Mandibular Spatial Reorientation and Morphological Alteration of Crouzon and Apert Syndrome.

BACKGROUND: From infancy to adulthood, the mandible develops increased ramus height, prominence of the chin, and laterally widened gonial angles. In Crouzon and Apert syndromes, both relative retrognathia and prognathic jaws have been reported. Growth is influenced by a variety of factors, including the growth and relative position of the skull base, functional coordination, and the spatial influence of the laryngopharynx. Thus, this study aimed to explore in detail the evolution of the mandible in both syndromes and its relationship with the entire facial structure and skull base. METHODS: One hundred twenty-three preoperative computed tomographic scans (Crouzon, n = 36; Apert, n = 33; control, n = 54) were included and divided into 5 age subgroups. Computed tomographic scans were measured using Materialise software. Cephalometrics relating to the mandible, facial structures, and cranial base were collected. Statistical analyses were performed using t test and statistical power analysis. RESULTS: In Crouzon syndrome, the angle between the cranial base and gnathion was increased prior to 6 months of age by 10.29 degrees (P < 0.001) and by adulthood to 11.95 degrees (P = 0.003) compared with normal. After 6 months of age, the distance between bilateral mandibular condylions (COR-COL) was narrower by 15% (P < 0.001) in Crouzon syndrome compared with control subjects. Before 6 months of age, Apert COR-COL decreased 16% (P < 0.001) compared with control subjects and 13% (P = 0.006) narrower than Crouzon. During 2 to 6 years of age, Apert mandibular ramus height caught up to, and became longer than, Crouzon by 12% (P = 0.011). The nasion-sella-articulare angle of the Apert skull was 5.04 degrees (P < 0.001) less than Crouzon overall. CONCLUSIONS: In Crouzon syndrome, the changes of the spatial relationship of the mandible to the cranial base develop earlier than the mandibular shape deformity, whereas in Apert syndrome, the spatial and morphological changes are synchronous. The morphological changes of the mandible are disproportional in 3 directions, initially significant shortening of the mandibular width and length, and, subsequently, reduced height. Crouzon has more shortening in mandibular height compared with Apert, reflecting the more shortened posterior cranial base length. The narrowed angle between the mandible and the posterior cranial base in Apert skulls is consistent with the more limited nasopharyngeal and oropharyngeal airway space.

The embryonic myosin R672C mutation that underlies Freeman-Sheldon syndrome impairs cross-bridge detachment and cycling in adult skeletal muscle.

Distal arthrogryposis is the most common known heritable cause of congenital contractures (e.g. clubfoot) and results from mutations in genes that encode proteins of the contractile complex of skeletal muscle cells. Mutations are most frequently found in MYH3 and are predicted to impair the function of embryonic myosin. We measured the contractile properties of individual skeletal muscle cells and the activation and relaxation kinetics of isolated myofibrils from two adult individuals with an R672C substitution in embryonic myosin and distal arthrogryposis syndrome 2A (DA2A) or Freeman-Sheldon syndrome. In R672C-containing muscle cells, we observed reduced specific force, a prolonged time to relaxation and incomplete relaxation (elevated residual force). In R672C-containing muscle myofibrils, the initial, slower phase of relaxation had a longer duration and slower rate, and time to complete relaxation was greatly prolonged. These observations can be collectively explained by a small subpopulation of myosin cross-bridges with greatly reduced detachment kinetics, resulting in a slower and less complete deactivation of thin filaments at the end of contractions. These findings have important implications for selecting and testing directed therapeutic options for persons with DA2A and perhaps congenital contractures in general.

Mandibular asymmetry in patients with the crouzon or apert syndrome.

The aim of this study was to describe directional and fluctuating mandibular asymmetry over time in children with Crouzon or Apert syndrome. Mandibular asymmetry of children between 7.5 and 14 years of age with Crouzon syndrome (n = 35) and Apert syndrome (n = 24) were compared with controls (n = 327). From panoramic radiographs, mandibular directional and fluctuating asymmetry was determined for the three groups. Multilevel statistical techniques were used to describe mandibular asymmetry changes over time. Patients with Crouzon and Apert syndromes showed statistically significant more fluctuating asymmetry for mandibular measures than did controls. Between the Crouzon and Apert syndromes groups, no statistical differences were found in directional and fluctuating asymmetry. The control group showed statistically significantly more directional asymmetry than did patients with Crouzon or Apert syndrome. The controls showed no change over time for the directional asymmetry of condylar-ramal height; however, the directional asymmetry of the gonial angle increased. Patients with Crouzon syndrome showed side dominance for only condylar-ramal height; whereas, patients with Apert syndrome did not show dominance for any of the measurements. Apert and Crouzon syndromes showed developmental instability, in contrast to the controls. No statistically significant longitudinal differences were found for either the directional or the fluctuating asymmetry between Crouzon and Apert syndromes. Findings for fluctuating and directional asymmetry for both syndromes may indicate an inability to cope with genetic and environmental stress during development and treatment, compared with untreated nonsyndromic individuals.

The spheno-occipital synchondrosis fuses prematurely in patients with Crouzon syndrome and midface hypoplasia compared with age- and gender-matched controls.

PURPOSE: Premature closure of the spheno-occipital synchondrosis (SOS) has been associated with midface hypoplasia in animal models and patients with specific forms of syndromic craniosynostosis. The present study aimed to characterize SOS fusion in patients with Crouzon syndrome. PATIENTS AND METHODS: A case-control study was performed in patients with Crouzon syndrome treated at the Children's Hospital of Philadelphia from 1984 to 2012. The cases included patients with Crouzon syndrome and at least 1 high-quality computed tomography (CT) scan in which SOS patency could be assessed. Age- and gender-matched control CT scans were identified for comparison. The patient age at the CT scan was evaluated as the predictor, with SOS patency identified as the outcome variable. Three independent reviewers with high inter-rater reliability graded the SOS patency as open, partially fused, or completely fused. The Wilcoxon rank sum test was used to compare the Crouzon group and the controls. RESULTS: During the study period, 30 patients were identified with Crouzon syndrome. A total of 24 patients, all with midface hypoplasia and with 112 cranial CT scans, met the inclusion criteria. Accordingly, 112 age- and gender-matched control CT scans were assessed. No patient in the control group had midface hypoplasia. Within the Crouzon group, the average age at complete closure (14.0 ± 3.4 years) evident on the CT scan was significantly younger than that in the control group (16.6 ± 2.2 years; P = .0152). The average age when the scans showed complete patency of the SOS in the Crouzon group (1.3 ± 1.1 years) was significantly younger than that in the control group (3.2 ± 2.3 years; P = .0001). CONCLUSIONS: The SOS closes significantly earlier in patients with Crouzon syndrome compared with age- and gender-matched controls. The strong statistical correlation supports premature closure of the SOS as a possible mechanistic contributor to midface hypoplasia.

Dental maturation in children with the syndrome of crouzon and apert.

Purpose : Developing teeth are used to assess maturity and estimate age in a number of disciplines. The purpose of this investigation was to study the dental maturation in children with Crouzon or Apert syndrome compared with nonsyndromic controls. Patients and Methods : Records of 40 children with Crouzon syndrome (18 boys and 22 girls, aged 4.0 to 17.9 years) and 28 children with Apert syndrome (10 boys and 18 girls, aged 3.9 to 15.1 years) were referred to the Department of Orthodontics, Cleft Palate Team and Craniofacial Team, Erasmus MC-Sophia. Data from syndromic children were compared with data from 451 nonsyndromic children (225 boys and 226 girls, aged 2.9 to 16.9 years). From panoramic radiographs, dental maturation was determined for patients with Crouzon and Apert syndromes and compared with data collected from control children. Logistic functions were constructed for dental maturation over time for syndromes and gender. Results : Statistically significant gender differences in dental maturation scores were found for girls with Crouzon (P < .05) and Apert syndrome (P < .05). Patients with Apert syndrome demonstrated a significantly delayed dental maturation (P < .05), while patients with Crouzon syndrome showed a nonsignificant delay. Conclusions : Dental maturation in patients with Apert syndrome was more delayed than in patients with Crouzon syndrome. The delay of tooth formation in patients with Crouzon or Apert syndrome suggests a possible common genetic association.

Cranial vault growth in multiple-suture nonsyndromic and syndromic craniosynostosis: a postoperative long-term anthropometric follow-up.

Long-term anthropometric follow-up of cranial vault growth may considerably add valuable information to current literature focusing on treatment strategies for premature multiple-suture craniosynostosis. The aim of this paper was to compare postoperative growth patterns of nonsyndromic and syndromic multiple-suture craniosynostotic children with sex-matched and age-matched children from the typically developing population. Forty-one multiple-suture craniosynostotic patients (19 nonsyndromic and 22 syndromic) were included in this 5-year follow-up. Anthropological data of sex-matched and age-matched normal Swiss children served as a control. A standardized time protocol for anthropometric skull measurements (head circumference and cephalic index) was used. Data were converted into Z-scores for standardized intercenter comparison. All patients showed a marked benefit in cranial vault shape after open skull remodeling. Significant differences in long-term cranial vault growth pattern could be seen between the nonsyndromic and the syndromic groups compared to the control group.

The Fgfr2 W290R mouse model of Crouzon syndrome.

PURPOSE: This study aimed to review and discuss the utility of the Fgfr2 (W290R) mouse mutant as a model of human Crouzon syndrome. METHODS: A review of current and past scientific literature on Fibroblast Growth Factor Receptor-2 (FGFR2) protein domain structure, FGFR mutations associated with human Crouzon syndrome, and phenotypic and molecular changes combined with recent observations and experimental data of the Fgfr2 (W290R) mouse mutant was conducted. A comparison of the Fgfr2 (W290R) mouse mutant with another mouse model of Crouzon syndrome, Fgfr2 (C342R) mouse mutant, was also performed. Finally, possible future research directions using the Fgfr2 (W290R) mutant mice were discussed. RESULTS: The Fgfr2 (W290R) heterozygous mouse exhibits defects characteristic of human Crouzon syndrome. At the molecular level, the defects observed in the mouse mutant are due to the dysregulation of signaling of both the IIIb and IIIc isoforms of Fgfr2. The involvement of the IIIb isoform of FGFR2 in the etiopathology of Crouzon syndrome is a novel finding in the craniosynostosis literature field. Dysregulated signaling of both IIIb and IIIc isoforms causes a broad spectrum of changes that explain some of the defects observed clinically in humans. Several of the defects observed in the Fgfr2 (W290R) homozygous mouse mutant are attributable to a loss-of-function mechanism in contrast to the frequently reported gain-of-function receptor function associated with mutated FGF receptors in craniosynostosis. CONCLUSIONS: The Fgfr2 ( W290R ) mouse model can be used as a model system to further investigate the cellular, molecular, and biochemical mechanisms of Crouzon syndrome.

Facial growth in patients with apert and crouzon syndromes compared to normal children.

OBJECTIVE: To evaluate vertical and sagittal facial growth in children with Apert and Crouzon syndromes and compare it to the growth patterns of a nonsyndromic control group. DESIGN: Case-control study. SETTING: Department of Orthodontics, Children's Hospital Erasmus Medical Centre, Sophia, Rotterdam, The Netherlands. PATIENTS, PARTICIPANTS: Sixty-two patients (37 patients with Crouzon syndrome and 25 patients with Apert syndrome) born between 1971 and 2001 (age range 3.9 to 32 years) and 482 nonsyndromic children as a control group. INTERVENTIONS: Lateral cephalograms performed prior to any midfacial surgery of 62 patients and 482 nonsyndromic children were traced and horizontal and vertical measurements were digitized. MAIN OUTCOME MEASURES: Cephalometric measurements of SNA, SNB, ANB, NSMe, and SN/palatal plane angles and lower facial height ratio. RESULTS: Horizontal measurements for the syndromic groups showed no change in SNA angle during growth. SNA angles were lower in patients with Apert syndrome compared to patients with Crouzon syndrome. The syndromic groups showed smaller values for ANB angles compared to the nonsyndromic group. Vertical measurements showed increased lower facial height ratios for the syndromic groups compared to control subjects. There was an increasing counterclockwise rotation of the palatal plane in relation to the anterior cranial base in syndromic patients. NSMe angles among the three groups were not significantly different. CONCLUSIONS: Based on the growth differences identified, the sagittal and vertical jaw relationships differ in patients with Crouzon syndrome, patients with Apert syndrome, and control subjects. Syndromic patients show aggravation of midfacial underdevelopment and anterior rotation of the mandible.

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, 132:215-221, 2022.

Early partial monolateral zygomatic arch defect leads to unilateral craniofacial malformation.

OBJECTIVE: This study used reconstructed three-dimensional imaging to examine the influence of early partial monolateral zygomatic arch defect on the craniofacial development in a minipig model. METHODS: Five 7-week-old Chinese minipigs were used in this study. Each of them underwent skull radiography, three-dimensional computed tomography (CT), and surgery at 8 weeks of age. Bilateral zygomatic arches were randomized and divided into the experimental side and the control side. A standard 2-cm-long zygomatic arch defect was made by an electric drill on the experimental side. The contralateral side was left intact. One of them underwent skull radiography and three-dimensional CT 2, 4, 8, and 12 weeks after surgery. The other 3 minipigs underwent scanning 4, 8, and 12 weeks after surgery. The bone defect was observed by radiography and three-dimensional CT. All three-dimensional CT data were examined by Mimics 10.01 software, and three-dimensional images were reconstructed. The length of both zygomatic arches, the length and width of the skull, and the hemicranial angles of both sides were measured and compared. RESULTS: The zygomatic arch developed to a summit at approximately 20 weeks of age. The zygomatic arch length of the experimental side is longer than that of the control side at each time point after surgery. The hemicranial angle of the experimental side is less than that of the control side at each time point after surgery. CONCLUSIONS: Early partial monolateral zygomatic arch defect accelerates its growth in the sagittal plane and impedes the hemicranial growth in the coronal plane. Early reconstruction of zygomatic arch defect may be essential to minimize the developmental craniofacial malformation in children.

Investigation on the structure of nasal cavity and its airflow field in Crouzon syndrome.

OBJECTIVE: Setup computational fluid dynamics (CFD) model of the nasal cavity in patients with Crouzon syndrome analyze inspiratory airflow hydrokinetics of its nasal cavity. After changing the morphosis structure of the nasal cavity by operation, compare the preoperative and postoperative alteration of the airflow field of the nasal cavity and evaluate the effect of operation on the physiological function of nasal ventilation. METHODS: Eleven patients with Crouzon syndrome were underwent spiral computed tomographic laminar scanning to obtain DICOM data and establish the CFD model. The field features of the nasal cavity with inspiratory static state phase were simulated and analyzed by the Fluent software. The changed data on preoperative and postoperative flow field in the nasal cavity in 5 of 11 patients were compared and analyzed. RESULTS: The nasal cavity of a patient with Crouzon syndrome reflected the structural features of relatively short and high-vaulted anteroposterior diameter. The nasal valve was the narrowest region in the nasal cavity and was the key region of producing obvious pressure drop. The inspiratory static state phase reflected comparatively high local airflow rate (approximately 2.469 m/s) and sheer force of the nasal wall. With the distance increasing from the anterior naris, the pressure inside the nasal cavity was decreased gradually. The pressure drop in the nasal cavity before the front end of the concha nasalis inferior (approximately 2 cm from anterior naris) accounted for most of the pressure of the whole nasal cavity (69%-88% of the overall pressure in nasal cavity and 79.24% on average). Osteotomy advancement and distraction osteogenesis increased the anteroposterior diameter of the nasal cavity and the changed nasal resistance. CONCLUSIONS: By analyzing the structure of the nasal cavity of patients with Crouzon syndrome and the CFD numerical simulation of patients after the procedure, airflow distribution in patients' nasal cavity and the effect of the surgery on the structure of the nasal cavity and airflow field were realized. Nasal valve played a pivotal role in the airflow field distribution of the nasal cavity. Operation changed the nasal resistance, improved the ventilation of nasal cavity, but did not affect the airflow field distribution of nasal cavity.

Airway Growth in Preoperative Patients with Crouzon Syndrome.

Background: Obstructive sleep apnea is common in patients with Crouzon syndrome, yet it may be caused by multiple factors. This study aims to investigate the natural history of airway development in preoperative Crouzon patients, from infants to adults. Methods: Preoperative computed tomography (CT) scans (Crouzon syndrome, n = 73; control, n = 87) were divided into five age subgroups. CT scans were measured using Materialise software. Results: Before 6 months of age, nasal airway volume in patients with Crouzon syndrome was smaller than normal by 37% (p = 0.002), and the cross-sectional area at the choana reduced by 45% (p < 0.001). The reduction of nasal airway volume and cross-sectional area reached their nadir at 2 years of age, with shortening of 44% and 63% (both p < 0.001), respectively. They gradually caught up to normal dimensions after 6 years of age. Between 2 and 6 years, the pharyngeal airway in patients with Crouzon syndrome reduced 44% (p = 0.011) compared with controls. However, the airway cross-sectional area at condylion and gonion levels was less than normal, before 6 months (35%, p = 0.024) and (44%, p = 0.006) after 2 years of age, respectively. This reduction remains into adulthood. Conclusion: Nasal airway volume is more limited in children with Crouzon syndrome who are younger than 2 years of age. Whereas after 2 years of age, the pharyngeal airway develops significant volume restriction, leading to timing and specific treatment area foci based on the site of temporal maximal constriction.

Surgical and prosthodontic rehabilitation in a patient with Freeman-Sheldon syndrome.

Dental and prosthetic rehabilitation possess significant challenges in patients who have Freeman-Sheldon syndrome. Microsomia is one of the main diagnostic criteria for Freeman-Sheldon syndrome, and it creates difficulty in working in the intraoral cavity. Most patients with small orifice often have difficulties in oral hygiene maintenance, and it gives rise to loss of some of the teeth. It incurs the need for dental and oral treatment. In the presented study, the patient with limited mouth opening that disabled the dentists to perform dental treatment was given prosthodontic therapy after having commissuroplasty and implant placement simultaneously.

Reossification of cranium and zygomatic arch after monobloc frontofacial distraction advancement for syndromic craniosynostosis.

Monobloc frontofacial advancement with distraction is becoming more routinely used within craniofacial surgery for faciocraniosynostosis, because of the simultaneous correction obtained on the exorbitism and of the respiratory impairment. Reossification of the cranium and zygomatic bone in monobloc frontofacial advancement with distraction has not been assessed previously on long series. In this study, 40 patients, 22 Crouzon, 11 Apert, and 7 Pfeiffer syndrome who underwent a frontofacial monobloc advancement by distraction osteogenesis, were retrospectively reviewed, after a mean of 2.1 years of follow-up. The bone linkage between both margin of the coronal and zygomatic osteotomy gap was evaluated on three-dimensional computed tomographic scan postoperatively. The correlations between reossification and some clinical situations (diagnosis, existence of previous anterior craniofacial procedure, use of bone paste, and the age at operation) were studied to determine factors that influence on reossification. "Good" or "fair" reossification on coronal gap was demonstrated by 68.2% of those with Crouzon and 54.5% of those with Apert syndrome. In contrast, 85.7% of those with Pfeiffer syndrome had "poor" or "absent" reossification. Rebridging of the zygomatic arch in Pfeiffer was also the poorest among 3 syndromes. Previous operations performed before the frontofacial monobloc advancement decreased reossification of distraction gap. In the group of patients in whom autologous bone paste on coronal osteotomy gap was applied, the bone formation was improved in all syndromes significantly. The reossification of the coronal osteotomy gap in patients with Pfeiffer syndrome is poor compared with those with Crouzon and Apert syndromes. Bone paste is extremely effective on increasing osteogenesis even in patients with Pfeiffer syndrome or the patients with previous surgery.

Reductions in ATPase activity, actin sliding velocity, and myofibril stability yield muscle dysfunction in Drosophila models of myosin-based Freeman-Sheldon syndrome.

Using Drosophila melanogaster, we created the first animal models for myosin-based Freeman-Sheldon syndrome (FSS), a dominant form of distal arthrogryposis defined by congenital facial and distal skeletal muscle contractures. Electron microscopy of homozygous mutant indirect flight muscles showed normal (Y583S) or altered (T178I, R672C) myofibril assembly followed by progressive disruption of the myofilament lattice. In contrast, all alleles permitted normal myofibril assembly in the heterozygous state but caused myofibrillar disruption during aging. The severity of myofibril defects in heterozygotes correlated with the level of flight impairment. Thus our Drosophila models mimic the human condition in that FSS mutations are dominant and display varied degrees of phenotypic severity. Molecular modeling indicates that the mutations disrupt communication between the nucleotide-binding site of myosin and its lever arm that drives force production. Each mutant myosin showed reduced in vitro actin sliding velocity, with the two more severe alleles significantly decreasing the catalytic efficiency of actin-activated ATP hydrolysis. The observed reductions in actin motility and catalytic efficiency may serve as the mechanistic basis of the progressive myofibrillar disarray observed in the Drosophila models as well as the prolonged contractile activity responsible for skeletal muscle contractures in FSS patients.

Findings, phenotypes, and outcomes in Freeman-Sheldon and Sheldon-Hall syndromes and distal arthrogryposis types 1 and 3: protocol for systematic review and patient-level data meta-analysis.

BACKGROUND: Freeman-Sheldon and Sheldon-Hall syndromes (FSS and SHS) and distal arthrogryposis types 1 and 3 (DA1 and DA3) are rare, often confused, congenital syndromes. Few studies exist. With reported diagnosis unreliable, it would be scientifically inappropriate to consider articles describing FSS, SHS, DA1, or DA3, unless diagnoses were independently verified, rendering conventional systematic review and meta-analysis methodology inappropriate and necessitating patient-level data analysis (PROSPERO: CRD42015024740). METHODS/DESIGN: As part of a clinical practise guideline development process, we evaluate (1) diagnostic accuracy from 1938-2017, using the Stevenson criteria; (2) the most common physical findings, possible frequency clusters, and complications of physical findings amongst patients with FSS; and (3) treatment types and outcomes. All papers reporting diagnosis of FSS, SHS, DA1, and DA3 are included in searching PubMed and Google Scholar from December 2014 to July 2015 and again before final analyses. Patients with FSS are divided into four phenotype-defined sub-types; all patients are grouped by published diagnosis and medical speciality. Significance of physical findings and historical data is evaluated by chi-square. Associations of physical findings and history with diagnosis and treatment outcome are evaluated by Pearson correlation and linear regression analysis. Two-tailed alpha level of 0.05 is used throughout. DISCUSSION: The need for detailed patient-level data extraction may limit the types of articles included and questions able to be answered. For treatment and psychosocial health outcomes, we anticipate enhanced difficulties, which may limit significance, power, and results' usability. We hope to outline knowledge gaps and prioritise areas for clinical investigation. SYSTEMATIC REVIEW REGISTRATION NUMBER: CRD42015024740 Universal Trial Number: U1111-1172-4670.

Minor Suture Fusion in Syndromic Craniosynostosis.

BACKGROUND: Infants with craniofacial dysostosis syndromes may present with midface abnormalities but without major (calvarial) suture synostosis and head shape anomalies. Delayed presentation of their calvarial phenotype is known as progressive postnatal craniosynostosis. Minor sutures/synchondroses are continuations of major sutures toward and within the skull base. The authors hypothesized that minor suture synostosis is present in infants with syndromic, progressive postnatal craniosynostosis, and is associated with major suture synostosis. METHODS: The authors performed a two-institution review of infants (<1 year) with syndromic craniosynostosis and available computed tomographic scans. Major (i.e., metopic, sagittal, coronal, and lambdoid) and minor suture/synchondrosis fusion was determined by two craniofacial surgeons and one radiologist using Mimics or Radiant software. RESULTS: Seventy-three patients with 84 scans were included. Those with FGFR2 mutations were more likely to lack any major suture fusion (OR, 19.0; p = 0.044). Minor suture fusion occurred more often in the posterior branch of the coronal arch (OR, 3.33; p < 0.001), squamosal arch (OR, 7.32; p < 0.001), and posterior intraoccipital synchondroses (OR, 15.84; p < 0.001), among FGFR2 versus other patients. Patients (n = 9) with multiple scans showed a pattern of minor suture fusion followed by increased minor and major suture synostosis. Over 84 percent of FGFR2 patients had minor suture fusion; however, six (13 percent) were identified with isolated major suture synostosis. CONCLUSIONS: Minor suture fusion occurs in most patients with FGFR2-related craniofacial dysostosis. Syndromic patients with patent calvarial sutures should be investigated for minor suture involvement. These data have important implications for the pathophysiology of skull growth and development in this select group of patients. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.

Syndromic craniosynostosis: neuropsycholinguistic abilities and imaging analysis of the central nervous system.

OBJECTIVE: To characterize patients with syndromic craniosynostosis with respect to their neuropsycholinguistic abilities and to present these findings together with the brain abnormalities. METHODS: Eighteen patients with a diagnosis of syndromic craniosynostosis were studied. Eight patients had Apert syndrome and 10 had Crouzon syndrome. They were submitted to phonological evaluation, neuropsychological evaluation and magnetic resonance imaging of the brain. The phonological evaluation was done by behavioral observation of the language, the Peabody test, Token test and a school achievement test. The neuropsychological evaluation included the WISC III and WAIS tests. RESULTS: Abnormalities in language abilities were observed and the school achievement test showed abnormalities in 66.67% of the patients. A normal intelligence quotient was observed in 39.3% of the patients, and congenital abnormalities of the central nervous system were observed in 46.4% of the patients. CONCLUSION: Abnormalities of language abilities were observed in the majority of patients with syndromic craniosynostosis, and low cognitive performance was also observed.

Otologic and audiologic features of Nager acrofacial dysostosis.

OBJECTIVE: To describe the otologic and audiologic characteristics of pediatric patients with Nager acrofacial dysostosis. DESIGN: Retrospective case series. SETTING: Multidisciplinary clinic in a tertiary care children's hospital. SUBJECTS: Patients less than 18 years of age with Nager acrofacial dysostosis. METHODS: Nager syndrome is a mandibulofacial dysostosis associated with preaxial limb abnormalities and multiple craniofacial anomalies. Ten patients with Nager syndrome were reviewed. Relevant literature, 1966 to the present, was reviewed with the assistance of Medline. RESULTS: External and middle ear abnormalities are common in Nager syndrome. All non-atretic ears had significant difficulty with otitis media, requiring an average of two sets of tympanostomy tubes. Cholesteatoma was diagnosed in one patient. Pure conductive hearing loss was identified in eight patients with mixed hearing loss noted in two patients. Conductive hearing loss greater than 30 dB HL was noted in 90% (9/10) of patients, with 40% (4/10) having 55-70 dB HL loss. Although amplification was effective, results of surgical interventions to correct conductive hearing loss were inconsistent. Two patients with mixed hearing loss developed the sensorineural component in later childhood, indicating that progressive or fluctuating sensorineural hearing loss is also possible in this population. CONCLUSIONS: Pediatric patients with Nager acrofacial dysostosis exhibit conductive hearing loss due to middle and external ear pathology. Prolonged ventilation of the middle ear via tympanostomy tubes and amplification with hearing aids are often required. Some patients also demonstrate mixed hearing loss that may be progressive and should be monitored carefully. Early and aggressive management in a multidisciplinary team approach is recommended.