Obliteration Of Sutures Research Articles

Cranial suture obliteration patterns as an ageing method for dog crania

Most of the fundamental methods for analyzing archaeological dog remains need to be better developed. This is particularly true for methods designed to estimate age at death. Most ageing methods are either destructive and specialized or useful only for identifying juveniles. Cranial suture closure and obliteration patterning are commonly examined to estimate the general age at death of human remains but have seen little use in zooarchaeology. This study develops a simple and non-destructive ageing method based on a suture and synchondrosis obliteration using a sample of over 700 modern dog crania. Scoring the extent of obliteration of individual sutures provides a valuable means of differentiating adult and juvenile crania. Combining the scores for multiple sutures permits the assignment of dog crania to an age group, albeit with less certainty among middle-aged and older adults. Breed, crania shape, sex, and body size all likely create variation in suture obliteration patterns and their relationships to dog age. The method should be used conservatively and in combination with other ageing methods when possible.

Topography of the mandibular canal in male human skulls originating from different time periods.

Dynamic advances in dentistry, especially in implantology has inspired researchers to carry out many studies investigating the topography of the mandibular canal and its ethnic differences. The aim of the study was a comparative analysis of variations in the position and topography of the mandibular canal based on radiographic images of human mandibles originating from modern and medieval skulls. Morphometric examination of 126 radiographs of skulls (92 modern and 34 medieval skulls) was included. The age and sex of individuals were determined based on the morphology of the skull, the obliteration of cranial sutures, and the degree of tooth wear. To define the topography of the mandibular canal on X-ray images, we took 8 anthropometric measurements. We observed significant differences in several parameters. The distance between the base of the mandible and the bottom of the mandibular canal, the distance between the top of the mandibular canal and the crest of the alveolar arch, and the height of the mandibular body. Significant asymmetry was found for two parameters of mandibles from modern skulls: the distance between the top of the mandibular canal and the crest of the alveolar arch at the level of the second molar (p < 0.05), and the distance between the mandibular foramen and the margin of the anterior mandibular ramus (p < 0.007). There were no significant differences between measurements taken on the right and left sides of the medieval skulls. Our study revealed differences in the position of the mandibular canal between modern and medieval skulls, confirming the presence of geographical and chronological differences between populations. Knowledge of variability in the position of the mandibular canal between different local populations is fundamental for the correct interpretation of findings from diagnostic radiological studies used in dental practice and in forensic odontology or analysis of archaeological bone materials.

Cranial Vault Suture Obliteration in Relation to Age: An Autopsy-Based Observational Study.

Age is one of the most critical identifiers for both living and dead. Forensic professionals in medical and legal matters are often presented with dismembered, disfigured, putrefied, or skeletal remains for analysis. In such situations, it is essential to identify individuals and estimate their ages. The skull is typically thewell-preserved part of the body in such situations. If an aged person needs their age officially established for employment, superannuation, pension settlements, senior citizen benefits, etc., they may turn to medical professionals for help in making that determination. It has always been controversial to use cranial suture obliteration as a reference for age. Different geographicallocations have been shown to have vastly different patterns of cranial suture closure. Therefore, this study was conceptualized to assess cranial vault sutureobliteration in relation to age in the Meo population. This study was conducted to determine whether obliteration of cranial sutures can be taken into account for the estimation of age in elderly in this region and its reliability along with the influence of other factors such as sexand right and left side differences. A total of 100 cases of more than 20 years of age brought for medicolegal autopsy were analyzed. The coronal, sagittal, and lambdoid sutures were studied ectocranially and endocranially. The degree of obliteration of sutures was scored ectocranially as well as endocranially. Data were analyzed using IBMSPSSStatistics for Windows, Version 21 (Released 2012; IBM Corp., Armonk, New York, United States). Descriptive statistics were evaluated for continuous data in terms of mean and standard deviation, and categorical data were presented by frequency and percentages. An independent t-test was applied to find out the mean difference between the right and left sides of suture closure for ectocranial and endocranial surfaces. The Spearman rank correlation test was carried out to find out the relationship between the age and score of suture closure both ectocranially and endocranially. Ectocranially and endocranially, the overall sagittal suture obliterates early followed by coronal sutures and then lambdoid sutures. On comparing the mean ectocranial and mean endocranial scores of 100 subjects by applying an independent t-test, a highly significant difference was observed in all three sutures. On correlating ectocranial sutures and endocranial sutures and age at death in all the cases through sagittal, right and left coronal, and lambdoid by applying the Spearman rank correlation coefficient, a highly significant correlation was found in all the subjects combined (p-value 0.000). However, no significant correlation (p-value >0.05) was found in ectocranial and endocranial sagittal sutures in individual age groups. We concluded that obliteration on the endocranial surface is more reliable than on the ectocranial surface. No statistically significant difference exists on the obliteration of sutures on the right and left sides of coronal and lambdoid sutures. The lapsed union was evident in all three sutures ectocranially. Endocranial suture obliteration can be used as a corroborative tool for age estimation.

Age estimation by evaluation of obliteration of the palatine sutures: a scoping review.

The age estimation (AE) of human remains is a challenging task since it is dependent on the state in which these remains are found. Since the macroscopic evaluation of palatal sutures has been proposed as a method for AE, the aim of this study was to review the literature on this method, considering that the cases of edentulous elderly are among the greatest challenges in anthropological and forensic contexts. A scoping review was performed using a specific search strategy in PubMed, Web of Science, SciELO, LILACS, and Google Scholar. The search identified 13 articles, among which the USA yielded the most information with 3 articles. Only 1 study was identified in Latin America (Peru). There was great diversity regarding the origin of samples, and the studies were carried out on both historical and modern populations. Only 6 articles exceeded the average sample size (168.08) and 4 articles studied samples of fewer than 100 individuals. Although 6 different methods were identified, Mann et al.'s revised method was the most used. The selection of appropriate methods for AE depends on what skeletal elements are present and the general age of the specimens. Although evaluation of the obliteration of the palatal sutures has been found to be simple and promising for AE in individuals over 60years of age, this method has been reported to have less precision than other more complex methods, which makes the use of a combination of methods necessary to increase the level of confidence and the percentage of success. Further research could resolve this weakness, and methodological refinement (perhaps the digitization and automation of processes, or the application of Bayesian methodology) could provide the necessary solidity to comply with international standards in the forensic scenario.

Pectus Arcuatum: A Pectus Unlike Any Other

BackgroundPectus arcuatum is often mistaken for a type of pectus carinatum. However, pectus arcuatum is a unique clinical form of pectus caused by premature obliteration of the sternal sutures (manubrial sternum, four sternebrae and xiphoïd process), whereas pectus carinatum is due to abnormal growth of the costal cartilage. In order to better describe pectus arcuatum, we analysed the files of patients with pectus arcuatum followed in our centers. MethodsMulticenter retrospective study of young patients’ files diagnosed with pectus arcuatum. ResultsThe clinical diagnosis of pectus arcuatum was made in 34 patients with a mean age at diagnosis of 10.3 years (4–23 years).A chest profile X-ray or a CT scan was performed in 16 patients (47%) and confirmed the diagnosis of PA by the presence of a sternal fusion. It was complete in 12 patients.A malformation was associated in 35% of cases (Noonan syndrome 33%, scoliosis 25% or cardiopathy 16%). 11 patients (32%) had a family history of skeletal malformation.Orthopedic treatment was initiated in 3 patients without any success. 11 patients underwent surgical correction, which was completed in 7 of them. ConclusionThe diagnosis of pectus arcuatum is based on clinical experience and if necessary, on a profile chest X-ray showing the fusion of the sternal pieces. It implies the search for any associated malformations (musculoskeletal, cardiac, syndromic). Bracing treatment is useless for pectus arcuatum. Corrective surgery, based on a sternotomy associated with a partial chondro-costal resection, can be performed at the end of growth. Level of EvidenceIV.

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.

Complete sagittal suture closure evaluation based on post mortem computed tomography

Age assessment at the time of death is of great importance when an unidentified skeleton or corpse is found. Obliteration of cranial sutures has been used for age assessment regarding anthropology as non - metrical method of direct bone inspection. The aim of our study was to assess sagittal suture closure in the contemporary population of Polish men using postmortem computed tomography. A total of 255 male skulls were analyzed with the use of multiplanar reconstruction (MPR) and volume rendering technique (VRT) images, which were based on whole-body postmortem computed tomography scans. The individuals of Polish origin were of precisely known metrical age. The sagittal sutures were analyzed across their entire thickness (including both the outer and inner aspect of bone) and along their entire length via frontal sections, using the sagittal suture division into 4 segments. This study showed that the earliest signs of suture closure occur in S4 on the inner side of the calvaria at a mean age of 50.48years, but the youngest person with starting obliteration process was 13.37years. This is prove that exist variability which must be count during biological age estimation. Additionally, VRT visualisation shows that the fourth state of obliteration does not mean that obliteration was ended. Further analyses of cranial suture closure are needed to obtain reliable methods for postmortem estimation of the age at the time of death in contemporary populations. The use of postmortem computed tomography may offer additional opportunities for contemporary analysis of skeletal material.

Childcare and Development of Paediatrics in Moravia (Czech Republic) in the Context of Palaeopathological Research Focusing on Congenital Malformations, Metabolic and Haematologic Diseases

Prezentovaná práce je součástí komplexní studie zaměřené na sledování původu a vývoje pediatrické péče na Moravě, jedné ze zemí dřívější Rakouské monarchie. Studie také bere v potaz sociální podmínky jako změny moravského zdravotnictví ve studovaném období v souvislosti s tereziánskými a josefínskými reformami. Novorozenecká úmrtnost byla v té době velmi vysoká, což souviselo i s nedostatkem péče o těhotné ženy. Studie sleduje zdravotní stav a příčiny úmrtí dětí od 13. do 19. století, na základě studia dostupných literárních zdrojů v kontextu paleopatologické analýzy dětských kosterních pozůstatků. Analýza koster dospělých jedinců sledované populace poskytuje důkaz vysoké úmrtnosti žen ve věku 20–30 let. Pozornost byla zaměřena na vrozené malformace, metabolická a hematologická onemocnění. Z vrozených malformací potvrdila paleopatologická analýza u dětské populace vývojovou dysplázii kyčelního kloubu a předčasnou obliteraci lebečních švů. Z hematologických a metabolických chorob byla nejčastěji zaznamenány známky anemie ve formě cribra orbitalia a stopy po kurdějích a křivici. Tyto choroby se nejčastěji vyskytovaly u dětí v chudobincích a sirotčincích. Podle literárních zdrojů jejich výskyt významně vzrůstal v závislosti na válečných událostech provázených hladomorem. Výsledky studie poskytují přímý důkaz výskytu sledovaných dětských nemocí na Moravě v období novověku.

A study on differences in the obliteration of cranial sutures and their clinical significance

Introduction: There are very few studies on the patency of cranial sutures, and this study analyzes the difference in sutural patency. The objective was to study the difference in the patency of coronal, sagittal, and lambdoid sutures in Indian human adult skulls. Material and Methods: This study involved 120 Indian human adult skulls. The suture patency was graded in accordance to a classification proposed by Sabini and Elkowitz on a scale of 0–4. An open suture was classified as 0; fused but not obliterated as 1; and Grades 2, 3, and 4 represented 50%, and 100% of obliteration, respectively. Results: The lambdoid sutures were observed to be the most patent and least obliterated. Grade 1 sutures were observed to be 44.71% in lambdoid, 8.4% in sagittal, and 7.3% in coronal sutures. Grade 2 sutures were observed to be 42.6% in lambdoid, 49.3% in sagittal, and 46.7% in coronal sutures. Grade 3 sutures were observed to be 10.1% in lambdoid, 32.1% in sagittal, and 36.2% in coronal sutures. Grade 4 sutures were observed to be 2.6% in lambdoid, 10.2% in sagittal, and 9.8% in coronal sutures. No open sutures were observed. Discussion and Conclusion: Lambdoid sutures are more patent than coronal and sagittal sutures. This can be attributed to the presence of more muscular contractile forces acting on the lambdoid suture when compared with other sutures. The mechanisms involved in suture closure are complex and involve genetic and environmental factors, age, and tissue interactions. Therefore, more advanced research is essential for a clearer insight on this subject, which has immense clinical implications in neuroscience.

A Preliminary Study of the Relationship between Obliteration of Cranial Sutures and Age at Time of Death

During a forensic investigation, the determination of age at death is typically based on the level of skeletal development. Cranial sutures may help a forensic investigator to determine age at death since there is a predictable interval of age linked to their obliteration. The progression of the obliteration is divided in four stages (from 0 to 3), with the last stage indicating complete obliteration, and specific locations on the sutures are considered most useful for the estimation of age at death. However as more of the sutures are obliterated, the traditionally reported interval of age at death grows wider, with a complete obliteration of the sutures referred to a range of 34 to 76 years. Thus one would expect that the cranial sutures of an older person should be completely obliterated. When completely closed, which should happen over the age of 80 years, the sutures nearly disappear and at the last level of obliteration they are no longer visible, in this preliminary study, the authors analyzed a sample of 100 skull photographs taken during post mortem examinations. This study is focused on a macroscopic study of sagittal and coronal sutures. In some cases, the complete obliteration of cranial sutures was visible for individuals with age ranging from 60 to 70 years old. In particular the authors observed the presence of sutures that were not completely obliterated in subjects aged more than 70 years. The aims of this study were to draw attention to these features; to avoid misinterpretation about the age of skeletal remains; and to offer evidence that these criteria may not be reliable for forensic investigation, at least until further study and recalibration to known data.

Skull deformations in craniosynostosis and endocrine disorders: Morphological and tomographic analysis of the skull from the crypt of the Silesian Piasts in Brzeg (16th–17th century), Poland

Resultsof morphological and tomographic (CT) studies of the skull that was found in the crypt of the Silesian Piasts in the St. Jadwiga church in Brzeg (Silesia, Poland) are presented and discussed here. The established date of burial of probably a 20–30 years old male was 16th–17th century. The analyzed skull showed premature obliteration of the major skull sutures. It resulted in the braincase deformation, similar to the forms found in oxycephaly and microcephaly. Tomographic analysis revealed gross pathology. Signs of increased intracranial pressure, basilar invagination and hypoplasia of the occipital bone were observed. Those results suggested the occurrence of the very rare Arnold-Chiari syndrome. Lesions found in the sella turcica indicated the development of pituitary macroadenoma, which resulted in the occurrence of discreet features of acromegaly in the facial bones. The studied skull was characterized by a significantly smaller size of the neurocranium (horizontal circumference 471mm, cranial capacity ∼1080ml) and strongly expressed brachycephaly (cranial index=86.3), while its height remained within the range for non-deformed skulls. A narrow face, high eye-sockets and prognathism were also observed. Signs of alveolar process hypertrophy with rotation and displacement of the teeth were noted. The skull showed significant morphological differences compared to both normal and other pathological skulls such as those with pituitary gigantism, scaphocephaly and microcephaly.

Pachycephalosauridae from the San Carlos and Aguja Formations (Upper Cretaceous) of West Texas, and observations of the frontoparietal dome

ABSTRACT Several fragmentary frontoparietal domes from the San Carlos and Aguja Formations (Campanian) of Brewster and Presidio Counties, Texas, are referable to Pachycephalosauridae (Dinosauria: Ornithischia) and represent a southern extension of the known range of these dinosaurs in North America. Although the specimens are insufficient for confident generic identification, the size, relative dome height and width, continuity of frontal and parietal portions of the dome, and obliteration of sutures between these bones suggest affinity with pachycephalosaurids as Stegoceras and Gravitholus. More than one taxon is probably represented in the collection. Sections taken from one of the domes reveal histological tissue zonation comparable to that found in other pachycephalosaurids and growth lines indicating that at least 5 years were required to attain adult size. The bone tissue is well suited for strengthening the dome to resist compressional loading, and is compatible with the hypothesis that these animals engaged in head-butting behavior.

Successful Isotretinoin Treatment of Acne in a Patient with Apert Syndrome

Sir, Apert syndrome (acrocephalosyndactyly type I), first described in 1906 by the French physician Eugene Apert, is a rare autosomal dominant congenital disorder characterized by the premature obliteration of the craniofacial sutures and syndactyly of the hands and feet (1). In most patients it is caused by a localized mutation in the gene encoding for the fibroblast growth factor receptor (FGFR2), which is responsible for the development of embryonic skeleton, epithelial structures and connective tissue (2). An incidence of 1:160,000 live births was found in a British study (1), but a higher birth prevalence (1:65,000 or 15.5 per million) was estimated several decades later (3). More than 98% of cases are caused by a new mutation, which is of paternal origin, and association with older paternal age has been implicated. The irregular obliteration of the cranial sutures results in different craniofacial deformities, hypertelorism, dental and palatal abnormalities and a tendency towards proptosis of the eyes (1, 4). Several other skeletal deformities as well as cardiovascular, urogenital, gastrointestinal, respiratory and skin abnormalities have been described. Increased intracranial pressure may lead to hydrocephalus, abnormal brain development, and different levels of mental retardation, blindness and death. Early neurosurgical intervention is therefore essential for a good prognosis in these patients (4). Since 1970 Apert syndrome has been discussed also in dermatological literature; Solomon et al. (5) were the first to describe pilosebaceous abnormalities in these patients. Early appearance of widespread and severe acne, resistant to conventional therapies, is a common feature in these patients. We describe here a patient with Apert syndrome and severe acne who had a good response to treatment with isotretinoin, and discuss previous reports of the use of oral isotretinoin in this syndrome.

The Craniofacial Phenotype of the Crouzon Mouse: Analysis of a Model for Syndromic Craniosynostosis Using Three-Dimensional MicroCT

To characterize the craniofacial phenotype of a mouse model for Crouzon syndrome by a quantitative analysis of skull morphology in mutant and wild-type mice and to compare the findings with skull features observed in humans with Crouzon syndrome. MicroCT scans and skeletal preparations were obtained on previously described Fgfr2(C342Y/+) Crouzon mutant mice and wild-type mice at 6 weeks of age. Three-dimensional coordinate data from biologically relevant landmarks on the skulls were collected. Euclidean Distance Matrix Analysis was used to quantify and compare skull shapes using these landmark data. Obliteration of bilateral coronal sutures was observed in 80% of skulls, and complete synostosis of the sagittal suture was observed in 70%. In contrast, fewer than 40% of lambdoid sutures were found to be fully fused. In each of the 10 Fgfr2(C342Y/+) mutant mice analyzed, the presphenoid-basisphenoid synchondrosis was fused. Skull height and width were increased in mutant mice, whereas skull length was decreased. Interorbital distance was also increased in Fgfr2(C342Y/+) mice as compared with wild-type littermates. Upper-jaw length was shorter in the Fgfr2(C342Y/+) mutant skulls, as was mandibular length. Skulls of Fgfr2(C342Y/+) mice differ from normal littermates in a comparable manner with differences between the skulls of humans with Crouzon syndrome and those of unaffected individuals. These findings were consistent across several regions of anatomic interest. Further investigation into the molecular mechanisms underlying the anomalies seen in the Crouzon mouse model is currently under way.

Patency and Obliteration of the Cranial Sutures: Is There a Clinical Significance?

Patency and Obliteration of the Cranial Sutures: Is There a Clinical Significance?

Time of closure of cranial sutures in northwest Indian adults

Time of closure of sagittal, coronal and lambdoid sutures was studied at autopsy in 538 male and 127 female adults of known ages belonging to Chandigarh zone of northwest India. The sagittal suture was divided into four segments and each side of the coronal and lambdoid sutures into three segments. Whether a segment was open or closed on either surface was recorded. On analysing the record, the authors came to the conclusions: (1) obliteration of sutures commences earlier in the males than in females, (2) suture obliteration starts earlier on endocranial surface than on the ectocranial and (3) commencement and complete obliteration of a segment or the entire suture is so erratic that it is not useful for estimating the age of a skull.

Transforming growth factor-beta 2 and TGF-beta 3 regulate fetal rat cranial suture morphogenesis by regulating rates of cell proliferation and apoptosis.

Cranial vault sutures are the major intramembranous bone growth sites during rapid expansion of the neurocranium. To function as bone growth sites, sutures need to remain patent, while allowing rapid bone formation at the edges of the bone fronts. Premature osseous obliteration of sutures (craniosynostosis) by fusion of bone fronts across the suture site prevents further bone formation at this site, often leading to severe facial dysmorphology. Although several growth factor receptor and transcription factor mutations have been implicated in craniosynostosis, the underlying mechanisms leading to sutural obliteration remain unclear. Previous studies have shown that dura secreted soluble factors responsible for maintaining suture patency and that suture fusion observed in the absence of dura was preceded by elevated levels of DNA synthesis and collagen production in the suture region. The use of neutralizing antibodies in a fetal calvarial culture model further demonstrated that removal of transforming growth factor (TGF) -beta 3 activity induced premature sutural obliteration, whereas removal of TGF-beta 2 activity prevented sutural obliteration. Data presented here demonstrate that suture obliteration induced by removal of TGF-beta 3 activity was preceded by elevated levels of DNA synthesis, similar to that seen upon removal of the dura. Addition of exogenous TGF-beta 3 to calvaria cultured without dura both prevented suture obliteration and reduced DNA synthesis to levels comparable to those seen with intact dura. Addition of exogenous TGF-beta 2 to calvarial cultures induced sutural fusion accompanied by elevated levels of cell proliferation. However, sutures rescued from obliteration by removal of TGF-beta 2 activity did not have decreased levels of cell proliferation, but rather appeared to be due to inhibited differentiation. In all calvaria in which sutures remained patent in culture, numbers of apoptotic cells were high within the suture, whereas in sutures destined to fuse, numbers of apoptotic cells were low. Results indicate that one of the critical regulators of suture patency is cell number. Alterations in cell number can trigger premature differentiation of cells, resulting in sutural obliteration. Furthermore, a complex interplay between closely related molecules is required to maintain cranial vault sutures in an unossified state, while allowing new bone to be formed at the edges of the bone fronts.

Dura Mater Maintains Rat Cranial Sutures in Vitro by Regulating Suture Cell Proliferation and Collagen Production

Craniosynostosis, the premature osseous obliteration of cranial vault sutures, can result from mutations in genes encoding components of growth factor signaling systems or the extracellular matrix (ECM). Little is known of the capacity of osteoprogenitor cells of the cranial sutures to divide or to synthesize ECM in situ. Osteoblasts derived from patients with prematurely fused sutures were reported to express alkaline phosphatase and osteocalcin at elevated levels, while proliferating at a rate comparable to control cells [DePollack et al., JBMR, 1996]; however, the suture osteoprogenitors, the population most likely to show proliferative abnormalities, were not present in the fused sutures used for this study. A model in which rat coronal sutures and associated bones develop normally in vitro, but in which sutures can be induced to fuse in the absence of dura mater, was used to examine cell proliferation and total protein synthesis in unfused sutures cultured in the presence of dura mater or in sutures induced to fuse in the absence of dura mater. Significantly increased cell proliferation was seen in suture cells prior to sutural obliteration, which returned to control levels as sutural fusion proceeded. Collagen synthesis in fusing sutures was elevated compared to non-fusing sutures and comparable to that seen in bone. Results indicated that in the absence of intercellular signals provided by the dura mater, suture cell proliferation increased initially, followed by increased synthesis of collagenous ECM within the suture and subsequent osseous obliteration of the suture. Thus factors originating in the dura mater affected suture cell proliferation and ECM production and were required for the maintenance of suture patency.

Dura mater secretes soluble heparin-binding factors required for cranial suture morphogenesis

Cranial sutures play a critical role in calvarial morphogenesis, serving as bone growth centers during skull enlargement. Defective suture morphogenesis, resulting in premature osseous obliteration of sutures and their failure to function appropriately, causes severe craniofacial anomalies. Previously published data demonstrated osseous obliteration of coronal suturesin vitro in the absence of dura mater and the rescue of sutures from osseous obliteration in rudiments cocultured with dura mater on the opposite sides of 0.45-μm polycarbonate filters. With thisin vitro culture system, experiments were designed to examine the nature of the soluble signal secreted by dura mater, required for maintaining intact sutures. The signal remained active in conditioned medium produced from dura mater, which was capable of rescuing coronal sutures from osseous obliteration in calvaria cultured without dura mater. When conditioned medium was segregated into heparin-binding and non-heparin-binding fractions, the signal capable of maintaining intact coronal sutures cosegregated with the heparin-binding component and remained functional in the absence of the non-heparin-binding component of conditioned medium. Evidence indicates that soluble, heparin-binding factors secreted by the dura mater act as osteoinhibitory signals at the suture site.

In the absence of periosteum, transplanted fetal and neonatal rat coronal sutures resist osseous obliteration.

Normal craniofacial development depends on expansion of the cranial vault by growth at the sutures. Inappropriate development of the sutures leads to global disruption of patterns of craniofacial growth. Tissue interactions between dura mater and suture matrix play a critical role in the phenotypic maintenance of cranial sutures. However, the function of the periosteum in this process remains under-reported and controversial. To examine the contribution of periosteum in maintaining the patency of coronal sutures, fetal and neonatal rat coronal sutures were transplanted to surgically created defects in adult rat host parietal bones. These sutures were examined for their ability to persist in the host milieu in the presence and absence of both donor and host periosteum. This study established that removal of both host and transplant periosteum, unlike removal of dura mater, did not lead to obliteration of either fetal or neonatal sutures. Thus, periosteum and dura mater are nonequivalent tissues with respect to influence on suture patency.