Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “SYNOSTOSIS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 865 records · Page 48Linked to original sources
PubMed2006

Testing causal mechanisms of nonsyndromic craniosynostosis using path analysis of cranial contents in rabbits with uncorrected craniosynostosis.

OBJECTIVE: Various causal mechanisms of familial nonsyndromic craniosynostosis have been presented. One hypothesis suggests that overproduction of bone at the suture is the primary origin of craniosynostosis, which affects brain and cranial growth secondarily through altered intracranial pressure (Primary Suture Fusion Model). Other hypotheses suggest that decreased cranial base growth or abnormal brain growth are the primary cause of craniosynostosis (Cranial Base, Brain Parenchyma Models, respectively). This study was designed to investigate which model best describes neurocranial changes associated with craniosynostosis in a rabbit model through multivariate path analysis. DESIGN: Serial magnetic resonance imaging scans and intracranial pressure measurements were obtained at 10, 25, and 42 days of age from 18 rabbits: six controls, six with delayed-onset synostosis, and six with early-onset synostosis. Five variables were collected from each rabbit: calvarial thickness at the affected suture, cranial base length, brain volume, cerebrospinal fluid volume, and intracranial pressure. This data set was used to test causal pathway relationships generated by the proposed models. Goodness of fit was measured by experimental group for each model. RESULTS: Primary Suture Fusion Model best explained the variables in both delayed-onset and early-onset synostotic rabbits (Goodness of fit = 93%, 97%, respectively). Cranial Base Model (Goodness of fit = 94%) best explained the data in control rabbits. CONCLUSION: Results suggest that the primary site of craniosynostosis in craniosynostotic rabbits is most likely the synostosed suture. Other cranial vault anomalies are most likely secondary compensatory changes. Results of the present study may provide insight regarding the causal pathway of craniosynostosis.

Animals↗
PubMed1990

Craniofacial growth disturbance after skull base and associated suture synostoses in the newborn chacma baboon: a preliminary report.

The purpose of this study was to create craniofacial growth disturbances via synostoses of sutures of the cranial base, as well as of other various selected sutures of the anterior cranial and posterior facial structures. Twelve sutures, single or in combination, were obliterated by means of autogenous bone transplantation in twenty-five baby baboons (Papio ursinus). The data obtained from the sacrificed animals were qualitatively analyzed. The results indicated that synostosis of any of the selected sutures does lead to craniofacial growth disturbances. Furthermore, no specific synostosed suture could be identified that might cause a specific type of craniofacial dysostosis, although unilateral facial deformities always occurred after unilateral suture synostosis.

Animals↗
PubMed1993

Psychological functioning of children with craniofacial anomalies and their mothers: follow-up from late infancy to school entry.

Twenty-three mothers and their 5- to 7-year-old children with craniofacial anomalies (CFA) who were assessed during the child's infancy were followed. Three types of CFA were included: cleft lip and palate (CLP), isolated cleft palate (CP), and sagittal synostosis. Measures of child status focused on behavior-problem frequency and self-concept. Mothers completed self-report measures of emotional well-being, marital satisfaction, and social support. Results indicated that (1) a sizable minority (18%) of the children with CFA had clinically significant behavior-problem scores shown in concordant reports by parent and teacher of behavior problems; (2) individual differences in child functioning within the CFA group were predicted by observational measures of earlier mother-infant interaction during play and teaching situations; (3) mothers of children with CLP reported less favorable social support than mothers of children with CP or sagittal synostosis.

Analysis of Variance↗
PubMed1996

Coronal suture pathology and synostotic progression in rabbits with congenital craniosynostosis.

The purpose of the present study was to describe coronal suture pathology and cross sectional synostotic progression in an inbred strain of rabbits with congenital craniosynostosis. Calvaria from 102 perinatal rabbits (39 unaffected; 63 bilateral or unilateral synostosis) were collected at fetal days 21 (n = 12), 25 (n = 20), 27 (n = 22), 30 (term) (n = 32), and 3 days post-term (n = 16) for gross morphologic and histologic examination. Synostotic foci, the extent of relative bony bridging, and suture morphology were evaluated qualitatively and quantitatively. Of the 204 coronal sutures examined, 91 sutures were synostosed, and 113 were patent. All synostosed sutures showed similar foci by day 25, which originated as bony bridges in the middle of each suture on the ectocortic surface. Bony bridging width increased significantly (p < .001) from day 25 through 3 days post-term, and was best described by a linear regression equation. Osteogenic front areas of synostosed sutures were up to 2.5 times greater than patent sutures in term fetuses. Findings demonstrate that coronal suture synostosis in the congenital rabbit model (1) begins early during suture morphogenesis (before 25 days of gestation); (2) consistently radiates from a single focus corresponding to a normal interdigitating region (i.e., a high-tension environment); (3) varies in onset and rate as evidenced by low R2 value between age and extent of bony bridging; and (4) is the result of early hyperostosis of the osteogenic fronts and sutural agenesis. A number of possible pathogenetic mechanisms are discussed.

Analysis of Variance↗
PubMed1998

Controversies in the diagnosis and management of craniosynostosis: a panel discussion.

This introductory article summarizes and comments on a group of four papers based in part on a panel discussion of craniosynostosis (CS) held at the 53rd annual meeting of the American Cleft Palate-Craniofacial Association. The purpose of this panel was to review the differential diagnosis of CS and the evidence for increased intracranial pressure (ICP) and developmental problems in CS patients. First, a correct diagnosis must be made, with true synostosis being differentiated from positional deformities and other normal variants. Second, medical indications must be balanced against the risks of operating on CS patients. Release of fused sutures is commonly undertaken to avoid increased ICP, although studies of ICP in infants and children with CS are hampered by a lack of normative data and by difficulties with measurement techniques. A subgroup of children with isolated craniosynostosis may have increased ICP, which can be deleterious to brain function. Longitudinal studies of children with isolated CS suggest an increased risk of mental retardation and learning disorders; surgical release of the suture may not diminish this risk. Patients with metopic suture fusion appear to be particularly at risk. These findings must be confirmed with a larger sample size. These uncertainties raise ethical issues and complicate medical decision-making for the infant with CS. A trusting and truthful relationship between the parents and the professional is necessary for a balanced discussion of the best interests of the child. All patients with confirmed synostosis should be followed for evidence of progressive deformity, intracranial hypertension, and neurodevelopmental problems.

Brain↗
PubMed1998

Mental development and learning disorders in children with single suture craniosynostosis.

OBJECTIVE: This study examined the global intellectual development and presence/absence of learning disorders in children with nonsyndromic metopic, sagittal, and unilateral coronal synostosis who had early surgery (under 1 year of age), late surgery (over 1 year of age), or no surgery to correct the synostosis across three time periods. DESIGN: The design was longitudinal. Children were assessed at initial team evaluation, 1 year after surgery or initial evaluation if surgery was not performed, and annually thereafter. PARTICIPANTS: Participants included 84 consecutively evaluated patients. Seventy-two children were evaluated at Time 1 (T1), 8 months; 57 at Time 2 (T2), 21 months; and 39 at Time 3 (T3), 50 months. Data on learning disorders or mental retardation were available on 34 children who were school age. MAIN OUTCOME MEASURES: The Mental Development Index from the Bayley Scales of Infant Development was the main outcome measure for T1 and T2. The General Cognitive Index from the McCarthy Scales of Children's Abilities was the main outcome measure for T3. Learning disorders were determined from school and clinical records. RESULTS: Repeated measures analyses of variance found no statistical differences in the development of children based on diagnosis or surgical status across time. Base rate of mental retardation at T1 was consistent with normative data; however, the incidence of retardation was two to three times the expected rate at T2 and T3. Learning disorders were present in 47% of school-age children who were not retarded. Chi-square analysis showed no significant differences between rates of retardation or learning disorders based on surgical status. CONCLUSIONS: Most children with nonsyndromic craniosynostosis obtain developmental quotients within the normal range in infancy. Rates of retardation may increase relative to normative expectations as children mature. A high rate of learning disorders was identified. Results are preliminary due to sample size.

Age Factors↗
PubMed2002

Children with suspected craniosynostosis: a cost-effectiveness analysis of diagnostic strategies.

OBJECTIVE: Our purpose was to evaluate the clinical and economic impact of three evaluation strategies in children at different risks of craniosynostosis. MATERIALS AND METHODS: A decision-analytic and cost-effectiveness model was constructed to compare three evaluation in strategies in children with suspected synostosis: no imaging, radiography (if abnormal, followed by three-dimensional CT [3D CT]), and 3D CT. Three risk groups were analyzed on the basis of the prevalence (pretest probability) of disease: low (completly healthy children; prevalence, 34/100,000), intermediate (healthy children with head deformity; prevalence, 1/115), and high risk (children with syndromic craniofacial disorders [i.e., Crouzon's syndrome or Apert's syndrome]; prevalence, 9-10/10). Test performance (sensitivity and specificity) of the evaluation strategies was obtained from the literature. Costs (not charge) estimates were obtained from the hospital cost-accounting database and from the Medicaid fee schedule. RESULTS: In the low-risk group, the radiographic and 3D CT strategies resulted in a cost per quality-adjusted life year (QALY) gained of more than $560,000. In the intermediate-risk group, the radiographic strategy resulted in a cost per QALY gained of $54,600. Three-dimensional CT was more effective than the two other strategies but at a higher cost-hence, with a cost per QALY gained of $374,200. In the high-risk group, 3D CT was the most effective strategy with a cost per QALY gained of $33,800. Less experienced radiologists and poor-quality studies increased the evaluation cost per QALY gained for all of the risk groups because of decreased effectiveness. CONCLUSION: Radiologic screening of completely healthy children (low risk) for synostosis is not warranted because of the high cost per QALY gained of the radiographic and 3D CT strategies. In healthy children with head deformity (intermediate risk), the radiographic strategy had a reasonable cost per QALY gained. Three-dimensional CT was more effective but had a high cost per QALY gained. In children with syndromic craniofacial disorders (high risk), 3D CT was the most effective strategy and had a reasonable cost per QALY gained. Selection of children with suspected craniosynostosis based on their risk group and use of the most appropriate evaluation strategy could maximize clinical and economic outcomes for these patients.

Child↗
PubMed1997

Occipital flattening in the infant skull.

Occipital plagiocephaly caused by lambdoid synostosis is rare. Positional flattening is more common and will most often respond to conservative measures. Surgical correction of a flat occiput is warranted if the deformity is profound. Skull molding devices may be effective for treating mild abnormalities but are ineffective in the more severe cases. An operative procedure is described that uses a microplate-reinforced median bar to provide a rigid scaffold to maintain the occipital correction. Seventy-three consecutive patients were evaluated over a 3-year period for occipital plagiocephaly. Of these individuals, only one had true lambdoid synostosis and six required surgery. There were no operative complications and cranial length was increased from 84 to 94% of age-matched controls after surgery. The need for operative intervention is rare; however, it should be based on the severity of the posterior deformity, especially when accompanied by compensatory frontal bossing, and not on the etiology of the flattening.

Journal Article↗
PubMed1980

The effects of mechanical immobilization on sutural development in the growing rabbit.

Methyl-2-cyanoacrylate was used to mechanically immobilize the coronal suture unilaterally in a series of New Zealand white rabbits at varying ages. The animals were separated into groups; some were sacrificed at 30 day and some at 60 days postoperatively. Amalgam markers were placed in the parietal and frontal bones across the coronal suture, and were measured immediately after surgery and at the time of sacrifice to confirm mechanical immobility. The animals were studied radiographically and histologically in order to document the presence or absence of sutural bone union. Based on the results of this study, it appears that immobilization of the coronal suture results in the formation of an ectocranial periosteal bone bridge in rabbits less than 8 weeks of age. Bone union was not found in animals older than 8 weeks of age. This age-related difference in response is believed to be due to decreased periosteal depository activity on the ectocranial surface of the calvaria once the brain ceases to expand actively. Furthermore, bone union or synostosis was never seen within or across the internal portion of the sutural ligament. It is suggested, therefore, that sutural immobilization at young ages in the rabbit does not result in sutural synostosis and that the term "periosteal bone bridge" should be used when referring to this biological response.

Age Factors↗
PubMed1983

Experimental craniosynostosis in growing rabbits. The role of the periosteum.

Reports on the role of the periosteum in premature sutural synostosis have been contradictory. The present study summarizes a series of six experiments designed to clarify these previously conflicting findings. Twenty-five male New Zealand White rabbits were divided into six experimental groups. In four of the groups, methyl-2-cyanoacrylate was used to glue the frontal and parietal bones together and temporarily immobilize the coronal suture. In the other two groups, the sutures were not immobilized. Polyethylene was used to separate the cyanoacrylate from the periosteum in two of the groups. The experiments were performed at 5 weeks of age, and the animals were killed at either 30, 45, or 180 days postoperatively. Metallic implants were placed in the frontal and parietal bones for monitoring growth and/or sutural immobilization. Sutural fusion was confirmed radiographically or histologically. Based upon the findings it seems that mechanical immobilization of a suture does not induce fusion of that suture in rabbits. Furthermore, it appears that the mere application of methyl-2-cyanoacrylate to the periosteum overlying a suture will consistently cause the formation of a bony bridge in growing rabbits but not in nongrowing animals. The adhesive does not consistently induce synostosis if the periosteum is excised.

Animals↗
PubMed1983

The surgical correction of coronal and metopic craniosynostoses.

Procedures for relief of coronal synostosis and metopic synostosis have resulted in some undesirable sequelae. The authors present combined neurological and plastic surgical modifications to prevent additional synostoses, forehead ridging, and lateral orbital wall step-off. They recommend bifrontal craniotomy with lateral wall osteotomy into the body of the zygoma and self-retaining grafts.

Craniosynostoses↗
PubMed1998

Endoscopic craniectomy for early surgical correction of sagittal craniosynostosis.

OBJECT: The authors sought to minimize scalp incisions, blood loss, and operative time by using endoscopically assisted strip craniectomies and barrel-stave osteotomies to treat infants with sagittal suture synostosis. METHODS: Four patients, aged 2, 4, 9, and 12 weeks, who presented with scaphocephaly underwent endoscopic midline craniectomies through small midline scalp incisions. The mean operative time for the procedure was 1.68 hours (range 1.15-2.8 hours); the mean blood loss was 54.2 ml (range 12-150 ml). Three patients did not require blood transfusions and were discharged within 24 hours. Postoperatively, all patients were fitted with custom cranial molding helmets. Follow-up evaluation ranged between 8 and 15 months. All patients had successful correction of their scaphocephaly with no mortalities, morbidities, or complications. CONCLUSIONS: The use of endoscopic techniques for early correction of sagittal synostosis is safe; decreases blood loss, operative time, and hospitalization costs; and provides excellent early surgical results.

Cranial Sutures↗
PubMed2001

Multiple-revolution spiral osteotomy for cranial reconstruction. Technical note.

Various combinations of cranial remodeling techniques are used in an attempt to provide optimal cosmetic results and to reduce possible sequelae associated with craniosynostosis. One element of deformity that is difficult to correct directly is an overly flattened area such as that found in the parietal area in sagittal synostosis, unilaterally in lambdoid synostosis, or even in severe positional molding. The authors present a novel application for recontouring cranial bone, namely the multiple-revolution spiral osteotomy. The advantages of this technique include the avoidance of large areas of craniectomy and immediate correction of the cranial deformity. The surgical procedure, illustrative cases, early results, and apparent benefits of this technique are discussed.

Craniosynostoses↗
PubMed2001

Dynamic cranioplasty for brachycephaly in apert syndrome: long-term follow-up study.

OBJECT: Brachycephaly is a characteristic feature of Apert syndrome. Traditional techniques of cranioplasty often fail to produce an acceptable morphological outcome in patients with this condition. In 1996 a new surgical procedure called "dynamic cranioplasty for brachycephaly" (DCB) was reported. The purpose of the present study was to analyze perioperative data and morphological long-term results in patients with the cranial vault deformity of Apert syndrome who were treated with DCB. METHODS: Twelve patients have undergone surgery performed using this technique since its introduction in 1991 (mean duration of follow-up review 60.2 months). Eleven patients had bicoronal synostosis and one had a combined bicoronal-bilambdoid synostosis. Perioperative data and long-term evolution of skull shape visualized on serial cephalometric radiographs were analyzed and compared with normative data. Changes in mean skull proportions were evaluated using a two-tailed paired-samples t-test, with differences being considered significant for probability values less than 0.01. The mean operative blood transfusion was 136% of estimated red cell mass (ERCM) and the mean postoperative transfusion was 48% of ERCM. The mean operative time was 218 minutes. The duration of stay in the intensive care unit averaged 1.7 days and the mean hospital stay was 11.8 days. There were no incidences of mortality and few complications. An improvement in skull shape was achieved in all cases, with a change in the mean cephalic index from a preoperative value of 90 to a postoperative value of 78 (p = 0.000254). CONCLUSIONS: Dynamic cranioplasty for brachycephaly is a safe procedure, yielding high-quality morphological results in the treatment of brachycephaly in patients with Apert syndrome.

Acrocephalosyndactylia↗
PubMed2005

A morphometric, neuroanatomical, and behavioral study on the effects of geometric constraint on the growing brain: the methyl 2-cyanoacrylate craniosynostosis model.

OBJECT: The effects of premature sutural synostosis on the developing brain remain unknown. A model of craniosynostosis in the perinatal rat was used to investigate the morphological and cytoarchitectural changes in the maturing brain as well as the neurobehavioral outcome. METHODS: A total of 56 perinatal rats, eight in each subgroup, were used in this study. Hypothermic arrest was induced in the rats and methyl 2-cyanocrylate was applied across the sagittal, coronal, and lambdoidal sutures at postnatal Days 0, 3, and 7. Sham rats underwent similar hypothermic arrest and application of methyl 2-cyanoacrylate but at a site different from the sutural lines. Age-matched rats that did not undergo any procedure were included as normal controls. Serial gross measurements were obtained to chart calvarial growth and computerized tomography scanning was performed to calculate mean calvarial volumes. At postnatal Day 30, the brains were fixed in situ and detailed morphological and cytoarchitectural analysis was conducted. There were no statistical differences in any of the analyses between sham rats and normal age-matched controls. In contrast, calvarial growth rates (analysis of variance, p < 0.05), mean brain weights (t-test, p < 0.01), and anterior-posterior and lateral diameter measurements (t-test, p < 0.01) were different for all synostotic rats compared with sham controls. On cytoarchitectural surveys, focal areas of nodular heterotopia and differences in cell density at the pyramidal cell layer were noted (t-test, p < 0.01). Open field testing also demonstrated excessive exploratory behavior in the synostosed animals. CONCLUSIONS: Early pan-calvarial sutural synostosis in the perinatal rat after administration of methyl 2-cyanoacrylate is associated with morphometrical and cytoarchitectural changes in the developing brain.

Animals↗
PubMed2006

Reformation of the sagittal suture following surgery for isolated sagittal craniosynostosis.

OBJECT: Data from animal studies have shown that in experimentally induced craniosynostosis, removal of the involved calvaria results in the formation of new calvaria with time, and sutures redevelop in their normal anatomical positions. However, the pattern of suture reformation following surgery in humans with craniosynostosis remains ill-defined. The aim of this study was to determine the pattern of postoperative suture reformation in children who have undergone surgery for isolated sagittal synostosis and assess possible factors related to suture reformation. METHODS: Records were retrospectively reviewed for 42 consecutive infants who had surgery for isolated sagittal synostosis between 1987 and 2000 and for whom postoperative skull radiographs were available. The radiographs were evaluated for sagittal suture morphology and patency of the coronal and lambdoid sutures. Surgery involved at a minimum 1) a vertex craniectomy, characterized by removal of the sagittal suture and a 1.5- to 2.5-cm piece of adjacent parietal bone with the attached pericranium bilaterally, and 2) parietal osteotomies and/or craniectomies. The median age at surgery was 3.9 months (range 1.9-7.6 months). The mean duration of follow up was 32.2 months (range 6-144 months). The sagittal suture had reformed in only seven (16.7%) of the children at follow up. In the other 35 (83.3%), the craniectomized bone defects had reossified without any part of the sagittal suture being visible on the radiographs. CONCLUSIONS: There is a very low incidence of suture reformation in children after surgery for isolated sagittal craniosynostosis. Genetic predisposition, inclusion of undiagnosed syndromic patients, and current operative techniques may be some of the factors responsible for the low incidence of suture reformation seen in this series.

Cranial Sutures↗
PubMedDate not supplied

Tracing craniosynostosis to its developmental stage through bone center displacement.

In metopic and coronal suture synostosis, the involved bone centers are abnormally situated just next to the affected suture. Bone centers are the starting point of ossification during embryogenesis from which bone growth spreads radially. In this paper, we describe a similar observation for sagittal suture synostosis, with both parietal bone centers located almost completely cranially. The (reduced) distance between the bone centers of a synostotic suture reflects the time during embryogenesis at which fusion took place. We suggest that in craniosynostosis the bone centers arise in their normal position, and initial outgrowth is undisturbed until the bone fronts meet. It is during this developmental stage that fusion occurs instead of suture formation. Due to the fusion, growth can only occur at the free bony rims from then on. The bone centers remain located at a fixed distance from one another in the middle of the fused bones, becoming relatively more displaced with time. This implies that the distance between the involved bone centers directly indicates the developmental period during which sutural growth was arrested. The same phenomenon of bone center displacement is found in types of craniosynostosis with and without fibroblast growth factor receptor (FGFR) or TWIST gene mutations.

Bone Development↗
PubMed1976

Clinical conference I. Calvarium and cranial base in Apert's syndrome: an autopsy report.

A post-mortem examination of a 22-month-old boy with Apert's syndrome is reported. A linear coronal craniectomy performed at 11 months of age had fused completely in spite of the insertion of polyethylene film between the bony edges. Furthermore, progressive synostosis of other cranial sutures was observed. Histological examination of the cranial base showed that the sphenofrontal suture was fused and that the entire cerebral surface, including the sella turcica, was characterized by bone resorption. The sphenooccipital synchondrosis was extremely wide and abnormally shaped, and the chondral growth activity seemed diminished. It was concluded that the patient exhibited primary as well as secondary growth distrubances in the calvarium and cranial base. The premature synostosis of the coronal and sphenofrontal sutures and the anomaly of the sphenooccipital synchondrosis were interpreted as primary defects. The altered shape of the calvarium and the marked resorption and shortening of the cranial base were considered secondary changes. Furthermore, the investigation indicated that the conventional linear coronal craniectomy cannot be expected to improve the craniofacial growth pattern in patients with Apert syndrome. Alternative surgical procedures were suggested.

Craniosynostoses↗