnum decompression if necessary - Prefer primary cases for FFMBA allowing systematic closure of anterior cranial fossa by bilateral anteriorly based pericranial flaps (those flaps rarely available in previously operated patients)- This step necessitates frontal bone elevation - Use 4 internal distractors with consolidation time of 4–6 months. - Sedation of 2–4 days useful in the immediate post-operative period. - Slow distraction rate to 0,5mm/day starting at day 3 until completion (20–25 mm). - Obtain overcorrection at orbital level, and at dental level if possible. - In the very young and very severe, a very early FFMBA could be performed with adjunction of transfacial pin and external traction during one week. - Postoperatively, reeducate mouth opening to prevent trismus

SYM9.9B Quantitative facial and orbital assessments of fronto-facial monobloc advancement with internal distraction in faciocraniosynostoses

SYM9.9B Quantitative facial and orbital assessments of fronto-facial monobloc advancement with internal distraction in faciocraniosynostoses

Correcting Exorbitism by Monobloc Frontofacial Advancement in Crouzon-Pfeiffer Syndrome: An Age-Specific, Time-Related, Controlled Study.

In FGFR2 craniosynostosis, midfacial hypoplasia features oculo-orbital disproportion and symptomatic exorbitism. Clinical consequences may mandate surgery at a young age to prevent globe subluxation, corneal ulceration, and potential loss of vision. Monobloc osteotomy and distraction osteogenesis (monobloc distraction) seek to correct exorbitism. A report of the age-related impact of monobloc osteotomy and distraction osteogenesis on orbital volume, globe volume, and globe protrusion is presented. Computed tomographic scan data from 28 Crouzon-Pfeiffer patients were assessed at preoperative, early postoperative, and 1-year follow-up time points. Orbital volumes, globe volumes, and globe protrusions were measured by manual and semiautomatic segmentation techniques, and these were compared to 40 age-matched controls. Crouzon-Pfeiffer syndrome orbital volumes are significantly small, and are significantly overexpanded by distraction to endpoints correcting symptomatic exorbitism. Globe volumes are significantly larger than controls under 5 years, do not independently correlate with globe protrusion, and are unaffected by surgery. Correlation between orbital volume expansion and reduction of globe protrusion is not significant. Age-related variations of postoperative growth potential occur to 1 year postoperatively. The Crouzon-Pfeiffer syndrome FGFR2 orbit exhibits early growth acceleration followed by premature growth arrest at 10 to 14 years. Orbital volume expansion by monobloc osteotomy and distraction osteogenesis is not the sole determinant of reduced globe protrusion. Mean volume relapse of the orbit at 1 year is insignificant across the series. Derived Crouzon-Pfeiffer growth curves suggest that "early functional monobloc" in infants occurs on a background of dynamic orbital growth, which remains programmed to a Crouzon-Pfeiffer FGFR2 phenotype and aligns with the incidence of delayed clinical regression and later secondary surgery. Therapeutic, IV.