Clinical and operative risk factors for complications after Apert hand syndactyly reconstruction

This study evaluated how Apert hand syndactyly presentations and reconstructive techniques influence reconstruction outcomes. All cases at a major paediatric hospital between 2007 and 2022 were analysed, including 98 web space reconstructions in 17 patients. Overall, 62% of hands developed complications and 15% required revision surgery. Upton hand type was significantly associated with postoperative complication incidence, specifically including range-of-motion deficits, flexion contracture, web creep and revision surgery. More severe syndactylies may benefit from additional measures to reduce complications. Rectangular commissural flaps showed 1.9 times greater complication risk than interdigitating triangular flaps, including 11.2 times greater risk of web creep. Zigzag volar finger flaps showed 1.8 times greater complication risk than straight-line incisions, including 3.8 times greater risk of web creep. Our study showed that interdigitating triangular commissural flaps and straight-line volar finger incisions are preferable to rectangular commissural and zigzag finger flaps in most cases of Apert hand syndactyly to minimize complications.

LEVEL OF EVIDENCE

III.

Skeletal changes after midface surgery in patients with craniofacial deformities: a three-dimensional quantification method

To determine the skeletal changes after midface surgery in patients with syndromic craniosynostosis who underwent Le Fort III (LFIII), monobloc (MB), or facial bipartition (FB). This was a retrospective study including 75 patients: 33 treated by LFIII, 29 by MB, and 13 by FB. Twenty-five had a diagnosis of Apert, 39 Crouzon, and 11 craniofrontonasal syndrome. A three-dimensional mesh was created from the preoperative scan and registered to the postoperative scan to visualise the advancement. LFIII at age 7-12 years effectuated a higher mean advancement in the maxillary (15.5 mm) and zygomatic (7.6 mm) regions when compared to ≥13 years (10.2 mm and 5.5 mm). After MB, mean advancement of the fronto-orbital region was higher at <7 years (16.4 mm), and similarly lower at ages 7-12 (13.8 mm) and ≥13 (12.5 mm). The mean preoperative inter-dacryon distance (34.4 ± 4.4 mm) was reduced by 8.7 ± 4.2 mm after FB without distraction (n = 10). More advancement was seen when midface surgery was performed at a younger age, due to more severe cases and a desire for overcorrection. The highest mean advancement was observed in the fronto-orbital region. Antero-inferior rotational movement was seen after all three techniques.

Successful reverse total shoulder replacement in a patient with Apert syndrome

Apert syndrome, first described in the literature by a French pediatrician Eugene Apert, is a rare congenital form of acrocephalodactyly with autosomal dominant inheritance. Classically, this syndrome is characterized by craniosynostosis, midface hypoplasia, and symmetrical syndactyly of hands and feet resulting from embryonic anomalies during the third week of gestation. It is also associated with a variety of abnormalities of the viscera, involving the neurological, genitourinary, and cardiorespiratory systems. Glenohumeral manifestations of Apert syndrome include glenoid dysplasia, an oblong humeral head with a prominence of the greater tuberosity, acromial prominence, and inferior subluxation of the glenohumeral joint. This pathological anatomy results in progressive degenerative changes, synchondrosis, and restriction in shoulder joint mobility, particularly in flexion and abduction. While surgical options for the accompanying deformities of the feet and spine are described, interventions for shoulder pathology are not well-defined. Joint replacement surgery could offer such patients pain relief and improved function. Reverse total shoulder arthroplasty is yet to be described in Apert syndrome and this case report presents the outcome in a 48-year-old male. Level of evidence: IV case report.

Ser252Trp mutation in fibroblast growth factor receptor 2 promotes branching morphogenesis in mouse salivary glands

OBJECTIVES

The purpose of this study was to perform morphological and immunohistochemical (IHC) analysis of the submandibular glands (SMGs) in early development in Apert syndrome model mice (Ap mice).

METHODS

ACTB-Cre homozygous mice were mated with fibroblast growth factor receptor 2 (Fgfr2+/Neo-S252W) mice; ACTB-Cre heterozygous mice (ACTB-Cre mice) at embryonic day (E) 13.5 served as the control group, and Fgfr2+/S252W mice (Ap mice) served as the experimental group. Hematoxylin and eosin (H&E) staining was performed on SMGs; Total SMG area and epithelial area were determined, and the epithelial occupancy ratio was calculated. Immunostaining was performed to assess the localization of FGF signaling-related proteins. Next, bromodeoxyuridine (BrdU)-positive cells were evaluated to assess cell proliferation. Finally, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining was performed to assess apoptosis in SMGs.

RESULTS

The epithelial occupancy ratio was significantly higher in SMGs of Ap mice compared with that in SMGs of controls. FGF7 and bone morphogenetic protein 4 (BMP4) exhibited different localizations in SMGs of Ap mice compared with SMGs of controls. Cell proliferation was higher in SMGs of Ap mice compared with that of controls; however, apoptosis did not different significantly between the two groups.

CONCLUSION

Our results suggest that enhanced FGF signaling conferred by missense mutations in FGFR2 promotes branching morphogenesis in SMGs of Ap mice.

Coexistence of Two Rare Conditions Complicating the Other's Management: Propionic Acidemia and Apert Syndrome

Introduction

Propionic acidemia (PA) is an inborn error of organic acid metabolism inherited in an autosomal recessive manner. The neonatal-onset disease may present with feeding difficulties and vomiting; seizures, coma, and death may occur if untreated. In addition, catabolic processes such as infections and surgical procedures could cause metabolic decompensation, so patients with organic acidemia should be followed closely.

Case Presentation

Here, a patient diagnosed with PA and Apert syndrome in the neonatal period and the complications caused by the coexistence of the two entities are mentioned. The difficulties precipitated by the coexistence of Apert syndrome and PA make this case unique. She has had prolonged hospitalizations due to metabolic decompensations after cranioplasty and inguinal hernia repair, both triggered by nosocomial respiratory infections, complicating both the surgical treatment of Apert syndrome and the management of PA.

Conclusion

Coexistence of these two serious disorders mandates a more prudent clinical management as Apert syndrome patients undergo several surgical procedures, rendering them susceptible to catabolic decompensations.

Cranial Morphology Associated With Syndromic Craniosynostosis: A Potential Detection of Abnormality in Patient's Cranial Growth Using Angular Statistics

INTRODUCTION

Apert, Crouzon, and Pfeiffer syndromes are common genetic syndromes related to syndromic craniosynostosis (SC), whereby it is a congenital defect that occurs when the cranial growth is distorted. Identifying cranial angles associated with these 3 syndromes may assist the surgical team to focus on a specific cranial part during the intervention planning, thus optimizing surgical outcomes and reducing potential morbidity.

OBJECTIVE

The aim of this study is to identify the cranial angles, which are associated with Apert, Crouzon, and Pfeiffer syndromes.

METHODS

The cranial computed tomography scan images of 17 patients with SC and 22 control groups aged 0 to 12 years who were treated in the University Malaya Medical Centre were obtained, while 12 angular measurements were attained using the Mimics software. The angular data were then divided into 2 groups (patients aged 0 to 24 months and >24 months). This work proposes a 95% confidence interval (CI) for angular mean to detect the abnormality in patient's cranial growth for the SC syndromes.

RESULTS

The 95% CI of angular mean for the control group was calculated and used as an indicator to confirm the abnormality in patient's cranial growth that is associated with the 3 syndromes. The results showed that there are different cranial angles associated with these 3 syndromes.

CONCLUSIONS

All cranial angles of the patients with these syndromes lie outside the 95% CI of angular mean of control group, indicating the reliability of the proposed CI in the identification of abnormality in the patient's cranial growth.

Exosome-mediated small interfering RNA delivery inhibits aberrant osteoblast differentiation in Apert syndrome model mice

OBJECTIVE

Apert syndrome, an autosomal dominant congenital disorder characterized by craniosynostosis, is caused by a missense mutation (S252W or P253R) in fibroblast growth factor receptor 2 (FGFR2). Exosomes are naturally occurring carriers that deliver nucleic acids, including small interfering RNA (siRNA), to induce gene silencing. This study aimed to develop siRNA-loaded exosomes (Ex-siRNA^Fgfr2S252W) to silence the Fgfr2^S252W gain-of-function mutation, thereby inhibiting the increased osteoblastic differentiation caused by the constitutive activation of FGFR2 signaling in calvarial osteoblastic cells isolated from Apert syndrome model mice.

DESIGN

Primary calvarial osteoblast-like cells were isolated from the embryonic calvarial sutures of the Apert syndrome model (Fgfr2^S252W/+) and littermate wild-type mice (Ap-Ob and Wt-Ob, respectively). Exosomes were extracted from the serum of wild-type mice, validated using biomarkers, and used to encapsulate siRNAs. After exosome-mediated siRNA transfection, cells were analyzed under a fluorescence microscope to validate the delivery of Ex-siRNA^Fgfr2S252W, followed by western blot and real-time reverse transcription polymerase chain reaction analyses.

RESULTS

After 24 h of Ex-siRNA^Fgfr2S252W delivery in both Ap-Ob and Wt-Ob, siRNA-loaded exosome delivery was validated. Moreover, p44/42 mitogen-activated protein kinase (MAPK) phosphorylation, runt-related transcription factor 2 (Runx2), and collagen type 1 alpha 1 (Col1a1) mRNA expression, and alkaline phosphatase (ALP) activity were significantly increased in Ap-Ob. The levels of phospho-p44/42 protein, Runx2, Col1a1, and ALP were significantly decreased after Ex-siRNA^Fgfr2S252W transfection but did not affect Wt-Ob.

CONCLUSIONS

These results indicate that exosome-mediated delivery of siRNA targeting Fgfr2^S252W is a potential non-invasive treatment for aberrant FGF/FGFR signaling.

Synchondrosis fusion contributes to the progression of postnatal craniofacial dysmorphology in syndromic craniosynostosis

Syndromic craniosynostosis (CS) patients exhibit early, bony fusion of calvarial sutures and cranial synchondroses, resulting in craniofacial dysmorphology. In this study, we chronologically evaluated skull morphology change after abnormal fusion of the sutures and synchondroses in mouse models of syndromic CS for further understanding of the disease. We found fusion of the inter-sphenoid synchondrosis (ISS) in Apert syndrome model mice (Fgfr2^S252W/+ ) around 3 weeks old as seen in Crouzon syndrome model mice (Fgfr2c^C342Y/+ ). We then examined ontogenic trajectories of CS mouse models after 3 weeks of age using geometric morphometrics analyses. Antero-ventral growth of the face was affected in Fgfr2^S252W/+ and Fgfr2c^C342Y/+ mice, while Saethre-Chotzen syndrome model mice (Twist1^+/- ) did not show the ISS fusion and exhibited a similar growth pattern to that of control littermates. Further analysis revealed that the coronal suture synostosis in the CS mouse models induces only the brachycephalic phenotype as a shared morphological feature. Although previous studies suggest that the fusion of the facial sutures during neonatal period is associated with midface hypoplasia, the present study suggests that the progressive postnatal fusion of the cranial synchondrosis also contributes to craniofacial dysmorphology in mouse models of syndromic CS. These morphological trajectories increase our understanding of the progression of syndromic CS skull growth.

Clinical manifestations of Apert syndrome

Apert syndrome presents similarly to the one we presented in this image, and a genetic study is used for confirmation. This image shows the typical findings of physical examination, so that if this appears in the outpatient department, the diagnosis of Apert syndrome should be assumed.

Apert Syndrome: Selection Rationale for Midface Advancement Technique

Apert syndrome is characterized by a wide spectrum of craniofacial clinical features that have been successfully addressed via a variety of midface advancement techniques. Although surgeons have individual preferences as to which specific procedures should be performed to best treat Apert patients, craniofacial plastic surgeons, working in tandem with pediatric neurosurgeons, can identify and evaluate functional limitations and facial morphologic disproportions, and establish appropriate criteria for effective midface advancement technique indication and selection. The purpose of this review article is to present and discuss our rationale for midface advancement technique selection based upon the most common craniofacial characteristics presented by Apert syndrome patients. The present article also provides a grading system that stratifies as major, moderate, and mild, the effect of each midface advancement technique on the different types of Apert syndrome facial features. Surgeons should take into consideration the maximum effect and benefit of each craniofacial osteotomy and how these procedures will alter the craniofacial skeleton. By understanding the long-term effect of each osteotomy on the most common craniofacial characteristics of Apert syndrome patients, craniofacial plastic surgeons and neurosurgeons will be able to customize the surgical procedures they perform in order to achieve the best possible outcomes.

Orthognathic Surgery in Patients with Syndromic Craniosynostosis

Patients with syndromic and nonsyndromic synostosis may have end-stage skeletal discrepancies involving the lower midface and mandible, with associated malocclusion. While orthognathic surgical procedures in this population can be reliably executed, the surgeon must be aware of the unique morphologic characteristics that accompany the primary diagnoses as well as the technical challenges associated with performing Le Fort I osteotomies in patients who have undergone prior subcranial midface distraction.

Three-dimensional analysis of the palatal morphology in growing patients with Apert syndrome and Crouzon syndrome

Patients with Apert syndrome or Crouzon syndrome present with severe defects in oral-maxillofacial growth and development. In this study, we conducted a quantitative three-dimensional (3D) analysis of the palatal morphology of patients with Apert syndrome and Crouzon syndrome. Four patients with Apert syndrome (average age, 11.0 ± 0.8 years) and five with Crouzon syndrome (average age, 10.1 ± 1.6 years) were investigated. The participants' maxillary dental casts were scanned and analyzed using 3D imaging. Palatal width, depth, cross-sectional area, and palatal angle (PW, PD, PCA, and PA, respectively) were measured, and standard scores were calculated based on sex- and age-matched Japanese standard values; the actual palatal surface areas (PSA) and palatal volumes (PV) were also measured. Our results show that patients with Apert syndrome and Crouzon syndrome had a very narrow PW (standard score: -3.79 and - 0.47, respectively). 3D analysis revealed that patients with Apert syndrome had a significantly shallower PD (standard score: -1.35) than those with Crouzon syndrome (standard score: 2.47), resulting in a smaller PCA (standard score: -5.13), PSA (5.49 cm² ), and PV (1.11 cm³ ) and larger PA (standard score: -0.12) than those in patients with Crouzon syndrome. This might be due to the former having a narrower and shallower palate caused by the predominant swelling of the palatal mucosa. These findings improve our understanding of the differences in palatal morphology between Apert syndrome and Crouzon syndrome patients.

Early Prenatal Ultrasound and Molecular Diagnosis of Apert Syndrome: Case Report with Postmortem CT-Scan and Chondral Plate Histology

Background Apert syndrome is characterized by craniosynostosis, midface hypoplasia and symmetric syndactyly. Case report: A 36-year-old mother, G2P1 underwent an ultrasound scan at 19 week's gestation. There was craniosynostosis, brachi-turricephaly and bilateral hand syndactyly. Genomic DNA from amniocentesis revealed the mutation C758C>Gp. (Pro to Arg substitution) at 252 of the exon 8 of the FGFR2 encoding for Apert syndrome. The pregnancy was terminated. Femoral chondral plate histology showed an increased interstitial matrix between bony trabeculae. Compared with normal, the trabeculae were thinner, more irregular with numerous osteoclasts suggesting abnormal bone remodeling. Hands and feet had an abrupt transition between resting and proliferating cartilage. Conclusion: Apert syndrome has increased intertrabecular matrix, thin trabeculae, increased remodeling, and irregular transition between the maturing and mineralization zones in the femur, and abnormal abrupt transition between the resting and proliferating cartilage in the fingers and toes.

Endoscopic strip craniectomy with orthotic helmeting for safe improvement of head growth in children with Apert syndrome

OBJECTIVE

Bilateral coronal craniosynostosis in Apert syndrome is traditionally managed with open cranial vault remodeling procedures like fronto-orbital advancement (FOA). However, as minimally invasive procedures gain popularity, limited data exist to determine their efficacy in this syndromic population. This study examines whether endoscopic strip craniectomy (ESC) is inferior to FOA in correcting head growth in patients with Apert syndrome.

METHODS

The authors conducted a retrospective review of children with Apert syndrome over a 23-year period. Postoperative head circumferences until 24 months of age were compared for patients treated with ESC versus FOA by using normative growth curves. Intraoperative and postoperative morbidity was compared between groups.

RESULTS

The median postoperative follow-up for the FOA (n = 14) and ESC (n = 16) groups was 40 and 28.5 months, the median age at operation was 12.8 and 2.7 months, and the median operative time was 285 and 65 minutes, respectively (p < 0.001). The FOA group had significantly higher rates of blood transfusion, ICU admission, and longer hospital length of stay (p < 0.01). There were no statistically significant differences in premature reossification rates, complications, need for further procedures, or complaints of asymmetry. Compared to normative growth curves, all patients in both groups had head circumferences comparable to or above the 85th percentile at last follow-up.

CONCLUSIONS

Children with Apert syndrome and bilateral coronal craniosynostosis treated with ESC experience early normalization of head growth and cephalic index that is not inferior to those treated with FOA. Longer-term assessments are needed to determine long-term aesthetic results and the correlation between head growth and neurocognitive development in this population.

Excessive osteoclast activation by osteoblast paracrine factor RANKL is a major cause of the abnormal long bone phenotype in Apert syndrome model mice

The fibroblast growth factor (FGF)/FGF receptor (FGFR) signaling pathway plays important roles in the development and growth of the skeleton. Apert syndrome caused by gain‐of‐function mutations of FGFR2 results in aberrant phenotypes of the skull, midface, and limbs. Although short limbs are representative features in patients with Apert syndrome, the causative mechanism for this limb defect has not been elucidated. Here we quantitatively confirmed decreases in the bone length, bone mineral density, and bone thickness in the Apert syndrome model of gene knock‐in Fgfr2^S252W/+ (EIIA‐Fgfr2^S252W/+) mice. Interestingly, despite these bone defects, histological analysis showed that the endochondral ossification process in the mutant mice was similar to that in wild‐type mice. Tartrate‐resistant acid phosphatase staining revealed that trabecular bone loss in mutant mice was associated with excessive osteoclast activity despite accelerated osteogenic differentiation. We investigated the osteoblast–osteoclast interaction and found that the increase in osteoclast activity was due to an increase in the Rankl level of osteoblasts in mutant mice and not enhanced osteoclastogenesis driven by the activation of FGFR2 signaling in bone marrow‐derived macrophages. Consistently, Col1a1‐Fgfr2^S252W/+ mice, which had osteoblast‐specific expression of Fgfr2 S252W, showed significant bone loss with a reduction of the bone length and excessive activity of osteoclasts was observed in the mutant mice. Taken together, the present study demonstrates that the imbalance in osteoblast and osteoclast coupling by abnormally increased Rankl expression in Fgfr2^S252W/+ mutant osteoblasts is a major causative mechanism for bone loss and short long bones in Fgfr2^S252W/+ mice.

Left Ophthalmic Segment Internal Carotid Artery Aneurysm Treated with Flow Diversion in a Child with Apert Syndrome: Technical Note

INTRODUCTION

Prevalence of intracranial aneurysms in children with Apert syndrome has not been described, and development of an aneurysm as a complication secondary to craniofacial surgery has never been reported.

CASE PRESENTATION

We report the rare case of a 10-year-old boy with Apert syndrome who underwent craniofacial reconstruction surgery consisting of subcranial Le Fort III osteotomies, bilateral lateral canthopexies, and nasal nares dilations for midfacial hypoplasia and resultant obstructive sleep apnea, and on routine follow-up magnetic resonance imaging (MRI) 1 year later, he was found to have a large left ophthalmic internal carotid artery (ICA) aneurysm that was not seen on MRI obtained 2 years prior. Immediately after the craniofacial surgery, the patient experienced a severe headache behind his left eye and extraocular movement abnormalities that subsided over the next days to months. Given the new and rapid growth of the aneurysm on follow-up MRI, the patient underwent a diagnostic cerebral angiogram followed by successful flow diversion treatment of the aneurysm with the pipeline embolization device (Medtronic, Dublin, Ireland).

CONCLUSION

Post-procedurally, over the next year, the patient developed word-finding difficulty and stuttering speech. He was found to have in-stent ICA stenosis and middle cerebral artery (MCA) stenosis at the first follow-up and underwent an initial angioplasty. After several weeks, ICA, MCA, and anterior cerebral artery stenoses were identified, and the patient underwent angioplasties for the ICA and MCA stenoses. On follow-up examination after the second procedure, the patient had tremendous improvement in his speech difficulties and was doing well clinically.

Tripod-shaped Syndactyly in Apert Syndrome with FGFR2 p.P253R Mutation

Apert syndrome is a rare acrocephalosyndactyly (craniosynostosis) syndrome characterized by craniofacial dysmorphism and syndactyly of the hands and feet. It is caused by FGFR2 mutations and inherited in an autosomal dominant manner. This article describes a novel clinical variant of Apert syndrome having bilateral symmetrical tripod-shaped syndactyly in hands with milder craniofacial features in a sporadic case, along with a mutation in the fibroblast growth factor receptor 2 ( FGFR2 ) gene. The patient had shown craniosynostosis, dysmorphic face, ocular hypertelorism, marked depression of the nasal bridge, long philtrum, and low set ears. Direct resequencing of the FGFR2 gene through Sanger's method identified a heterozygous missense mutation; FGFR2c.758C>G (FGFR2p.P253R) in the exon-7 of the gene.

Differential diagnosis of syndromic craniosynostosis: a case series

Purpose

Syndromic craniosynostosis is a rare genetic disease caused by premature fusion of one or multiple cranial sutures combined with malformations of other organs. The aim of this publication is to investigate sonographic signs of different syndromic craniosynostoses and associated malformations to facilitate a precise and early diagnosis.

Methods

We identified in the period of 2000–2019 thirteen cases with a prenatal suspected diagnosis of syndromic craniosynostosis at our department. We analyzed the ultrasound findings, MRI scans, genetic results as well as the mode of delivery, and postnatal procedures.

Results

Eight children were diagnosed with Apert Syndrome, two with Saethre Chotzen syndrome, one with Crouzon syndrome, and one with Greig cephalopolysyndactyly syndrome. One child had a mutation p.(Pro253Leu) in the FGFR2 gene. We identified characteristic changes of the head shape as well as typical associated malformations.

Conclusion

Second trimester diagnosis of syndromic craniosynostosis is feasible based on the identified sonographic signs. In case of a suspected diagnosis a genetic, neonatal as well as surgical counseling is recommended. We also recommend to offer a fetal MRI. The delivery should be planned in a perinatal center.

Long-term Management of a Patient with Apert Syndrome

AIM AND OBJECTIVE

To present an Apert syndrome patient with midfacial growth deficiency treated with Le Fort III distraction osteogenesis and subsequent two-jaw surgery.

BACKGROUND

Apert syndrome is expressed as a severe and irregular craniosynostosis, midfacial hypoplasia, and symmetric syndactyly in the fingers and toes. For craniosynostosis syndromes, treatment planning is complex due to the disharmony between facial profile and occlusion.

CASE DESCRIPTION

A 4-year-and-5-month-old boy, diagnosed with Apert syndrome, showed a concave profile accompanied with midfacial hypoplasia, moderate exorbitism, a reversed occlusion of -10.0 mm, an anterior open bite of -5.0 mm, and skeletal class III jaw-base relationship. The patient, aged 15 years and 4 months, underwent a Le Fort III osteotomy, and subsequent osteodistraction was performed via a rigid external distraction (RED) device. His midfacial bone was advanced by approximately 7.0 mm. One year after the distraction, preoperative treatment with 0.018-in preadjusted edgewise appliances was initiated. Two-jaw surgery with a Le Fort I osteotomy and bilateral sagittal split ramus osteotomy was performed after 42 months of preoperative orthodontic treatment. At the age of 20 years and 9 months, his facial profile dramatically changed to a straight profile, and an acceptable occlusion with an adequate interincisal relationship was obtained. A functional occlusion with an excellent facial profile was maintained throughout the 2-year retention period, although the upper dental arch width was slightly decreased, resulting in the recurrence of the left posterior crossbite.

CONCLUSION

Our report indicates the necessity of long-term follow-up in patients with craniosynostosis because of syndrome-specific growth and methodologically induced relapse.

CLINICAL SIGNIFICANCE

The two-stage operation combining early distraction osteogenesis and postgrowth orthognathic surgery proves to be an effective therapy for correcting midfacial hypoplasia and skeletal mandibular protrusion caused by Apert syndrome.

Does different cranial suture synostosis influence orbit volume and morphology in Apert syndrome?

This study was performed to compare the orbital and peri-orbital morphological variations in Apert syndrome patients with different cranial vault suture synostosis, so as to provide an anatomic basis for individualized surgical planning. Computed tomography scans of 57 unoperated Apert syndrome patients and 59 controls were subgrouped as follows: type I, bilateral coronal synostosis; type II, pansynostosis; type III, perpendicular combinations of cranial vault suture synostoses. Orbit bony cavity volume was significantly reduced in type I and type II, by 19% (P < 0.001) and 24% (P < 0.001), respectively. However, the reduction of orbital cavity volume in type III did not reach statistical significance. Globe volume projection beyond the orbital rim, however, increased by 76% (P < 0.001) in type III, versus an increase of 54% (P < 0.001) in type I and 53% (P < 0.001) in type II, due to different ethmoid and sphenoid bone malformations. Maxillary bone volume was only significantly reduced in type I bicoronal synostosis (by 24%, P = 0.048). Both type I and type II developed relatively less zygoma and sphenoid bone volume. Different cranial vault suture synostoses have varied influence on peri-orbital development in Apert syndrome. Instead of mitigating the abnormalities resulting from bicoronal synostosis in type I, additional midline suture synostosis worsens the exorbitism due to a more misshaped ethmoid.

Complex Airway Management in Patients with Tracheal Cartilaginous Sleeves

OBJECTIVES/HYPOTHESIS

A tracheal cartilaginous sleeve (TCS) is a rare anomaly characterized by anterior fusion of tracheal cartilages. TCS is associated with syndromic craniosynostoses including Apert, Crouzon and Pfeiffer syndromes and FGFR2, FGFR3, and TWIST1 variants. This study presents a 30-year review of patients with syndromic craniosynostosis and TCS and describes diagnostic methods, genetic variants, surgical interventions, and long-term outcomes.

STUDY DESIGN

Retrospective, single-institution review.

METHODS

This review included patients with syndromic craniosynostosis and TCS treated at Seattle Children's Hospital from 1990 to 2020. Tracheostomy, genetic variants, and additional surgery were primary measures. Fisher's exact test compared need for tracheostomy in patients with proposed high-risk (FGFR2 p.W290 or FGFR2 p.C342) versus low-risk genetic variants.

RESULTS

Thirty patients with TCS were identified. Average age at diagnosis was 12 months (range 2-weeks to 7.9-years; standard deviation 19.8 months). Syndromes included Pfeiffer (37%), Apert (37%), and Crouzon (26%). Severe obstructive sleep apnea was present in 76% of patients. Tracheostomy was performed in 17 patients (57%); five were successfully decannulated. Additional interventions included adenotonsillectomy (57%), nasal (20%), laryngeal (17%), and craniofacial skeletal surgery (87%). All patients with Pfeiffer syndrome and FGFR2 p.W290C variants and 83% of patients with FGFR2 p.C342 variants required tracheostomy, differing from other variants (P = .02, odds ratio 33, 95% confidence interval 1.56-697.96). One patient (3%) died.

CONCLUSION

TCS contributes to multilevel airway obstruction in patients with syndromic craniosynostosis. Genetic testing in patients with FGFR2-related syndromic craniosynostoses may identify those at risk of TCS and facilitate early intervention. A better understanding of this patient population may foster individualized airway management strategies and improve outcomes.

LEVEL OF EVIDENCE

4 Laryngoscope, 2021.

Syndrome-related outcomes following posterior vault distraction osteogenesis

PURPOSE

The most commonly occurring syndromic craniosynostoses are Apert syndrome, Crouzon syndrome, Pfeiffer syndrome, and Saethre-Chotzen syndrome. There is insufficient data regarding postoperative syndrome-related outcomes following the posterior vault distraction osteogenesis (PVDO) procedure, as well as data addressing whether or not additional procedures will be subsequently necessary to comprehensively treat children who undergo PVDO. Thus, the objective of this study is to describe and compare syndrome-related potential complications and outcomes associated with the PVDO procedure.

METHODS

An observational retrospective study was performed on consecutive patients (n=24) with Apert syndrome, Crouzon syndrome, Pfeiffer syndrome, or Saethre-Chotzen syndrome, respectively, who underwent PVDO between 2012 and 2019. Demographic data (patient gender and age when the PVDO procedure was performed), diagnosis, surgery-related data, and outcome data (perioperative and midterm complications and need for additional surgery) were verified.

RESULTS

Total relative blood transfusion volumes per kilogram for the patients were as follows: 22.75 ± 9.30 ml for Apert syndrome, 10.73 ± 2.28 ml for Crouzon syndrome (Apert versus Crouzon, p<0.05), 18.53 ± 8.08 ml for Pfeiffer syndrome, and 19.74 ± 9.12 ml for Saethre-Chotzen syndrome. None of the patients required a secondary procedure to alleviate intracranial pressure except for a Saethre-Chotzen patient.

CONCLUSION

PVDO is an effective technique to address elevated intracranial pressure in SC patients that alleviates the need for secondary procedures at midterm follow-up. Apert syndrome patients presented relatively higher total blood transfusion rates than Crouzon syndrome patients who were operated on at a later age and weighed more.

Treating Syndromic Craniosynostosis with Monobloc Facial Bipartition and Internal Distractor Devices: Destigmatizing the Syndromic Face

Monobloc and facial bipartition combined with distraction osteogenesis (MFBDO) has gained popularity over the past several years as a treatment of syndromic craniosynostosis, in part because this surgical technique effectively removes many stigmatic clinical features associated with the syndromic face. The objective of this study is to detail the surgical planning used to achieve medialization of the orbits and describe the authors' experience using MFBDO to destigmatize the syndromic face. By using MFBDO, hypertelorism, vertical orbital dystopia, and downslanting of the palpebral fissure were surgically corrected in all patients, thereby destigmatizing the syndromic face.

Le Fort II Distraction with Simultaneous Zygomatic Repositioning

Severe midface hypoplasia is often managed by Le Fort III distraction. Le Fort II distraction with zygomatic repositioning is a modification of the Le Fort III distraction operation aimed to correct abnormal facial ratios of patients with greater central than lateral midface deficiency. The operation starts with Le Fort III osteotomies and is followed by separation and fixation of bilateral zygomas. The central nasomaxillary Le Fort II segment is then distracted to achieve independent movements of the central and lateral midface. The Le Fort II zygomatic repositioning operation has become our procedure of choice for patients with Apert facial dysmorphology.

Apert syndrome: A case report of prenatal ultrasound, postmortem cranial CT, and molecular genetic analysis

Apert syndrome is characterized by craniosynostosis, mid-facial hypoplasia, and symmetric syndactyly. Prenatal diagnosis is challenging until the skull and facial anomalies become more pronounced during the third trimester. We present a case in which typical sonographic signs of Apert syndrome were observed after 23 weeks of gestation. Following termination of the pregnancy, both clinical features such as craniofacial abnormalities and syndactyly and cranial 3D-CT images showed high correlation with the previous sonographic findings. Furthermore, genetic analysis revealed a spontaneous mutation, c.755C≥G (p.S252W), in the FGFR2 gene, with this mutation implicated in the etiology of Apert syndrome.

Apert syndrome diagnosed by prenatal ultrasound combined with magnetic resonance imaging and whole exome sequencing: A case report

BACKGROUND

Most cases of Apert syndrome (AS) are found after birth. Cases of AS diagnosed by ultrasound combined with magnetic resonance imaging (MRI) and whole exome sequencing (WES) during pregnancy are rare.

CASE SUMMARY

We present the case of a 34-year old female patient (gravida 2, para 1) whose fetus was diagnosed with AS during pregnancy. Fetal ultrasound performed at 30, 2/7 wk of pregnancy showed abnormalities. MRI and three-dimensional ultrasound performed at 31, 1/7 wk of pregnancy showed the possibility of AS. Chromosome examination and core family WES were conducted at 31, 5/7 wk of pregnancy. The results showed that FGFR2 in the fetus had a c.755C>G missense mutation in its nucleotide, and AS was confirmed.

CONCLUSION

This case highlights the importance of imaging examinations. Prenatal ultrasound combined with MRI can identify fetal morphological abnormalities accurately, which can be confirmed by WES.

Is the Apert foot an overlooked aspect of this rare genetic disease? Clinical findings and treatment options for foot deformities in Apert syndrome

BACKGROUND

Apert syndrome is characterised by the presence of craniosynostosis, midface retrusion and syndactyly of hands and feet, thus, synonymously referred to as acrocephalosyndactyly type I. Considering these multidisciplinary issues, frequently requiring surgical interventions at an early age, deformities of the feet have often been neglected and seem to be underestimated in the management of Apert syndrome. Typical Apert foot features range from complete fusion of the toes and a central nail mass to syndactyly of the second to fifth toe with a medially deviated great toe; however, no clear treatment algorithms were presented so far. This article reviews the current existing literature regarding the treatment approach of foot deformities in Apert syndrome.

STATE-OF-THE-ART TOPIC REVIEW

Overall, the main focus in the literature seems to be on the surgical approach to syndactyly separation of the toes and the management of the great toe deformity (hallux varus). Although the functional benefit of syndactyly separation in the foot has yet to be determined, some authors perform syndactyly separation usually in a staged procedure. Realignment of the great toe and first ray can be performed by multiple means including but not limited to second ray deletion, resection of the proximal phalanx delta bone on one side, corrective open wedge osteotomy, osteotomy of the osseous fusion between metatarsals I and II, and metatarsal I lengthening using gradual osteodistraction. Tarsal fusions and other anatomical variants may be present and have to be corrected on an individual basis. Shoe fitting problems are frequently mentioned as indication for surgery while insole support may be helpful to alleviate abnormal plantar pressures.

CONCLUSION

There is a particular need for multicenter studies to better elaborate surgical indications and treatment plans for this rare entity. Plantar pressure measurements using pedobarography should be enforced in order to document the biomechanical foot development and abnormalities during growth, and to help with indication setting. Treatment options may include conservative means (i.e. insoles, orthopedic shoes) or surgery to improve biomechanics and normalize plantar pressures.

LEVEL OF EVIDENCE

Level V.

Le fort II distraction osteogenesis with a hybrid system for an Apert syndrome patient: A case report

Background

Le Fort II advancement is considered for normalizing the facial appearance in Apert syndrome. When these procedures are performed during growth, overcorrection of midface advancement is required. We developed a system that can control the distance and vector of movement for the central midface to create more normal facial proportions. This case report shows Le Fort II distraction osteogenesis with this hybrid system for an Apert syndrome patient.

Case

The patient was a girl with Apert syndrome with midfacial-nose hypoplasia and skeletal class III malocclusion. She was healthy without respiratory problems and had no learning disabilities. She underwent our Le Fort II distraction osteogenesis with the hybrid system at 10 years and 6 months of age. Her midface was elongated 22 mm at point Or forward and moved 5° downward to the Frankfort horizontal plane compared to the standard position of average Japanese adult women on the cephalogram. Examining the facial image, the midfacial depression was improved 4 years after the operation.

Discussion

Overcorrection of midface advancement is required for patients to reduce the number of procedures during growth. The system that we developed could control the distance and vector of movement steadily when the central midface was overcorrected to try to create normal adult facial proportions.

Apert syndrome: Cranial procedures and brain malformations in a series of patients

Background:

Apert syndrome is one of the most severe craniofacial disorders. This study aims to describe the craniofacial surgeries and central nervous system malformations of a cohort of children with Apert syndrome treated in the past 20 years and to compare these data with previously published data.

Methods:

Retrospective analysis of a series of patients with Apert syndrome treated between 1999 and 2019 in our hospital. Information was analyzed regarding craniofacial procedures, hydrocephalus and presence of shunts, Chiari malformation Type 1, and other brain malformations such as corpus callosum and septum pellucidum anomalies.

Results:

Thirty-seven patients were studied. Ventriculoperitoneal shunt prevalence was 24.3%, and 8.1% of patients required decompressive surgery for Chiari malformation. All of them needed at least one cranial vault remodeling procedure. The median age for this procedure was 8 months. In 69.7% of patients, the first cranial vault intervention was performed in the fronto-orbital region. In 36.4% of patients, a midface advancement had been performed at the time of this review, although this proportion was very dependent on the follow-up period and the age of the patients. The median age for the midface advancement procedure was 5.25 years. Anomalies of the corpus callosum and the septum pellucidum were reported in 43.2% and 59.5% of patients, respectively.

Conclusion:

Apert syndrome is a type of syndromic craniosynostosis, and patients usually require one or more cranial and facial surgeries. In comparison with other syndromic craniosynostosis types, Apert syndrome less frequently requires a VP shunt or treatment for a Chiari malformation.

Assessment of long-term quality of life in patients with syndromic craniosynostosis

Several studies have analyzed the long-term stability of cranioplasty and midface distraction in patients with craniosynostosis; however, few studies have investigated long-term quality of life (QOL) and complications in adults with syndromic craniosynostosis. This study aimed to investigate the QOL (social, physical, and psychosocial) of patients with adult syndromic craniosynostosis. Patients aged ≥20 years with syndromic craniosynostosis, who were surgically treated at a single craniofacial institution, were included in this study. We investigated everyday inconvenience (using the World Health Organization Disability Assessment Schedule questionnaire), any ongoing treatment, marital status, and number of children. Totally, 18 patients aged 22-48 years (mean: 31.4 ± 9.2 years) answered the questionnaire (Crouzon syndrome, 9; Apert syndrome, 5; Pfeiffer syndrome, 4). Of these, only one Crouzon syndrome patient was married; she was also the only one with a child. Apert syndrome patients were found to have difficulty in understanding, communication, and self-care because of their mental retardation and hand and foot handicaps; however, their participation in society was the most aggressive. In contrast, Crouzon syndrome patients had especially poor participation in society. In all patients, any ongoing hospital treatment was due to ophthalmological conditions. Crouzon syndrome patients have extremely poor QOL; the absence of mental retardation and hand and foot handicaps forces them to live in mainstream society, for which they are emotionally ill-equipped. It is necessary to treat these patients without any residual deformity to provide psychological support and to create an accepting society.

Genotype-Phenotype Correlation of Tracheal Cartilaginous Sleeves and Fgfr2 Mutations in Mice

OBJECTIVES

To characterize tracheal cartilage morphology in mouse models of fibroblast growth factor receptor (Fgfr2)-related craniosynostosis syndromes. To establish relationships between specific Fgfr2 mutations and tracheal cartilaginous sleeve (TCS) phenotypes in these mouse models.

METHODS

Postnatal day 0 knock-in mouse lines with disease-specific genetic variations in the Fgfr2 gene (Fgfr2^C342Y/C342Y , Fgfr2^C342Y/+ , Fgfr2^+/Y394C , Fgfr2^+/S252W , and Fgfr2^+/P253R ) as well as line-specific controls were utilized. Tracheal cartilage morphology as measured by gross analyses, microcomputed tomography (μCT), and histopathology were compared using Chi-squared and single-factor analysis of variance statistical tests.

RESULTS

A greater proportion of rings per trachea were abnormal in Fgfr2^C342Y/+ tracheas (63%) than Fgfr2^+/S252W (17%), Fgfr2^+/P253R (17%), Fgfr2^+/Y394C (12%), and controls (10%) (P < .001 for each vs. Fgfr2^C342Y/+ ). TCS segments were found only in Fgfr2^C342Y/C342Y (100%) and Fgfr2^C342Y/+ (72%) tracheas. Cricoid and first-tracheal ring fusion was noted in all Fgfr2^C342Y/C342Y and 94% of Fgfr2^C342Y/+ samples. The Fgfr2^C342Y/C342Y and Fgfr2^C342Y/+ groups were found to have greater areas and volumes of cartilage than other lines on gross analysis and μCT. Histologic analyses confirmed TCS among the Fgfr2^C342Y/C342Y and Fgfr2^C342Y/+ groups, without appreciable differences in cartilage morphology, cell size, or density; no histologic differences were observed among other Fgfr2 lines compared to controls.

CONCLUSION

This study found TCS phenotypes only in the Fgfr2^C342Y mouse lines. These lines also had increased tracheal cartilage compared to other mutant lines and controls. These data support further study of the Fgfr2 mouse lines and the investigation of other Fgfr2 variants to better understand their role in tracheal development and TCS formation.

LEVEL OF EVIDENCE

NA Laryngoscope, 131:E1349-E1356, 2021.

The impact of chemo- and radiotherapy treatments on selfish de novo FGFR2 mutations in sperm of cancer survivors

STUDY QUESTION

What effect does cancer treatment have on levels of spontaneous selfish fibroblast growth factor receptor 2 (FGFR2) point mutations in human sperm?

SUMMARY ANSWER

Chemotherapy and radiotherapy do not increase levels of spontaneous FGFR2 mutations in sperm but, unexpectedly, highly-sterilizing treatments dramatically reduce the levels of the disease-associated c.755C > G (Apert syndrome) mutation in sperm.

WHAT IS KNOWN ALREADY

Cancer treatments lead to short-term increases in gross DNA damage (chromosomal abnormalities and DNA fragmentation) but the long-term effects, particularly at the single nucleotide resolution level, are poorly understood. We have exploited an ultra-sensitive assay to directly quantify point mutation levels at the FGFR2 locus.

STUDY DESIGN, SIZE, DURATION

‘Selfish’ mutations are disease-associated mutations that occur spontaneously in the sperm of most men and their levels typically increase with age. Levels of mutations at c.752–755 of FGFR2 (including c.755C > G and c.755C > T associated with Apert and Crouzon syndromes, respectively) in semen post-cancer treatment from 18 men were compared to levels in pre-treatment samples from the same individuals (n = 4) or levels in previously screened population controls (n = 99).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Cancer patients were stratified into four different groups based on the treatments they received and the length of time for spermatogenesis recovery. DNA extracted from semen samples was analysed using a previously established highly sensitive assay to identify mutations at positions c.752–755 of FGFR2. Five to ten micrograms of semen genomic DNA was spiked with internal controls for quantification purposes, digested with MboI restriction enzyme and gel extracted. Following PCR amplification, further MboI digestion and a nested PCR with barcoding primers, samples were sequenced on Illumina MiSeq. Mutation levels were determined relative to the spiked internal control; in individuals heterozygous for a nearby common single nucleotide polymorphism (SNP), mutations were phased to their respective alleles.

MAIN RESULTS AND THE ROLE OF CHANCE

Patients treated with moderately-sterilizing alkylating regimens and who recovered spermatogenesis within <3 years after therapy (Group 3, n = 4) or non − alkylating chemotherapy and/or low gonadal radiation doses (Group 1, n = 4) had mutation levels similar to untreated controls. However, patients who had highly-sterilizing alkylating treatments (i.e. >5 years to spermatogenesis recovery) (Group 2, n = 7) or pelvic radiotherapy (Group 4, n = 3) exhibited c.755C > G mutation levels at or below background. Two patients (A and B) treated with highly-sterilizing alkylating agents demonstrated a clear reduction from pre-treatment levels; however pre-treatment samples were not available for the other patients with low mutation levels. Therefore, although based on their age we would expect detectable levels of mutations, we cannot exclude the possibility that these patients also had low mutation levels pre-treatment. In three patients with low c.755C > G levels at the first timepoint post-treatment, we observed increasing mutation levels over time. For two such patients we could phase the mutation to a nearby polymorphism (SNP) and determine that the mutation counts likely originated from a single or a small number of mutational events.

LIMITATIONS, REASONS FOR CAUTION

This study was limited to 18 patients with different treatment regimens; for nine of the 18 patients, samples from only one timepoint were available. Only 12 different de novo substitutions at the FGFR2 c.752–755 locus were assessed, two of which are known to be disease associated.

WIDER IMPLICATIONS OF THE FINDINGS

Our data add to the body of evidence from epidemiological studies and experimental data in humans suggesting that male germline stem cells are resilient to the accumulation of spontaneous mutations. Collectively, these data should provide physicians and health-care professionals with reassuring experimental-based evidence for counselling of male cancer patients contemplating their reproductive options several years after treatment.

STUDY FUNDING/COMPETING INTEREST(S)

This work was primarily supported by grants from the Wellcome (grant 091182 to AG and AOMW; grant 102 731 to AOMW), the University of Oxford Medical Sciences Division Internal Fund (grant 0005128 to GJM and AG), the National Institute for Health Research (NIHR) Oxford Biomedical Research Centre Programme (to AG) and the US National Institutes of Health (to MLM). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. None of the authors has any conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

NA

Circummaxillary Sutures in Patients With Apert, Crouzon, and Pfeiffer Syndromes Compared to Nonsyndromic Children: Growth, Orthodontic, and Surgical Implications

OBJECTIVE

To evaluate patency of circummaxillary sutures in children with Apert, Crouzon, and Pfeiffer Syndromes and to compare it to a nonsyndromic matched control group.

DESIGN

Case-control study.

SETTING

Tertiary care public hospital.

MATERIALS AND METHODS

Thirty-eight computed tomography (CT) scans of patients affected by syndromic craniofacial synostosis (13 patients with Apert syndrome, 20 patients with Crouzon syndrome, and 5 patients with Pfeiffer syndrome), average age 5 ± 2.8 years, range 1.9 to 12 years, were compared to age- and sex-matched control CTs of 38 nonsyndromic children. Computed tomography scans of the study group had to be performed prior to any midfacial surgery.

MAIN OUTCOME MEASURES

Midpalatal suture, zygomaticomaxillary sutures, and pterigomaxillary sutures were evaluated and scored.

RESULTS

The syndromic group showed a significant earlier ossification of all sutures compared to the nonsyndromic group. Significant differences were already present in early childhood and continued through adolescence.

CONCLUSIONS

Based on the differences in terms of maxillary sutural ossification identified, midfacial hypoplasia does not seem to be only secondary to premature cranial base ossification, but also to primary synostosis of facial sutures, thus providing new insights into the pathogenesis of midface deficiency in children with craniofacial-synostosis. Care should be taken when planning any maxillary orthopedics, such as expansion or maxillary protraction, given the high frequency of early fusion of circummaxillary sutures.

Social Experiences of Turkish Parents Raising a Child With Apert Syndrome: A Qualitative Study

OBJECTIVE

Apert syndrome is a rare and understudied craniofacial condition with regard to its psychosocial impact on children and their parents. Due to the lack of studies focusing solely on the social experiences of children and families with Apert syndrome, it is difficult to develop interventions and strategies to support well-being and positive adjustment for this particular population. This study addressed this gap by assessing the unique social experiences of parents who are raising their children with Apert syndrome including difficulties they face and strategies they use to cope with challenges.

DESIGN

Descriptive qualitative study using thematic analysis.

PARTICIPANTS

Participants included 21 parents of 12 children (aged 1-12 years) with Apert syndrome (9 couples, 2 fathers, and 1 mother) who were recruited from a pediatric neurosurgery unit in Turkey.

RESULTS

The qualitative analysis yielded four main themes describing the experiences of parents including (1) social challenges; (2) coping with negative reactions; (3) promoting socialization and independence; and (4) sources of strength.

CONCLUSIONS

Parents reported several challenges, including social stigmatization, and utilized a range of strategies to support both their own and their child's positive adaptation and resiliency, including the use of religion and reliance on their spouses for support. Results offer clinically relevant insights about the strengths and challenges of families coping with Apert syndrome.

An Overview of Craniosynostosis Craniofacial Syndromes for Combined Orthodontic and Surgical Management

This article provides an overview of epidemiology, genetics, and common orofacial features of those with craniosynostosis. Patients with craniosynostosis require several surgical procedures along with continuum of care. The earliest surgical interventions are done during the first few years of life to relieve the fused sutures. Midface advancement, limited phase of orthodontic treatment, and combined orthodontics/orthognathic surgery treatment are usually required during later years. This article presents several examples of cases with outcomes associated with these procedures.

Radiographic Characteristics of the Hand in Apert Syndrome

Background: In a small series, it has been postulated that delayed release of complex syndactyly of the 3rd web in Apert syndrome patients causes compression on epiphyses, with early epiphyseal closure, leading to symphalangism and reduced capitate ossification. We wished to see whether this remains true in a larger series. Methods: We reviewed radiographs of 48 patients (86 hands) with Apert syndrome seen in the department of Plastic and Reconstructive Surgery, Great Ormond Street Hospital, between the years 2001-2012. Patients underwent surgical release of syndactyly in a staged fashion with the 3rd web release left until last. We measured the size of the capitate ossification center relative to that of the hamate and determined the relative position of the middle finger metacarpal relative to the ring finger metacarpal. Results: We found agreement with many findings, however we weren't able to demonstrate the catch-up growth of the capitate after release of the third web. The failure of normal distal migration of the 3rd metacarpal appeared to occur until the 3rd web release is performed. Conclusions: Consistent findings of delayed ossification of the capitate and failure of normal distal migration of the third metacarpal add support to the initial hypothesis, however, we cannot fully conclude that an earlier release of the third web is recommended, further research is still needed.

An internal distraction device for midface distraction osteogenesis: The NAVID system type Z'gok

Midface advancement with distraction osteogenesis is more routinely used for faciocraniosynostosis. Distraction devices are generally classified into external and internal types. Compared with external distractors, internal distractors are smaller and better tolerated, but their removal is complicated. Here, we introduce a refined internal distraction device and describe its applicability. Unlike the previous anterior fixation plate that utilises screws, the refined internal distraction (type Z'gok) has 3 claws. This anterior point of the distractor is positioned behind the malar eminence, or the lateral orbital wall. Eight patients with syndromic craniosynostosis underwent midface distraction osteogenesis using the type Z'gok between 2016 and 2017 (Z'gok group). Twelve patients were treated using conventional internal distractors (control group). Patient age ranged from 6 to 21 years. Among them, 4 patients underwent Le Fort III distraction osteogenesis, while the others underwent Le Fort IV distraction osteogenesis. The operative time to remove the distractors in the Z'gok group was 65 ± 18 min, shorter than 89 ± 12 min in the control group. The blood loss per kilogram of body weight in the Z'gok and control groups was 3.6 ± 3.3 mL/kg and 4.7 ± 1.7 mL/kg, respectively. In conclusion, the type Z'gok is a reliable and effective internal distractor for midface distraction osteogenesis.

Molecular analysis of exon 7 of the fibroblast growth factor receptor 2 (FGFR2) gene in an Indonesian patient with Apert syndrome: a case report

BACKGROUND

Apert syndrome, Online Mendelian Inheritance in Man number 101200, is a rare genetic condition, with autosomal dominant inheritance, characterized by craniosynostosis, midfacial malformation, and severe symmetrical syndactyly. Apert syndrome is associated with other systemic malformations, including intellectual disability. At least seven mutations in fibroblast growth factor receptor 2 (FGFR2) gene have been found to cause Apert syndrome. Most cases of Apert syndrome are caused by one of the two most frequent mutations located in exon 7 (Ser252Trp or Pro253Arg).

CASE PRESENTATION

A 27-year-old Javanese man presented borderline intellectual functioning and striking dysmorphisms. A clinical diagnosis of Apert syndrome was previously made based on these clinical features. Furthermore, POSSUM software was used before molecular analysis and the result showed suspected Apert syndrome with a cut-off point of 14. Molecular genetic analysis of FGFR2, targeting exon 7, was performed by direct sequencing. In this patient, a missense mutation c.755C>G was detected, changing a serine into a tryptophan (p.Ser252Trp).

CONCLUSION

We report the case of an Indonesian man with Apert syndrome with a c.755C>G (p.Ser252Trp) mutation in the FGFR2 gene. Our patient showed similar dysmorphism to previously reported cases, although cleft palate as a typical feature for p.Ser252Trp mutation was not present. In spite of the accessibility of molecular genetic testing in a few parts of the world, the acknowledgement of clinically well-defined syndromes will remain exceptionally imperative in developing countries with a lack of diagnostic facilities.

Multidirectional cranial distraction osteogenesis technique for treating bicoronal synostosis

Fronto-orbital advancement by distraction osteogenesis is a useful means of surgically correcting bicoronal synostosis. However, the scope for morphological revision is limited. To address this issue, we developed a multidirectional cranial distraction osteogenesis (MCDO) technique that we quantitatively assessed in patients with bicoronal synostosis. In this case series, five patients with bicoronal synostosis were treated with MCDO at a mean age of 13.4 months (range 9-22 months). Distraction started 5 days after surgery and the activation period was 11.2 days (range 10-14 days). The distraction devices were removed 47.2 days (range 33-67 days) after completing distraction. Improved cranial shape was confirmed by CT data. Mean preoperative CI, APL, and ICV readings of 102.1%, 13.5 cm, and 1179.4 ml, respectively, had reached 94.0%, 14.9 cm, and 1323.9 ml, respectively, upon device removal. These values were well preserved at 1 year (90.4%, 15.8 cm, and 1461.3 ml, respectively). In conclusion, MCDO successfully enables both cranial expansion and correction of a flat forehead, constituting a valid treatment alternative for patients with bicoronal synostosis.

Mandibular dysmorphology due to abnormal embryonic osteogenesis in FGFR2-related craniosynostosis mice

One diagnostic feature of craniosynostosis syndromes is mandibular dysgenesis. Using three mouse models of Apert, Crouzon and Pfeiffer craniosynostosis syndromes, we investigated how embryonic development of the mandible is affected by fibroblast growth factor receptor 2 (Fgfr2) mutations. Quantitative analysis of skeletal form at birth revealed differences in mandibular morphology between mice carrying Fgfr2 mutations and their littermates that do not carry the mutations. Murine embryos with the mutations associated with Apert syndrome in humans (Fgfr2^+/S252W and Fgfr2^+/P253R) showed an increase in the size of the osteogenic anlagen and Meckel's cartilage (MC). Changes in the microarchitecture and mineralization of the developing mandible were visualized using histological staining. The mechanism for mandibular dysgenesis in the Apert Fgfr2^+/S252W mouse resulting in the most severe phenotypic effects was further analyzed in detail and found to occur to a lesser degree in the other craniosynostosis mouse models. Laser capture microdissection and RNA-seq analysis revealed transcriptomic changes in mandibular bone at embryonic day 16.5 (E16.5), highlighting increased expression of genes related to osteoclast differentiation and dysregulated genes active in bone mineralization. Increased osteoclastic activity was corroborated by TRAP assay and in situ hybridization of Csf1r and Itgb3. Upregulated expression of Enpp1 and Ank was validated in the mandible of Fgfr2^+/S252W embryos, and found to result in elevated inorganic pyrophosphate concentration. Increased proliferation of osteoblasts in the mandible and chondrocytes forming MC was identified in Fgfr2^+/S252W embryos at E12.5. These findings provide evidence that FGFR2 gain-of-function mutations differentially affect cartilage formation and intramembranous ossification of dermal bone, contributing to mandibular dysmorphogenesis in craniosynostosis syndromes.

This article has an associated First Person interview with the joint first authors of the paper.

Summary: FGFR2 gain-of-function mutations differentially affect cartilage formation and intramembranous ossification of dermal bone, resulting in abnormal embryonic osteogenesis of the mandible.

Unilateral Coronal Craniosynostosis in an Apert-Like Patient

Background and Significance

Apert syndrome is a congenital disorder of patients who typically present with bilateral coronal craniosynostosis and varying degrees of complex syndactyly of the hands and feet, among other features. We describe a unique presentation of a rare Apert-like patient with unilateral coronal craniosynostosis and complex syndactyly of the hands and feet.

Case Report

A 2-year-old male patient presented to the craniofacial clinic with his mother due to a concerning head shape. The patient also had bilateral syndactyly of the hands and feet and underwent prior surgical release of the third web space. Computerized tomography of the head illustrated a small open anterior fontanelle, a left harlequin orbit, complete left coronal craniosynostosis, and a patent right coronal suture. The patient subsequently underwent fronto-orbital advancement for expansion of the cranial vault and correction of the asymmetric forehead and orbit. The procedure resulted in improvement of his deformity.

Conclusion

This case illustrates a unique presentation of an acrocephalosyndactyly (ACS) syndrome with asymmetric, unilateral coronal craniosynostosis and complete complex syndactyly of the hands and feet that is most consistent with Apert syndrome. Although the majority of patients with ACS can be categorized into known syndromes, other more unusual presentations must still be considered. Such unique cases are exceedingly rare and only through additional reporting and review of unique phenotypes can new subtypes of common ACS syndromes be classified.

Apert syndrome without craniosynostosis

BACKGROUND

Apert syndrome is a rare form of syndromic craniosynostosis, also known as acrocephalosyndactyly, which is a disorder characterized by a unique set of craniofacial, hand, and foot abnormalities. Diagnosis is made through a genetic analysis, where the mutation of FGFR2, Ser252Trp, and Pro253Arg confirms the diagnosis.

CASE PRESENTATION

Although craniosynostosis is the most common characteristic in clinical presentation, we present an atypical case of a one-and-a-half-year-old girl with Apert syndrome confirmed by genetic testing but without craniosynostosis.

Variable phenotypic expression of Apert syndrome in monozygotic twins

Apert syndrome in monozygotic twins can lead to different phenotypic expression of the disease in the two fetuses. Apert syndrome can be associated with congenital left diaphragmatic hernia and cleft palate.

Aberrant growth of the anterior cranial base relevant to severe midface hypoplasia of Apert syndrome

Background

A 9-year-old male showed severe defects in midface structures, which resulted in maxillary hypoplasia, ocular hypertelorism, relative mandibular prognathism, and syndactyly. He had been diagnosed as having Apert syndrome and received a surgery of frontal calvaria distraction osteotomy to treat the steep forehead at 6 months old, and a surgery of digital separation to treat severe syndactyly of both hands at 6 years old. Nevertheless, he still showed a turribrachycephalic cranial profile with proptosis, a horizontal groove above supraorbital ridge, and a short nose with bulbous tip.

Methods

Fundamental aberrant growth may be associated with the cranial base structure in radiological observation.

Results

The Apert syndrome patient had a shorter and thinner nasal septum in panthomogram, PA view, and Waters' view; shorter zygomatico-maxillary width (83.5 mm) in Waters' view; shorter length between the sella and nasion (63.7 mm) on cephalogram; and bigger zygomatic axis angle of the cranial base (118.2°) in basal cranial view than a normal 9-year-old male (94.8 mm, 72.5 mm, 98.1°, respectively). On the other hand, the Apert syndrome patient showed interdigitating calcification of coronal suture similar to that of a normal 30-year-old male in a skull PA view.

Conclusion

Taken together, the Apert syndrome patient, 9 years old, showed retarded growth of the anterior cranial base affecting severe midface hypoplasia, which resulted in a hypoplastic nasal septum axis, retruded zygomatic axes, and retarded growth of the maxilla and palate even after frontal calvaria distraction osteotomy 8 years ago. Therefore, it was suggested that the severe midface hypoplasia and dysostotic facial profile of the present Apert syndrome case are closely relevant to the aberrant growth of the anterior cranial base supporting the whole oro-facial and forebrain development.

Central Coalition Osteotomy of Phalangeal Synostoses in the Management of the Type III Apert Hand

PURPOSE

We report a technique in the management of the type III Apert hand. The proposed approach facilitates the creation of a 5-fingered hand in 3 stages.

METHODS

We reviewed records of patients with Apert syndrome and type III hands surgically treated at our institution from 1995 through 2014. In all cases, syndactyly release was performed in 3 stages with prioritization of the border digits. In addition, limited retrograde, axial osteotomies between the phalangeal segments of the conjoined index, middle, and ring fingers were performed during the first stage. Medical records were reviewed for demographics, clinical presentation, operative findings, and postoperative outcomes.

RESULTS

Twelve pediatric patients with type III hands underwent syndactyly release. Median patient age was 10.0, 15.8, and 29.6 months at operative stages 1, 2, and 3, respectively. A thumb and 4 fingers were achieved for all but 1 hand. The median duration of hospital stay was 2 days for each stage. No infections or major complications were observed.

CONCLUSIONS

We demonstrate this method as a safe and effective means of creating 5 digits in the Apert patient with type III hands. Our opinion is that the additional aesthetic and functional gains offset the requirement of a 3-stage approach.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Midface and upper airway dysgenesis in FGFR2-related craniosynostosis involves multiple tissue-specific and cell cycle effects

Midface dysgenesis is a feature of more than 200 genetic conditions in which upper airway anomalies frequently cause respiratory distress, but its etiology is poorly understood. Mouse models of Apert and Crouzon craniosynostosis syndromes exhibit midface dysgenesis similar to the human conditions. They carry activating mutations of Fgfr2, which is expressed in multiple craniofacial tissues during development. Magnetic resonance microscopy of three mouse models of Apert and Crouzon syndromes revealed decreased nasal passage volume in all models at birth. Histological analysis suggested overgrowth of the nasal cartilage in the two Apert syndrome mouse models. We used tissue-specific gene expression and transcriptome analysis to further dissect the structural, cellular and molecular alterations underlying midface and upper airway dysgenesis in Apert Fgfr2^+/S252W mutants. Cartilage thickened progressively during embryogenesis because of increased chondrocyte proliferation in the presence of Fgf2 Oral epithelium expression of mutant Fgfr2, which resulted in a distinctive nasal septal fusion defect, and premature facial suture fusion contributed to the overall dysmorphology. Midface dysgenesis in Fgfr2-related craniosynostosis is a complex phenotype arising from the combined effects of aberrant signaling in multiple craniofacial tissues.