Suture Fusion Research Articles

Three-Dimensional Evaluation of Dental Arches in Individuals with Syndromic Craniosynostosis.

Individuals with syndromic craniosynostosis present alterations in the dental arches due to anomalies caused by the early fusion of the craniomaxillary sutures. This study aimed to compare intradental and interdental dimensions between individuals with Apert and Crouzon syndromes and nonsyndromic controls. Digital models were obtained from the archive of a public tertiary care hospital. The sample consisted of 34 patients (Apert n = 18, Crouzon n = 16) and 34 nonsyndromic controls matched for gender and age. Measurements of perimeter, length, intercanine and intermolar distances (upper and lower), overjet, and molar ratio were performed. Statistical comparisons were performed using ANOVA and Tukey tests (p < 0.05). Patients with Apert and Crouzon syndromes have severely reduced maxillary transverse dimensions, perimeter, and length of the upper arch compared to the control group (p < 0.001). The lower arch is less impacted. Patients with Apert syndrome had an anterior crossbite (p < 0.001), while patients with Crouzon syndrome had an edge-to-edge bite (p < 0.011). Patients with Apert and Crouzon syndromes do not have serious transverse proportion problems when comparing the upper and lower arches. In this sample, both the Apert and Crouzon groups have severely compromised upper arches compared to the control group. Mild dentoalveolar expansion in the maxilla should be sufficient for the transverse adaptation of the dental arches before frontofacial advancement.

Maternal hyperthyroidism increases the synthesis activity and the osteogenic markers expression of calvarial osteoblasts from offspring in a murine model

To evaluate the characteristics and synthesis activity of osteoblasts extracted from the calvaria of offspring of rats exposed to maternal hyperthyroidism. Twelve adult Wistar rats were divided into two groups, one control and one treated with daily administration of L-thyroxine by an orogastric tube (50 µg/animal/day) during pregnancy. Three days after delivery and confirmation of the mothers’ hyperthyroidism, the offspring were euthanized for the extraction of osteoblasts from the calvaria. At 7, 14, and 21 days, proliferation activity was assessed using MTT assay, while alkaline phosphatase (ALP) activity was assessed by the BCIP/NBT method. At 21 days, the total area of the mineralized matrix stained by von Kossa was evaluated by morphometry. The expression of gene transcripts for Runx2, Bmp2, Fgfr1, collagen type 1 (Col1), osteocalcin (Oc), and osteopontin (Op) were evaluated by real-time RT-PCR. Means were compared using the Student’s t-test. FA activity was significantly higher at 14 and 21 days in cultures of osteoblasts extracted from offspring exposed to maternal hyperthyroidism, while MTT conversion was significantly lower at 21 days in this group. Osteoblast cultures of neonates exposed to maternal hyperthyroidism also showed a larger total area of mineralized matrix and greater expression of gene transcripts for Oc and Op. Maternal hyperthyroidism increases the activity of matrix synthesis, alkaline phosphatase activity, and expression of gene transcripts for osteocalcin and osteopontin in the osteoblasts, extracted from the calvaria of the offspring, which may be one of the mechanisms of premature fusion of cranial sutures.

An Autopsy Based Comparative Study Between Males and Females Age of Sagittal Suture fusion at Tertiary Health Care Center at Jaipur (Rajasthan)

Background: A reasonably correct estimation of age in elderly people is essential in legal, medical, social andadministrative matters. Skulls are usually well preserved in decomposed, mutilated state or in fragmentary bodies.Sagittal suture has a very wide range of fusion. The aim of this study is to collect data of sagittal suture fusion ofmale and female and comparing with each other, so the more appropriate estimation of age can occur by includingsexual dimorphism of sagittal sutural fusion.Material and Methods: This study was conducted in 100 autopsy cases of Department of Forensic Medicine, S.M.S.Medical College &amp; Attached Hospital, Jaipur of aged between 20 to 70 yrs, With making group of male and femalefor each year of age. The obliteration of the sutures was ascertained endocranially as well as ectocranially. TheSagittal suture was studied in four parts and Scale for closure is studied by Acsadi-Nemeskeri complex methodResults: Ectocranially the start of fusion of sagittal suture was observed at the age of 51-60 yrs age group in femalesand in 46-50 yrs in males and endocranially at 31-40 yrs in males and 41-50 yrs in females.Conclusion: When comparison between males and female subjects for ectocranially closure were made, closure wasearlier in males. Completion is perfected at the age of 61-70 years. The study showed that fusion of endocraniumbegan first on S4 &amp; last on S1 in both sexes.Though consensus of opinion in our country is that the obliteration of the skull sutures in females is somewhatearlier than that of males, in the present study no such pattern in difference was noticed in endocrinal suturalfusion.

Crouzon syndrome and the eye

Abstract Crouzon syndrome is characterized by premature fusion of cranial sutures (craniosynostosis) which can impair proper brain and craniofacial development. Craniofacial abnormalities include frontal bossing, midface hypoplasia, parrot beak nose, and hypoplastic maxilla. The most common ophthalmic manifestations of Crouzon syndrome are proptosis, exotropia, exposure keratopathy, hypertelorism, and optic atrophy secondary to chronic papilledema. Here we report a case of Crouzon syndrome with ocular complications.

Complications in craniosynostosis surgery in patients with rickets: illustrative case and systematic review of literature.

Craniosynostosis (CSS) is the premature fusion of calvarial sutures associated with identified genetic mutations or secondary to alterations in intracranial pressure, brain, or bone growth patterns. Of the metabolic etiologies implicated in CSS, X-linked hypophosphatemic rickets (XLHR) is the most common, with dysfunctional bone mineralization leading to progressive hyperostosis and delayed synostosis. There is a paucity of literature discussing the unique surgical considerations for XLHR-related CSS. A 26-month-old male with XLHR-related sagittal CSS underwent cranial vault remodeling (CVR). Surgery was complicated by the presence of diploic hypertrophy with significant intraoperative estimated blood loss (EBL). EBL greatly exceeded reference ranges for CVR in all-cause CSS. As a result, the surgical goals were modified and the complete planned procedure aborted. Subsequent review of preoperative imaging revealed multiple fine vascular lacunae within the bone. A systematic literature review was conducted to identify reported complications relating to surgical intervention for rickets-associated CSS. Future considerations for patients with XLHR-related CSS should emphasize awareness of metabolic risk factors with associated complications, and the need for selection of approach and operative management techniques to avoid EBL. Further research is required to elucidate underlying mechanisms and determine whether the encountered phenomenon is characteristic across this patient population and potentially minimized by preoperative medical therapy.

A Retrospective Study: ABO and Rh Phenotype Blood Group Distribution Amongst Different Types of Craniosynostosis Patients

Background: Craniosynostosis refers to the premature fusion of cranial sutures. Premature closure can impair brain development and cognitive problems. Only available treatment of craniosynostosis is through surgical intervention which is associated with excessive blood loss. Objectives: In this study, we investigate the prevalence of each ABO/Rh blood group amongst patients with different types of craniosynostosis. Methods: We included 163 patients, under craniosynostosis treatment, in Imam Hossein children’s hospital at Isfahan, Iran. A retrospective analysis was performed and the frequency of blood groups as well as types of craniosynostosis were reported. Moreover, the connection between ABO/Rh blood groups and the types of craniosynostosis was examined by chi-square test. Results: Of 163 cases reviewed; The majority of participants had blood group A positive (32.5%), followed by O positive (31.3%). The rest of the blood groups were reported in order: B positive (22.1%), B negative (4.9%), AB positive (4.3%), O negative (2.5%), A negative (1.8%), AB negative (0.6%). Also, the most common type of craniosynostosis was metopic (27%) and the other types were pansynostosis (23.9%), sagittal (21.5%), coronal (16.6%), multisuture (10.4%) and lambdoid (0.6%) respectively. Due to connection between ABO/Rh blood groups and the types of craniosynostosis, no significant relationship was observed. Conclusion: Based on the results of the present study, it was found that the frequency of ABO blood groups in children with craniosynostosis can be different from the population of the same area. Also, the ratio of different types of craniosynostosis was different from previous data.

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 (Fgfr2S252W/+ ) around 3 weeks old as seen in Crouzon syndrome model mice (Fgfr2cC342Y/+ ). 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 Fgfr2S252W/+ and Fgfr2cC342Y/+ 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.

Sickle Cell Disease Association with Premature Suture Fusion in Young Children.

Background:Sickle cell disease (SCD) leads to the formation of an atypical hemoglobin tetramer with reduced capacity to carry oxygen. Although correlation between SCD and craniosynostosis (CS) has been mentioned, these are mostly small series or case reports. This article aimed to study any correlation between these entities in a large pediatric population.Methods:We retrospectively reviewed head CT scans of SCD patients from 0 to 8 years of age who required a CT for issues unrelated to their head shape between 2012 and 2020. We excluded patients with known history of CS or any CS-related syndrome, hydrocephalus, shunt placement, history of cranial surgery, or any reported cerebral or cranial shape abnormality.Results:Ninety-four CT scans were analyzed. The mean age at imaging was 4.48 ± 2.30 years. CS prevalence in this cohort was 19.1%. Analysis between independent variables and patients with +CS showed that SCD-associated vasculopathy, first-degree relatives with SCD, and the use of folic acid had a statistically significant association with CS development.Conclusions:Approximately 20% of pediatric patients with SCD developed CS. This association was higher in those patients who had a family history of SCD, used folic acid, and had SCD-associated vasculopathy. While the clinical impact of these findings needs more extensive study, centers that manage patients with SCD should be aware of the relatively high concordance of these diagnoses, vigilantly monitor head shape and growth parameters, and understand the potential risks associated with unidentified or untreated CS.

Suture Fusion, Cephalic Index, and Head Shape in Non-syndromic Sagittal Craniosynostosis

INTRODUCTION: Sagittal craniosynostosis may present with complete or partial fusion of the sagittal suture.1 Previous studies describe high heterogeneity of phenotypic presentation for non-syndromic sagittal craniosynostosis in absence of particularly compelling evidence explaining such heterogeneity.1 One postulation for variation in head shape at presentation is degree and location of suture fusion; however, relationships between extent of sagittal suture fusion and head shape are currently poorly described.1 The aim of this study was to characterize the degree of sagittal suture fusion in a cohort of patients with non-syndromic sagittal craniosynostosis and determine associations with CI and head shape, including frontal bossing and occipital bulleting. METHODS: Patients with non-syndromic sagittal craniosynostosis at a tertiary care center with available CT imaging between 2014 and 2021 were retrospectively included in this study. Three-dimensional CT head images were imported into Materialise Mimics and parietal bones were manually isolated. The ‘measure’ tool was used to measure the distance of fused suture. The percentage of total sagittal suture fusion was quantified by dividing the distance of fused suture by the total length of the sagittal suture. Similar calculations were performed for anterior and posterior halves, and anterior, middle, and posterior thirds. Degree of sagittal suture fusion was compared to head shape characteristics, including cephalic index (CI), frontal bossing, and occipital bulleting, with Mann-Whitney U tests, Spearman’s correlations, and univariate and multivariate linear and logistic regression models. RESULTS: Ninety patients (69 male) were included in this retrospective study. The sagittal suture was on average 85.6 ± 20.1% fused, and 45 (50.0%) patients demonstrated complete fusion of the sagittal suture. CI was associated with increased degree of fusion for the anterior one-half (ρ = 0.26, p = 0.033) and anterior one-third (ρ = 0.30, p = 0.012) of the sagittal suture. Complete fusion of the anterior one-third of the sagittal suture predicted higher CI (β = 13.86, SE = 6.99, z = -0.25, p = 0.047). Logistic regression models revealed percentage of middle one-third sagittal suture fusion predicted the presence of frontal bossing (β = 2.42, SE = 0.96, z = 2.53, p = 0.012). Total degree of sagittal suture fusion was not predictive of CI or head shape in any analysis (all p > 0.05). CONCLUSION: Percentage of total sagittal suture fusion was not associated with CI or head shape in patients with non-syndromic sagittal craniosynostosis in this cohort. Decreased fusion of the anterior one-third of the sagittal suture was paradoxically associated with higher CI and more severe scaphocephalic head shape. These findings raise additional questions regarding suture fusion and head-shape morphology, and further research is needed to substantiate these results in patients with non-syndromic sagittal craniosynostosis. These findings may have implications for understanding suture fusion patterns in other variations of craniosynostosis. REFERENCE: 1. Di Rocco, F., Gleizal, A., Szathmari, A., Beuriat, P. A., Paulus, C., & Mottolese, C. (2019). Sagittal suture craniosynostosis or craniosynostoses? The heterogeneity of the most common premature fusion of the cranial sutures. Neurochirurgie, 65(5), 232-238.

The Impact of Genes and the Environment on Calvarial Bone Repair and Remodeling in a Murine Model of Craniosynostosis

INTRODUCTION: TWIST1 mutation leads to Seathre-Chotzen syndrome involving coronal craniosynostosis. Recent studies have shown that exposure to a selective serotonin reuptake inhibitor, citalopram, can cause craniosynostosis. The purpose of this study is to investigate the genetic and environmental mechanisms underlying aberrant bone repair in a murine model of craniosynostosis. METHODS: Thirteen Twist1+/– mutant mice and wild-type (WT) mice with or without in utero citalopram exposure were generated (n = 5 per group): WT, Twist1+/–, WT + citalopram (n = 5), and Twist1+/– + citalopram. Mice underwent calvarial defect surgery followed by microCT imaging at 1, 2, 3, and 4 weeks postoperatively, at which point they were sacrificed for histological analysis. RESULTS: All mice were fully ambulatory after surgery, with no perioperative complications. MicroCT analysis demonstrated that all Twist1+/– mice exposed to citalopram had craniosynostosis and exhibited excessive and disorganized bone growth after injury. Some Twist1+/– mice without citalopram treatment also developed craniosynostosis and exhibited a similar excessive bone growth pattern; Twist1+/– mice without suture fusion had bone repair similar to that of WT mice. WT defects remained incompletely healed at 4-weeks postoperatively. In contrast, the Twist1+/– mice with citalopram exposure demonstrated full bone fill of the defect at 4-weeks. Twist1+/– mice without citalopram demonstrated more bone fill than WT, but the defect was not entirely filled. CONCLUSION: These preliminary findings after calvarial defect surgeries improve our understanding of bone repair in craniosynostosis. By investigating the mechanisms of bone dynamics in craniosynostosis, we can better understand and prevent the factors implicated in resynostosis after surgery.

Townes-Brocks syndrome with craniosynostosis in two siblings

This report describes a novel truncating c.709C > T p.(Gln237*) SALL1 variant in two siblings exhibiting sagittal craniosynostosis as a unique feature of Townes-Brocks syndrome (TBS, OMIM #107480). TBS is a rare autosomal dominant syndrome with variable phenotypes, including anorectal, renal, limb, and ear abnormalities, which results from heterozygous variants in the SALL1 gene, predominantly located in the 802 bp “hot spot region” within exon 2. Recent studies have suggested that aberrations in primary cilia and sonic hedgehog signalling contribute to the TBS phenotypes. The presence of the novel c.709C > T p.(Gln237*) SALL1 variant was confirmed in both the siblings and their father, whereas no mutations currently associated with craniosynostosis were detected. We hypothesise that the truncating c.709C > T p.(Gln237*) SALL1 variant, which occurs outside the “hot spot region” and inside the glutamine-rich domain coding region, could interfere with ciliary signalling and mechanotransduction, contributing to premature fusion of calvarial sutures. This report broadens the genetic and phenotypic spectrum of TBS and provides the first clinical evidence of craniosynostosis as a novel feature of the syndrome.

A CADAVERIC STUDY OF SEEMANTA MARMA

Background: The marma sharira is a prime territory of Rachana sharira. Sushruta had elaborated marma sharira at a certain depth. Marma (vital area) is described in the Hindu scripture Atharva Veda. During the Vedic era, the Marma Sharira had particular importance in the case of war field. The seemanta marma is shira marma, kalantara pranahara. The nature of this marma is sandhi marma. Aims: There are very few studies regarding the cadaveric study of seemanta marma. This study aims to identify the possible anatomical structure and analyze those structures. Perhaps it could be helpful for future scholars of Ayurveda. Material and method: The review was performed based on traditional Ayurvedic classics and contemporary medical sciences, journals, publications, articles, e-journals etc. The region of seemanta marma and surrounding area was dissected, and complete anatomical study was done. Discussion: The term seemanta indicates that the bony joint is present in the skull region. The joints present in the skull region are mainly sutural joints and fibrous, which provide malleable head quality. There are five major sutures in adult like coronal suture, sagittal suture, lambdoid suture and two squamous sutures, the frontal sutures present in infant and children. Conclusion: It has a significant role during delivery and brain development, which allows normal vaginal birth of the head. It also offers normal cranial growth by proper fusion if the premature fusion of sutures occurs (craniosynostosis), which results in cranial malformation.

ERF-related craniosynostosis and surgical management in the paediatric cohort.

ERF mutation is one of the most recently identified genetic aberrations associated with syndromic craniosynostosis. Data on the pattern of craniosynostosis, surgical management of ERF-related craniosynostosis and outcomes is limited. We report on our single-centre experience in paediatric cohort of patients with syndromic craniosynostosis secondary to ERF mutation. A retrospective review of all paediatric craniofacial cases was performed over an 8-year period (2014-2022). All patients with genetically confirm ERF-related craniosynostosis were identified, and clinical parameters including, age, sex, pattern of craniosynostosis, associated tonsillar herniation and follow-up period were further analysed from electronic clinical and imaging systems. All patients were selected and discussed in multidisciplinary craniofacial meeting (composed of neurosurgical, maxillofacial, plastics and genetics teams) prior to any surgical intervention. Overall, 10 patients with ERF-related craniosynostosis were identified with a male-to-female ratio of 4:1 with mean age at the time of surgery of 21.6months with a mean follow-up period of 5.2years. ERF-confirmed cases led to variable craniosynostosis pattern with multi-sutural synostosis with concurrent sagittal and bilateral lambdoid involvement as the most common pattern (7/10). No patient pre-operatively had evidence of papilloedema on ophthalmological assessment. Eight out of 10 patients had associated low-lying tonsils/hind brain hernia pre-operatively. Eight out of 10 patients required surgery which included 2 fronto-orbital advancement, 3 calvarial remodelling, 2 posterior calvarial remodelling/release and 1 insertion of ventriculoperitoneal shunt. Involvement of sagittal and lambdoid sutures is the most common pattern of craniosynostosis. ERF-related craniosynostosis can have variable pattern of suture fusion, and management of each patient requires unique surgical planning and execution based on clinical needs for the optimal outcomes.

The genetic overlap between osteoporosis and craniosynostosis.

Osteoporosis is the most prevalent bone condition in the ageing population. This systemic disease is characterized by microarchitectural deterioration of bone, leading to increased fracture risk. In the past 15 years, genome-wide association studies (GWAS), have pinpointed hundreds of loci associated with bone mineral density (BMD), helping elucidate the underlying molecular mechanisms and genetic architecture of fracture risk. However, the challenge remains in pinpointing causative genes driving GWAS signals as a pivotal step to drawing the translational therapeutic roadmap. Recently, a skull BMD-GWAS uncovered an intriguing intersection with craniosynostosis, a congenital anomaly due to premature suture fusion in the skull. Here, we recapitulate the genetic contribution to both osteoporosis and craniosynostosis, describing the biological underpinnings of this overlap and using zebrafish models to leverage the functional investigation of genes associated with skull development and systemic skeletal homeostasis.

Management of Chiari 1 Malformation and Hydrocephalus in Syndromic Craniosynostosis

Chiari 1 malformation and hydrocephalus are frequent findings in multi-suture and syndromic craniosynostosis patients. In this article, we review the pathogenesis, clinical significance, and management options for these conditions with comments from our own experience. The role of premature fusion of skull base sutures leading to a crowded posterior fossa and venous outflow obstruction resulting in impaired cerebrospinal fluid (CSF) absorption is highlighted. Management options are unique in this group and we advocate early (prior to 6 months of age) posterior vault expansion by distraction osteogenesis (DO) in the management of Chiari 1 malformation. Foramen magnum decompression is recommended for a select few either as part of posterior vault expansion or at a later date. Treatment of hydrocephalus, utilizing a ventriculoperitoneal (VP) shunt with preferably a programmable high-pressure valve and anti-siphon device, is required in a small percentage of cases despite successful posterior vault expansion. Patients need to be carefully selected and managed as hydrocephalus often serves as an important cranial vault growth stimulus. Further, they require careful monitoring and thought to ensure the management of these conditions and the timing of any intervention provides the optimal long-term outcome for the patient.

Craniosynostosis: A Pediatric Neurologist's Perspective.

Craniosynostosis is premature fusion of sutures of the cranium, resulting in an abnormal skull shape and restriction of brain growth. It may affect either a single suture or multiple sutures. In most cases, craniosynostosis is secondary to an underlying abnormality of the growing brain; however, syndromic craniosynostosis is not uncommon. It might lead to several complications such as raised intracranial pressure, neurological deficits, and neurodevelopmental disabilities. Pediatric neurologists do play a significant role in early identification and treatment, and thereby ensure a better clinical and neurodevelopmental outcome in such children.

De novo mutations in the BMP signaling pathway in lambdoid craniosynostosis.

Lambdoid craniosynostosis (CS) is a congenital anomaly resulting from premature fusion of the cranial suture between the parietal and occipital bones. Predominantly sporadic, it is the rarest form of CS and its genetic etiology is largely unexplored. Exome sequencing of 25 kindreds, including 18 parent-offspring trios with sporadic lambdoid CS, revealed a marked excess of damaging (predominantly missense) de novo mutations that account for ~ 40% of sporadic cases. These mutations clustered in the BMP signaling cascade (P = 1.6 × 10-7), including mutations in genes encoding BMP receptors (ACVRL1 and ACVR2A), transcription factors (SOX11, FOXO1) and a transcriptional co-repressor (IFRD1), none of which have been implicated in other forms of CS. These missense mutations are at residues critical for substrate or target sequence recognition and many are inferred to cause genetic gain-of-function. Additionally, mutations in transcription factor NFIX were implicated in syndromic craniosynostosis affecting diverse sutures. Single cell RNA sequencing analysis of the mouse lambdoid suture identified enrichment of mutations in osteoblast precursors (P = 1.6 × 10-6), implicating perturbations in the balance between proliferation and differentiation of osteoprogenitor cells in lambdoid CS. The results contribute to the growing knowledge of the genetics of CS, have implications for genetic counseling, and further elucidate the molecular etiology of premature suture fusion.

Data-driven Normative Reference of Pediatric Cranial Bone Development.

Background:Available normative references of cranial bone development and suture fusion are incomplete or based on simplified assumptions due to the lack of large datasets. We present a fully data-driven normative model that represents the age- and sex-specific variability of bone shape, thickness, and density between birth and 10 years of age at every location of the calvaria.Methods:The model was built using a cross-sectional and multi-institutional pediatric computed tomography image dataset with 2068 subjects without cranial pathology (age 0–10 years). We combined principal component analysis and temporal regression to build a statistical model of cranial bone development at every location of the calvaria. We studied the influences of sex on cranial bone growth, and our bone density model allowed quantifying for the first time suture fusion as a continuous temporal process. We evaluated the predictive accuracy of our model using an independent longitudinal image dataset of 51 subjects.Results:Our model achieved temporal predictive errors of 2.98 ± 0.69 mm, 0.27 ± 0.29 mm, and 76.72 ± 91.50 HU in cranial bone shape, thickness, and mineral density changes, respectively. Significant sex differences were found in intracranial volume and bone surface areas (P < 0.01). No significant differences were found in cephalic index, bone thickness, mineral density, or suture fusion.Conclusions:We presented the first pediatric age- and sex-specific statistical reference for local cranial bone shape, thickness, and mineral density changes. We showed its predictive accuracy using an independent longitudinal dataset, we studied developmental differences associated with sex, and we quantified suture fusion as a continuous process.

Syndromic Craniosynostosis: Cranial Vault Expansion in Infancy.

Syndromic craniosynostosis (CS) represents a relatively uncommon disease process that poses significant reconstructive challenges for the craniofacial surgeon. Although there is considerable overlap in clinical features associated with various forms of syndromic CS, key extracranial features and close examination of the extremities help to distinguish the subtypes. While Virchow's law can easily guide the diagnosis of single suture, nonsyndromic CS, syndromic CS traditionally results in atypical presentations inherent to multiple suture fusion. Coronal ring involvement in isolation or associated with additional suture fusion is the most common pattern in syndromic CS often resulting in turribrachycephaly.

Degree of Sagittal Suture Fusion, Cephalic Index, and Head Shape in Nonsyndromic Sagittal Craniosynostosis.

Sagittal craniosynostosis may present with complete or partial fusion of the sagittal suture, but relationships between degree of sagittal suture fusion and head shape are currently poorly described. The aim of this study was to characterize sagittal suture fusion patterns and determine associations with head shape in a cohort of patients with nonsyndromic sagittal craniosynostosis. Patients with nonsyndromic sagittal craniosynostosis at a tertiary care center with available computed tomography imaging were included in this study. The anterior and posterior distances of sagittal suture patency were measured along 3-dimensional parietal bones. Degree of sagittal suture fusion was compared to head shape characteristics, including cephalic index (CI), frontal bossing, and occipital bulleting. Ninety patients (69 male) were included in this retrospective study. The sagittal suture was on average 85.6±20.1% fused, and 45 (50.0%) patients demonstrated complete fusion of the sagittal suture. CI was associated with increased degree of fusion for the anterior one-half (ρ=0.26, P =0.033) and anterior one-third (ρ=0.30, P =0.012) of the sagittal suture. Complete fusion of the anterior one-third of the sagittal suture predicted higher CI (β=13.86, SE=6.99, z =-0.25, P =0.047). Total degree of sagittal suture fusion was not predictive of CI or head shape in any analysis. Decreased fusion of the anterior one-third of the sagittal suture, but not total suture, may paradoxically predict increased severity of scaphocephaly as quantified by CI in nonsyndromic sagittal craniosynostosis.