Monobloc Advancement Research Articles

Timing of Ossification of the Anterior Skull Base in Syndromic Synostosis.

The anterior skull base undergoes a progressive ossification after birth. This has implications on the epidural dissection of early trans-craniofacial osteotomy procedures such as monobloc advancements. Our purpose was to determine the rate of ossification in syndromic synostosis patients relative to a normal cohort to establish when maturation of the anterior skull base is complete. The authors analyzed CT scans from 35 patients with Crouzon, Apert or Pfeiffer syndrome, and 84 patients without any craniofacial anomaly between the ages of 0 and 6 years. The non-ossified anterior skull base area was measured using 3D Slicer. The authors compared the sizes of the defects at different ages between the three syndromes and with the control group using Mann-Whitney test. Significance was set at P < 0.05. All patients less than 12 months of age had a measurable defect anterior to the cribriform whereas patients greater than five years of age had full ossification of the anterior skull base with no evidence of defect. The relationship of defect size and age at scan was non-linear, with most defects closing rapidly in the first six months. The temporal closure pattern of the defect was similar between the three syndromes and the control group with no significant difference. Our findings indicate that syndromic children undergo skull base maturation at the same rate as non-syndromic cases, with the majority ossified by three years of age. Anterior skull base surgeries performed before three years should optimize visualization of this area during dissection.

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.

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

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

Complication rates following a monobloc advancement using distration osteogenesis with customized distractor

Complication rates following a monobloc advancement using distration osteogenesis with customized distractor

Orbital volume changes in monobloc advancement using distration osteogenesis with a customized distractor

Background: Syndromic craniofacial synostosis is characterized by cranial morphological alterations and hypoplasia of the midface that may result in obstructive sleep apnea and exorbitism.

Dental consequences of pterygomaxillary dysjunction during fronto-facial monobloc advancement with internal distraction for Crouzon syndrome

Crouzon syndrome is a syndromic faciocraniosynostosis that can be associated with severe fronto-facial retrusion leading to major functional impairments: extreme exorbitism may be vision-threatening and severe respiration impairment can be life-threatening. 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. 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. We showed that early FFMBA has significant dental consequences, and that these dental effects are correlated with an early age at surgery. Although the indications of early FFMBA in Crouzon syndrome with severe functional repercussions are not questionable, our results should be compared to dental outcomes of FFMBA performed with an intra-oral PMD.

Anterior Skull Base and Pericranial Flap Ossification after Frontofacial Monobloc Advancement.

Frontofacial monobloc advancement creates a communication between the anterior cranial fossa and nasal cavities. To tackle this issue, transorbital pericranial pedicled flaps are routinely performed in the authors' center. This study aimed to assess the postoperative ossification of the anterior skull base and pedicled flaps following frontofacial monobloc advancement, and to identify factors influencing this ossification. Measurements of the skull base only and of the ossified pedicled flaps together with the skull base were performed on computed tomographic scans at the nasofrontal and the nasoethmoid frontal junctions. The total thickness of the skull vault was measured and a qualitative defect score for the anterior skull base was computed. Twenty-two patients who underwent frontofacial monobloc advancement at a median age of 3.1 years (range, 1.9 to 3.6 years) were included: 14 with Crouzon, five with Pfeiffer, and three with Apert syndrome. One year and 5 years after surgery, the distraction gap was completely ossified in the anterior skull base midline in all patients. Ossified pedicled flaps together with the skull base were thicker in patients than in controls at these two time points (p < 0.005 and p < 0.02). Patients with Pfeiffer syndrome had a significantly thicker skull base only and ossified pedicled flaps together with the skull base thicknesses (p = 0.01 and p = 0.03) and lower defect scores than patients with Crouzon or Apert syndrome (p = 0.03) 1 year postoperatively. As ossification of the pedicled flaps and total reossification of the anterior skull base midline were observed in all patients, the authors indicate that performing pedicled flaps in frontofacial monobloc advancement surgery could promote the reossification of the anterior skull base. Therapeutic, IV.

Comparison of Complication Rate Between LeFort III and Monobloc Advancement With or Without Distraction Osteogenesis.

LeFort III osteotomies or monobloc advancements, with or without distraction, can be used to treat mid-facial hypoplasia causing exorbitism and obstructive sleep apnea in syndromic patients. This report is a meta-analysis of the complication rates following LeFort III osteotomies or monobloc advancement with or without distraction. Triple database search was conducted to identify articles addressing mid-facial hypoplasia treated with LeFort III or monobloc in which complications were detailed. Complications were considered major if they required a second operation or were potentially life threatening. Statistical analysis was performed with Student t test. Fifteen studies fit inclusion criteria. This yielded 363 total patients. In patients treated with a monobloc advancement, there was a statistically higher rate of major (P < 0.0001) and minor (P < 0.0001) complications, death (P = 0.02), cerebrospinal fluid (CSF) leaks (P < 0.0001), and meningitis/abscess (P < 0.0001) when distraction was used. In patients treated with a LeFort III, there was a statistically higher rate of reoperation when distraction was used (P = 0.001). In patients treated without distraction, there was a statistically higher rate of major (P < 0.0001) complications, death (P = 0.008), CSF leaks (P = 0.003), and reoperation (P < 0.0001) with a monobloc and a statistically higher rate of minor complications (P < 0.001) with a LeFort III. LeFort III proved to be a safer technique for the treatment of mid-facial hypoplasia. Although distraction was initially introduced to reduce complications, in this review, monobloc with distraction had the highest rate of major complications. There are multiple confounding factors that influence success of mid-face surgery and every patient must be evaluated and treated individually.

The Role of Bipartition Distraction in the Treatment of Apert Syndrome.

Apert syndrome is characterized by hypertelorism, a negative canthal axis, and central midfacial hypoplasia, resulting in a biconcave face. Bipartition distraction partially corrects these facial anomalies. This study investigates limitations of bipartition distraction using linear, angular, and geometric morphometric analysis. Preoperative and postoperative three-dimensional computed tomographic craniofacial constructs of 10 patients with Apert syndrome (aged 12 to 21 years) were annotated with 98 landmarks. Twelve age-, sex, and ethnicity-matched normal skulls provided control data. Principal component analysis was used to analyze shape characteristics within and between the groups and describe the changes occurring with surgery. Results were displayed graphically using difference color maps. Conventional point-based measurements documented midfacial width, height, and asymmetry. Apert three-dimensional constructs exhibited reduced upper midfacial height and greater extrinsic symmetric variation relative to controls. Facial bipartition partially corrected excessive midfacial width and interorbital distance but did not adequately correct deficient upper midfacial height. Excessive orbital diameter was unaltered by surgery. There was no demonstrable effect on intrinsic or extrinsic midfacial asymmetry. Principal component analysis demonstrated improved midfacial projection and correction of central biconcavity. Bipartition distraction corrects midfacial retrusion, exorbitism, and hypertelorism. It does not treat midfacial height disproportion or correct orbital shape. It leaves the face too wide at the zygomatic level and does not correct facial asymmetry. Although bipartition distraction is an improvement on the unmodified monobloc advancement, further refinements are needed to fully correct Apert dysmorphology.

What's New in Syndromic Craniosynostosis Surgery?

After studying this article, the participant should be able to: 1. Understand the role of prenatal screening and counseling of parents of unborn children with syndromic craniosynostosis. 2. Recognize the genetic abnormalities, craniofacial phenotype, associated anomalies, and challenges associated with each of the five major forms of syndromic craniosynostosis. 3. Identify the pros and cons associated with timing and types of cranial vault remodeling techniques in this patient population. 4. Understand the risks and benefits associated with midface advancement with Le Fort III, Le Fort II plus zygomatic repositioning, monobloc, and facial bipartition. 5. Understand the important role of psychological counseling throughout childhood in this at-risk group. Crouzon, Apert, Pfeiffer, Muenke, and Saethre-Chotzen syndromes are the five most common forms of syndromic craniosynostosis. Although each has different genetic underpinnings and associated anomalies, their hallmark finding is turribrachycephaly most often associated with bicoronal craniosynostosis. The role of prenatal screening and counseling is growing, with caregivers becoming involved before birth. Multidisciplinary care from birth onward involves craniofacial plastic surgeons, neurosurgeons, otolaryngologists, ophthalmologists, orthodontists, anesthesiologists, psychologists, speech therapists, and geneticists. Early partial, or regional, craniectomy may be urgently indicated in multisuture cases with signs of increased intracranial pressure. Others may be managed successfully with posterior cranial vault distraction, middle vault expansion, or fronto-orbital advancement. Some authors have advocated early monobloc advancement for those patients who require acute airway intervention and globe protection, although the risks of these procedures are high. Many patients will require midfacial advancement with a Le Fort III, Le Fort II plus zygomatic repositioning, monobloc, or facial bipartition. The indications, risks, and benefits for each midfacial procedure must be considered, as this step in the treatment algorithm may carry the greatest functional and aesthetic benefits but also the potential for the greatest morbidity. At the culmination of facial growth, it is not uncommon for patients to require conventional orthognathic surgery and other bony contouring and soft-tissue procedures. Finally, an understanding of the psychological aspects of craniofacial difference, both in affected individuals and in their families, is essential to a successful, holistic approach.

The benefits of differential fronto-orbital advancement remodelling and midface monobloc advancement with on table external distractors for the management and complexities of craniofacial manifestations of Pfeiffer syndrome

The benefits of differential fronto-orbital advancement remodelling and midface monobloc advancement with on table external distractors for the management and complexities of craniofacial manifestations of Pfeiffer syndrome

Stratégie craniofaciale pour les faciocraniosténoses

The complexity of treatment of faciocraniosynostosis justifies the treatment in a reference center for rare diseases. The growth disturbances in the skull and face being variable according to the type of mutation in the FGFr (Crouzon, Pfeiffer, Apert), the strategy is adapted to the phenotype according to the following principles: posterior expansion with or without distraction around 6months to limit the descent of the cerebellum tonsils and to prevent the turricephalic development; fronto-facial monobloc advancement with internal distraction around the age of 18months in case of severe exorbitism or breathing impairment. The dissociated strategy (fronto-orbital advancement first, followed by facial osteotomy of Le Fort 3 type). The growing evolution dictates the sequence of subsequent surgeries according to the monitoring of intracranial pressure by fundus examination and of the respiration by polysomnography. Le Fort 3 and transversal maxillary distraction may be repeated if necessary. Orthognathic surgery is almost always compulsory after the age of 14, before the aesthetic refinements which can be undertaken ultimately (rhinoplasty, genioplasty, canthopexies, fat grafting…).

Apert syndrome: Surgical outcomes and perspectives.

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. 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. 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. 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.

Frontofacial Monobloc Advancement With Simultaneous Frontal Cranioplasty in Adolescents With Residual Apert Syndrome Deformations.

The treatment of faciocraniosynostosis has steadily evolved since the introduction of craniofacial surgery in the 1950s. The aim of this study is to demonstrate the positive results obtained by frontofacial monobloc advancement with simultaneous frontal cranioplasty in adolescents with adult facial bones and residual Apert syndrome deformations. Three adolescents underwent surgery between September 1, 2010 and March 31, 2011. All had faciocraniosynostosis in the context of Apert syndrome and had undergone brain decompression surgery during the first year of life. However, they presented intracranial hypertension. The authors carried out frontofacial monobloc advancement with internal distraction and frontal cranioplasty. The mean frontal advancement was 13.8 mm. The mean maxillary advancement was 16.3 mm. About exorbitism, 2 patients had grade III and 1 had grade I before surgery. After monobloc advancement, 2 patients had no exorbitism and 1 had grade I. About dental occlusion, 3 patients had class III before surgery and were overcorrected in class II after advancement. Frontofacial monobloc advancement yields satisfactory functional and esthetic results in these cases. In conclusion, simultaneous frontofacial monobloc advancement and cranioplasty appears to be a promising technique for the treatment of adolescents with residual craniofacial deformations.

Orbitofrontal monobloc advancement for Crouzon syndrome

IntroductionUsually, patients suffering from Crouzon syndrome have synostosis of coronal sutures, exophthalmia, hypertelorism, and hypoplasia of the middle third of face. Sometimes maxillary retrusion is absent, so these patients have class I or II relationship. In these cases, frontofacial monobloc advancement, which is the gold standard, increases the maxillo-mandibular dysmorphia. Therefore we propose orbitofrontal monobloc advancement minus dental arch, without splits of the pterygoid plates. Case reportA 12-year-old girl with Crouzon syndrome had intracranial hypertension, exophthalmia, a middle third retrusion and a class II occlusion. We achieved orbitofrontal monobloc advancement which is frontofacial monobloc advancement minus maxillary dental arch. Four distractors KLS Martin were used. After 20 days of distraction, the final advancement was 10.2 mm for cranial distractors and 10.5 mm at fronto-zygomatic. Distractors were removed after 8 months. DiscussionWe offer patients suffering from Crouzon syndrome with class I or II relationship a change from the classic frontofacial monobloc advancement leaving the maxillary dental arch in place, thus avoiding the worsening of the maxillo-mandibular dysmorphia related to surgery. The idea of associating Le Fort I osteotomy with a frontofacial monobloc advancement or Le Fort III osteotomy has already been described, mainly by Tessier and Obwegeser, however they probably achieved a complete Le Fort I osteotomy while we don't split the pterygoid plates.The patient's morphology and his surgical history determine the choice between Le Fort III and monobloc advancement. Dental occlusion needs to be taken into account for surgical indication.