Spheno-occipital Synchondrosis Research Articles

Preoperative laminagraphic evaluation of the sphenoid sinus for transsphenoidal surgery.

In recent years the transethmoidal and transnasal approaches to the pituitary gland have become increasingly popular. In each case, detailed preoperative analysis of the anatomy of the sphenoid sinus and its boundaries is crucial in facilitating entry to the pituitary fossa and in reducing intraoperative complications. Certain operative difficulties and complications are the result of the marked variability in the anatomy of the sphenoid bone and its sinus. These include: loss of orientation within a capacious sinus; perforation of the carotid artery or cavernous sinus; injury to the optic nerve or ophthalmic artery; and violation of the subarachnoid space with resultant pneumocephalus or cerebrospinal fluid rhinorrhea. Pneumatization develops originally within the presphenoid, beginning anteriorly and proceeding posteriorly. Around the time of puberty the pneumatization usually penetrates up to the spheno-occipital synchondrosis. Dense bony septa remain within the sinus along the plane of fusion of the various sphenoidal segments. Preoperative laminagraphy of these ridges and septa is extremely helpful in planning the safest and most direct route to the sella. Laminagraphy is preferable to routine skull films because the septal detail is unobscured by overlying facial structures. Pleuridirectional laminagraphic motion (circular or hypocycloidal) is preferred to linear motion because of the clarity and detail that they provide.

The effect of rhombencephalic hypoplasia on posterior cranial base elongation in rodents

A single intraperitoneal injection of methylazoxymethanol acetate in circumnatal rats produces a dose dependent cerebellar hypoplasia. All other tissues, including skeletal, are unaffected. Consequent decrease, in the ventral length attained by the growing rhombencephalon is accompanied by a corresponding decrease in the length of the basioccipital bone relative to that of the normally dimensioned basisphenoid bone. The width of the sphenooccipital synchondrosis is also proportionally decreased, with characteristic alterations in the structure of the several zones of this synchondrosis as compared to controls. Three autosomal recessive mutant mice strains were also studied in which the defect is manifested solely as decreased cerebellar neuronal neogenesis. Again, proportional linear decreases occurred in the ventral length of the rhombencephalon, the basioccipital bone and in width of spheno-occipital synchondrosis. The histological changes observed between normal and mutant mice were related to these differences. These data suggest that posterior cranial base elongation and the processes of endochondral ossification in the spheno-occipital synchondrosis of rodents are significantly regulated by the demands of functionally related growing neural masses.

Evolutionary concepts relating language and the morphology of the oral complex: Peter S. VigTrans. Eur. Orthod. Soc., 1972

Magnetic resonance images and the histology of spheno-occipital synchondrosis were examined in young monkeys in order to compare the magnetic resonance images with their histologic observations. In serial magnetics resonance images of posterior cranial base, the spheno-occipital synchondrosis showed a low signal zone with unclear boundaries, running through the posterior cranial base perpendicularly to the clivus. The zone was always interposed between nonsignal zones. These observations were the same as those in young juvenile human beings. The histologic sections also revealed that the low signal zone was really the spheno-occipital synchondrosis, which consisted of hyaline cartilage and that the nonsignal zones were bone tissues. The chondroblasts in the spheno-occipital synchondrosis were arranged bipolarly. Intense alkaline phosphatase activity was located in the areas along the bone. Tetracycline labeling was also noticed in the bone formed in the endochondral ossification. These results suggest that magnetic resonance imaging enables us to observe the spheno-occipital synchondrosis in the posterior cranial base and also to elucidate its influences on the growth of maxilla and mandible in the future. (Am J Orthod Dentofacial Orthop 1999;115:138-42)

The human spheno-occipital synchondrosis. II. A histological and microradiographic study of its growth: B. Thilander and I. IngervallActa Odontol. Scand.31: 323–336, 1973

The human spheno-occipital synchondrosis. II. A histological and microradiographic study of its growth: B. Thilander and I. IngervallActa Odontol. Scand.31: 323–336, 1973

The human spheno-occipital synchondrosis. II. A histological and microradiographic study of its growth.

The spheno-occipital synchondrosis, dorsum sellae and clivus were studied post mortem in tissue samples from 53 males and 25 females, aged 2 days to 24 years 11 months. The investigation aimed at ascertaining the growth and remodelling changes in these structures during the growth period. Light microscopic and microradiographic techniques were used. In the early ages the organization of the synchondrosis was similar to that of an epiphyseal disc, except that the morphology of the synchondrosial cartilage was bipolar. With increasing age the hyaline cartilage in the upper part of the synchondrosis was replaced by fibro-cartilage, while the central zone in the lower part underwent asbestos transformation. The synchondrosis was completely ossified by 16—17 years of age in girls, and about two years later in boys. Appositional growth and endochondral ossification continued up to 3 years of age in cartilage covering the superior and clival aspects of the dorsum sellae. The cartilage on the superior aspect of d...

The Different Relationship of the Sella Point to Growth Sites of the Cranial Base in Fetal Life

Histological observations of the fetal cranial base in 17 human specimens showed that the sella point was identified closely with the dorsum sellae, and occupied an intermediate position in relation to the growth sites of the spheno-occipital synchondrosis. The cancellous structure of the sphenoid bone clearly demonstrated that the pituitary fossa, and hence the sella, moved upward and backward during growth.

In vivo cerebral implantation of the anterior and posterior halves of the spheno-occipital synchondrosis in rats

Anterior and posterior halves of the spheno-occipital synchondrosis from 5-day-old rats were implanted in the left cerebral hemisphere of litter-mates for a period of 11 days. Twenty-four implants were available for evaluation. Measurements before and after implantation revealed that considerable growth had occurred. Histological examination showed that the process of cartilage growth in both anterior and posterior implants was similar to normal. It was concluded that the anterior and the posterior part of the spheno-occipital synchondrosis have an independent growth potential.

The human spheno-occipital synchondrosis. I. The time of closure appraised macroscopically.

The spheno-occipital synchondrosis and clivus in 32 males and 21 females, aged 2 days to 24 years 11 months, were studied post mortem to ascertain the time of closure of the synchondrosis. The mate...

Time and mode of closure of the spheno-occipital synchrondrosis determined on human autopsy material.

Time and mode of closure of the spheno-occipital synchrondrosis determined on human autopsy material.

Cranial suture closure in two species of South American monkeys.

AbstractCranial suture closure is examined in two species of South American monkeys, Saimiri sciureus and Saguinus nigricollis. Sequences in closure were sought as indicators of skeletal age. Some sutures seem to be more reliable determinants of skeletal age than others, and these sutures and their sequence of closure are different in the two species examined. The sphenooccipital synchondrosis and the palatal portion of the Interpremaxillary suture show regular fusion associated with age in both species. In Saimiri the maxillopremaxillary sutures are also reliable indicators of age, whereas they are not in Saguinus; however, in the latter the presphenoid‐postsphenoid synchondrosis closes regularly whereas it does not in Saimiri. In Saimiri the predictable sequence is (1) maxillo‐premaxillary, (2) transverse maxillo‐premaxillary, (3) spheno‐occipital, (4) interpremaxillary. In Saguinus it is (1) presphenoid‐postsphenoid, (2) spheno‐occipital, (3) interpremaxillary. It is possible that the sequences of suture closure and the variability in this process may indicate genetic and taxonomic relationships.

A cephalometric study of the closure of the spheno-occipital synchondrosis in a group of subjects exhibiting Class II dentoskeletal relations

The aim of this study was to determine among young orthodontic patients the relation between the spheno-occipital synchondrosis (SOS) fusion and the cervical vertebral maturation (CVM) and to look for an eventual impact of gender, skeletal class and vertical pattern on their association.CBCT scans and lateral cephalometric radiographs of 117 patients, aged between 8 and 18 years, were selected. SOS fusion was assessed on a mid-sagittal cut of the CBCT scans. CVM was evaluated on the lateral cephalograms as well as ANB and GoGn-SN angles. Spearman correlation test was used to assess the relationship between SOS and CVM. Fisher's exact test was performed at every CVM stage to analyse the association between SOS and other variables (gender, skeletal class, and vertical pattern). Cohen's kappa analysis was used for reliability.A strong correlation was found between SOS maturation and CVM (r = 0.852, P < 001). Fisher's exact test indicated significant association only between gender and SOS in CVM stage 2 group, and between vertical pattern and SOS in CVM stage 4. Cohen's kappa analysis showed moderate inter and intra-rater reliability for CVM index (k = 0.50 and 0.53 respectively, P < .001), strong inter-rater reliability (k = 0.80, P < .001) and almost perfect intra-rater reliability (k = 0.85, P < .001) for SOS index.SOS fusion correlates well with CVM and might be a reliable tool for skeletal maturation assessment. Girls seem to have an earlier fusion of SOS in relation to their respective CVM compared to boys, and the vertical pattern could influence the association between SOS and CVM stages.

Time of closure of the spheno-occipital synchondrosis determined on dry skulls—A radiographic craniometric study: Birte MelsenActa odont. scandinav.27:73–90, March, 1969

Time of closure of the spheno-occipital synchondrosis determined on dry skulls—A radiographic craniometric study: Birte MelsenActa odont. scandinav.27:73–90, March, 1969

Effects of mandibular hyperpropulsion on the prechondroblastic zone of young rat condyle

In a previous article1 we reported that, as evidenced in organ culture, the spheno-occipital synchondrosis and the cartilage of the nasal septum, where growth takes place by the division of differentiated chondroblasts, manifest an independent growth potential but that the calvaria and facial sutures, where growth occurs by the division of young connective cells, do not. We also reported that only when growth takes place by proliferation of young connective cells are the mechanical forces able to stimulate or inhibit it.? In the present article we will describe research conducted to study the effects of an orthopedic treatment type of hyperpropulsion in young rat condylar cartilage, in which growth occurs mainly by mitoses of the young cells in the prechondroblastic zone and only to a minor degree by mitoses of the differentiated cells of the chondroblastic zone.’

Cranial growth centers: Facts or fallacies?

This study aimed to determine the effect of C-type natriuretic peptide (CNP) overexpression on craniofacial growth during the pubertal growth period in mice.Six-week-old C57BL/6 mice were injected with pLIVE-Empty vectors (Control mice) and pLIVE-NPPC vectors (CNP mice) using the hydrodynamic method. Morphological analyses were performed at the age of 12 weeks.Micro–computed tomography (µCT) images showed significant (p < 0.05) hyperplasia in the maxilla along the sagittal plane (CNP mice: 13.754 mm, Control mice: 13.215 mm). Further, the images revealed significant bone overgrowth in the sagittal direction in the sphenoid (CNP mice: 6.936 mm, Control mice: 6.411 mm) and occipital (CNP mice: 4.051 mm, Control mice: 3.784 mm) bones in the CNP mice compared with that in the Control mice. Compared with SAP-Nppc-Tg mice in previous studies, although there was no effect on nose length and nasal bone length, the effect was sufficient to improve craniofacial hypogrowth. Furthermore, CNP promoted sagittal cranial growth by increasing the thickness of the spheno-occipital synchondrosis in organ cultures and nasal septal cartilage in micromass cultures, which were derived from 6-week-old mice.We have previously shown that the elevated blood levels of CNP from the neonatal period affect midfacial skeletogenesis by promoting endochondral ossification using mice (SAP-Nppc-Tg mice). The overexpression of CNP, even in 6-weeks-old mice, promoted growth in the sagittal direction within the maxillary region. These findings indicate the therapeutic potential of CNP for the treatment of midfacial hypoplasia during the pubertal growth spurt.

Non-experimental aural pathology in squirrel monkeys (Saimiri sciureus) and marmosets.

In the marmoset, with the clusters of mastoid and apical pneumatic cells in wide communication to the central tympanic space, an undivided cavity is created. Simultaneous involvement of the entire area by infectious processes is bolstered by the lack of walling-off partitions. The tegmen is everywhere readily and frequently penetrated. From the apical cell group the spheno-occipital synchondrosis was predominantly seen invaded: with the consequence of an osteomyelitis of the cranial base. Frequency of otitis media, advancing to lethal endocranial complications, is, in its portent, equivalent to other generally listed causes of death, as: pulmonary, intestinal, parasitic ones. The inner ear is surrounded by pneumatic cells. In spite of being suspended in a similarly exposed situation it is less prone to react to infections. Suppurative processes of the middle ear when reaching the inner ear are mostly “toned down” to a sero-fibrinous one. The otic capsule was never seen penetrated by suppuration. Anatomical arrangement around cochlea and vestibulum results in their ready accessibility from all directions: a circumstance of considerable advantage in experimental work on the inner car.

TIME OF ERUPTION OF THE PERMANENT TEETH, CEPHALOMETRIC AND TOOTH MEASUREMENT AND SULPHATION FACTOR ACTIVITY IN 45 PATIENTS WITH TURNER'S SYNDROME WITH DIFFERENT TYPES OF X CHROMOSOME ABERRATIONS.

ABSTRACT The time of eruption of the permanent teeth, the development of the cranial skeleton, and the size of the teeth and dental arches as well as the serum sulphation factor activity were studied in 45 patients with Turner's syndrome with different types of X chromosome aberrations. A tendency to an earlier eruption of the permanent teeth was found. The significance of hormonal factors and of the dysplastic skeletal structure for the eruption of the teeth are discussed. The cephalometric analysis revealed a retarded development of the cranial skeleton. Appositional and sutural growth as well as growth in the condylar cartilage and the spheno-occipital synchondrosis, were affected. The development of the facial skeleton reached a level corresponding to that of 11 year-old girls, while that of the posterior portion of the cranial base did not reach this level. The latter finding may explain the posterior rotation of the facial skeleton in relation to the cranial base. The mesio-distal width of the permanent teeth was smaller than normal, and the frequency of root resorptions of the idiopathic type was increased in the patients. The space and space differences of the dental arches were normal. The mean level of the serum sulphation factor activity was increased. It seems likely that the abnormal X chromosome constitutions form the background to the changes in the hard tissues and that these tissue changes may be of major significance for the disturbed development of the teeth and skeleton in patients with Turner's syndrome.

Closure of the spheno-occipital synchondrosis: By Thomas V. Powell and Allan G. Brodie, Graduate College, University of Illinois, Department of Orthodontics, Chicago, Ill.

Closure of the spheno-occipital synchondrosis: By Thomas V. Powell and Allan G. Brodie, Graduate College, University of Illinois, Department of Orthodontics, Chicago, Ill.

Roentgen determination of the time of closure of the spheno-occipital synchondrosis.

The spheno-occipital synchondrosis is the joint between the basal portions of the sphenoid and occipital bones in that portion of the skull base usually designated as the clivus. The articulation is similar to the cartilaginous junction between the epiphyses and metaphyses of long bones. A synchondrosis is a temporary union since the connecting cartilage becomes ossified with advancing age. While the times of union of epiphyses to primary centers of the skeleton have been widely studied, a paucity of information is available concerning the normal closure of the spheno-occipital synchondrosis. Embryologic and Anatomic Considerations In the human embryo the earliest evidence of the cranium is found in dense masses of mesenchyme which surround the cranial end of the notochord. Cartilage formation in the developing mesenchyme in this area is apparent at the beginning of the second month of embryonic life. During the ninth and tenth weeks of embryonic life, ossification centers begin to appear in the occipital...

Cranial base development: A follow-up x-ray study of the individual variation in growth occurring between the ages of 12 and 20 years and its relation to brain case and face development

Cranial base development: A follow-up x-ray study of the individual variation in growth occurring between the ages of 12 and 20 years and its relation to brain case and face development

Changing Philosophies in Cleft Palate Management

Summary Cleft palate individuals as a group show deficient patterns of maxillary growth, laterally, anteroposteriorly, and vertically. Early and traumatic surgery results in the greatest deformity. There is a positive correlation between the number of operations, the amount of scar tissue, and the degree of insult. To minimize interference with growth centers, it seems advisable to postpone surgical correction at least until the end of the fourth year of life, when fivesixths of the total maxillary width has been accomplished. However, it must be remembered that downward and forward growth, which depends primarily on the spheno-occipital synchondrosis and sutural activity continues until 20 years of age. It appears that the surgically repaired palate grows more slowly than the surrounding soft tissue. This results in increasing functional difficulty and ultimate structural inadequacy. Patients whose palatal clefts have not been surgically manipulated show a pattern of maxillary growth that is essentially normal. Closure of nonoperated clefts by prostheses scems quite successful, if judged by the general intelligibility of speech and ease of mastication and deglutition. Rehabilitation requires the coordination in one organization of all the skills and knowledge peculiar to the cleft palate problem. Only by grouping services and correlating information and ideas can each man render the fullest value of his particular field.